Huerta's Inferno

The 5 Layers of Huerta’s Hell

Level 1
Huerta was walking down a lonely road on his way home from work. His arms were heavy with the day's newspapers (he was a paperboy) and his bike was busted. He let out a sigh as he thought "Just 5 more minutes and I'll be home," but no sooner had the thought entered his mind, when a black car appeared and two armed men forced him into the backseat and placed a bag over his head. He awoke and saw a man leaning against the side of a busted table nearby, his back to him. Huerta grabbed a shovel randomly laying next to him on the hard cuboidal shaped concrete bricks. He approached the figure slowly, shovel in hand, ready to knock him a good one, “Either you tell me who you are, or I make you friends with my shovel here!” He said as bravely as he could, trying his hardest to not let his voice get all squeaky with fear. The man glanced back his way “Homie, you better be joking! I save your life and you threaten me with a freakin' shovel?" He paused examining Huerta's pale face with a bored expression, "I'm Laquanda, and I’ve been trapped in the Stratum Basale for the last month or so.” “Stratum Basale? What’s that?” “It’s the first floor of this house, the Epidermis House, they call it.” "Epidermis house?" Huerta questioned "You must live in a box to not have heard of this place" Huerta did answer, but he didn't put down his shovel either. He was an economy student, he was supposed to stay in his box. "There are five floors, each more gruesome then the last. The only way out is to make it to the 5th floor" "Well why haven't you tried to get out" "Pssh, I did try, I barely made it back down here in one piece" Laquanda froze, his hand moved quickly to the inner part of the jacket he wore, he took out a small knife "Hey! What's with the knife?" Huerta yelled out panicked, Laquanda threw the knife and it hit it's target dead center. The sound of the shovel hitting the cuboidal stone echoed through out the dank basement. He got to his feet and pulled the dagger out of the columnar walls. A spider-like creature bigger then this fist plopped to ground at his feet. "What is that thing?" Huerta asked, he was as white a ghost and had almost peed his pants (but he wasn't about to admit that) "They're called Stratum Germinative, just a single bite and you join the rest of those keratinocyte ghosts that haunt this place. I" "We have to get out of here" Huerta said, his voice laced with fear. " "Since there are two of us now, I guess it's worth a go" Laquanda said pocketing his weapon as he walked up to Huerta. The short Mexican could do nothing but take in the sheer height of his ally. He was TALL. "Let's get moving then. They only open the doors to the outside world once every two weeks, and that two week mark is today" Huerta followed Laquanda to an old beaten up door on the other side of the room. "You ready? This isn't going to be easy, dude." Huerta nodded his head repeatedly at a rather quick pace, as if trying to reassure himself. Laquanda looked at him with a cocked brow. "Okay, dude. You need to calm down" He stopped to make to sure he was ready for the fight that was sure to come, he bent down and tied his shoe, you don't want to worry about tripping when you're facing those things. Huerta noticed a small cut on his leg through a tear in his pants "What happened?" Laquanda straightened himself quickly, "Just a cut, nothing big. We're going to see much worse" He pulled open the creaky door and led Huerta out of the columnar and cuboidal room and up a long staircase.


Level 2
Laquanda and Huerta entered the most elegant and luxurious ballroom they had ever seen. It consisted of 8-10 layers of grand crystal windows that reached the ceiling. Oil paintings hung around the walls, intermingling with the windows, and casting off beautiful lights… Out of those lights arose shadows which slowly materialized into ghosts. They appeared friendly at first, doing nothing more than smiling and dancing, and a merry wave here and there. But as the minutes passed, they morphed, just ever so slowly. Their arms and legs duplicated, and became long and spindly, but their bodies shrunk continuously, until all that was left was a dead and shrunken skull atop 8 hairy legs. “Keratinocytes” whispered Laquanda in a hushed tone, “we need to leave, NOW!” And with that final word, Laquanda and Huerta took off across the ball room, running for their lives, with Huerta screaming at the top of his lungs. They climbed flight after flight of stairs, trying to put some distance between them and the Keratinocytes, but those hairy creatures had come together to make a gigantic spider webs, thus blocking the left exit, and their last hope.
The Keratinocytes were now closing in, their legs tapping impatiently, anxious to feed. Huerta appeared to be reciting his will and Laquanda closed his eyes and held is breath, waiting for the bite that never came.
Echoing around the ballroom walls was a Tarzan-like cry uttered by a shirtless man atop a balcony on the opposite wall. Across his chest the word “Roach” was written in bold letters. And without further ado, he cut a thread from the spider web and swung across the room. He was of course, aiming to land close enough to Huerta and Laquanda, so as to make a quick and speedy exit, but instead he ran-over, head-first, a dozen Keratinocytes.
That moments distraction was all Huerta and Laquanda needed to slip past the keratinocytes, and follow a very fast, yet slightly disoriented Roach up the staircase and out of harms way.

Level 3
All was silent on this floor, a sense of calm overwhelmed Huerta and Laquanda, despite the abnormal floating candles in the dark.
They agreed to rest and catch their breath before going an further, and as they did so, Roach recounted how he himself go into the house.
“All I remember was milking goats in Lebanon, and that’s a lot harder than you think. You’ve got to treat the goats with respect; like a sheet of music, ‘cause once you hit a wrong chord--”
“Just tell us how you got here!” yelled Laquanda and Huerta.
“Alright, alright,” replied Roach “Well, like I said, I was just out milking the goats when I heard this strange noise outside. I poked my head out to see what was going on and called out to see if it was my mom or something, but there was nothing. So I went back inside to continue milking the goat. And as I sat down on the stool, I noticed that my milk pail was gone, I turned around to look for it, but the last thing I remember was that milk pail coming at my head.”
“That’s it? Someone whacked you with a flimsy pail and you were out????” asked Laquanda almost indignantly.
“Well, it was more than half-filled…”
“Roach, don’t even talk to me anymore” said Laquanda
The silence lasted only for a few minutes before a strong wind momentarily blew the candles out. When they reignited, Roach, Huerta, and Laquanda looked at the ceiling and saw row after row of dead and flattened keratinocytes covered in tonofilament spider webs lining the walls.
Large glass doors now appeared before them, and they heard black sludge ooze from the wall and floor cracks .
“Get away from the walls! That black sludge, it’s keratohyalin, it turns the tonofilament spider webs into keratinocytes!” screamed Roach.
No sooner had he said it, when dozens of keratinocytes scuttled down the walls, heading for the three. They ran for the glass doors, jumping and leaping over keratinocytes, anxious to miss those deadly stingers. Panting, Laquanda made it through the glass doors first, followed closely by Huerta, but poor Roach never did.
He was just inches away when the glass doors slide shut. Roach desperately beat his hands against the doors screaming “OPEN UP! OPEN UP!!!!!” But try as they might, Huerta and Laquanda could not get the door to budge. They watch in horrified silence as Roach is submerged by keratinocytes.
They hear an evil laugh above and manage to catch a glimpse of a figure on a balcony, and watch as the figure struggles with what appears to be a pump, now emitting a green gas. They hear a stir on the other side of the glass doors, and watch as Roach slowly gets on his feet.
“ROACH! ROOOAAACCCHHH!!!” screamed Huerta.
But by know Roach had started mumbling incoherent descriptions about llamas and Lebanon.
“Shut up! He can’t hear you!” yelled Laquanda.
“But we can’t just leave him there!” retorted Huerta.
“Look, that’s Apoptosis gas and unless you want to--”
They heard a small explosion, and Roach fall on his knees, headless.
“ROACH!!!!!!!” cried Huerta.
“Unless you want to go the way of that goat-milker, I suggest we leave now, seeing as how the Apoptosis gas could leak through the cracks any minute!”
Suddenly the keratinocytes on the wall began to secrete a new liquid (“lamellar granules” shuddered Laquanda).
The silvery lamellar granules became compacted, and rushed with force at the glass doors, breaking them. But by then Huerta and Laquanda had gone, and were well on the way to the next floor.

