ch 4 vocab - tissue level of organization: epithelium + connective Flashcards
two major categories of epithelial tissue
epithelia and glands
epithelia
covers surfaces and lines body cavities
epithelial tissue 4 essential functions
- physical protection
- controls permeability
- provide sensation
- produce specialized secretions
epithelia structure
- apical (free) surface: allows for absorption and secretion
- basolateral surface
glands
cells that secrete substances
characteristics of epithelial tissue
- polarity
- high cellularity, tightly bound by cell junctions
- attachment - base of epithelium bound to noncellular basement membrane
- avascularity
2 major types of glands
endo and exocrine
endocrine glands
releases hormones into bloodstream
- no ducts
exocrine glands
secretes products via DUCTS onto epithelial surfaces
characteristics of epithelial cells
- closlely packed cells
- avascular
-arranged in single (secretes/absorbs) or multiple layers (protective)
cell adhesion molecules (CAMS)
group of transmembrane proteins that allow cells to adhere to each other
cell junctions
specialized areas of the plasma membrane that attach a cell to another cell or extracellular materials
type of cell junctions (3)
- gap
- tight
- desmosomes
gap junctions
cell to cell communication, allows the passage of small molecules and ions between cells
tight junctions
- form a band around cells whose membranes join together to form a virtually impermeable barrier to fluid
- found in bladder
desmosomes
CAMs and proteoglycans link opposing plasma membranes
2 types of desmosomes
spot and hemidesmosomes
spot desmosomes
small discs that stabilize the shape of the cell
hemidesmosomes
looks like 1/2 of a spot desmosomes and anchor cells to the basement membrane
layers of the basement membrane
- basal lamina: layer closer to the epithelium, functions as a selective
- reticular lamina: deeper portion of the basement membrane that consists of reticular fibers and ground substance
tendon vs ligaments
-tendon: cords of dense regular connective tissue that connects MUSCLE to BONE
-ligament: bundles of elastic and collagen fibers that connects BONE to BONE
shapes of epithelium cells
squamos - flat
cuboidal - square
columnar - rectangle
simple squamos epithelium function
reduces friction, controls vessel permeability, performs absorption and secretion
simple squamos epithelium location
lining of ventral body cavities
- heart, lungs
– forms serous membranes
transitional epithelium
epithelium that stretches and relaxes
goblet cells
secrete mucin/mucus
simple columnar epithelium lines the ____ and its function is ______
lines the stomach and other digestive organs
function is protection, absorption, secretion
simple cuboidal epithelium occurs as _______ and its function is _____
occurs as tubules in the kidney
function: limited protection, secretion, absorption
endothelium
epithelium that lines internal surface of heart and blood vessels
STRATIFIED squamos epithelium is found _____ and its function is to ________
- found in top layer/surface (epidermal) of skin
- to provide physical protection
this category of epithelia is found in areas exposed to abrasion and friction
STRATIFIED squamous epithelia
able to transport mucus across its surface
pseudostratified ciliated columnar epithelium
connective tissue
- most abundant body tissue
- fills internal spaces + joind sbody parts together, supports other tissues, transports material, and stores energy
2 basic elements of connective tissues
- sparse cells
- abundant extra cellular matrix (fibers + fluids)
3 major groups of connective tissues
- connective tissue proper (loose + dense)
- fluid connective (blood + lymph)
- supporting connective (cartilage + bone)
connective tissue fibers (3)
collagen fibers
reticular fibers
elastic fibers
collagen fibers
-structure
- color
- location
- extremely strong yet flexible/gives the tissue strength
- white fibers
- found in bone, cartilage, tendon, ligaments
elastic fibers
-structure
- color
- location
- strong fibers that stretch and recoil/give the tissue flexibility
- THIN yellow fibers
- found in skin, lungs, and blood vessels
reticular fibers
-structure
- location
- forms branching networks of interwoven fibers
- found in soft tissue organs like spleen and lymph nodes
loose fibrous connective tissue
fibers create loose, open framework
Fills internal spaces, cushions organs, and supports epithelia
types of loose connective tissues
- areolar
- adipose
- reticular
areolar - loose connective tissue
- function
- cells
- matrix
- cushions organs, forms a superficial layer between the skin and deeper structures and helps to loosely attach the skin to those deeper structures
- cells: fibroblast, macrophages, adipocytes
- matrix: collagen, elastic, reticular fibers
adipose - loose connective tissue
- function
-location
insulates, provides reserve fuel source for cells, and protects (absorb shock)
- found around heart
reticular - loose connective tissue
- function
- location
- packed of….
