Final Exam Prep Flashcards
Which muscles are involved with eye movement?
6 skeletal muscles (control them voluntarily):
1.lateral rectus
2.medial rectus
3.inferior rectus
4. superior rectus
5. superior oblique
6. inferior oblique
Lateral rectus
Controlled by abducens VI: Moves eye laterally, abducts the eye
Medial rectus
Controlled by oculomotor (III). Moves eye medially
called rectus because….
They go straight back
inferior rectus
controlled by: oculomotor (III)
moves eye down
all eye muscles except the ____ move back to the common tendinous ring
inferior oblique
Cornea
can be transplanted without fear of rejection because it has no blood vessels
superior rectus
controlled by oculomotor (III): moves eye up
all cranial nerves involved in eye movement move through…
superior orbital fissure:
cranial nerves that go through this structure are:
oculomotor iii
trochlear iv
abducens vi
and ophthalmic division of v
superior oblique
controlled by trochlear iv: depresses eye and turns it laterally
innervates an eye muscle that loops through a pulley-shaped ligament in orbit
inferior oblique
controlled by oculomotor iii: moves the eye up and laterally
CN5
Trigeminal
stimulates the lacrimal gland, mucous membranes, and the submaxillary and sublingual glands. Provides sensory innervation to the face.
Largest cranial nerve
decubitus ulcer
pressure sores, result from skin breakdown. common in older patients with fragile skin. Its common in areas of bony processes, ischial tuberosities, greater trochanter, sacrum. This is why we do turns every 2 hours. if peron isnt moved, can get skin breakdown. very careful with diabetic patients who have less skin sensitivity
stages of decubitus ulcers
- skin is unbroken, but inflamed and red
- skin is broken down to epidermis or dermis
- ulcer extends to subcutaneous fat layer. gets down pretty deep. infections can spread easily
4.Ulcer spreads down to muscle or bone
Third degree burn
1.caused by a burn that spreads below the follicles,
- burns all the way through the dermis below the follicles.
3.no more progenitor stem cells left.
4.may need skin graft.
5.also called a full thickness burn
Basal cell carcinoma
1.cancer in the basal cells.
2.least likely to metastasize.
3.least malignant, slow growing.
4.Fully cured by surgical excision in 99% of cases
basal cell carcinoma occurs in
the basal cell layer of the epidermis. Stratum basale. caused by UV radiation. Most common (80% of skin cancers)
describe basal cell carcinoma
stratum basale cells proliferate, invading dermis and subcutaneous tissue.
appearance of basal cell carcinoma
most often on sun exposed areas of the face. look like shiny dome-shaped nodules that develop a central ulcer with a pearly beaded edge.
Squamous cell carcinoma
1.second most common type of skin cancer.
2.comes from keratinocytes of the stratum spinosum. likely to grow rapidly and metastasize.
- if caught early and removed surgically or by radiation therapy, the chance of complete cure is good
4.keratinocytes break through basal layer of the epidermis, doesnt have basement membrane cap
appearance of squamous cell carcinoma
scaly, reddened papule, (small rounded elevation). most often on head (scalp, ears, lower lip) and hands
why is basal cell carcinoma unlikely to metastasize?
basal cells have built-in ability to make fibers and proteins tend to seal themselves off
Why is it bad for keratinocytes and other epidermal cells to break into the dermis?
cancerous epidermal cells lose their positional information. They grow out of control and enter the bloodstream.
melanoma
cancer or melanocytes. most dangerous skin cancer. highly metastatic and resistant to chemotherapy. Accounts for 1% of skin cancers
why is melanoma likely to metastasize?
melanocytes naturally have the ability to produce cytoplasmic extensions. so theyre quick to invade other tissues
function of cytoplasmic extensions on melanocytes
transfer melanin granules to keratinocytes
neoplasm
new growth
what kind of skin cancer accounts for most skin cancer deaths?
melanoma. Only about 1% of skin cancers, but 85-90 % of all skin cancer deaths.
melanoma caused by
Mutations occur in the DNA of a melanocyte, which has the ability to produce cytoplasmic extensions.
stratum spinosum named for
pointy ends: protruding cell processes that join cells together via a desmosome.
melanoma can begin wherever there is
pigment
melanomas can appear from
pre-existing moles approximately 1/3. looks like spreading brown to black patch
melanomas are likely to metastasize to
lymph and blood vessels
key to surviving melanoma
early detection. survival rates decline with increasing thickness of the melanoma
ABCDE
Asymetrical
Border:irregular border
Color:2 or more colors
Diameter: diameter greater than a pencil eraser head
Evolution or elevation:is it growing upward or elevated?