Level 4
Laquanda and Huerta raced up the stairs panting, not far ahead Laquanda could see the door leading to next floor. "We're almost there!" he called out. They burst through the multi-colored door and shut it behind them as quickly as they possibly could. A white light filled the room, so bright they couldn't see a thing. "Where are we?" Huerta ask as he attempted to shield his eyes from the burning light, "Either the 4th or 5th level, I'm not sure. This place changes sometimes, as soon as the light dies down we'll be able to tell which floor we came out on" As he said those words the searing light began to fade away to a dull yellow light that they could both handle easily. The room was a lot smaller compared to the last few rooms they had run through. The room was filled with old grey keratinocytes, they came in the form of what seemed to be simply the outline of elderly people, they didn't seem to notice them and they moved very slowly. "Why are you so old and see through?" Huerta whispered. "The one's here are transparent, something about the Stratum Lucidum. Keratinocytes move through each floor when they get older, while new ones are being added to house on that bottom floor where you woke up at" "You mean . . ." Huerta paused as he tried to comprehend what Laquanda was saying. "You mean, we were supposed to become keratinocytes?" "That's exactly what I'm saying. As they move through each floor they make their way to the 5th level where they will be let go." "Let go?" "They get rid of them, new ones are coming in, they don't need the old keratinocytes on the verge of death. Come on, we need to keep going" As they followed the old hollowed out wall, avoiding the old geezers hobbling along a loud new voice me their ears. "Hold it right there!" They spin around and see a keratinocyte in the form of a young short girl with chinky eyes standing in front them. "Where are you two going?" She yelled out. "Out the door" Laquanda answered. "OBJECTION!" She yelled out, "You're not going anywhere . . . Unless you take some of this pan de ube with you" The keratinocyte pulled a plastic bag out from behind her back containing the said bread. The two stared at her in shock. "Who are you?" Laquanda asked. "My name's Jessyca, I lead all the passing keratinocytes to the 5th level to be shed from the Epithelium House. " "So you know the way out then?" Huerta asked quickly and without thinking, which was totally normal for him. "Oh yeah, I even know how to get out without passing by Chrystina Taylor." "What's a Chrystina Taylor?" Huerta asked Jessyca gave him a funny look, "Surely you know who she is, I mean, Chrystina has been the queen of the Epithelium House since before that little Stratum Germinative made me a keratinocyte." "Chrystina Taylor is the ruler of the keratinocytes. Her step-father ruled and left the title to Chrystina, even though he has a daughter of his own. Haleigh, the mostawesomest of all the keratinocytes, was left with nothing after he was shed, but that's not going to last much longer" That last bit Laquanda had muttered under his breath. "I'm sorry, what was that?" Jessyca asked "I missed that last thing you said" "Nothing" Laquanda said before turning his back to her, "We need to keep going." "Where are you two heading to?" "We're heading for shedding" Huerta replied. "I can show you a short cut if you would like" "Sure, that's cool" Laquanda nodded, "Let's get going"

Level 5
Haleigh watched as the trio raced up the staircase from a heavily shadowed spot on the beams above them. Soon the Epidermis would be hers once and for all. Soon she would take what was hers!

Flashback
King Swain lay on his death bed, his two daughters stood before him. One, his daughter from his first marriage, beautiful and strong-headed, the other, his step-daughter powerful and intimidating. "Girls" he began, his voice quivering from the strain "I would want nothing more then to let both of you rule, but I can only choose one to take on the responsibilities of running the Epidermis . . .Chrystina, you will be the next ruler of this house."

Haleigh practically shock from her rage. "I will get what is mine" she whispered.

