Epithelial Tissue

Question 1

GAPS =

Answer 1

Glands, Absorption, Protection, Secretion

Question 2

Lining in ducts secretes products of cells

Answer 2

Glands

Question 3

o the microvilli of the gut are cells that absorb nutrients

o Ex.) AA’s, carbohydrates, fats, water, vitamins, minerals

Answer 3

Absorption

Question 4

o the skin and other linings protect the underlying structures

Answer 4

Protection

Question 5

the serous membranes secrete serous fluid from both surfaces, parietal and visceral

Answer 5

Secretion

Question 6

Classification by layer

Answer 6

o Simple (single layered) or stratified (2/more layers) – always attached to membrane (basal surface), opposite is (apical surface)

Question 7

Classification by shape

Answer 7

o Squamous(thin, flattened), cuboidal(square, box-like), columnar(thick/elongated, tall/column shaped)

Question 8

♣ A single layer of flattened cells with disc-shaped nuclei and sparse cytoplasm
♣ Present in the tubes
• Ex.) kidney glomeruli, blood vessels, lymphatic vessels
• Called endothelium
♣ Present in linings
♣ Lungs - alveoli, capillaries
♣ Heart and lungs outer surface – the serosa
o Functions
♣ Diffusion and filtration
♣ Provide a slick, friction-reducing lining lymphatic and cardiovascular systems

Answer 8

Simple Squamous

Question 9

o Thick membrane composed of several layers of cells
o Linings of the esophagus, mouth, rectum, anus, and vagina (non-keratinized cells)
o The external part of the skin’s epidermis (keratinized cells)
♣ Keratin is tough protein – provides protection, waterproofing
♣ Mitosis occurs in basal layer, adjacent to basement membrane

Answer 9

Stratified Squamous

Question 10

o Single layer of cube-like cells with large, spherical central nuclei
o Present in kidney tubules, ducts and secretory portions of small glands (pancreas, thyroid), the retina, and surface of the ovary
o Function in secretion and absorption

Answer 10

Simple Cuboidal

Question 11

o Contains cells that are flattened and cells that are cuboidal – hence “transitional”
o Found in urinary bladder, and start of ureters in renal calyx
o Allows stretching and thinning without leaking (urine is kept inside)

Answer 11

Transitional Epithelium

Question 12

o Single layer of tall cells with oval nuclei; many contain cilia
o Goblet cells are often found in this layer – produce mucous
o Function in absorption and secretion
o Non-ciliated type
♣ Line digestive tract (with many microvilli covering the surface) and gallbladder
o Ciliated type
♣ Line small bronchi, uterine (fallopian) tubes, and some regions of the uterus
♣ Cilia help move substances through internal passageways

Answer 12

Simple Columnar

Question 13

o PSCC = Pseudostratified Ciliated Columnar Epithelium
o Present in the male sperm – carrying ducts (non-ciliated) and respiratory system
♣ Nasal cavity, larynx, trachea, and bronchi
♣ Cilia propel debris (in mucus) to pharynx, then swallowed or expectorated
o Single layer of cells with different heights; some do not reach the free surface
o Nuclei are seen at different layers

Answer 13

Pseudostratified Columnar (PSCC) = Pseudostratified Ciliated Columnar Epithelium
(pseudo = false)