anatomy unit 1 test mp1

differentiation

each cell specializes to perform a certain function; 200 different types of cells

types of tissues (4)

epithelial, connective, muscular, neural

epithelial tissue

tightly packed cells covering surfaces and lining cavities, cells regenerate quickly

4 functions:

• physical protection, control permeability, provide sensation, secretions

tight junctions

prevent leaks bxt cells; adhesion belt underneath

gap junctions

allow for intercell communication

desmosomes

cell to cell anchoring junctions, resist stretching

hemidesmosomes

cells that anchor other cells to the basement membrane

basement membrane

thin layer under epithelia

apical/microvilli

exposed surface/surface area for absorption

stem cells

unspecialized cells in the basement membrane

epithelial classifications

simple, stratified

squamous, cuboidal, columnar

simple epithelium

single layer of cells; cover basement membrane; thin and fragile → in protected areas of the body; permeable → in areas of absorption/digestion

stratified epithelium

multiple layers of cells above basement membrane; more protection/shock absorption → in areas with mechanical stress/friction (ex skin)

squamous epithlium

thin, flat cells → easy secretion/absoprtion

cuboidal epithelium

hexagonal boxes that form rows of cells; secretion & absorption

columnar epithelium

tall, hexagonal boxes; protection

pseudostratified epithelium

columnar epithelium w/mix of cell types; appears layered but is simple; possesses cilia

transitional epithelium

columnar epithelium that goes thru cycles of stretching & recoiling; lines bladder/uterus

exocrine glands

produce secretions onto int/ext surfaces

endocrine glands

produce secretions into fluids/blood

merocrine secretion/glands

exocytosis; forms mucus; sweat around body

apocrine secretion/glands

loss of cytoplasm + secretion; sweat in armpits & public areas (glands developed with puberty)

types of exocrine glands (3)

• serous: produce watery substances w/enzymes

• mucous: produce mucus

• mixed: produce both substances

connective tissue

connects, supports, and protects other parts of body; composed of 3 things:

• specialized cells

• extracellular protein fibers

• ground substance

matrix

accounts for majority of the volume of connective tissue; composed of 2 parts:

• ground substance

• protein fibers (collagen)

connective tissue functions (5)

• support & hold the body together

• protection (ex bones)

• defense (ex antibody production)

• transportation (ex blood)

• storage (ex adipose cells)

mesenchyme

early embryonic tissue; where all connective tissue comes from

connective tissue types (3)

• connective tissue proper

• fluid connective tissue

• supporting connective tissue

connective tissue proper

soft, flexible; ex tendons & ligaments; contains fibroblasts, fibrocytes, macrophages, adipocytes, mast cells, antibodies, 3 fibers (collage, elastic, reticular), ground substance

fibroblasts & fibrocytes

most abundant cells; produce/maintain fibers and ground substance

macrophage

found throughout matrix; phagocytize pathogens; fixed and free types

mast cells

small, mobile; release chems for body’s defense

connective tissue fibers (3)

• collagen: small, flexible, most common

• elastic: stretch, contain elastin, branched structure

• reticular: least common, woven bxt organs

types of connective tissue proper (5)

• areolar tissue: contains cells and blood, no oxygen

• adipose (fat)

• reticular: composed of fibers that stabilize other functional cells

• dense reg: collagen fibers in parallel structure (ex tendons and ligaments)

• dense irreg: interwoven meshwork, strengthens and supports

fluid connective tissue

made of blood and lymph

• blood: red blood cells, white blood cells, platelets, plasma

supporting connective tissue

bone and cartilage

cartilage + types (3)

matrix w/firm gel; is avascular

3 types:

• hyaline: most common, tightly packed fibers

• elastic (flexible)

• fibrocartilage: dense, durable, tough

osseous tissue (bone)

mostly calcium and cartilage; canaliculi (in bony matrix); periosteum (covers all bone surface except joints)

mucous membrane

line ext cavities (digestive, respiratory, urinary, reproductive tracts); lined w/epithelia

serous membrane

simple epithelium supported by areolar tissue; minimizes friction thru secretion of serous fluid

pleura, peritoneum, periosteum

cutaneous membrane

aka skin; covers body w/stratified squamous epithelium; thick, waterproof, dry

synvovial membrane

lines articulations (joints) + its secretions lubricate joints; composed of areolar tissue

skeletal muscle

multinucleus; cannot divide → rely on stem cells; have striations and voluntary motion

cardiac muscle

uninucleus; striations and involuntary motion; intercalated disks; few stem cells

smooth muscle

no striations and involuntary motion; found across organ systems

neural tissue

conducts electric impulses thru body; in brain and spine

neurons

neural cells that allow for thought and communication in brain/body; 3 parts

• cell body (nucleus)