"Come on" Jessyca said as led them through a darkened path lit by only a few lamps hanging from the ceiling. "Where are we, the throne room isn't anywhere near here" "No, I told you that I was going to take you to the exit without passing through the throne room, remember?" Tracy frowned as he followed Jessyca through the hall. Suddenly the lights were gone and the group was engulfed in darkness, they could hear the sounds of footsteps, of a small gasp, someone was struggling. Then silence. The lights flickered back on. "Where's Laquanda?!" Jessyca called out, "I think we better worry about ourselves first, look!" Huerta said pointing further down the narrow hallway where an army of spider keratinocytes were making their way towards them. "Oye! It's time to get going!" Jessyca grabbed Huerta's upper arm and turned around and began running as fast as she could. She pulled him into a darkened turnoff that Huerta hadn' t noticed when they had walked past it. "Come on!" Jessyca yelled again. She let go of his arm and assumed he would follow her when she continued to run. In the middle of the hallway coming up quickly as Jessyca raced through was a thin plastic orange fence, it was barely visible through the darkness, but she saw it and she leapt as high as she could . . . Her foot caught in the fence and she fell. Her slipper was torn, "Oh no!" She cried out as Huerta stopped to help her up, the Keratinocytes were close. Their eyes got wide as she stumbled to her feet, ripping the shoe off her foot, it was too messed up to run in. "We have to keep going" Huerta yelled, panic filled his voice. They took off again. And once again they were forced to ground. This time they ran into something moving. "Laquanda!" Jessyca yelled out. "Finally! I found you guys!" He looked up and saw the hoard of Keratinocytes rampaging towards them, "Yeah, we should get going" He dragged the two to their feet and led them down the hall he was just exited from. "This way!" He called out. They burst through extremely large double doors, shutting them behind them. They could hear the sound of the keratinocytes colliding with the door outside. "Where are we?" Huerta asked aloud as he looked around the room in awe. It was large and ornately decorated. The shimmering lights and sparkling crystal windows shone brightly "We're in the Stratum Corneum. The topmost layer" Laquanda answered. "More then that. We're in the Throne Room" Jessyca added a bit nervously, "We have to get out of here before -" The shaking ground cut Jessyca off in mid-sentence. "Before what?" Echoed a monstrous voice coming from, of all places, the ceiling. They all looked up quickly. Hanging from a thick web was a giant keratinocyte. "It's her!" Jessyca whispered, her voice overflowing with fear. "Queen Chrysitna T, also known as Queen Gohma!" "Huerta!" Laquanda demanded, "You must fight her. You are the only one who can defeat her!" "Why me?" "There are stories about you, you're the chosen one sent from the heavens to rid us of the darkness. Only you can do it!" Huerta turned to see the giant spider-keratinocyte queen hovering above him laughing hysterically. "I can do this." He repeated over and over. He shut his eyes tight and when he opened them he was ready for battle. He longer wore the beat up old clothes he wore every other day, instead he was wearing a long green tunic, with brown tights and high brown hunting boots. On his head was green cap, one you might confuse with a sleeping cap. He reached for the sheath that was suddenly at his waist and pulled out the Kokiri sword ready for battle. His trusty sling-shot also ready at his waist. The monster attack and Huerta dodged. As Queen Chrystina turned searching for Huerta with her one giant eye Huerta pulled out his sling-shot and hit her eye dead center. Kokiri sword in hand he took one good slash at the injured keratinocyte queen and took her out."

"DUDE!" Laquanda cried out. "You did it!" Panting Huerta grinned at Laquanda and Jessyca, he turned back to the body of the keratinocyte queen as a small blue fairy rose from her body. Huerta approached it, a glass bottle in hand ready to catch it. Just as he uncorked the bottle the fairy it transformed into a gorgeous woman with long blue hair adorned with gold bands and ringlets hanging from the ends. Her skin itself had a bluish tint. She was dressed in a skimpy icy blue bikini. That was when Huerta noticed her claw like nails. This woman was beautiful, but obviously a force to be reckoned to with. As her feet touched the floor Huerta took in her height . . . or lack of it, she couldn't have been taller than 5 feet. She tossed her hair out her face before her hard gaze met Huerta's. It was a look that could freeze over Hell. Huerta took a step in both shock and fear. You would think that he would have learned that short women were the ones you really have to look out for. Behind him Laquanda dropped to one knee, "I have done all that you have asked, my lady, or should I say, Queen Haleigh" Haleigh's gaze turned to Laquanda's bowed head. "Yes you did quite well. I am very pleased" Laquanda rose to his feet and stepped to Haleigh's side, "What do we do with these two useless sacks of keratin?" Laquanda asked with an evil grin. "Dispose of them, they are not of any use to me" Haleigh replied with toss of her hand. "Dispose?" Huerta questioned quickly, "Laquanda, what is she talking about what's going on?" That's when it hit him, everything suddenly made sense, "You . . . The cut on your leg. . . You're disappearing . . . You're a keratinocyte!" "A bit slow aren't we? I was never on your side, I was never trying to get you out, you were just the only one who could take out the spider" "I should have known, how you always knew which way to go, someone living In the Stratum Basale would have never known all that stuff you knew" "And yet it took you until now to realize it" "Did you get shorter?" Jessyca asked out of the blue. "What?" Laquanda replied, "You look shorter." That's when Laquanda really look in his height loss, he was almost the same size as Haleigh . . . "What's going on?" He asked looking as his body in shock, "I'm turning into an Asian kerantinocyte" "Oh, did I forget to mention that? You traveling through the levels of the Epidermis means you're getting flatter, shorter. You being short, means you're practically useless to me . . . No, let me correct that, you are useless to me." "You promised me a share of your power!" Laquanda growled. "Did I? You must have misheard me, I would never promise my power, my right to rule, to a misshapen keratinocyte like you." Laquanda fell to knees as he was just about ready to charge at the new queen. "Well it looks like it's time for you to be shed." Haleigh said mockingly as she stood above Laquanda as he lay on the ground clutching his stomach in pain. She looked up just as the other two fell to their knees as well. "It looks like it's time for all of you to go." With a snap of her delicate hand big strong keratinocytes appeared and dragged the near lifeless bodies to the shedding site. "Bye now" Haleigh said laughing as she turned her back on the trio making her way through the grand throne room to her throne where she would rule for as long as she may.

Physiology –Muscles Table

FACIAL

Name	Location	Description	Action
Frontalis	Runs vertically on forehead, originates in tissue on scalp	Composed of medial & lateral parts	Draws eyebrows & skin upward
Occipitalus	Lips		Elevates lips
Orbicularis Oris	Schimeter muscles around mouth	Mucous membrane, muscles inserting into lips	Closes lips
Obicularis Oculi	Around eyes Outer: Medial orbit     Palpebral: Palpebal ligament	Three parts: Orbitial, Palpebral, & lacrimal	Projecting and moistening eyes, expressive displays, constrict skin, reduces opening, closes the eye
Zygomatic	Major: Cheek bone (near mouth corner)     Minor: Lateral part of cheek	Inverted by zygomatic & buccal branches	Lifts corner of mouth upward (smiling     Draws skin of lip upward laterally
Levator Labii Superioris	Upper lip & cheek	Two parts: Nasal & lateral Nasal: Originates near/on cheek bone     Lateral: From medial part of orbit	Raises upper lip straight up Raises upper lip, stretched nasal wing up, & wrinkles nose
Depressor Labii Inferioris	Originates in chin part & inserts into skin of lower lip	Inverted by mandibular & buccal branches of facial nerve	Pulls red parts of lips (lower) straight down & skin of lower lip laterally down
Mentalis	Part of mandible below the front teeth	Associated by mandibular & buccal branches of facial nerve	Pushes chin boss upward
Buccinator	Lips	Maxilla & mandible (inserts into)	Maintains cheeks near teeth & food in position for chewing
Platysma	From upper chest through neck to lower cheek	Innverted by deep cervical branch of facial nerve	Assists in depressing mandible & tightens the fascia of neck     Lowers jaw and lip

 
 

