Chapter 5 Flashcards
four major types of tissues
epithelial, connective, muscle, nervous
tissue
groups of similar cells (and extracellular material) that work together to form common functions
extracellular matrix (ECM)
anything in the tissue that isn’t a cell
epithelial
composed of one or more layers of closely packed cells; little to no ECM; covers/lines things and forms glands
connective
composed of cells, proteins, fibers, ground substance; binds, supports and protects
muscle
contains contractile proteins; moves the skeleton/organs
nervous
contains neurons and glial cells; transmits impulses, processes information
common characteristics of epithelia
- mostly cells, minimal ECM
- avascular
- extensively innervated
- able to regenerate
lumen
central cavity or open space within an organ
apical surface
surface of epithelial cell facing lumen or external environment
basement membrane
aids in attaching epithelial tissue; formed by underlying connective tissue
basal surface
surface of epithelial cell facing the basement membrane
functions of epithelial tissue
- physical protection
- selective permeability
- secretions and sensations
simple epithelium
one layer of cells; all epithelial cells are in contact with basement membrane
where is simple epithelia found?
- where stress is minimal
- where filtration/absorption/secretion is primary function
stratified epithelium
contains two or more layers of epithelial cells; basal layer of cells is in contact with basement membrane
functions of stratified epithelium
- structural support
- better protection for underlying tissue
- cells in basal layer regenerate as cells in apical layer are lost due to abrasion
cell shapes of epithelial cells and their appearance?
- squamous; flat
- cuboidal; square-like with round nucleus (may sometimes appear circular)
- columnar; rectangular with elongated nucleus
transitional cells
can easily change their shape from polyhedral to more flattened depending on the degree to which the epithelium is stretched
pseudostratified
appears to have more than one layer, but all cells are connected to the basement membrane as one layer
structure of simple squamous epithelium?
single layer, flat cells; nucleus bulges at center
function of simple squamous epithelium?
rapid diffusion and filtration; secretion in serous membranes
location(s) of simple squamous epithelium?
alveoli, lining of lumen of blood/lymph vessels (endothelium), serous membranes of body cavities (mesothelium)
structure of simple cuboidal epithelium?
single layer, cells are square/rounded; spherical and centrally located nucleus
function of simple cuboidal epithelium?
absorption and secretion; forms secretory tissue of most glands and small ducts
location(s) of simple cuboidal epithelium?
lining of kidney tubules, thyroid gland follicles, surface of ovary, secretory regions and ducts of most exocrine glands
structure of nonciliated simple columnar epithelium?
single layer, nonciliated rectangular cells with oval nucleus
(may contain microvilli and goblet cells)
function of nonciliated simple columnar epithelium?
absorption and secretion
location(s) of nonciliated simple columnar epithelium?
lining of most of digestive tract; stomach, small intestine, large intestine (gastrointestinal)
structure of ciliated simple columnar epithelium?
single layer, ciliated rectangular cells with oval nucleus
(may contain goblet cells)
function of ciliated simple columnar epithelium?
secretion of mucin, movement of mucus along apical surface of epithelium by cilia, oocyte movement thru uterine tube
location(s) of ciliated simple columnar epithelium?
lining of the larger bronchioles (air passageways) of the lung, uterine tubes
structure of ciliated pseudostratified columnar epithelium?
single layer of cells with varying heights, but all of them connect to the basement membrane
(contains goblet cells and cilia)
function of ciliated pseudostratified columnar epithelium?
protection and secretion
location(s) ciliated pseudostratified columnar epithelium?
lining of larger airways of respiratory tract, nasal cavity, pharynx, larynx, trachea, bronchi
structure of nonciliated pseudostratified columnar epithelium?
single layer of cells with varying heights but all of them connect to the basement membrane, but not all cells reach apical surface
(lacks goblet cells and cilia)
function of nonciliated pseudostratified columnar epithelium?
protection
location(s) of nonciliated pseudostratified columnar epithelium?
rare; lining of male urethra and epididymis
difference between keratinized and nonkeratinized stratified squamous epithelium?
keratinized; superficial cell layers are dead
nonkeratinized; cells are living
structure of keratinized stratified squamous epithelium?
many layers, basal cells are cuboidal/polyhedral and alive while superficial/apical cells are dead
little bonus: what is keratin?
a tough and protective protein that strengthens tissue
structure of keratinized stratified squamous epithelium?
many layers; basal cells are cuboidal/polyhedral and alive while superficial/apical cells are squamous and dead (lack nucleus)
function of keratinized stratified squamous epithelium?
protection of underlying tissue from abrasion
location(s) of keratinized stratified squamous epithelium?
epidermis of skin
structure of nonkeratinized stratified squamous epithelium?
many layers; basal cells are cuboidal/polyhedral and alive while superficial/apical cells are alive (contain nucleus)
function of nonkeratinized stratified squamous epithelium?
protection of underlying tissue from abrasion
location(s) of nonkeratinized stratified squamous epithelium?
lining of oral cavity, pharynx, larynx, esophagus, lining of vagina, anus
structure of stratified cuboidal epithelium?
two/more layers; cells at apical surface are square/round
function of stratified cuboidal epithelium?
