BLG 101 Chapter 4
Tissues - answerGroups of cells that are similar in structure that can perform common
or relates function
Histology - answerstudy of tissues
epithelial tissue - answeris a sheet of cells that covers a body surface or lines a body
cavity
- covering and lining epithelia
- on external and internal surfaces (skin)
- Glandular Epithelia
- Secretory tissue in glands
main functions- protection, absorption, filtration, excretion, secretion and sensory
receptors
Distinguishing Characteristics epithelial tissue
(Conner rolled as Paul squealed) - answer1. polarity
2. specialized contacts
3. supported by connective tissues
4. avascular but innervated
5. Regeneration
Polarity
-apical surface
- basal surface - answer- cells have polarity
Apical Surface- upper free side, is exposed to surface or cavity (mircovilli)
Basal Surface- lower attached side, faces inward toward body
specialized contacts - answer- epithelial tissue need to fit closely together
- specialized contact points bind adjecents epithelial cells together
-tight junctions
-desmosomes
Cells are very close together
Supported by connective tissue - answerall epithelial sheets are supported by
connective tissue
- basement membrane
, - made up of basal and reticular lamina
-reinforces epithelial sheet
-resists to stretching and tearing
-defines epithelial boundary
- gives it strength
Avascular but innervated - answerNo blood vessels are found in epithelial tissue
Must be nourished by diffusion from underlying connective tissues
Epithelia are supplied by nerve fibres
-O2 and nutrients
-connective tissue is feeding epithelia
Regerneration - answer- epithelial cells have high regenerative capacities
- stimulates by loss of apical-basal polarity and broken lateral contacts
- some cells are exposed to friction, some to hostile substances, resulting in damage so
must be replaced
- our skin heals fast, fast cell cycle
Simple Epithelia - answerone layer of cells
involved in absorption, secretion or filtration processes
Stratified epithelia - answermultiple layers thick for protection
Squamous - answerflat scale like
Cuboidal - answerbox-like, cube
Columar - answertall, column-like
simple squamous epithelium - answer- function where rapid diffusion is a priority
-cells are flatted laterally, and cytoplasm is sparse
-endothelium: lining the lymphatic vessels, blood vessel and heart
- mesothelium: serous membranes in the ventral body cavity
simple cuboidal epithelium - answer-single layer of cells
-secretion and absorption (carry urine)
they look like potato
simple columnar epithelium - answer- Made up of a single layer of tall cells that fit
closely together
-Function: absorption, secretion of mucus, enzymes and other substances
-found in the digestive tract
Pseudosratified columnar epithelium - answer-single layer of cells with different heights
- secrete substances, particularly mucus
- they are all connects
Tissues - answerGroups of cells that are similar in structure that can perform common
or relates function
Histology - answerstudy of tissues
epithelial tissue - answeris a sheet of cells that covers a body surface or lines a body
cavity
- covering and lining epithelia
- on external and internal surfaces (skin)
- Glandular Epithelia
- Secretory tissue in glands
main functions- protection, absorption, filtration, excretion, secretion and sensory
receptors
Distinguishing Characteristics epithelial tissue
(Conner rolled as Paul squealed) - answer1. polarity
2. specialized contacts
3. supported by connective tissues
4. avascular but innervated
5. Regeneration
Polarity
-apical surface
- basal surface - answer- cells have polarity
Apical Surface- upper free side, is exposed to surface or cavity (mircovilli)
Basal Surface- lower attached side, faces inward toward body
specialized contacts - answer- epithelial tissue need to fit closely together
- specialized contact points bind adjecents epithelial cells together
-tight junctions
-desmosomes
Cells are very close together
Supported by connective tissue - answerall epithelial sheets are supported by
connective tissue
- basement membrane
, - made up of basal and reticular lamina
-reinforces epithelial sheet
-resists to stretching and tearing
-defines epithelial boundary
- gives it strength
Avascular but innervated - answerNo blood vessels are found in epithelial tissue
Must be nourished by diffusion from underlying connective tissues
Epithelia are supplied by nerve fibres
-O2 and nutrients
-connective tissue is feeding epithelia
Regerneration - answer- epithelial cells have high regenerative capacities
- stimulates by loss of apical-basal polarity and broken lateral contacts
- some cells are exposed to friction, some to hostile substances, resulting in damage so
must be replaced
- our skin heals fast, fast cell cycle
Simple Epithelia - answerone layer of cells
involved in absorption, secretion or filtration processes
Stratified epithelia - answermultiple layers thick for protection
Squamous - answerflat scale like
Cuboidal - answerbox-like, cube
Columar - answertall, column-like
simple squamous epithelium - answer- function where rapid diffusion is a priority
-cells are flatted laterally, and cytoplasm is sparse
-endothelium: lining the lymphatic vessels, blood vessel and heart
- mesothelium: serous membranes in the ventral body cavity
simple cuboidal epithelium - answer-single layer of cells
-secretion and absorption (carry urine)
they look like potato
simple columnar epithelium - answer- Made up of a single layer of tall cells that fit
closely together
-Function: absorption, secretion of mucus, enzymes and other substances
-found in the digestive tract
Pseudosratified columnar epithelium - answer-single layer of cells with different heights
- secrete substances, particularly mucus
- they are all connects