- forms framework of soft organs, binds, and filters
- found in lymph nodes, spleen, liver
- packed mostly of reticular fibers + cells
dense connective tissue proper
matrix with protein fibers tightly woven / fibers densely packed
types of dense connective tissue
- regular
- irregular
-elastic
regular dense connective tissue proper
- structure
- function
- location
- parallel tightly packed collagen fibers
- provides strength (for bi-directional pulling forces)
- found in tendons (m/b) and ligaments (b/b)
irregular dense connective tissue
- structure
- function
- location
- mostly collagen fibers arranged irregularly/no consistent pattern
- provides strength (multi directional pulling forces)
- found in dermal layer of skin
elastic dense connective tissue
- structure
- function
- locations
- matrix of elastic fibers
- allows for stretching
- found in walls of arteries and skin
fibroblasts
fixed cell that produces and maintains the extracellular matrix
macrophages
ingests dead cells
mast cells
releases histamine
cartilage
solid rubbery MATRIX/tissue made up of chondrocytes (cartilage cells) in lacunae
types of cartilage (3)
hyaline, elastic + fibrocartilage
hyaline
- matrix and function
- most abundant + weakest cartilage
- matrix: closely packed fine collagen fibers, lacks fibers in the matrix
- gives flexibility and support, shock absorber
hyaline cartilage location
long ends of bones, nose, rib ends, fetal skeleton
fibrocartilage
- strongest cartilage
- think bundles of collagen fibers that provide support and rigidity
fibrocartilage location
intervertebral discs, pubic symphysis (holds hip bone together)
elastic cartilage
- elastic fiber matrix
- supportive and flexible, while maintaining shape
- found in external ear
types of cartilage growth
interstitial: enlarges cartilage from within
appositional: add to the outer surface of cartilage
bone (osseous tissue)
- has a solid (calcified) matrix
- contains osteocyte cells in lacunae
two types of bone
- spongy (cancellous)
- compact
characteristics of bone
-matrix: mineral deposits (Ca) gives hardness + collagen gives strength
-provides support protection and storage
-where blood cells are made
- site if muscle attachment
osteon
column of bone tissue
osteoblasts
cells that function in bone growth and repair
osteoclasts
dissolves portion of bone matrix
lacuna
small space surround a cell in bone
canaliculi
nutrient channels in bone matrix
blood
- liquid matrix called plasma that contains erythrocytes (RBCs), leukocytes (WBCs) + platelets
red blood cells (erythrocytes)
carry oxygen from lungs to rest of the body
white blood cells (leukocytes)
helps fight infections
platelets
prevent and stop bleeding
lymph
interstitial fluid that enters lymphatic vessels
Name the 2 excitable connective tissues?
nerves and muscles
merocrine secretion
release their secretion through exocytosis with no harm to the glandular cell itself
holocrine secretion
produce secretions that involve the destruction of glandular cells.
apocrine secretion
produce secretions that involve the loss of cytoplasm.
mesenchymal cells
divide and differentiate to replace damaged tissue
mucous membrane
lines passageways and chambers, such as the digestive and respiratory tracts, that communicate with the body’s exterior
deep fascia
dense irregular connective tissue arranged in multiple layers in which the collagen fibers in one layer run in the same direction, while the fibers in other layers run in different directions