BIOL G220: Ch. 4 Flashcards
Terms and concepts from Chapter 4: Tissues and lab slides/models
tissue
group of similar cells and extracellular products that perform a common function
four types of tissue in the body
epithelial tissue
connective tissue
muscle tissue
nervous tissue
tissues vary in structure, function and the content of their ______
extracellular matrix
extracellular matrix
a substance produced by the cells of a specific tissue and can contain protein, salts, water, and dissolved macromolecules
located outside of cells
epithelial tissue general characteristics (6)
cellular polar attached avascular innervated high regeneration capacit
organs are line on the ____ and ___ by epithelial tissues
outside, inside
The majority of ____ are derived from epithelial tissue
glands
How much ECM does epithelial tissue hold?
little to none
cellularity
composed almost entirely of cells with little extracellular matrix
cells are bound together by _____
intercellular junctions
polarity
epithelial cells have an apical and basal surface where they attach to underlying cells
attachment
basal surface is attached to a thing basement membrane
basement membrane
an acellular structure product by both epithelial and underlying connective tissue cells
avascularity
lacking blood vessels
where does epithelial tissue gain their nutrients from if it is avascular?
receive nutrients by diffusion from underlying tissues
innervation in epithelia
richly innervated to detect changes in environment at a body or organ region
epithelial tissue’s regeneration capacity and why
high because apical surface is constantly exposed to the environment
epithelial cells are frequently damaged/die and are replaced as quickly as they are lost
three different surfaces of epithelium
apical surface, lateral surface, basal surface
functions of epithelial tissue (4)
physical protection
selective permeability
secretion
sensation
physical protection with epithelial tissue
from dehydration and abrasion, as well as physical, chemical, and biological agents
selectively permeability with epithelial tissue
regulate the passage of certain molecules in or out of certain region of the body
secretion with epithelial tissue
some epithelial cells called exocrine (and endocrine) cells produce secretions such as sweat or oil
sensation with epithelial tissue
possession of nerve endings that can detect light, taste, sound, smell, and hearing
basement membrane function
provides physical support and anchoring of epithelium tissue
acts as a barrier to regulate passage of large molecules between epithelium and underlying connective tissue
intercellular junctions
membrane specializations found on the lateral surfaces of epithelial cells
types of junctions (4)
- tight junctions
- adhering junctions
- desmosomes
- gap junctions
tight junctions (what it is and its function)
stitch one cell to another
encircle cells near apical surface
prevent molecules from traveling between cells (molecules must go through rather than between)
“gatekeepers”
adhering junctions (what is it and its function)
mechanical strength - connecting to each other
formed completely around the cell deep to the tight junction
**microfilaments act to stabilize the apical surface of the cell
desmosomes (what is it and its function)
like a button or snap between adjacent cells
appears at locations of mechanical stress between cells
thickened protein plaque on each of the apposed cell membranes with a fine network of proteins spanning the intercellular space between the plaques
on cytoplasmic side, intermediate filaments attach to the plaques and produce support and stability to the structure shared between the two cells
gap junctions
fluid-filled channels that directly connect the cytoplasms of apposed cells sharing these structures
allow adjacent cells to communicate with each other by flow of ions and other small molecular messengers
epithelial tissue is classified by ____ and ____
number of layers of cells. shape of cells
classification by number of cell layers
simple
stratified
pseudostratified
simple epithelium
single layer of cells with all cells having an apical surface and attached to the basement membrane
stratified epithelium
two or more layers of cells; not all cells have an apical surface nor do all cells attach to the basement membrane
pseudostratified epithelium
cell nuclei give the appearance of a multilayered epithelium, not all cells reach the apical surface
classification by cell shape
squamous
cuboidal
columnar
squamous
flat, wide, and somewhat irregular in shape
cuboidal
about the same size on all sides; nucleus is usually centrally located
columnar
taller then they are wide; nucleus is oval and located in the basal region of the cell
types of epithelium (10)
simple squamous simple cuboidal simple columnar, nonciliated simple columnar, ciliated stratified squamous, keratinized stratified squamous, non-keratinized stratified cuboidal stratified columnar pseudostratified columnar (ciliated with goblet cells or non-ciliated without goblet cells) transitional
transitional epithelium
oddly shaped cells on apical surface found in areas of distension
when transitional epithelium is stretched, it will appear more ____, whereas when epithelium is wrinkled, cells will appear more ____.