• axons (send signals

• dendrites (receive signals)

injury response (2 steps)

1. inflammation: heat, swelling, pain; trigger mast cells → release chems → blood vessels dilate & produce pain; nutrients, oxygen, and white blood cells delivered

2. regeneration: damaged tissue replaced; fibroblasts produce scar tissue
   a) epithelia and smooth muscle regenerate well
   b) cartilage and cardiac muscle don’t regenerate

aging effect on tissue

• repairs slow

• epithelia more fragile

• cartilage less resilient

• osteoporosis: reduced bone strength (women)

• cancer probability increases

epidermis

stratified squamous tissue, has 4-5 layers, makes up skin surface

stratum basale

aka strata germinative; deepest layer of epidermis; has epidermal ridges and dermal papillae; germinative (stem) cells that replace cells lost at surface; has melanocytes

intermediate strata

stratum spinosum: bottom of intermediate strata adds thickness, helps replace cells

stratum granulosum: produces keratin and moves cells upwards

stratum lucidum: only in thick skin, densely packed cells

stratum corneum

exposed skin, 15-30 layers of dead, keratinized cells, cells connected by desmosomes

keratin

water resistant, tough material that forms hair/nails

carotene

orange/yellow pigment in skin

melanin

brown/black pigment in skin, produced by melanocytes

albinoism

have melanocytes but they don’t produce melanin

cyanosis

when the skin turns blue due to a lack of circulation → no oxygen in blood

basal cell carcinoma

originates in stratum basale, no mets → easily survivable

squamous cell carcinoma

cancer in superficial layers of the skin, no mets → easily survivable

malignant melanoma

melanocytes grow uncontrollably, mets often in lymphatic system → dangerous

dermis

skin layer bxt epidermis and hypodermis, 2 layers (papillary & reticular)

papillary layer

areolar tissue, supports epidermis, has capillaries

reticular layer

dense irreg tissue w/elastic and collagen fibers

cutaneous plexus

network of blood vessels in skin, provides dermis w/nutrients and excretes waste

hypodermis

layer of skin beneath dermis and connected to basement membrane, barrier bxt skin and deeper tissues/organs; composed of areolar tissue w/adipocytes; distribution changes thru puberty and life; is elastic w/few capillaries

hair fuctions

protects scalp & insulates skull; guards nostrils/ears/eyes; sensory nerves

hair follicle

small organ that produces hair; in dermis/hypodermis

hair papillae

epithelium and base of hair follicle; connective tissue; has nerves

hair matrix

contains epithelial cells that produce hair; allows cells to be pushed up & cycle of keratinization → death to occur

hair shaft

contains 3 layers of keratinized cells

• cuticle: surface layer of hair, shingle-like

• cortex: contains melanin

• medulla: core of hair

arrector pili

smooth muscle cells that surround hair follicles and cause contraction (hair “standing”)

sebaceous glands

discharge oil into hair/skin; lipids released thru holocrine secretion (cell death); based on sex hormones and puberty (cause for acne)

sebum

secretion of sebaceous glands, inhibits bacteria growth

sebaceous follicle

large glands that discharge sebum directly onto skin

sweat glands

aka sudoriferous glands; 2 types:

• apocrine

• merocrine

apocrine sweat glands

produce sweat in puberty areas; actually uses merocrine secretion; sweat attracts bacteria → odor

merocrine sweat glands

secrete sweat onto skin elsewhere on body (ex palms); purpose is to cool the body; sweat protects body by diluting chemicals on skin surface

nail

protects fingertips/toes from mechanical stress

nail body

mass of dead, keratinized cells

nail root

produces nail (NOT nail bed)

cuticle

formed by stratum corneum

lunula

pale crescent bxt nail root and cuticle

4 stages of regeneration

enhanced blood flow, scab formation, fibrin production, scar tissue formation

4 stages of wound healing

hemostasis, inflammation, proliferative, remodeling