CHEST

Sternocladiomastiod	Manubrium of sternum	Inserts into mastoid process of temporal bone	Lateral flexion to same side & rotation to opposite sides     Flexion of head & neck
Pectoralis Major	Sternum to 7th rib	Inserts to crest of greater tubercle of humerus	Flexion of humerus, extension of humerus returning from flexion
Pectoralis Minor	3rd, 4th, & 5th ribs	Inserts into caracoid process of scapula	Tilts scapula forward, depresses & abducts scapula
Deltoid	Lateral 1/3 of clavicle	Inserts into deltoid tuberousity	Abducts the shoulder joint
Serratus Anterior	Scapula fossa of scapula	Inserts into lesser tubercle of humerus	Medially rotates shoulder joint
Subscapularis	Originated at the inner surface of the scapula	Inserts into inferios lateral aspect of clavicle	Elevates first rib, stabilizes sternoclavicular joint

 
 

ABDOMINALS

Rectus abdominus	Front of lower torso	This bands of connective tissue	Flex the spine
Transverse Abdominus	Deepest muscle to the core wrap under abs	Acts as a natural weight belt	Essential for trunk stability as well as keeps stomach tight
Internal Obliques	Flank rectus abs/ run diagonally no body allowing for angles movement	Runs opposite of internal	Twisting of torso     Rotate torso & stabilizes abs
External Obliques	Each side of rectus/ run diagonally on body allowing for angled movement	Runs opposite of external	Twisting/ Rotate torso & stabilizes abs
Trapezius	Runs down upper section of spinal cord	Long, trapezoid shape	Scapular elevation
Latisimus Dorsi	From side of body toward spinal area     Attached to the upper humerus to vertebral	Largest in back     Fan shaped	Pulls arm toward pelvis

 

Physiology -Notes- Bone Growth

Bone Growth

• Bones grow from the epiphyseal plate during infancy and youth
  
• Facial bones continue to grow until your demise
  
• Replacement of cartilage cells by bone cells only on the sides of the diaphysis
  
• Controlled by sex & growth hormones
  
• Bone growth is completed at 25 years in males and 19 years in females
  

~3 Different Zones~

1.) Growth Zone: cartilage undergoes mitosis, push up on epiphyseal plate

2.) Transformation Zone: older cells begin to break down (hypertrophy) and enlarge

-These cells begin to calcify

-Cartilage turned into bone

3.) Osteogenic Zone: formation of medullary cavity

~Growth is Dependent on 4 Factors~

1.) Adequate Minerals: Ca²⁺, B, Mn

2.) Hormones: thyroid, growth, sex, parathyroid, calcitonin

3.) Vitamins: A, B₁₂, C, D

4.) Exercise: weight bearing stress

Physiology -Worksheet- Bones of the Pectoral Girdle and Upper Limb

Physiology -Chap 7- Outline

(FIRST IS THE OUTLINE FROM MS. HATFIELD AND BELOW THE LINE ARE MY OWN NOTES (BEST IF USED TOGETHER))

Chapter 7 : The Skeletal System

• Divisions
  
  
• Axial: Consists of bones that lie around the longitudinal axial of the body.
  
  

  Includes: Skull, Hyoid, Auditory Ossicles, Vertebral Column, and the Thorax
  

• Appendicular: Consists of the bones that make up the upper and lower limbs and the girdles that connect the limbs to the axial
  
  

  Includes: Pectoral, Upper Limbs, Pelvic Girdle, and the Lower Lombs
  

• Girdles: Connect limbs to axial skeleton
  
  
• Types of Bones
  
  
• Long: Greater length than width, slightly curved for strength
  
  
  • Consists of shaft and a variable number of extremities
    
  • Mostly compact bone in shaft, spongy at ends
    
• Short: Somewhat cube shaped, width and length almost equal
  
  
  • Almost all spongy except at surface
    
• Flat: Thin
  
  
  • Consists of two nearly parallel plates of compact bone tissue enclosing spongy bone tissue
    
• Irregular: Complex shapes
  
  
  • Vary in amount of spongy and compact bone preasent
    
• Sesamoid:Only a few millimeters in diameter
  

Bone Surface Markings

• Depressions: Forms joints or allow the passage of soft tissue
  

Processes: Projections or outgrowths that either help form joints or serve as attachment points for connective tissue

* Know the table 7.2 *

• cleft palate
  
• cleft lip
  
  

Skull

• Function: Protects brain, blood vessels, lymphatic vessels, and nerves through the attachment of their inner surfaces
  
  

  Also provide attachment for some muscles that produce facial expressions
  

• Number of Bones Total:
  
  
• Cranial: Form the cranial cavity which encloses and protects the brain
  
• Facial: Forms the face
  

Vertebral Column

Physiology-

Total number: Cervical

Thoracic

Lumbar

Sacral

Coccygeal

Intervertebral discs:

Characteristics of a Typical Vertebrae-

Body-

Vertebral arch-

Processes-

• transverse-
  

• spinous-
  

Facets-

• inferior
  
  

  2. superior
  

Cervical Vertebrae:

Number:

Special characteristics:

Special movements:

Thoracic Vertebrae

Number:

Special characteristics:

Special movements:

Lumbar Vertebrae

Number:

Special characteristics:

Special movements:

Sacrum

Number:

Special characteristics:

Special movements:

Coccyx-

Number:

Special characteristics:

Special movements:

_________________________________________________________________________________________________

Divisions of the Skeletal System

• The bones of adults are grouped into two main categories:
  
  
  • Axial
    
  • Appendicular
    
• The girdle connect the limbs of the appendicular to the axial bones
  
  

  Note: Functionally the ossicles in the ear are not a part of the axial, but are included for convenience
  

  Types of Bones
  

• All bones can be classified into five main types based on shape
  
  
  • Long: Curved for strength
    
    
    • Curve absorbs the stress of the bodies weight at several different points (like an arch)
      
    • If bones were straight the weight would not be even distributed and would be more easily fracture
      
  • Short
    
  • Flat: Afford more protection and provide extensive areas for muscle attachment
    
  • Irregular: Cannot be grouped into any other areas
    
  • Sesamoid: Develop in certain tendons where there is considerable friction, tension, and physical stress
    
    
    • Vary in number from person to person
      
    • Not completely ossified
      
    • Protect tendons from excessive wear and tear
      
    • Often change the direction of pull of a tendon, improve mechanical advantage at a joint
      
• There is one other type of bone that is classified by location rather than shape
  
  
  • Sutural bone
    
    
    • Small bones located in sutures (immovable joints) between cranial bones
      
      

      
      

  Bone Surface Markings
  

• Bones have surface markings: structural features adapted for specific functions
  
  
  • Most not present at birth, but tension causes them
    
• Two major types of surface markings
  
  
  • Depressions and openings
    
  • Processes
    
    

    
    