Alopecia areata
Autoimmune disorder where immune system attacks the hair follicles. Results in hairless patches.
alopecia
absence of hair from areas of the body that normally have hair
decubitus ulcer cause
Interference with blood supply. Caused by continuous pressure
etiology of alopecia areata
1.immune system targets hair follicles which disrupts the normal hair life cycle.
2.alopecia areata disrupts hair growth leading to hair loss.
- thought to be caused by genetic and environmental factors like, stress, and viral infections and certain medications.
4.Has no cure
vitiligo etymology
a vine winding.
vitiligo
most prevalent skin pigmentation disorder. caused by a loss of melanocytes and uneven dispersal of melanin. unpigmenetd light spots are visible surrounded by normally pigmented areas
Can happen to anyone.
Patches of no pigmentation.
Is autoimmune disorder where immune system incorrectly attacks melanocytes.
80% of all autoimmune cases are in women
why do some people have darker skin than others?
darker skin: delivery of lots of melanosomes into keratinocytes in stratum spinosum. more resistant to UV radiation. less likely to get cancer. need more sunlight for vitamin d needs
mole
benign growth of melanocytes
everyone has the same number of
melanocytes. only type and amount of melanin that varies producing different skin tones
Hair bulge and hair bulb
Bulge: hold progenitor stem cells around where arrector pilli muscle attaches.
Hair bulb: holds hair
Functions of epithelial tissues
covering and lining membranes,
glandular epithelium
function of covering and lining epithelium
- Makes outer layer of skin
- lines body cavities
- covers organs and walls of organs
function of glandular epithelium
fashions glands of body
t/f:nearly all substances given off or received by the body must pass through an epithelium?
nearly all substances given off or received by the body must pass through an epithelium?
TRUE
roles of epithelium
- protection
- absorption
- Filtration
- excretion
- secretion
- sensory reception
five distinguishing characteristics of epithelium
- apical basal polarity
- specialized contacts
- supported by connective tissue
- avascular but innervated
- regeneration
apical surface:
not attached to surrounding tissue. Exposed to either outside of the body or cavity of internal organ
basal surface attached to
attached to underlying connective tissue
simple epithelia
single cell layer
where is simple epithelia found?
where absorption, filtration and secretion occur
stratified epithelia
two or more cell layers stacked on top of one another. where protection is important. Skin surface, lining of mouth.
squamous, cuboidal columnar
- squamous: flat, disc shaped
- cube shaped
- column shaped
stratified epithelia are named after
shape of cells in apical layer
endothelium
inner covering. Single layer of squamous cells that line the walls of the heart, blood vessels and lymphatic vessels
mesothelium
found in serous membranes lining ventral body cavity and covering its organs
capillaries consist exclusively of
endothelium
functions of simple cuboidal epithelium
secretion and absorption. Ducts of glands and kidney tubules
simple columnar epithelium
absorption and secretion. has dense microvilli on absorptive cells
has tubular glands that secrete mucus containing intestinal juice. some have cilia that move substances along
simple columnar epithelium location
lines digestive tract from stomach to rectum
pseudostratified columnar epithelium function
secretes or absorbs substances. Lines most of the respiratory tract
most widespread of the stratified epithelium
stratified squamous epithelium
describe stratified squamous epithelium
free squamous surface cells, cells of deeper layers are cuboidal or columnar
where is stratified squamous epithelium found?
wear and tear. External surface of the skin. Extends a little into every body opening that is continuous with the skin. Outer layer is keratinized.
stratified cuboidal epithelium found in
ducts of larger glands. sweat glands and mammary glands. Rare. Two layers of cuboidal cells
stratified columnar epithelium location
Pharynx, male urethra. lining glandular ducts. Transition areas. Junctions between other types of epithelia. Only apical layer is columnar
transitional epithelium
forms lining of hollow urinary organs. stretches. Apical cell shape varies on degree of distension
gland
one or more cells that secretes a particular product
fundamental types of epithelial tissues
- simple squamous epithelium
- simple cuboidal epithelium
- simple columnar epithelium
- pseudostratified columnar epithelium
- stratified squamous epithelium
- stratified cuboidal epithelium
- stratified columnar epithelium
- transitional epithelium
basal lamina made of
made of glycoprotein secreted by epithelial cells. Adhesive supporting sheet. Faces epithelium
reticular lamina
has fine network of collagen fibers, faces the connective side
neuromuscular junction
where a motor unit meets a muscle. place where synaptic knob hovers over a special area called a motor ends plate
Innervated skeletal muscle
why does motor end plate wind back and forth?
