Anatomy Chapter 4-6

nervous tissue

internal communication

• brain, spinal cord, and nerves

muscle tissue

contracts to cause movement

• muscles attached to bone (skeletal)

• muscles of heat (cardiac)

• muscles of walls of hollow organs(smooth)

connective tissue

supports, protects, binds other tissues together

• bones, tendons, fat and other soft padding

epithelial tissue

forms boundaries between different environment, protects, secretes, absorbs, filters

• skin surface (epidermis)

• lining of GI tract organs and other hollow organs

2 types of epithelium

covering or lining epithelium

glandular epithelium

epithelium

sheet of cells lining a body surface or cavity

functions as an interface tissue

protection, absorption, filtration, excretion, secretion, sensory reception

epithelium: special charasteristics (never alone always with tissue)

1.polarity

• apical (look at) and basal

2.specialized contacts

3.supported by connective tissue (basal surface)

• basement membrane = basal laminate and reticular lamina together

4.innervated by avascular (no direct blood supply)

5.regeneration (mitosis)

gland

consists of one or more cells that make and secrete a particular product, secretion made of protein

endocrine gland

ductless

produce hormones secreted directly into the extracellular space within the body

exocrine gland

secretes through ducts

includes: mucous, sweat, oil, saliva, bile, mammary

has unicellular exocrine glands and multicellular gland

unicellular exocrine glands

single cells scattered in an epithelial sheet with other cells types

• no duct

• includes golblet cells

multicellular glands

epithelium derived duct and secretary unit of secretary cells

Goblet cell- single celled gland

associated with simple columnar and pseudostratified epithelia

found in the respiratory and intestinal tract

secretes mucin, the protein component of mucous by exocytosis

2 distinct regions to exocrine gland

duct

secretory cells

simple duct structure

duct doesn’t branch

compound duct structure

duct branches

alveolar

sac

merocrine

products are secreted by exocytosis

• pancreas, sweat, and salivary glands

holocrine

products are secreted by the rupture of gland cells

• sebaceous glands

connective tissue (found everywhere in body)

most widely distributed and abundant of primary tissues

non cellular or cellular

connective tissue (major functions)

binding and support

protection

insulation

transportation of substances or heat within the body (blood)

connective tissue (common properties)

common origin- mesenchyme

extracellular matrix- majority is non cellular

degreees of vascularity (actually lacks uniformity)

connective tissue (structural elements)

ground substance

fibers (both form extracellular)

cells - produce extracellular elements

ground substance

proteoglycan structure

unstructured material filling space between cells

cell adhesion proteins

proteoglycans

intersitial fluid

cell adhesion proteins

connects tissue cells to matrix elements

laminin and fibronectin

proteoglycans (chargaes on it attact water)

have a protein core that glycosaminoglycans (GAGs) attach

intertwine and trap H2O; regulalte GS viscosity

interstitial fluid (water)

water is a weak polar molecule

fibers (3)

collagen

elastic

reticular

collagen fibers

fibrous collage protein

secreted into extracellular space, spontaneoously assembles into cross linked fibers

high tensile strength

Ex: connects kneecaps under patella, achillies

elastic fibers

elastin protein (w some collagen)

stretch and recoil

Found in skin, lung and blood vessels

reticular fibers

delicate networks

• fine collagenous fibers

basement membrane

short collagen fibers

Ex: Lymph nodes, tonsils

all connective tissue cells

ectoderm (outer) - nervous tissue

mesoderm (middle)- muscle and connective tissue

endoderm (inner)

connective tissue has

proper, cartilage, bone tissue, blood

Proper- adipocytes (fat cells) (amitotic cells) all derived from fibroblasts.

mesenchyme (development)

first tissue formed from mesoderm layer

• composed of mesenchymal cells, fluid and ground substance

differentiates into all other connective tissue

some mesenchymal cells remain undifferentiated

decendants of mesenchyme are

fibroblasts, chondroblasts, osteoblasts, hematopoietic stem cell

blast

cells that are still mitotically capable

fibroblast (proper)

all 3 fiber types collagen, reticular, elastic

gel like ground substance

connective tissue proper (loose)

areolar

adipose

reticular

connective tissue (dense)

regular

irregular

elastic

chondroblast

could turn into chondrocytes

cartilage (come from chondroblast)

• hyaline cartilage

• fibrocartilage

• elastic cartilage

fibers

• collagen

• elastic fibers in some

Osteoblasts

encased in bone become osteocytes (amitotic)

osseous (bone)