  Skull
  

• Has 22 bones
  
• Rests of superior end of the vertebral column
  
• The bones of the skull are grouped into two categories:
  
  
  • Cranial bones:
    
    
    • Frontal bone, two parietal bones, two temporal bones, the occipital bone, and sphenoid bone, and the ethmoid bone
      
  • Facial bones:
    
    
    • Two nasal bones, two maxillae, two zygomatic bones, the mindible, two lacrimal bones, two palatine bones, two inferior nasal conache, and the vomer
      

  General Features and Function
  

• Also forms smaller cranial cavities
  
• Certain skull bones contain cavities called paranasal sinuses that are linked with mucous membranes and open into the nasal cavity
  
• Other than the auditory ossicles the mandible is the only movable bone of the skull
  
  

  Cranial Bones
  

  Frontal Bone
  

• Frontal bone
  
  
  • Forms forehead, roof of orbits, ad most of the anterior part of the cranial floor
    
    

    
    

  
  

Physiology -Chap 6- End of Chap Questions

1. Match the Following:
   

   
   

   -3- (a)Space w/in the shaft of the bone that contains yellow bone marrow: Medullary Cavity
   

   -9- (b) Triglyceride storage tissue: Yellow Bone Marrow
   

   -8- (c) Hemopoietic tissue: Red Bone Marrow
   

   -1- (d) Thin layer of hyaline cartilage covering the ends of bones when they form a join: Articular Cartalige
   

   -5- (e) Distal and proximal ends of bones: Epiphyses
   

   -4- (f) The long, cylindrical main portion of the bone the shaft: Diaphysis
   

   -6- (g) in a growing bone, the region that contains the epiphyseal plate: Metaphysis
   

   -7- (h) The though membrane that surrounds the bone surface wherever cartilage is not present: Periosteum
   

   -12- (i) Layer of hyaline cartilage in the area between the shaft and end of a growing bone: Epiphyseal Plate
   

   -2- (j) Membrane lining the medullary cavity: Endosteum
   

   -11- (k) A remnant of the active epiphyseal plate; a sign that the bone has stopped growing in length: Epiphyseal line
   

   -10- (l) Bundles of collagen fibers that attach periosteum to bone: Perforating Fibers
   

   
   

2. Match the Following:
   

   
   

   -12- (a) Small spaces between lamellae that contains osteocytes: Lacune
   

   -13- (b) Perforating canals that penetrate compact bone vessels, carry blood vessels, lymphatic vessels, and nerves from the periosteum: Volkmann's Canals
   

   -8- (c) Areas between osteons: fragments of old osteons
   

   -6- (d) Cells that secrete the components required to build bone: Osteoblasts
   

   -3- (e) Microscopic unit of compact bone tissue: Osteons (Haversian System)
   

   -9- (f) Interconnected, tiny canals filled with extracellular fluid; connect lacunae to each other and to the central canal:
   

   -4- (g) Canals that extend longitudinally through the bone and connect blood vessels and nerves to the osteocytes: Haversian Canals
   

   -10- (h) Large cells derived from monocytes and involved in bone resporption: Osteoclasts
   

   -7- (i) Irregular lattice of thin columns of bone found in spongy tissue
   

   -5- (j) Rings of hard calcified matrix found just beneath the periosteum and in the medullary cavity: Concentric Lamellae
   

   -2- (k) Mature cells that maintain the daily metabolism of bone: Ostocytes
   

   -11- (l) An opening in the shaft of the bone allowing an artery to pass into the bone
   

   -1- (m) Unspecialized stem cells derived from mesenchyme: Osteogenic Cells
   

   
   

3. Match the Following:
   

   
   

   -3- (a) A broken bone in which one end of the fractured bone is driven into the end of other: Impacted Fracture
   

   -7- (b) A condition of porous bones characterized by decreased bone mass and increased susceptibility to fractures: Osteoporosis
   

   -6- (c) Splintered bone, with smaller fragments lying between main fragments: Comminuated Fracture
   

   -1- (d) A broken bone that not break through the skin: Closed Fracture
   

   -4- (e) A partial break in a bone in which one side of the bone is broken and the other side bends: Greenstick Fracture
   

   -2- (f) A broken bone that protrudes through the skin: Open Fracture
   

   -5- (g)Microscopic bone breaks resulting from the inability to withstand repeated stressful impact: Stress Fracture
   

   -9- (h) A degeneration or articular cartilage allowing the bony ends to tough; worsens due to friction between the bone: Osteoarthritis
   

   -8- (i) Condition characterized by failure of new bone formed by remodeling to calcify adults: Osteomalacia
   

   -10- (j) An infection of bone: Osteomyelitis
   

Physiology -Chap 6.3- Outline

Bones and Homeostasis

• Bone Remodeling: Continuous replacement of old bone tissue
  
  • Involves bone resorption: Removal of minerals and collagen fibers from bone by osteoclasts
    
  • Involves bone
    deposition: Addition of minerals and collagen fibers to bone by osteoblasts
    
    • Resorption causes destruction of EC-M
      
    • Deposition causes formation of EC-M
      
  • Takes place at different rates in different regions
    
  • Benefits:
    
    • If new bone is placed under stress it thickness becoming stronger than old bone
      
    • Shape can be altered for proper support based on stress patterns
      
    • More resistant to fracture
      

  *Remodeling and Orthodontics*
  

• Orthodontics: Dentistry concerned with prevention and correction of poorly aligned teeth
  
• Braces
  
  • Places stress on bone that forms the sockets that anchor the teeth
    
  • In response the osteoclast/blasts remodel the sockets so the teeth align
    
    • Osteoclasts attach to bone surface at endosteum and forms a leak-proof seal
      
    • Releases lysosomal enzymes and acids
      
    • Osteoclasts carve a tunnel into bone
      
      • The minerals carved out are resorbed
        
    • Osteoclasts leave and osteoblasts come in and rebuild
      

  Factors Affecting Bone Growth and Bone Remodeling
  

• Factors in growth
  
  • Minerals: Calcium and phosphorus needed when bones are growing
    
  • Vitamins: Vitamin C in needed for synthesis of collagen and for differentiation of osteoblasts into osteocytes
    
    • Also needed: K, B12, and A
      
  • Hormones:
    
    • Childhood:
      
      • Insulin-like growth factors (IGF)
        
        • Produced by liver and bone tissue
          
        • Stimulate *blasts, promote cell division, and enhance synthesis of proteins
          
      • Thyroid hormones also promote bone growth by stimulating *blasts
        
    • Puberty:
      
      • Sex
        hormones:
        
        • Include: Estrogen and testosterone
          
        • Responsible for increased *blast activity and synthesis of bone EC-M and the 'growth spurt'
          
