Anatomy

Integumentary System

-consists of skin and accessory structures (hair, sebaceous glands, sweat glands, ceruminous glands, mammary glands and nails)

protection, body temp regulation, sensation, excretion, vitamin D production

Functions of the integumentary system

integumentary system: protection

protects against UV light, bacterial invasion and dehydration

integumentary system: body temp reg

by way of blood flow(heat up) and sweating(cool down)

integumentary system: sensation

nerve endings and receptors that detect temp, touch, pressure and pain

integumentary system: excretion

removal of wastes through sweat

Integumentary system: vit D prod

UV light helps to prod, we do need some sunlight for it but we overexpose ourselves

The skin

protective barrier, 7% of total body weight, divided into two regions

hypodermis

just below the dermis, fatty layer

epidermis

composed of stratified squamous keratinized epithelial, avascular tissue

keratinocytes

epithelial cells, majority of cells, produce protein called keratin, phagocytose the melanin and destroy it

melanocytes

not epithelial cells, found in stratum basale, produce melanin(pigment)

melanin

inclusion(miscellaneous) substance found in some cells, protects nucleus of cells from UV radiation in sunlight

Problem with sunlight

excessive UV radiation mutates DNA, melanin is nat sunblock and protects cells, darker skin = more melanin at surface and less in cells to protect nucleus

thick skin

five layers form the epidermis, found on the palms of hands, fingertips and soles of feet, no hair follicles present

thin skin

four layers form the epidermis, found everywhere else, hair follicles present

layers of the epidermis (deep -> superficial)

stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, stratum corneum

stratum basale

deepest layer of the skin, one layer thick, mitosis occurs here, melanocytes found here, keratinocytes are born here and old ones are pushed to the surface where they die and fall off

stratum spinosum

spiny layer, several layers thick, lots of DESMOSOMES present, gives spiky appearance

stratum granulosum

layer with granules, 2-5 cell layers thick, contains diff types of granules keratohyaline granules and lamellated bodies

keratohyaline granules

contained in the stratum granulosum, think of these when keratin is referred to, give epidermis strength, visible under a microscope

lamellated bodies

wrinkled fingers in bath(water is moving in and causing swelling), lipid filled bodies give the epidermis it's water-proofing properties, not visible on slide

stratum lucidum

clear layer, by the time the keratinocytes reach this layer they are dead, they fill up with keratin and die, so no nuclei are visible, this layer is only found in thick skin (this is the extra layer)

stratum corneum

dead layer, 20-30 cells thick, provides protection from external enviro, all dead cells, thicker in thick skin than thin skin

dermis

deep to the epidermis, connective tissue layer of skin, richly supplied with nerves, blood vessels, lymphatics, oil and sweat glands, divided into two regions (papillary and reticular layer)

papillary layer

superficial layer of the dermis, composed of loose connective tissue, has dermal papillae, seperation of this layer of the dermis from the epidermis can result in the formation of a blister, repeated stress leads to calluses and stronger dermis

dermal papillae

has projections which indent into the epidermis, nipple-like structures, reduces the friction between the dermis and the epidermis

reticular layer

deepest layer of the dermis, deep to the papillary layer, composed of dense irregular connective tissue

Skin Cancer: basal cell carcinoma

least malignant and most common, cells of the stratum basale proliferate and invade the dermis and hypodermis, appears as shiny dome-shaped nodules

Skin Cancer: squamous cell carcinoma

arises in keratinocytes of the stratum spinosum, appears as small, scaly, red elevations, metastasizes, can be cured if caught early

Skin Cancer: malignant melanoma

cancer of the melanocytes, VERY dangerous, 5% of skin cancers but is on the rise, survival is only 50%

Conversion of Cholesterol into vit D

7-dehydrocholesterol ->UVB into the epdiermis of skin-> vit D3 Cholecalciferol(gets pushed down through skin and into blood via hi to lo conc grad and gets to liver)->liver->vit D3 Calcidiol->kidney->vit D3 calcitriol

albinism

genetic cond in which melanocytes do not prod melanin, they lack tyrosinase

vitiligo

loss of pigment, resulting in irregular pale patches, autoimmune disease that destroys melanocytes, michael jackson

free radicals

damage DNA, proteins, membranes. UV rays cause oxidation via production of these. Act like a pinball. Created nat. but a diet of fruits and veggies and the body itself can help soak them up.