protection/secretion
location(s) of stratified cuboidal epithelium?
ducts of most exocrine glands and ovarian follicles
structure of stratified columnar epithelium?
two/more layers; cells at apical surface are rectangular
function of stratified columnar epithelium?
protection/secretion
locations of stratified columnar epithelium?
large ducts of salivary glands, conjunctiva, lining of male urethra
structure of transitional epithelium?
varies depending if the tissue is relaxed or distended
- relaxed = cuboidal/polyhedral cells
- distended = flattened cells
function of transitional epithelium?
accommodates urine volume changes in the urinary bladder, ureters, and urethra
locations of transitional epithelium?
urinary bladder lining, ureters, part of urethra
what are glands?
individual cells/organs composed mainly of epithelial tissue
what do glands do?
secrete substances for use in the body or elimination from the body
endocrine glands vs exocrine glands
endocrine; lack ducts and secrete products (hormones) into blood to be transported thru the body
exocrine; has ducts and discharges contents on epithelial surface
anatomic forms of exocrine glands (5)
simple, compound, tubular, acinar, tubloacinar
simple glands
have a single, unbranched duct
compound glands
have branched ducts
tubular glands
consistent diameter
acinar
expanded sac shape
tubloacinar
has both tubes and sacs
exocrine secretion methods (3)
merocrine, apocrine, holocrine
merocrine secretion
packages secretions into secretory vesicles; releases them thru exocytosis; glandular cells stay intact
apocrine secretion
produces secretory material when apical part pinches off; releases cytoplasmic content; cells repair itselves
holocrine
cell accumulates product then disintegrates; ruptured dead cell is replaced
common characteristics of connective tissue
- cells are specific to the type of tissue they are in
- most cells are not in direct contact w/ each other
- contains resident cells and wandering cells
examples of wandering cells in connective tissue
leukocytes (white blood cells)
examples of resident cells in connective tissue
fibroblasts, adipocytes, mesenchymal, fixed microphages
fibroblasts
immature cells that produce fibers and ground substance
adipocytes
fat cells
mesenchyme
embryonic stem cell
fixed microphages
large cells derived from leukocytes; engulfs damaged cells and pathogens
types of protein fibers and their properties
collagen - strong but flexible, resists stretch
reticular - thinner and branches, tough but flexible
elastic - wavy and branches, stretches and recoils
general functions of connective tissue
protection, support/structure, storage, transport, immune protection
two types of embryonic connective tissue?
mesenchyme and mucous
mesenchyme vs mucous
mesenchyme - tissue from which all other connective tissues are formed
mucous - umbilical cord only
connective tissue proper
loose and dense
supporting connective tissue
cartilage and bone
fluid connective tissue
blood and lymph
functions of areolar connective tissue?
protects tissues and organs, binds skin to deeper tissues, gives space for vessels and nerves
where can areolar connective tissue be found?
skin; beneath epidermis, digestive tract, respiratory system
where can elastic cartilage be found?
epiglottis of larynx, external ear
what structures of dense connective tissue are tightly packed together?
fibers
where can dense irregular connective tissue be found?
dermis of the skin
muscle tissues that contain striations?
skeletal, cardiac
muscle tissue that displays branching when under a miscroscope
cardiac
what muscle tissue doesn’t have striations?
smooth
signature feature of cardiac muscle tissue
intercalated discs
what cells are in blood connective tissue?
leukocytes, erythrocytes, thrombocytes
(WBCs, RBCs, platelets)
function of fibrocartilage?
support; forms fetal skeleton
what are some structures found in bone connective tissue?
osteon, lamella, osteocyte, central canal, cannaliculi
5 properties of muscle tissue
contractile, conductive, elastic, extensible, excitable
is skeletal muscle tissue voluntary or involuntary?
voluntary; somatic nervous system
is the cardiac muscle tissue voluntary or involuntary?
involuntary; autonomic nervous system
is smooth muscle tissue voluntary or involuntary?
involuntary; autonomic nervous system
where can you find skeletal muscle tissue?
attached to bone/skin; external urethral/anal sphincters
where is cardiac muscle tissue located?
myocardium (muscles of the heart)
what is a function of cardiac muscle tissue?
moves the blood through the heart and vessels
where is smooth muscle tissue located?
walls of most internal organs, iris of the eye
what are some functions of smooth muscle tissue?
controls pupil size, propels material through the organ
neurons
conduct signals
is nervous tissue vascular or avascular ?
vascular
structures in nervous tissue
cell body, dendrites, axons, glial cells
glial cells
supportive functions
axon
carries signals out/away from cell body
dendrites
receives info and brings it to cell body
where is nervous tissue located?
brain, spinal cord, nerves
functions of nervous tissue?
receive/process/transmit nerve impulses (glial cells protect/nourish/support neurons)
four types of body membranes
mucous, serous, cutaneous, synovial
mucous membranes
line structures open to the external environment
location of mucous membrane
digestive, respiratory urinary, and reproductive system
serous membrane
line structures not exposed to external environment, covers many organs
cutaneous membrane
skin, external body surfaces
synovial membrane
found in joints reduces friction and provides nutrition