    • Adulthood:
      
      • Sex hormones:
        
        • Slow resorption of old bone and promotes deposition of new bone
          

  Fracture and Repair of Bone
  

• Fracture: Break in any bone
  
  • Named for sensitivity, shape, or position of line:
    
    • Open fracture: Broken ends protrude through skin
      
    • Comminuted fracture: Bone splinters at site of impact and smaller bone fragments lie between the two main fragment
      
    • Greenstick fracture: Partial fracture in which one side is broken and other bends
      
    • Impacted fracture: One end is forcefully driven into the interior of other
      
    • Pott's fracture: Fracture of the distal end of the lateral leg bone, with serious injury of the distal tibial articulation
      
    • Colles' Fracture: Fracture of the distal end of the lateral forearm bone in which the distal fragment is displaced posteriorly
      
  • Stress fracture: Series of microscopic fissures in bone that forms without any evidence of injury to other tissues
    
• Repairing a bone:
  
  • Formation of Fracture Hematoma
    
    • Blood vessels crossing the fracture line (FL) are broken
      
    • Clots are formed as blood leaks (Fracture hematoma)
      
    • Nearby bone cells die
      
      • Causes swelling and inflammation
        
  • Fibrocartilaginous Callus Formation
    
    • Fibroblasts invade fracture site and produce collagen
      
    • Cells from periosteum develop into chondroblasts and produce fibrocartilage
      
      • Lead to development of fibrocartilaginous
        callus
        
        • Repair tissue consisting of collagen that bridges broken ends
          
  • Bony Callus Formation
    
    • Osteogenic cells develop into osteoblasts which produce spongy bone trabeculae
      
    • Fibrocartilage is converted to spongy bone and callus referred to bony callus
      
  • Bone Remodeling
    
    • Dead portion of original fragment is resorbed
      
    • Compact replaces spongy around periphery of the fracture
      

  *Treatments for Fracture
  

• For bones to unite properly the ends must be brought to alignment
  
  • Called reduction
    
    • Closed reduction: Fractured ends of bone brought into alignment by manual manipulation
      
      • Skin remains intact
        
    • Open reduction: Brought together during a surgery
      

  Bone's Role in Calcium Homeostasis
  

• Small changes in calcium concentration could be fatal
  
  • High=Heart may stop
    
  • Low=Breathing may stop
    
• Bone buffers the calcium level
  
  • Releasing when too low
    
  • Absorbing when too high
    
• Regulated by hormones:
  
  • Parathyroid
    hormone (PTH)
    
    • Secreted by parathyroid glands
      
    • Increases blood calcium level
      
    • Operates with a negative feedback system
      
    • Acts on kidneys to decrease loss calcium in urine so more stays in the blood
      
    • Stimulates formation of calcitriol
      
      • Inhibits activity of osteoclasts
        
      • Speeds blood calcium uptake by bone
        
      • Accelerates calcium deposits
        

  Exercise and Bone Tissue
  

• When placed under stress bone tissue becomes stronger through increased deposition of mineral salts
  
• Without mechanical stress bone does not remodel normally
  
  • Resorption occurs more quickly than formation
    
• Walking and weight lifting (weight bearing activities) build and retain bone mass
  

  Aging and Bone Tissue
  

• More bone tissue is produced than lost
  
• As levels of sex hormones decrease there is a decrease in bone mass
  
  • Because bone resorption by osteoblasts outpaces deposition of osteoblasts
    
• Two aging effects
  
  • Loss of bone mass:
    
    • Results from demineralization
      
  • Brittleness
    
    • Results from decreased rate of protein synthesis
      

Physiology -Chap 6.2- Outline

Bone Scan

• A diagnostic procedure
  
  • Takes advantage that bone is living tissue
    
  • Radioactive tracer is absorbed by bone is injected
    
  • Measures radiation emitted by bone
    
    • X-Ray
      
• Normally appear as gray
  
  • Darker-hot spot-increased metabolism
    
  • Lighter-cold spot-decreased metabolism
    

  Bone and Nerve Supple of Bone
  

• Blood vessels pass into bone from periosteum
  
• Arteries
  
  • Periosteal
    
    • Enter the diaphysis through perforating canals
      
    • Supply periosteum and outer part of compact bone
      
  • Nutrient
    
    • Passes through hole in compact bone called nutrient foramen
      
    • Divides into proximal and distal branches
      
    • Supply the inner part of compact bone tissue and spongy bone tissue and red marrow
      

  (Long bones supplied by matephyseal plate and epiphyseal arteries
  

  Arise from arteries that supply the associated joint)
  

  • Metaphyseal
    
    • Enter the metaphyses with nutrient artery
      
    • Supply RBM and bone tissue of metaphyses
      
• Veins
  
  • Nutrient Veins
    
    • Accompany nutrient artery in the diaphysis
      
  • Epiphyseal & Metaphyseal
    
    • Exit in epiphyses
      
  • Periosteal
    
    • Exit with respective arteries in the periosteum
      
• Periosteum
  
  • Rich in sensory nerves
    
    • Carry pain sensations
      
    • Sensitive to tearing or tension
      

      
      

  Bone Formation
  

• Ossifacation/ Osteogensis
  
  • Formation of bone
    
• Skeleton of embryo
  
  • Composed of loose mesechymal cells
    
    • Shaped like bones
      
    • Provide template for subsequent ossifacation
      
• Methods of ossifacation
  
  • Intramembranous
    
    • Bone forms directly within mesenchyme arrange in sheet-like layers
      
      • Resembles membranes
        
  • Endochondral
    
    • Bone forms within hyaline cartilage that develops from mesenchyme
      

  Intramembranous Ossification
  

• Simpler
  
• Skull and jaw formed this way
  
• Hardening of fetal skull:
  
  • Development of ossifacation center
    
    • Chemical message causes mesenchymal cells to cluster and differentiate
      
    • Osteoblasts secrete organic EC-M until they are surrounded
      
  • Calcification
    
    • Secretion of EC-M stops and osteocytes lie in lacunae and extend cytoplasmic processes into canaliculi that radiate in all directions
      
    • In a few days it all hardens
      
  • Formation of Trabeculae
    
    • EC-M develops into trabeculae
      
      • Fuses with one another to form spongy bone
        
  • Development of the Periosteum
    
    • Mesenchyme condenses and develops into periosteum
      
    • Thing layer of compact bone replaces surface of spongy bone
      
    • Much of newly formed bone is remodeled as bone is transformed into its adult size and shape
      

  Endochondral Ossifacation
  

• Replacement of cartilage by bone
  
• Process:
  
  • Development of the Cartilage Model
    
    • Chemical messages cause mesenchymal calls to crowd in the shape of the future bone
      
    • Develop into chondroblasts
      
      • Secrete EC-M
        
      • Produce cartilage model
        
      • Perichondrium membrane develops around it
        
  • Growth of the Cartilage Model
    
    • Model grows further by continual cell division of chondrocytes and further secretion of EC-M
      
      • Called interstitial growth
        
      • Results in an increase of length
        
    • Thickness due to addition of EC-M material
      
      • Appositional growth
        
    • Chondrocytes and surroundings EC-M calcifies
      
  • Development of the Primary Ossifacation Center
    
    • Proceeds inward from external surface of bone
      
    • Nutrient artery penetrates perichondrium, and cart. Model
      
      • Stimulates osteogenic cells to differentiate into osteoblasts
        
    • Once perichondrium starts of form the bone it's known as periosteum
      
    • Growth
      of primary ossifacation center
      
      • Where bone tissue replaces cart.
        
