Anatomy/physiology Lecture 2

mucus

a lubricating fluid that is composed of water and mucins and is produced by unicellular and multicellular glands along the digestive, respiratory, urinary, and reproductive tracts

squamous epithelium

cells are flat and white with a disc shaped nucleus

columnar epithelium

cells are taller than they are wide

what are the characteristics of epithelial tissue

cellularity, polarity, attachment, avascularity, innervation, regeneration

transitional epithelium

change shape depending on the state of stretch in the tissue

what are the three categories of connective tissue?

connective tissue proper, supporting connective tissue, fluid connective tissue

lymph

derived from plasma and has no formed elements

holocrine secretion

destroys the cell, which becomes packed with secretions before finally bursting

what are the three embryonic tissue layers?

endoderm, mesoderm, ectoderm

macrophages

engulf damaged cells or pathogens that enter the tissue

examples of exocrine secretions

enzymes entering digestive tract, sweat, and breast milk

gland cells

epithelial cells that produce secretions

what are the 4 basic types of tissues?

epithelial, connective, muscle, nervous

gap junction

essential to coordination of muscle contraction

endo means

inside

epithelia cover ___ and ___ body surfaces

internal, external

apocrine secretion

involves the loss of cytoplasm as well as the secretory product

ecto means

outside

where are endocrine secretions produced?

pancreas, thyroid, pituitary gland

tight junction

prevents the passage of water and solutes between cells

synovial membrane

produces synovial fluid in joint cavities

what are the main functions of epithelial tissues?

protection, selective permeability, secretion, sensation

what are the functions of connective tissue?

protection, support, binding, storage, and transport

antibodies

proteins that destroy invading microorganisms or foreign substances

epithelia functions

provide physical protection, control permeability, provide sensation, produce specialized secretions

what are 3 common types of cell junctions

tight junctions, gap junctions, desmosomes

lymphatic vessels

transport lymph back to cardiovascular system

Hemidesmosomes

resemble half of a spot desmosome and attach a cell to the basement membrane

glands

secretory structures derived from epithelia

Perichondrium

separates cartilage from surrounding tissues

cardiac muscle tissue

short, branched, striated, single nucleus, interconnected by intercalated discs

smooth muscle tissue

short, spindle shaped, non striated, single nucleus

simple epithelium

single layer of cells

what does the mesoderm embryonic layer become?

skeleton, muscle, kidneys, heart, blood

what does the ectoderm embryonic layer become?

skin and nervous system

intercalated dics

specialized attachment sites containing gap junctions and desmosomes

muscle tissue

specialized for contraction

adipose tissue

stores energy, cushions organs, insulates against external environments

dense connective tissue

strong, has fibers (mostly collagen) packed tightly together

exfoliative cytology

study of cells shed or removed from epithelial surfaces

histology

study of tissues

What do connective tissues do?

support

areolar tissue

surrounds and protects, connects epithelium to deeper tissue

cutaneous membrane

the skin that covers the surface of your body

how many different types of cells are in the body?

200

tissues

Collections of specialized cells and cell products that perform a limited number of functions.

ligaments

Connect bone to bone

elastic fibers

Contain elastin, branched and wavy, return to original length after stretching

pseudostratified epithelium

Contains one layer of epithelial cells, but appears to have more than one

mast cells

A connective tissue cell that when stimulated releases histamine and heparin, initiating the inflammatory response,

cartilage

A connective tissue with a gelatinous matrix containing an abundance of fibers

basement membrane

A layer of filaments and fibers that attach an epithelium to the underlying connective tissue

chondocytes

cartilage cells

periosteum

Layer that surrounds a bone, consisting of an outer fibrous and inner cellular region

exocrine secretion

Secretion onto a body surface

what is connective tissue composed of?

cells and extracellular matrix

fibroblasts

The only cells that are always present in connective tissue proper, produce connective tissue fibers and ground substance

cuboidal epithelium

cells are as tall as they are wide, with a spherical nucleus

loose connective tissue

acts as packing material, found in spaces around organs

what is the cause of anencephaly

an incomplete anterior neural tube closure

reticular tissue

anchors epithelial tissues

epithelium

avascular layer of cells that forms a barrier that covers internal/external surfaces

meso means

between, middle

osteocytes

bone cells

What does the neural tube become?

brain and spinal cord (central nervous system)

connective tissue proper

contains collagen fibers, elastic fibers, and reticular fibers

myosin and actin

contractile proteins

what do nervous tissues do?

control

tendons

cords of dense regular connective tissue that attach skeletal muscles to bones

visceral layer

covers external surface of organs

what is the cause of spina bifida

incomplete posterior neural tube closure

fibrocartilage

extremely durable and tough

elastic cartilage

extremely resilient and flexible, forms external flap of external ear, epiglottis, and small cartilages in the larynx

adipocytes

fat cells

why have neural tube defects become less common?

folic acids

connexons

form a narrow passageway that lets small molecules and ions pass from cell to cell in a gap junction

dense irrecular connective tissue

forms organ capsules, bone/cartilage sheaths, deep dermis of skin

dense regular connective tissue

forms tendons and ligaments, collagen fibers run in a single parallel direction

what does the endoderm embryonic layer become?

gut, liver, lungs

elastic dense connective tissue

has the least amount of support

endocrine secretion

hormones, released by gland cells into surrounding tissue fluid

articulations

joints

mucous membranes (mucosae)

line passageways and chambers that communicate with the exterior

serous membrane

line the body's sealed internal cavities of the trunk

parietal layer

lines inner surface of body cavity

serous pericardium

lines pericardial cavity and covers heart

peritoneum

lines peritoneal cavity and covers abdominal organs

skeletal muscle tissue

long, cylindrical, multinucleate cells, striated

reticular fibers

made up of the same protein subunits as collagen fibers, but arranged differently. The least common of the three fibers, thinner than collagen fibers. forms branching, interwoven framework in various organs.

fibrocytes

maintain the connective tissue fibers of connective tissue proper

methods of glandular secretion

merocrine, apocrine, holocrine

Canaliculi

microscopic passageways between cells

stratified epithelium

more than one layer of cells

collagen fibers

most common fiber in connective tissue proper. long, straight, unbranched

merocrine secretion

most common method of secretion, product is released through exocytosis.

hyaline cartilage

most common type of cartilage, tough but flexible. covers breastbone, respiratory tract, and opposing bone surfaces within joints

what do muscle tissues do?

movement

ground substance

unstructured material that fills the space between the cells and surrounds fibers

leukocytes

white blood cells

avascular

without blood vessels