To increase the surface area so we can have more ligand-gated sodium channels
motor end plate
made of ligand gated receptors on the sarcolemma. ACh binds to ligand gated sodium channels and causes influx of sodium into neighboring cell
Anatomy of neuromuscular junction . Include cellular level details for the motor neuron and the muscle fibers it innervates.
- The action potential arrives at the axon terminal of the motor neuron
2.Voltage gated Ca 2+ channels open. Ca 2+ enters the axon terminal, moving down it’s electrochemical gradient. - Ca2+ entry causes ACh (a neurotransmitter) to be released by exocytosis
4.ACh diffuses across the synaptic cleft and binds to ACh receptors on the sarcolemma.
- ACh binding opens chemically gated ion channels that allow the simultaneous passage of Na+ into the muscle fiber and K+ out of the muscle fiber. More Na+ ions enter than K+ ions exit, which causes a local change in membrane potential called the end plate potential
- ACh effects are terminated by its breakdown in the synaptic cleft by acetylcholinesterase and diffusion away from the junction
epimysium
surrounds groups of fascicles together
deep fascia
wraps in and around groups of muscles and organs above the epimysium
perimysium
around each fascicle
fasicle
groups of muscle cells together
sarcoplasm
cytoplasm of a muscle fiber
sarcoplasmic reticulum
Same as endoplasmic reticulum. Important for synthesis of proteins. Does normal endoplasmic reticulum stuff in muscle fibers and around myofibrils, but it becomes an important storage location for calcium.
difference between sarcoplasm and cytoplasm?
sarcoplasm has large amounts of glycogen and myoglobin (red pigment that stores oxygen)
Why is the sarcoplasmic reticulum important?
- protein synthesis
- helps store calcium
calcium is important to the signaling pathways that leads to muscle contractions taking place
Sarcolemma
Plasma membrane of a muscle fiber
Myofibrils
Rod-like bundle of contractile filaments (myofilaments) found in muscle fibers (cells)
Myofilaments
Filament that constitutes myofibrils. Of two types: actin and myosin.
compact bone:
compact bone:
-On outer surface of bone
-Made of osteons (look like tree stumps)
-On the surface and end of long bones where bone is packed very close together
-replaces the immature spongy bone duing intramembranous ossification
-diaphysis made of mostly compact bone
osteons
unit of bone, interconnecting canals in microscopic structure of adult compact bone
trabeculae
pointy parts in spongy bone. Allows bone to be lighter. Looks random but arranged along stress lines
stress lines
Help distribute stress evenly on a bone reducing the risk of fractures or injuries. help bear weight. Lines formed in response to mechanical stress
pagetic bone
has abnormally high ratio of spongy bone to compact bone. Reduced mineralization causes weakening of the bones
Describe the roles of osteoclasts and osteoblasts
during bone remodeling (controlled by hormones like growth hormone, estrogen, testosterone, calcium ion levels in blood):
- osteoclasts: bone is resorbed by osteoclasts. Breaks down at the ends.In endosteum. Remove bone from inner surface of the diaphysis
- osteoblasts add bone by appositional growth (on the sides)(bones grow in width). Osteoblasts in the periosteum add bone matrix to the outside of the diaphysis.
- Bone is resorbed by osteoclasts at the center.
osteoprogenitor cells found in
The inner osteogenic layer next to the bone surface contains osteoprogenitor cells (primitive stem cells that give rise to most bone cells).
osteocytes
mature bone cells that occupy lacunae, maintain matrix. Connected to eachother by central canal and canaliculi.
What role does each cell type play in bone remodeling?
osteoclasts,
osteoprogenitor cells,
osteoblasts,
osteocytes
osteoclasts: responsible for breaking down or resorbing old or damaged bone tissue
osteoprogenitor cells. Release enzymes that help dissolve the mineralized matrix of bone. after old bone is resorbed…. osteoblasts
Osteoprogenitor cells: also called osteogenic cells, are mitotically active stem cells found in the membranous periosteum and endosteum. In growing bones they are flattened or squamous cells. When stimulated, these cells differentiate into osteoblasts, while others persist as osteoprogenitor cells.
osteoblasts: produce proteins and other substances that form the new bone matrix. Which eventually mineralizes to become new bone tissue. bone-forming cells that secrete the bone matrix. Like their close relatives, the fibroblasts and chondroblasts, they are actively mitotic. The unmineralized bone matrix they secrete includes collagen (90% of bone protein) and calcium-binding proteins that make up the initial unmineralized bone, or osteoid. As described later, osteoblasts also play a role in matrix calcification.When actively depositing matrix, osteoblasts are cube shaped. When inactive, they resemble the flattened osteoprogenitor cells or may differentiate into bone lining cells. When the osteoblasts become completely surrounded by the matrix being secreted, they become osteocytes.
osteocytes:mature bone cells that occupy spaces (lacunae) that conform to their shape.