    • Start of formation of spongy bone tabeculae
      
  • Development of the Medullary Cavity
    
    • Osteoclasts break down newly formed spongy bone trabeculae
      
      • Leaves a cavity in the diaphysis
        
        • Eventually replaced by compact bone
          
  • Development of the Secondary Ossifacation Centers
    
    • Formed when epip. artery enter the epiphyses
      
    • Spongy bone remains in the interior
      
    • Proceeds outward
      
  • Formation the Articular Cartilage and the Epiphyseal Plate
    
    • Hyaline cart. that covers the epiphyses becomes the articular cart.
      
    • Epiphyseal plate=Responsible for lengthwise growth of long bones
      

  Bone Growth
  

  Growth in Length
  

• Epiphyseal contains for layers:
  
• Zone of Resting Cartilage
  
  • Consists of small scattered chodrocytes
    
  • Cells do not function in growth
    
    • Anchor to epiphyseal plate to the epiphyses of the bone
      
• Zone of Proliferating Cartilage
  
  • Chondrocytes arranged in stacks
    
    • They divide to replace those that die at the diaphyseal side
      
• Zone of Hypertrophic Cartilage
  
  • Consists of large maturing chondrocytes arranged in columns
    
• Zone of Calcified Cartilage
  
  • Only a few thick
    
  • Consists of dead chondrocytes
    
    • Dead by calcified EC-M
      
• At maturation plate fades leaving the bony structure called the epiphyseal
  line
  

  Growth in Thickness
  

• Appositional growth:
  
  • Cells in the periosteum differentiate into osteoblasts
    
    • Secrete collagen fibers and other molecules that form EC-M
      
    • Become surrounded by EC-m and turn into osteocytes
      
      • Forms ridges
        
  • Ridges fold together and fuse
    
    • Groove become tunnel that encloses blood vessel
      
    • Periosteum=endosteum
      
  • Osteoblasts deposit bone EC-M
    
    • Forms new concentric lamellae
      
      • Proceeds inward
        
  • Ostoblasts under periosteum deposit new outer circumferential lamellae
    

    
    

    
    

    
    

  
  

Physiology -Chap 6- Outline

The Skeletal System: Bone Tissue

Functions of Bone and The Skeletal System

• The functions of the skeletal system
  
  • Support: Framework for the body, supports soft tissues and provides attachment point for tendons of most skeletal muscles
    
  • Protection: Protect most important internal organs from injury
    
  • Assistance in Movement: Attach to bones; when the contract, they pull on bones to produce movement
    
  • Mineral Homeostasis: Bone tissue stores several minerals (calcium & phospherus)
    
  • Blood Cell Production: CT called red bone marrow produces more RBC, WBC, and platelets (called hemopoisis
    
  • Triglyceride Storage: Yellow bone marrow consists of adipose cells which store Trigly. The stored Trygly. Are a potential chemical energy reserve
    

    
    

  Structure of the Bone
  

• Lone bone=Greater length than width
  
• Long bone consists of:
  
  • Diaphysis
    
  • Epiphyses
    
  • Metaphyses
    
  • Epiphyseal Plate
    
  • Articular Cartalidge
    
  • Periosteum
    
  • Medullary Caivity
    

    
    

  
  

  Histology of Bone Tissue
  

• Bone tissue contains EC-M
  
  • 25% water, 25% Collagen fibers, 50% crystallized mineral salts.
    
    • Calcium phosphate + calcium hydroxide = hydroxyapatite
      
      • Califacation started by bone building cells
        
        • Process requires presences of collagen fibers
          
• Hardness = crystallized minerals
  
• Flexibility = collagen fibers
  
  • Provide tensile, strength, and resistance
    
• Four cells in tissue:
  
  • Osteogenic Cells: Unspecialized stem cells derived from mesenchyme, the tissue from which all CT are made from
    
  • Osteoblasts: Bone building cells. Synthesizes and secrete collagen
    
  • Osteocytes: Mature bone cells are the main cells in bone tissueand maintain it's daily metabolism
    
  • Osteoclasts: Cells derived from fusion of as many as 50 monocytes and are concentrated in the endosteum
    

    
    

  Compact Bone Tissue
  

• Compact bone tissue contains few spaces
  
• Strongest form of BT
  
• Found beneath periosteum, makes up bulk of long bones
  
• Blood vessels, lymthpatic vessels, ect. Transverse perforating canals
  
• Central canals
  
  • Around those are the concentric lamellae
    
  • Between lamellae are the lacunae
    
    • Tiny canaliculi filled with EC fluid
      
• Components of compact bone tissue are arranged into repeating units calls osteons or haversian systems
  
  • Parallel in shaft
    
    • Does not bend or fracture
      
    • Lines of stress change as baby starts to walk
      
• Area between osteans contain interstitial lamellae
  

  
  

  Spongy Bone Tissue
  

• No osteons
  
• Refers to appearance
  
• Consists of lamellae arranged in lattice of thin columns called trabeculae
  
  • Lacunae contain osteocytes
    
• Spongy bone tissue make up most of bone tissue of short flat, and irregularly shaped bones
  

  
  

  
  

  VOCAB:
  

  
  

  Diaphysis:Shaft of bone; long cylindrical main portion
  

  Epiphyses: Distal and proximal ends of bone
  

  Metaphyses: Regions in mature bone where the diaphysis join the epiphyses. Each meta. Includes an
  

  
  

  Epiphyseal Plate: Layer of hyaline cartilage that allows diaphylsis of bone in great length
  

  Epiphyseal Line: The boney result of the cartilage in the epip. plate being replaced by bone, caused by the stop of growth of the bone
  

  Articular Cartalidge Thin layer of hyaline cartilage covering epip. where the bone forms a joint with another bone
  