Production of melanin

Tyrosinase is stim by UVA and UVB rays (mainly UVB)->converts tyrosine into dopamine-> dopamine is converted into melanin

eumelanin

brown and black pigment

pheomelanin

red/brown pigment, more in lips, nipples, glans penis and vagina

the blood vessels to dilate, blood to be diverted toward the surface of the skin and heat to be lost

An increase in temp. would cause...

the blood vessels to constrict, blood is diverted from the surface of the skin and heat loss from the blood is minimized

A decrease in temp. would cause....

Sensory receptor: Meissner's corpuscle and Merkel's disk

detects light touch, near the surface

sensory receptor: Pacinian Corpuscle

detects deep pressure, deep under surface of the skin

sensory receptor: Ruffini's corpuscle

detects cont touch and pressure

Sensory receptor: free nerve ending

responds to pain, crude touch, temp, itch and tickle, layer of skin depends on what kind of touch it is a receptor for

psoriasis

chronic disease marked by pink/red lesions with silvery scaling, not contagious, no cure, pruritis(itching) often present, treatment: topical creams with cortisone, cause: unknown, poss genetic

atopic dermatitis/eczema

more common than psoriasis, can go away, generalized inflammation assoc with inc sensitivity and allergy(can be more of an allergic rxn), pruritis and red vesicles present, most common in infants and young adults, treatment: allergy creams; steroidal creams, no cure

urticaria/hives

become more sensitive after each outbreak, typically appear right away, marked by inflamm of capillaries under skin, pruritis often present, followed by eruption of skin itno red warts, usually acute: hours to less than 6 weeks (chronic greater than six weeks), treatment- antihistamines, corticosteroids, avoidance of trigger (cause)

dematophytosis/ringworm

infection cause by fungus, spread by direct or indirect contact, affects all parts of the body (athlete's foot; thick, yellow nails), called diff things in diff regions, treatment: antifungal meds, topical anti-fungal creams

impetigo

caused by bacteria, highly contagious skin infection caused by either strep or staph infection, spread by direct(touching) or indirect contact(objects), forms yellow crusts, lesions form around mouth, nose and neck, pruritis present, treatment: antibiotics

warts

viral, elevated skin lesion, skin cells are dividing abnormally, spread by direct or indirect contact, caused by the human papillomavirus (HPV- causes wart, can cause cervical cancer), treatment: salicylic acid, cryotherapy(freeze therapy), surgery with plantar warts(within the foot, cannot freeze off, requires surgery)

shingles/herpes zoster

viral, you can see the track left along the nerve, caused by the varicella zoster virus of chickenpox, compromised immune system, stress, aging are leading causes, red, swollen vesicles in a single dermatome that ruptures and crusts, lasts approx two to three weeks, treatment: anti-viral therapy along with anti-inflamm drugs

herpes

viral, lesions caused by the herpes simplex virus, 50% of adults have oral herpes, 20% of adults have genital herpes, spread most likely during active periods, can be spread during dormant periods, cold sore + oral sex = no no, no cure, arginine is a trigger, treatment: suppression with anti-viral therapy, L-lysine starves the virus

hair

also acts as a receptor, found on all surfaces except the palms, soles and feet

root

portion of the hair below the skin surface

shaft

portion of the hair above the skin surface

matrix

sole dividing cells of the hair, pushes other cells to the top(keratinize as they move up), makes the hair grow

hair follicle

hair grows from this, invagination of the epidermis, hold the root and shaft

functions of the hair

protection(eyebrows prevent sweat from entering eyes, eyelashes and tears work together to prevent debris from entering the eyes, nose and ear hair prevent debris from entering the body) and sense organ(allows for the detection of light touch)

nails

contain mostly compressed keratin, protects the ends of fingers and toes, they grow at a rate of about 1 to 4 inches per year, grow twice as fast on fingers as they do on toes