Osteocytes monitor and maintain the bone matrix.
They also act as stress or strain “sensors” and respond to mechanical stimuli (bone loading, bone deformation, weightlessness).
Osteocytes communicate this information to the cells responsible for bone remodeling (osteoblasts and osteoclasts) so that bone matrix can be made or degraded as mechanical stresses dictate. Osteocytes can also trigger bone remodeling to maintain calcium homeostasis as we will see shortly.
Bone remodeling process
1.Osteoblasts and osteoclasts work together in a bone remodeling cone.
2.Breaks down bone in front (osteoclasts)
Osteoclasts release calcium phosphate in bloodstream, break down collagen into Amino acids. Called the cutting core
- Osteoprogenitor cells: in middle or reversal zone
- In reversal zone, you have reversal cells. In transition zone between osteoclasts and osteoblasts
- In back, the cone is using osteoblasts to lay down collagen and calcium phosphate. Angiogenesis also occurs which is the creation of new arteries and veins. In compact bone, central canal is also being created. Creating new nerves and new lymphatic vessels
- Describe how an action potential is initiated in a neuron. How does it propagate down the axon? What processes are involved with the release of neurotransmitters from synaptic knobs. Discuss the key role of IPSPs and EPSPs in the propagation (or lack thereof) of an action potential.
Excitatory post synaptic potentials must build at axon hillock and surpass threshold value. -55 mv
-depolarization & repolarization
-depolarization happens after -55mv threshold value is reached. voltage gated sodium ion channels open and Na goes into the cell raising the voltage. gets more positive until +30 mV
-repolarization starts to occur once +30 mv is reached. Na channels close and K channels open. charge becomes lowe because positively charged K is leaving the axon. Trying to lower charge to get closer to resting potential . goes past -70 resting value and results in hyperpolarization. Hyperpolarization occurs because channels are slow to close
- hyperpolarization is fixed by NaK pump. pumps 3 Na out and two K into resitablish the concentration gradient
- Absolute refractory period: axon cannot be stimulated to send a message. Occurs when cell is being depolarized up until the cell approached its resting membrane potential during repolarization. Cnat pass any more signals
-relative refractory period: Takes a stronger stimulus to send impulse. Occurs from hyperpolarization to where its reaching resting membrane potential
-at the end of the axon terminals in the synaptic knob. Voltage gated Ca2+ ion channels are activated. influx of Ca2+ causes vesicles with Neurotransmitters like ACh to travel accross the synaptic cleft and bind to ligandgated Na channels in neighboring neuron, passing signal along. The way you stop ACh transmission is with the help of acetycholineesterase. Enzyme that breaks down Ach
What role do osteoclasts play in bone remodeling?
- resorb old bone or damaged bone by releasing enzymes that help dissolve the mineralized matrix of bone
What role do osteoprogenitor cells play in bone remodeling?
- Also called osteogenic cells
- Mitotically active stem cells
- Some can differentiate into osteoblasts, while others stay as osteoprogenitor cells.
Location of osteoprogenitor cells?
membranous periosteum and endosteum. In growing bones they are flattened or squamous cells.
Role of osteoblasts during bone remodeling
- Make proteins and other substances that make the bone matrix, which eventually mineralizes to become new bone
- Actively mitotic
Role of osteocytes in living bone tissue
1.mature bone cells that occupy spaces (lacunae) that conform to their shape
2. monitor and maintain matrix. Act as stress sensors and respond to mechanical stimuli. (bone loading, bone deformation, weightlessness ). Can trigger repair or remodeling
What are the specialized contacts of epithelial tissue
except for glandular epithelium, epithelial cells fit cosely to make continous sheets. Joined by tight juctions and desmosomes.
Types of bones
Long,
Short,
Flat,
Irregular
Epiphysis
Ends of long bones, have spongy bone, covered by articular cartilage
-site of bone lengthening in children
-spongy bone in epiphysis
Diaphysis
Shaft, mostly compact bone
Articular cartilage
Made of hyaline cartilage, lets bones slide against each other
Periosteum
-Thin layer of cells underneath dense connective tissue.