  Periosteum: Tough sheath of dense irregular CT that surrounds the done surface, enable bones to grow in thickness, not length. Aids in healing of bone
  

  Medullary Caivity: space within the diaphysis that contains fatty yellow bone marrow in adults
  

  Endosteum: Thin membrane that lines the medullary cavity. Contain single layer of bone forming cells and a small amount of CT
  

  Bone/Osseous Tissue: CT, contains abundant EC-M
  

  Hydroxyapatite: Calcium phosphate + calcium hydroxide
  

  Califacation:
  Process of minerals combining to form other minerals
  

  
  

epiphyseal plate

Physiology -Chap 4- Outline.2

Chapter 4 (Pgs. 111-118)

Covering and Lining Epithelium

• The types and covering and lining epithelial tissue are classified according to two characteristics: the arrangement of cells into layers and the shapes of the cells

Arrangement of Cells in Layers

• Cells are arranged in one or more layers depending on the functions the epithelium performs

~Simple Epithelium: a single layer of cells that functions in diffusion, osmosis, filtration, secretion, and absorption

• 4 Types:

A.) Simple squamous epithelium

-Consists of a single layer of flat cells (resembles a tile floor)

-Nucleus: a flattened oval sphere

-Not found in body areas that are subject to mechanical stress (wear and tear)

-Lines the heart, blood vessels, and lymphatic vessels (a.k.a. endothelium)

-Forms the epithelial layer of serous membranes (a.k.a. mesothelium)

--Both endothelium and mesothelium are derived from mesoderm

B.) Simple cuboidal epithelium

-Cell nuclei are usually round and centrally located

-Found in the thyroid gland and kidneys

-Performs secretion and absorption

C.) Simple columnar epithelium (non-ciliated and ciliated)

*Oval nuclei near the base

~Non-ciliated Simple Columnar Epithelium~

-Microvilli: fingerlike cytoplasm projections

--increase the surface area of the plasma membrane

--increase the cells rate of absorption

-Goblet Cells: modified columnar epithelial cells

--secrete mucus at their apical surfaces (gives it that goblet look)

--mucus- lubricant for the linings of the digestive, respiratory, & reproductive tracts, and most of the urinary tracts

--mucus- forms a film over the airway surface that traps inhaled foreign particles

~Ciliated Simple Columnar Epithelium~

-Contains cilia at the apical surface

--Cilia beat in unison; move the mucus and any foreign particles toward the throat, to be coughed up and swallowed or spit out

--Coughing/ sneezing speeds up the movement of cilia/mucus

--Help move oocytes expelled from the ovaries through the fallopian tubes into the uterus

-Goblet cells are interspersed among ciliated columnar epithelia in certain parts of the airways of the upper respiratory tract

D.) Pseudostratified columnar epithelium (non-ciliated and ciliated)

*Appears to have several layers because the nuclei of the cells are at various depths

*All cells are attached to the basement membrane; not all reach the apical surface

~Pseudostratified Ciliated Columnar Epithelium~

-Cells that extend to the surface either secrete mucus or bear cilia

--Secreted mucus traps foreign particles

--Cilia sweep away mucus for eventual elimination

~Pseudostratified Non-Ciliated Columnar Epithelium~

-Contains cells without cilia and lacks goblet cells

*Secretion: the production and release of substances such as mucus, sweat, or enzymes

*Absorption: the intake of fluids or other substances such as digested food from the intestinal tract

~Pseudostratified Epithelium: appears to have multiple layers of cells because the cell nuclei lie at different levels and not all cells reach the apical surface

-It’s cells rest on the basement membrane (therefore it’s a simple epithelium)

-Cells that extend to the apical surface may contain cilia

-Goblet cells secrete mucus

~Stratified Epithelium: consists of two or more layers of cells that protect underlying tissues in locations where there is considerable wear and tear

*Has 2 or more layers of cells

*More durable; can better protect underlying tissues

*Some cells produce secretions

4 Types

A.) Stratified squamos epithelium (keratinized and non-keratinized)

*Apical layer cells are flat

*Deep layer cells vary from cuboidal to columnar

*The basal (deepest) cells continually undergo cell division

*As new cells grow, the cells of the basal layer are pushed upward toward the apical layer

*As they move farther from the deeper layers (and from their blood supply) in the underlying connective tissue, they become dehydrated, shrunken, harder, and then die

*Dead cells lose their cell junctions, are sloughed off, then replaced

~Keratinized Stratified Squamous Epithelium~

-Apical layer and several layers deep to it are partially dehydrated and contain a layer of keratin

--Fibrous protein that helps protect the skin and underlying tissues from heat, microbes, and chemicals

-Forms the superficial layer of the skin

~Non-Keratinized Stratified Squamous Epithelium~

-Found in the lining of the mouth and esophagus

-Does not contain keratin in the apical layer

-Remains moist

*Both types form a first line of defense against microbes

B.) Stratified cubical epithelium

-Cells in the apical layer are cuboidal-- fairly rare

-Mainly serves a protective function; also has a limited role in secretion and absorption

C.) Stratified columnar epithelium

-Usually the basal layers consist of shortened, irregularly shaped cells; only the apical layer has cells that are columnar in shape--uncommon

-Functions in protection and secretion

D.) Transitional epithelium

-Present only in the urinary system; has a variable appearance

-In its relaxed or unstretched state, transitional epithelium looks like stratified cubical epithelium, except that the cells in the apical layer tend to be large and rounded

-As the tissue is stretched, its cells become flatter, giving the appearance of stratified squamous epithelium

-Elastic

-Lines the urinary bladder; it allows it to stretch and hold a variable amount of fluid without rupturing

Cell Shapes

• Squamous cells: are arranged like floor tiles and are thin, which allows for the rapid passage of substances

• Cuboidal cells: are as tall as they are wide and are shape d like cubes or hexagons

~May have microvillus at their apical surface and function in either secretion or absorption

• Columnar cells: are much taller than they are wide, like columns, and protect underlying tissues

~Apical surfaces may have cilia or microvilli

~Often specialized for secretion and absorption

• Transitional Cells: change shape, from flat to cubical, as organs such as the urinary bladder stretch (distend) to a larger size and then collapse to a smaller size

Papanicolaou Test

• Papanicolaou Test (a.k.a. Pap test, or Pap smear): involves collection and microscopic examination of epithelial cells that have been scraped off the apical layer of a tissue

• A very common type of Pap test involves examining the cells from the non-keratinized stratified squamous epithelium of the vagina and cervix of the uterus

~Performed to detect early changes in the cells of the female reproductive system that may indicate cancer or a precancerous condition