nail root

where the nail starts growing, area of the nail that is hidden by the cuticle, contains lunula as part of structure

eponychium/nail cuticle

fuses nail plate to the skin, provides waterproof barrier, fold of skin that holds onto the nail

lunula

the white, crescent shaped region at the base of the thumb, the germinal layer where growth is initiated

nail body/nail plate

visible area of the nail, what you put nail-polish on

quick/nail bed

body lies in a bed, layer of epithelial cells where the nail attaches to fingers and toes, well vascularized(therefore, appears pink in color), adds material to the nail thus thickening it

hyponchium

where you clean the dirt out from under your nails, area of the skin at the tip of your fingers, fuses nail plate to the skin, provides a waterproof barrier

brittle nails

can be due to drying out of nails, cold, dry cond or overexposure to water

yellow nails

can be due to fungal infection, poss respiratory disease or diabetes mellitus

white spots

most often due to trauma to nail body, could be indication of zinc defiency

pitting

can be due to psoriasis beneath the nail body

concave

can be due to an iron deficiency, can take time to manifest

sebaceous glands

look like bunches of grapes, generally attached to hair follicles by ducts, most numerous on face and scalp, secrete oily substance called sebum, it oils the hair and lubricates the skin, helps prevent water loss, inhibits the growth of certain bacteria, activity of these glands coincide with sexual maturity

eccrine/merocrine sweat glands

contain a duct that extends through the epidermis to the skin surface, aids in body temp reg(secretion of sweat)

apocrine sweat glands

found in certain areas(armpits, areola, anus, genitals), secrete thick, sticky sweat into hair follicle, decomposed by skin bacteria and becomes odorous, coincides with sexual maturity

burns

one of the most serious and frequent problems that affect the skin, rule of nines

severity of burns

based on the number of tissue layers involved; first degree (minor sunburn, no peeling, redness, partial thickness burn), second degree(bad sunburn, peeling, partial thickness burn) and third degree(fires, really bad, crispy, full thickness burn, will not heal nat)

skin graft: autograft

skin from unburned region of the affected person, nerve endings regenerate and connect

skin graft: homograft

skin from cadaver, risk of rejection

major problems for burn victims

fluid loss, serious bacterial infection(organs can become infected)

components of the skeletal system

cartilage, bones, ligaments, and sometimes tendons

support of the skeletal system

bone provides framework, cartilage provides support within certain structures, ligaments hold bones together, tendons support various joints

protection in the skeletal system

skull, ribcage, vertebrae. but it breaks and can puncture valuable things, it also cannot swell (issues in brain injuries)

movement of the skeletal system

skeletal muscles are attached to bones by tendons, the shape of the bones at a joint determines the types of movements that can be made at the joint

storage of the skeletal system

stores minerals (calcium) and adipose tissue

blood cell production of the skeletal system

occurs within the red marrow cavities of certain bones, most red bone marrow is in the axial skeleton

purpose of cartilage

type of connective tissue, it's composed of cells and ECM, avascular, when damaged it's unlikely to repair

hyaline cartilage

super strong, shiny, smooth, located at the ends of long bones, ribs, trachea, bronchi, nose and the embryonic skeleton. functions- provides smooth surfaces for joints, provides support

fibrocartilage

locations: pubic symphisis, invertebral disks, and menisci. functions: support

elastic cartilage

locations: epiglottis, external ear, auditory tube. functions: support with flexibility

long bones

longer than wide, name reflects shape rather than overall size, bones of the limbs (humerus, femur, radius, ulna, bones of fingers)

short bones

cube like bones of the wrist and ankle

irregular bones

all other bones (vertebrae and hip bones)

sutural bones

located within the sutures of the skull, not always present

sesamoid bones

acts like a pulley system, shaped like a sesame seed, bone is surrounded by a tendon, patella is an example

diaphysis

shaft(long axis) of a long bone, composed primarily of compact bone, contains the marrow cavity (filled with yellow bone marrow)

epiphyses

ends of the long bones, joint surfaces, composed primarily of spongy bone, covered with articular cartilage