squamous; cuboidal
glands
individual cells or multicellular organs that perform a secretory function (i.e. mucin, hormones, enzymes, waste products)
two categories of glands
endocrine glands
exocrine glands
endocrine glands
do not possess ducts and secret directly into the interstitial fluid or the bloodstream
exocrine glands
possess ducts and their cells secrete their products into their ducts
structures of exocrine glands (8)
acinus duct lobules loves septum capsule lobe parenchyma
acinus
secretory portion (sac)
duct
conducting portion
stroma
septum and capsule
lobules
within a lobe
connective tissue
most diverse, abundant, widely distributed, and structurally varied of all four tissue types
“glue”/”filler”
examples of connective tissue
tendons, ligaments, fat, bones, cartilage, and blood
characteristics of connective tissue
cells, protein fibers, ground substance
cells in connective tissue
different cells for different types of connective tissue (i.e. fibroblasts, osteocytes, adipocytes)
proteins fibers in connective tissue
elastic fibers, collagen, reticular fibers
ground substance in connective tissue
a mixture of proteins and carbohydrates with variable amounts of salts and water
protein fibers and ground substance comprise the ____ of connective tissue
extracellular matrix
mesenchymal cell
stem cell
fibroblast
builds fibers
functions of connective tissue (6)
- physical protection
- support and structural framework
- binding of structures
- storage
- transport
- immune protection
classification of connective tissue
- connective tissue proper
- supporting connective tissue
- fluid connective tissue
cell types in connective tissue proper
- resident cells (i.e. fibroblasts, adipocytes, fixed macrophages, and mesenchymal cells
* staying permanently - wandering cells (i.e. mast cells, plasma cells, free macrophages, and other leukocytes)
* floating about and leaving to destination as needed
mast cells
small cells with granule-filled cytoplasm
there are three general types of _______ produced by CT cells and secreted into the extracellular matrix
protein fibers
collagen fibers
long, unbranching, strong, flexible, and resistant to stretching
collagen fibers make up _____ of all protein in the human body, making the collagen the most abundant protein
25%
elastic fibers
thinner than collagen, stretch easily, branch, and rejoin (wavy)
reticular fibers
thinner than collagen fibers; form a branching, woven framework
reticular fibers are found in the ____ of organs with abundant spaces such as liver, lymph nodes, and spleen
stroma
ground substance of connective tissue proper
combination of proteins and carbohydrates
gelatinous
additional content like water or salts can result in varying texture (semi-fluid like adipose to hard like bone)
categories of connective tissue proper
- loose connective tissue
2. dense connective tissue
loose connective tissue
serves as the body’s packing material, found in spaces around organs
dense connective tissue
strong, has fibers (mostly collagen) packed tightly together
types of loose connective tissue
areolar, adipose, or reticular
types of dense connective tissue
dense regular, dense irregular, or elastic
areolar connective tissue structure
fibroblasts; lesser amounts of collagen and elastic fibers; viscous ground substance
areolar connective tissue function
binds and packs around organs
adipose connective tissue structure
adipocytes
adipose connective tissue function
protects; stores fat; insulates
reticular connective tissue structure
meshwork of reticular fibers; contains fibers, fibroblasts, and leukocytes
reticular connective tissue function
forms stroma of lymphatic organs
dense regular connective tissue structure
densely packed collagen fibers are parallel to directions of stress
dense regular connective tissue function
provides great strength and flexibility primarily in a single direction
dense irregular connective tissue structure
densely packed collagen fibers are interwoven; fibers are irregularly clumped together and project in all directions
dense irregular connective tissue function
provides tensile strength in all directions
elastic connective tissue structure
elastic and collagen fibers are arranged irregularly
elastic connective tissue function
provides framework and supports organs; elastic fibers provide ability to stretch and recoil
supporting connective tissue types (2)
- cartilage
2. bone
cartilage
firm, gel-like extracellular matrix composed of protein and ground substance
cartilage cells
chondrocytes
chondrocytes occupy small spaces enclosed by their ECM called ______
lacunae
cartilage function
support and withstand deformation
types of cartilage (3)
- hyaline cartilage
- fibrocartilage
- elastic cartilage
hyaline cartilage
most common type, but also the weakest
found at articulations
glassy matrix
articulation
bone meets bone (joint)
fibrocartilage
densely interwoven collagen fibers contribute to the durability
elastic cartilage
abundant elastic fibers
bone cells
osteocytes
ECM of bone
mixture of collagen and calcium salts providing flexibility from organic components and compressional strength from inorganic components
bone structure
calcified matrix arranged in osteons
fluid connective tissue
blood
fluid connective tissue composition
plasma, erythrocytes, leukocytes, platelets
plasma
water ground substance containing proteins fibers in blood; contains soluble proteins
erythrocytes
red blood cells
leukocytes
white blood cells
platelets
fragments of blood cells involved in blood clotting
muscle tissues
comprised of cells called fibers; when stimulated by the nervous system, fibers shorten causing movement
classification of muscle tissues
- skeletal muscle tissue
- cardiac muscle tissue
3 . smooth muscle tissue
skeletal muscle tissue cell structure
cylindrical and long
multinucleated
striated, parallel, unbranched, and voluntary
skeletal muscle tissue location
attached to bones of skeleton and sometimes skin
cardiac muscle tissue cell structure
branched, Y-shaped, shorter than skeletal fiber cells
striated, involuntary, attached end to end by strong gab junctions at intercalated discs that allow rapid passage of electrical current from one cell to the next during each heartbeat
cardiac muscle tissue location
wall of the heart (myocardium), causes movement of blood
smooth muscle tissue cell structure
relatively short, wide in the middle, and tapered at the ends (fusiform)
non-striated and involuntary
smooth muscle tissue location
walls of most internal organs (i.e. stomach, intestines, urinary bladder)
contraction causes movement of food, blood, sperm
nervous tissue
function in communication and control of body functions
nervous tissue location
brain, spinal cord, nerves
types of nervous tissue cells
neurons
glial cells
neurons
cells that are capable of initiating and conducting electrical activity throughout the body; contain cell processes called axons and dendrites
glial cells
cells that support and protect neurons; lacks axons and dendrites