• compact bone

• spongy (cancellous) bone

gel like ground substance calcified with inorganic salts

fibers

• collagen

hematopoietic stem cell

blood cells (and macrophages)

blood - blood cell formation and differentiation are quite complex

bone marrow

no fibers

plasma

cells: RBC, WBC, platelets

embryonic mesenchyme (under loose)

gives rise to all other connective tissue types

if this doesn’t develop, we don’t. this is what we grow on

loose areolar

wraps and cushions organs; its macrophages phagocytize bacteria; plays important role in inflammation; holds and conveys tissue fliud

mostly non cellular

lots of ground substance with some fibers

loose adipose

provides reserve food fuel; insulates against heat loss; supports and protects organs

loose reticular

fibers form a soft internal skeleton (stroma) that supports other cell types including white blood cells, mast cells, and macrophages

short and delicate.

found in spleen

dense regular

attaches muscles to bones or to muscles , attaches bones to bones; withstands great tensile stress when pulling force is applied in one direction

tendon has 2points of stress

dense irregular

able to withstand tension exerted in many directions; provides structural strength

there are mulitple points of stress

Dense elastic

allows recoil of tissue following stretching, maintains pulsatile flow of blood through arteries; aids passive recoil of lungs following inspiration (aorta)

all connective tissue proper is from

fibroblasts

cartilage

properties are intermediate qualities to bone and dense connective tissue include:

• avascular

• lacks nerve fibers

• ground substance (rich in GAGs)

• can withstand both tension and compression forces

Primary cell type is Chondroblast which secretes matrix

3 cartilage types (hyaline, fibrocartilage, elastic)

hyaline

function: supports and reinforces; has resiient cushioning properites; resists compressive stress

Ex: costal cartilages in rib cage

most abundant

chondroblast becomes chondrocyte - has lacuna

elastic cartilage

function: maintains the shape of a structure while allowing great flexibility

Ex: external ear, epiglottis (trachea that opens and closes)

fibrocartilage

function: tensile strength with the ability to absorb compressive shock

Ex: intervertebral discs

very tough meaning lots of collagen

osteocyte and osteoblast are both

mitotic

bone, osseous

compact and spongy

both come from osteoblasts and become an osteocyte

function: bone supports and protects (by enclosing) provides levers for the muscles to act on; stores calcium and other minerals and fat; marrow inside bones is the site for blood cell formation (hematopoiesis)

blood

classified as a connective tissue

1. develops from mesenchyme

2. blood cells surrounded by a fluid matrix- plasma

3. blood fibers only visible during clotting

epithelial membranes

continuous multicellular sheet composed of at least 2 primary tissue types

• connective tissue

• epithelium

cutaneous membrane

THE SKIN

2 components (epidermis and dermis)

epidermis - keratinized stratified squamous epithelium (lots of desmosomes)

dermis- areolar and dense irregular connective tissue

*dry membrane

mucous membrane

line body cativities OPEN to the exterior

digestive, respiratory, urogenital organs (open to exterior)

*wet/moist - due to secretions or urine

stratified squamous or simple columnar or pseudostratified epithlia

loose connective tissue -lamina propria (thick)

Serous membrane (serosae)

found on CLOSED ventral body cavities

*moist

simple squamous on loose areolar connective tissue

enrich capillary fluid with hyaluronic acid- lubricant

• allow paritetal and viceral layers to slide across each other

viseral layer connected to organ, move with organ in size, physically in contact with the organ itself

paritetal layer is portion of serous membrane that is not connected to the organ itself

^ slide across each other and limit friciton

HAS TO BE AN ENCLOSED SAC

inflammation def

INNATE, non specific response to tissue injury (occur with any type of tissue)

Regeneration def

replacement of damaged tissue with same type of(mitosis)

Fibrosis def

proliferation of fibrotic connective tissue (scar)

3 steps of tissue repair

1. inflammation stage

2. organization

3. regeneration adn fibrosis

inflammation stage (tissue repair)

occurs the second of the injury

1a inflammatory chemicals (pain)

• chemoattractants (active and attract cells)

  • injured cells

  • macrophages

  • mast cells

  • clotting proteins

  • *platelets (plug up any leaking blood) CLOTTING

1b increase capillary permeability

• increase fluid leakage

• seal off wound

• fluid accumulaiton (swelling and edema)