articular cartilage

hyaline cartilage found on the ends of long bones (provides smooth service, reduces friction, absorbs shock)

epiphyseal lines

located between the diaphysis and epiphyses (forming the growth plate)

periosteum

connective tissue membrane which surrounds the external surface of diaphysis

endosteum

connective tissue membrane which surrounds the internal surfaces of the bone

osteoblasts

build more bone, make bone, produce and secrete osteoid, turn into osteocytes

osteocytes

maintain bone tissue, mature bone cells, look like spiders

lacunae

cell bodies of osteocytes sit in these spaces

canaliculi

little canals, cell processes (arms) of osteocytes sit in these spaces

osteoclasts

resorb bone, multinucleated, breakdown bone

ECM of bone

primarily composed of osteoid and hydroxyapatites

osteoid

secreted by osteoblasts, accounts for bones strength

hydroxyapatites

accounts for hardness of bone, due to calcium salts

compact bone

external layer of bone, composed of osteons

osteon

tube of bone ECM formed by rings called concentric lamellae, osteocytes are located in lacunae between the lamellae, osteocytes communicate with each other by way of their cell processes, each one has a central canal, central canals are connected to each other by perforating canals

concentric lamellae

tube of bone matric formed by rings, osteocytes are located in lacunea between these

central canal

each osteon has one, connected to each other by perforating canals

spongy (cancellous) bone

found internally, surrounded by compact bone, no osteons present, composed of plates of bone called trabeculae

trabeculae

support beams, align along lines of stress, constantly remodeled, bone is remodeled as a result of mechanical stress (muscle pull and gravity), keeps bones strong, anatomy of bone reflects the stresses it encounters

ossification

bone development, process of forming the bony skeleton

intramembranous ossification

bone originates from connective tissue membranes, developed from mesenchyme (embryonic connective tissue)

endochrondral ossification

bone originates from hyaline cartilage, most bones of the skeleton

high blood calcium or phosphate levels, activity of osteoblasts increases

what would cause calcium and phosphate move from blood into bone when osteoblasts produce bone, decreases blood calcium and phosphate levels toward normal

low blood calcium or phosphate levels, activity of osteoclasts increases

calcium and phosphate move from bone into blood when osteoclasts resorb bone, increases clood calcium levels toward normal

hematopoeisis/hemopoesis

process of blood cell and platelet production, occurs in the red bone marrow

zone of resting cartilage

contains randomly arranged chondrocytes(cartilage cells), anchors the epiphyseal plate to the epiphysis(no role in growth)

zone of proliferation

chondrocytes divide and arrange in columns, replace dying chondrocytes of the zone of calcification, secrete collagen fibers and proteoglycans

zone of hypertrophy

something gets bigger, chondrocytes mature and enlarge, calcification cont.

zone of calcification

calcification of chondrocytes is completed, they die and are replaced by osteoblasts, osteoblasts produce bone via endochondral ossification

growth hormone and thyroid hormones

increase mitosis of chondrocytes and osteoblasts, increase protein synthesis (collagen), cause an increase in bone growth

parathyroid hormone

increase osteoclast activity, maintains Ca homeostasis, causes resorption of bone in response to low blood calcium- inc blood calcium levels, main hormone involved in calcium homeostasis, inhibits osteoblasts

calcitonin

causes production of bone in response to high blood calcium, therefore it decreases blood calcium levels, decrease osteoblasts activity

sex hormones(estrogen and testosterone)

promote apoptosis of osteoclasts(break down bone), cause an increase in bone growth, can't have too much of them because it will use up the growth plate too quickly

osteoporosis

risk breeaking bone, shrinkage, a decrease in the density of bone, calcium lost in bone due to resorption, prevalent after age 50 esp women, maybe a lack of vit D

Vitamin D

necessary for normal absorption of calcium in the intestines, osteomalacia(adults) and rickets (kids), a decrease in the density of bone (soft bone)

Vitamin C

needed for the synthesis of collagen, low levels in kids can lead to growth retardation

