Tissues Flashcards
What are the two components of tissue?
cells and extracellular matrix
Epithelial tissue
covers surfaces and lines cavities
Function of epithelial tissue
protection
What can epithelial tissue form?
glands
Gland’s function
secretion
What are the characteristics of epithelial tissue?
- tightly packed cells (little ECM)
- polar (has distinct opposite sides)
- avascular
- extensive innervation (to detect stimuli)
- high regeneration capacity (rich in stem cells)
What components make up the structure of epithelial tissue?
apical surface, lateral surface, basal surface, and basement membrane
Apical surfaces can sometimes carry what?
projections
What are the kinds of projection attached to the apical surface of epithelial tissue?
microvilli and cilia
Microvilli
membrane folds that increase surface area
Cilia
hair-like structures for movement
Lateral surface
contains intercellular junctions
Basal surface
bound to the basement membrane
Basement membrane
supportive layer rich in collagen and other fibers
How is epithelial tissue layered from top to bottom?
- apical surface
- lateral surface
- basal surface
- basement membrane
- connective tissue
Avascular
a lack of blood vessels
Extensive innervation
abundant in nerves
Stem cells
stem cells divide to form more cells called daughter cells.
What does “apical” mean?
top
What does “lateral” mean?
side
How is epithelial tissue classified?
two-part name consisting of:
- number of strata
- cell shape
What does “strata” mean?
layer
What are the types of epithelial strata?
simple, stratified, and pseudostratified
Simple ET
- one layer
Stratified ET
- more than one layer
Pseudostratified ET
fake layered; one layer that looks like more than one
Simple ET function
transport
Stratified ET function
withstand stress
What are the types of epithelial cell shapes?
squamous, cuboidal, columnar, and transitional
Transitional
changes shape in response to stretching
What type of epithelium is transitional epithelial tissue?
stratified
What are the two types of glands?
endocrine and exocrine
Endocrine glands
secrete hormones into the blood
Exocrine glands
glands that secrete substances on to an epithelial surface by means of a duct
How are exocrine glands classified?
by method of secretion
What are the three types of exocrine glands?
merocrine, apocrine, and holocrine
Merocrine
package their secretions into secretory vesicles and release the secretions by exocytosis
What are examples of merocrine glands?
tear glands, sweat glands, salivary glands, etc.
Apocrine glands
produces secretion by/when pinching off of the apical surface of the cell
What are examples of apocrine glands?
mammary glands
Holocrine
secretion is produced by the destruction of the cell; the disintegrating cells become the secretion
What are examples of holocrine glands?
oil-producing glands
What are the components of connective tissue?
cells (dispersed) and extracellular matrix (a lot)
What are two major components of the ECM in connective tissue?
ground substance and protein fibers
Ground substance
holds the connective tissue components
What are the types of protein fibers?
collagen, reticular and elastic
Collagen fibers
thick and strong
Reticular fibers
thin, branching net/networks
Elastic fibers
thin wavy fibers that stretch and recoil easily
Fibroblast CT
produce fiber and ground substance of ECM
Mesenchymal CT
embryonic stem cell that divide to replace damaged cells
Fixed macrophages CT
ear damaged cells or pathogens (immune cells)
Adipocyte CT
store fat
Adipocyte function
long term energy storage
What does -“cyte” mean?
cell/mature cell
What is the origin of connective tissue?
mesenchyme (embryonic CT)
What are the three classifications of CT?
- connective tissue proper - supporting connective tissue
- fluid connective tissue
What are the two types of CT proper?
loose and dense
Loose CT
less fibers, more ground space
Dense CT
more fibers, less ground space
What are the types of loose CT?
areolar, reticular, and adipose
What are the types of dense CT?
elastic, regular, and irregular
Areolar CT
“airy”
Reticular CT
“net/network”
Adipose CT
“fat bubbles”
Elastic CT
“wavy”
Regular CT
all going in the same direction
Irregular CT
randomly arranged; in different directions
What are the two types of supporting CT?
cartilage and bone
Cartilage
semisolid rubbery matrix with chondrocytes
Bone
solid hard matrix with osteocytes
What is responsible for bones hardness?
CA2+/calcium
What are the types of cartilage CT?
hyaline, fibrocartilage, and elastic
Hyaline
“glassy”
Fibrocartilage
thick and moving in the same directions
Elastic
“branching network”
What are the types of bone CT?
compact and spongy
What are the two types of fluid CT?
blood and lymph
Blood
fluid matrix, called plasma with suspended:
- erythrocytes
- leukocytes
- thrombocytes
Lymph
fluid matrix with very few cells, and mostly leukocytes
What are the structures suspended in blood?
erythrocytes, leukocytes, and thrombocytes
Erythrocytes
red blood cells
Leukocytes
white blood cells
Thrombocytes
platelets
Lacunae
the small cavity containing an osteocyte in bone, or a chondrocyte in cartilage
Muscle tissue function
contraction (movement)
What are the types of muscle tissue?
skeletal m., cardiac m., and smooth tissue
Where is smooth muscular tissue found?
lining the walls of internal organs
Nervous tissue function
signaling (communication)
What are the two types of nervous tissue?
neurons and glial cells
Neurons function
signaling
Glial function
support