• WBC know where to go becauase they follow the chemical trail of the injury

• RBC help with pain, redness, swelling, heat

1c clot formation

• stops bleeding

• prevents contamination

organization restores blood supply (tissue repair)

Granulaiton tissue formed

• capillaries form

• collagen fibers bridge gap

• macrophages phagocytize debris

• regeneration (begins before the regeneration stage) (can’t begin until collagen has been formed) of epithelial cells

Regeneration and fibrosis (tissue repair)

3a regeneration

• epithelium

• macrophages

3b fibrosis

• connective tissue

3c 1 week later

• scar (fibrotic area)

• continued regeneration

What 6 things skin does

1. functions of the skin

2. body temp regulation

3. cutaneous sensation

4. metabolic function

5. blood reservoir

6. secretion/excretion

skin (integumentary) is composed of 2 distinct layers

epidermis - stratified squamous epithelium

• intermediate filaments (desmosomes)

dermis - connective tissue

epidermis is composed of 4 different types of cells

Keratinocytes, langerhans cells, merkel cells, melanocytes

keratinocytes

Intermediate filament

• product keratin

• connected by desmosomes

• arise from a deeper mitotically active layer

• dead at surface

langerhans cells

dendritic cells

activate immune system

merkel cells

low level and it communicates directly to a neuron that sends information to the brain

• epidermal-dermal junction

• associated with sensory nerve endings

• receptor for touch

melanocytes

synthesize melanin

found in deepest layers

epidermis may have 4 or 5 differnet layers (depending on region of the body)

stratum basale

stratum spinosum

stratum granulosum

stratum lucidum (only on palms or soles of feet)

stratum corneum

stratum basale

deepest layer, attached to dermis single row of youngest keratinocytes

where it regenerates (how we repair and produce new skin cells)

melanocyte cell, merkel cells

stratum spinosum

several layers thick flat irregular shaped keratinocytes

desmosome (synthesize) attachments

stratum granulosum

where keratinocytes go to die (through apoptosis)

3-5 layers

nuclei and organelles disintegrate accumulate keratohyline granulates

stratum lucidum

only in thick skin

additional layer

Palms and soles of feet

between granulosum and corneum

dead, flat layer

stratum corneum

you see when you look at skin

20-30 layers thick

glycolipid between cells

Dermis has 2 layers of connective tissue

1 dermal papillae (papillary layer of dermis)( loose areolar tissue and most superficial) (you can see holes where the ground substance is )

2 reticular layer (lots of collagen) can see the collagen fibers

loose and dense are determined by

amount of fibers

cleavage lines

collagen fibers arranged in bundles from cleavage (tension) lines

incisions made parallel to cleavage lines heal more readily

flexure lines (palms of hand and soles of feet)

skin appendages

derivatives of epidermis with a role in maintaining homeostasis

sweat glands

(sudoriferous glands) (merocrine)

found everywhere except nipples and external genitalia

eccrine glands

(temperature regulation, everywhere)

most abundant

high density on palms, sole of foot and forehead

secrete sweat

apocrine glands

confined to axillary and anogenital area, little role in thermoregulation

larger ducts empty into hair follicles

secretion

• sweat and fatty substances and proteins (milky color), androgen regulation decomposition by bacteria caues odor

similarity to sexual scent gland- sexual foreplay increases activity

secrete water/fatty mixture

associated with body odor when surface bacteria metabolize lipid

mammary glands

produce colostrum and milk

found in breasts

ceruminous glands

produce ear wax in external ear canal

bitter

sebaceous (oil) glands puke to keep your skin soft and smooth

alveolar glands

everywehre except palms and soles of feet

secrete sebum (holocrine)

lipid and cell fragments

function: lubrication

• skin; slowing water loss

• hair; prevents brittleness

• bactericidal function

stimulated by androgens

Acne develops when

hair follicles become plugged

• sebum

• dead skin cells

bacteria then trigger;

• inflammation

• infection

stages of acne (5)

1. normal follicle

2. open comedone (blackhead)

3. closed comedones (whitehead)

4. papule

5. pustule

hair is distributed over the sentire skin surface except

palms, soles, lips

nipples and portions of the external genitalia

Hair

filamentous strands of dead keratinized cells (epithelial cells)

shaft projecting from the skin while root embedded in the dermis

cells contain HARD KERATIN

(bellas dormant is hari not seen under the skin)

Hair consists of 3 layers of cells

medulla (soft keratin)

• air pockets within it cause white hair

• cells cause gray hair

cortex (hard keratin)

cuticle (hard keratin)