Peak Bone Mass

greatest density of bone one will attain during one's lifetime, thought to occur between ages of 30 and 35

articulation

site where two or more bones meet (joint), give skeleton mobility and hold it together, as mobility inc the stability dec

functional classification of a joint

based on the amt. of movement occurring at the joint; inc, synarthroses, amphiarthroses, diarthroses

structural classifications of a joint

based on what binds the bones together, inc. fibrous joints, cartilaginous joints and synovial joints

synarthroses

non-movable joint, ex- sutures of the skull

amphiarthroses

slightly movable joint, ex- acromioclavicular

diarthroses

freely movable joint, ex- glenohumeral

fibrous joints

bones are united by collagen fibers, ex- sutures of the skull

cartilaginous joints

bones are united by a plate of cartilage, ex- pubic symphisis, composed of fibrocartilage

synovial joints

bones are seperated by a fluid filled cavity, very movable, joints of the limbs, most joints of the body

features of synovial joints

articular cartilage, joint(synovial) cavity, synovial fluid, joint capsule, reinforcing ligaments

joint (synovial) cavity

space that surrounds the joint, the two bones that are articulating

synovial fluid

reduced friction, nourishes cartilage cells

joint (articular) capsule

encloses the joint, compopsed of a fibrous capsule and a synovial membrane

fibrous capsule

outer layer of the joint capsule, composed of dense irregular connective tissue, lots of protein fibers in the ECM randomly arranged

synovial membrane

lines inside of the fibrous capsule, produces synovial fluid where articular cart begins and synovial membrane stops

reinforcing ligaments

can be found inside and outside of the joint cavity or can form part of the joint capsule

bursae (bursa sacs)

breast implant example, sacs filled with synovial fluid that reduce friction

bursitis

overuse of the bursa sac

tendon sheath

pencil and snakey thing example, elongated bursae which wrap around tendons, reduce friction

shoulder (glenohumeral) joint

most moveable joint in the body (ball and socket), formed by the head of the humerus and the glenoid fossa (cavity) of the scapula

glenoid labrum

fills empty space, rim of fibrocartilage which deepens the joint cavity-> more stable, cereal bowl example

ligaments of the shoulder

help to stabilize the shoulder joint, major ligaments associated with the shoulder include the glenohumeral, acromioclavicular, coracoacromial and coracoclavicular

rotator cuff muscles

supraspinatus, infraspinatus, teres minor, and subscapularis, play a MAJOR role in stabilizing the joint

hip (coxal) joint

very strong, stable joint, formed by the head of the femur and the acetabulum of the coxal bone

acetabular labrum

circular rim of fibrocartilage that helps deepen the joint cavity

ligaments of the joint capsule

thickenings of the joint capsule that help strengthen the coxal joint

ligamentum teres

round ligament, attaches the head of the femur to the acetabulum, plays no role in strengthening the coxal joint, contains an artery that helps supply oxygenated blood to the head of the femur, damage to the artery can lead to arthritis

knee joint

most complex joint in the body, formed by the medial and lateral condyles of the femur and the medial and lateral articular surfaces of the tibia

menisci(medial and lateral)

fibrocartilage discs located between the tibial condyles and femoral condyles, help to deepen the joint cavity and help absorb shock

patellar ligament

below patella, continuation of the patellar tendon, attaches the quads to the tibial tuberosity of the tibia, used to check knee-jerk reflex

medial collateral ligament

proximal attachment: medial epicondyle of the femur, distal attachment: medial tibia, function to strengthen the knee joint

lateral collateral ligament

proximal attachment: lateral epicondyle of the femur, distal: head of the fibula, function to strengthen the knee joint laterally

anterior cruciate ligament

proximal: medial surface of the lateral condyle of the femur, distal: anterior portion of the intercondylar eminence, function to prevent anterior sliding of the tibia on the femur and hyperextension of the knee, usually damage this when MCL is damaged

posterior cruciate ligament

proximal: lateral portion of the medial condyle of the femur, distal: posterior portion of the intercondylar eminence, function to prevent the posterior of the tibia on the femur and the hyperextension of the knee

sprain

when a ligament is stretched or torn, heals very slowly due to poor blood supply

dislocation

bones are foced out of alignment