- Fibrous layer around outside of bone
-not on joint surfaces
-helps nourish the bone
Endosteum
Lines inner bone cavities
Connective tissue membrane that covers internal bone surfaces. Helps with bone remodeling and repair.
Medullary cavity
Contains yellow or red bone marrow. In middle of bone.
Bone marrow
Hematopoiesis occurs here. Gives rise to formed elements of blood
Osteogenic layer
Inner layer of periosteum
-has osteoprogenitor cells
-has osteoclasts and osteoblasts
Central canal
Canal in center of each osteon that has small blood vessels and nerve fibers that serve the osteon’s cells
Perforating canals
Connect blood and nerve supply of central canals. At right angle of central canals.
Endochondral ossification
Bone develops by replacing hyaline cartilage
Intramembranous ossification
Bone develops from a fibrous membrane
Which bones form by endochondral ossification?
All bones below the base of the skull, except for clavicles
Why is endochondral ossification more complex than intramembranous ossification?
Hyaline cartilage must be broken down as ossification proceeds
Fascia
Layers of fibrous tissue covering and separating muscle
Tendon
Cord of dense regular connective tissue attaching muscle to bone
Aponeuroses
Flat, sheet like tendons that attach muscles to bone, or attach muscles to muscles
Triad
a structure formed by the interface between a T-tubule and 2 terminal cisternae of the sarcoplasmic reticulum (SR).
Helps control muscle contractions
Motor neurons leave through which root?
Ventral root
Myasthenia gravis
autoimmune disorder that attacks ligand gated sodium channels that bind ACh.
Starts in face, causing partial paralysis of facial muscles
Usually stops at face.
Can sometimes lead to early mortality.
How to fix myasthenia gravis
How to fix: immune suppressants
Some drugs affect acetylcholinesterase in synaptic cleft, ach stays longer to find ligand gated sodium channels in receiving muscle cell
Botulism
Disrupts nerve muscle communication
when a person eats food contaminated with botulinum toxin or the spores, the toxin gets in the blood stream and travels to neuromuscular junctions. the botulinum toxin blocks the release of ACh and prevents communication between motor neurons and muscle fibers resulting in paralysis. Affects breathing, swallowing and movement.
Rigor mortis
muscle stiffness caused by chemical changes in muscles, without oxygen the cells can’t make ATP needed for muscle contractions.
Muscles can’t relax and become rigid
Creatine phosphate
back up source of energy in cells. quick source of energy
creatine phosphate donates a P to ADP making ATP. Provides quick boost of energy.
Role of glycogen in muscle contraction
can be broken down into ATP
Cellular respiration role in muscle contraction
glucose and oxygen are consumed to make large amounts of ATP.
Lactic Acid
made during high intensity physical activity where cells may not receive enough oxygen to meet the energy demands needed for muscle contraction
Isotonic muscle contraction
Under load, the muscle is actually going to shrink or lengthen under the load. The muscle itself changes length. Lifting a weight and the muscle length changes
Isometric contraction
Does not change length
Holding a weight in place
Muscle tone
level of contraction or tension present in a muscle when the muscle is at rest. All muscle is always partially contracted
Fast twitch fibers and slow twitch fibers
Fast glycolytic, slow oxidative.
Endurance training increases slow oxidative fibers (red has myoglobin, helps make ATP)
Sprinting training develops what kind of fibers?
White glycolytic fibers
Multi unit smooth muscle
each individual muscle fiber is innervated by its own nerve. controls movement where coordination is not necessary..found in arrector pili muscles, airways to lungs and large arteries.
Visceral smooth muscle
in walls of hollow organs
involuntary moves food through peristalsis. important in digestion, circulation and urination
Peristalsis
Smooth muscle contracts in wave-like motion to push substances down
Calmodulin
calcium binding protein. Helps regulate the timing and strength of muscle contraction.
Norepinephrine
especially important in smooth muscle tissue regulation. released by adrenal glands in response to stress. modulates muscle tone and contractility. binds to the adrenergic receptors in smooth muscle cells
Origin
Attachment of a muscle that remains relatively fixed during muscle contraction
Insertion
Movable attachment of a muscle
Agonist
Muscle that bears the major responsibility for effecting a particular movement. A prime mover
Antagonist
Muscle that opposes the movement of another muscle
Synergists
Aids action of prime mover by doing same movement or by stabilizing joints
Epidermis
Superficial layer of skin composed of stratified squamous keratinized epithelium
Dermis
Layer of skin below the epidermis. Made of mostly dense irregular connective tissue
The dermis has connective tissue, blood vessels, oil and sweat glands, nerves, hair follicles, and other structures. It is made up of a thin upper layer called the papillary dermis, and a thick lower layer called the reticular dermis.
Hypodermis/ subcutaneous layer
Has adipose tissue.
mostly fat and connective tissue. Cushions underlying organs and bones. Gives insulation and fuel storage. Has vessels that help nourish skin
Melanin is produced in which layer of the epidermis?
Stratum basale
Stratum basale
Source of new cells for epidermal growth
Stratum spinosum
Gets name from spinelike extensions of keratinocytes.The spines do not exist in living cells. Cells shrink while holding tight their many desmosomes.
Dendritic cells are most abundant here.
Stratum granulosum
Keratinazation begins here
Stratum lucidum
Only found in thick skin like palms and soles of feet rows of few flat dead keratinocytes
Stratum corneum
outermost layer
made of dead skin cells, acts as barrier that prevents dehyyand regulates body temperature
Keratin
Fibrous protein found in the epidermis, hair and nails. Makes structures hard and water resistant.
Melanin
Dark pigment formed by cells called melanocytes. Imparts color to skin and hair.
Melanosomes
Membrane bound granules that make melanin. Melanin is then transferred out via spider legs
Pheomelanin
Colors red hair
Eumelanin
Produces brown and black colors
Langerhans dendritic cells
Engulf antigens , migrate to lymph nodes and present the antigen to T cells. Found in skin
Merkel cells
Plugged into epidermis with sensory neurons connected to them
Pressure receptors
Papillary layer of dermis
Superficial 20% called papillary dermis. Made of mostly loose areolar connective tissue.holds things that help protect if dermis is breached.
Has: mast cells, macrophages and fibroblasts
-mast cells: initiate inflammatory response. Helps bring WBCs. Release histamine release heparin. Help mediate inflammation response.
-Macrophages
-fibroblasts:help lay down collagen, elastic fibers, new reticular fibers. Help hold damaged area together
Reticular layer of dermis
- Bottom 80% of dermis:
Very strong. Made of mostly dense irregular connective tissue. Fibers overlap in multiple directions. Called reticular dermis .
Creates tension lines (tension lines are general direction that collagen fibers go) if cut is parallel to tension lines, then the wound will close up reapproximate. If you cut perpendicular to tension lines, the wound gapes.
Surgeons try to cut parallel to tension lines.
Hair root
Hair root:embedded in hair follicle
anchors hair follicle in place
Hair bulb
hair bulb: rounded structure that contains living cells for making new hair
Hair shaft
hair shaft: visible part that extends above the skin’s surface.
Sebaceous glands
Attached to hair follicles,
Holocrine glands. (Glandular cells inside are constantly dividing) Glandular cells inside form sebum.
Sebum
Lipid protein rich substance. Keeps epidermis and hair health
Apocrine sweat glands
Apocrine sweat glands that release into axillary areas and groin
produce milky secretion. has odor after coming into contact with skin bacteria.
Arrector pili muscles
small muscles attached to hair that contract in response to cold Temp, fear or emotional stress. cause hair to stand on end creating goosebumps
Holocrine glands
Burst, sebaceous
Role of integumentary system in body temperature regulation
sweat glands in skin produce sweat which evaporates and helps cool the body down
when body becomes too cold, arrector pili muscles in the skin contract causing the hair to stand on end and creating an insulating layer of air around the body. Blood vessels in the skin constrict to reduce blood flow.
First degree burn
Only epidermis is damaged
Second degree burn
Epidermis and upper region of dermis is damaged
Third degree burn
Damages the entire thickness of the skin, entire epidermis and dermis
Usually require skin grafting
4th degree burn
Burn that affects epidermis, dermis subcutaneous tissue, muscle and even bone
Autograft
Skin graft from the same person
Allograft
Most common type of transplant.
Transplant from different individuals of the same species. ABO blood group antigens must be assessed
Xenograft
Tissue or organ taken from a different species
Spongy bone
spongy bone:
-On inside of bone
- filled with trebeculae (unit of spongy bone) (spike shaped structures)
-filled with bone marrow
-spongy bone gets strong by remodeling trabeculae laid down on stress lines
-found in epiphysis
Dendritic cells are most abundant in?
Stratum spinosum
