Ch 4 Epithelium Flashcards
An avascular tissue lining exterior body surfaces and internal cavities. ex: skin (35 cards)
1
Q
Simple Squamous
A
- -Vascular system-Exchange, barrier sys in CNS
- Bowman’s capsule-Exchange,lubrication,-
- Lung spaces-Barrier
- Body cavities-Exchange
2
Q
Simple Cuboidal
A
- Small ducts of exocrine gland-Absorption, conduit
- Surface of ovary: Barrier
- Kidney tubules: Absorption,secretory
3
Q
Simple columnar
A
- Small intestine and colon: absorption, secretion
- Stomach lining and gastric glands; secretion
- Gallbladder: absorption
4
Q
Pseduostratified
A
- Trachea/bronchial tree:secretion,conduit
- ductus deferens: same
- efferent ductules of epididymis: absorption, conduit
5
Q
stratified squamous
A
- epidermis: barrier, protection
- oral cavity/esophagus-same
- vagina-same
6
Q
stratified cuboidal
A
- sweat gland ducts; barrier conduit
- large ducts of excocrine glands: same
- anorectal junction: same
7
Q
stratified columnar
A
- largest ducts of exocrine glands: barrier, conduit
- anorectal junction
8
Q
transitional (urothelium)
A
Renal calyces
Ureters
Bladder
Urethra-Barrier,distensible property
9
Q
What are 3 types of junction?
A
- Tight junctions (Zone occludens, facia occludens)
- Adhering, Anchoring junction: Zonula Adherens, Hemidesmosomes, desmosomes
- Gap junction
10
Q
Give Epithelium functions
A
- secretion
- absorption
- transport
- protection
- receptor function
11
Q
Types of multicellular glands
A
- Simple tubular:large intestine,
- Simple coiled tubular: Skin, sweat glands
- Simple branched tubular: Stomach, pylorus, mucous secreting
- Simple acinar: urethra
- Compound tubular: duodenum
- Compound acinar: pancreas, excretory portion
- Compound tubuloacinar: Submandibular salivary gland
12
Q
Give 3 basic release mechanisms
A
- Merocrine-to apical, vesicle fusion (pancreatic cells). excocytocis
- Apocrine: w/ cytoplasm/plasma memb surrounding vesicle (Lactating mammary gland). “Pinching off” of cytoplasm
- Holocrine: programmed cell death releases product (sebaceous glands in skin). bulk release of whole cells.
13
Q
What does epithelium derive from?
A
- ectoderm- skin
- endoderm - digestive tract
- mesoderm - serous linings of body cavities
- mesothelium
- lining of circulatory system
14
Q
Ex of simple squamous
A
pulmonary alveoli, parietal layer of Bowman’s capsule, thin segments of Henle’s loop in kidney, rete testis, inner ear, endothelium of blood and lymph vessels
15
Q
ex of simple cuboidal
A
-follicles of thyroid, surface of ovary, choroids plexus, capsule of lens, pigment epithelium of retina, ducts of glands
16
Q
ex of simple columnar:
-ciliated
A
- epithelium of digestive tract, large excretory ducts of some glands
- uterus, oviducts, pulmonary bronchi, paranasal sinuses, central canal of spinal cord
17
Q
ex of stratified squamous:
-keratinized
A
- skin, lining of oral cavity, epiglottis, esophagus, conjunctive and cornea, vagina, distal portion of urethra
- dry scales, exposed surfaces, lose nucleas,
18
Q
ex stratified columnar epithelium:
-ciliated
A
- fornix of conjunctiva, cavernous urethra, pharynx, small areas of anal mucous membranes, large excretory ducts of salivary glands
- nasal surface of soft palate, larynx, fetal esophagusu
19
Q
ex of pseudostratified:
-ciliated
A
- male urethra, excretory duct of parotid gland
- trachea, primary bronchii, auditory tubes, part of tympanic membrane, lacrimal sac
20
Q
ex of transitional (uroepithelium)
A
-urinary bladder:
empty-many layers, distended-2 layers
-urinary tract-renal calyxes of urethra
21
Q
Tight of occluding junctions:
- zonula occludens
- fascia occludens
A
-partitioning function of connecting ridges that occlude intercellular space; selective seal
- continuous belt-like, made up of integral membrane proteins, selective diffusion barrier
- actin filaments
- occludens
- actin filaments
-interrupted tight junctions, strip or band-shaped ex endothelial cells of blood vessels
-
22
Q
Adhering or Anchoring junctions:
- Zonula adherens or adhesion belt
- Macula adherens or Desmosomes
- Gap Junctions
A
- -below zonula occludens
- “terminal bars together with occludens
- slight e- dense material contain adhesion domains of cell membrane glycoproteins
- major site of anchorage of microfilaments
- lateral adhesion
- cadherin-catehin complex + vinculin & alpha-actinin -> actin filaments
- calcium-dependent
- -circular and spot-like
- separate plaques arranged in row
- convergence of intermediate filaments by attachment plaques
- transmembrane linker glycoproteins bind adj identical molecules of neighboring cell-strong cell-to-cell adhesion (cahedrin zipper)
- wider intercellular space
- Hemidesmosomes: half of desmo, anchor keratin-containing filaments to underlying basement membrane
- permits passage of ions and small molecules to diffuse freely between cells
- reduce resistance to passage of electric current
- 2 Connexons in each channel- hexonally packed annular units, cylindrical, dumbbell-shaped, made of 6 connexins
23
Q
Lateral Interdigitating
A
increase surface area, engaged in fluid and electrolyte transport
24
Q
Basement membrane
- define
- consists of
- zones
- function
-structures for attachment to connective tiss
A
- thin supporting layer bet epithelium and underlying connective tissue
- type IV collagen, laminin, proteoglycans, entactin & fibronectin
- lamina lucida and densa
- lamina propria-the connective tiss layer of mucous membrane.
- support epithelium, passive molecular sieve or ultrafilter, repair tissue, compartmentalization
- reticular fibers underlies basal lamina
- Anchoring fibrils, fibrilin microfibrils, discrete projects of the lamina dense
25
Classifying Exocrine glands
1. Duct arrangement:
- Simple-unbranched
- Compound-branched
2. Shape of Secretory units:
- tubular
- alveolar or acinar
- tubuloalveolar
- saccular
3. Type of secretion
- Serous
- Mucous
- Mixed: (bulk-mucous glands, serous demilunes)
4. Secretory Mechanism
- merocrine
- holocrine
- apopcrine
26
Simple Exocrine Glands
- Simple tubular: straight tubules, (-) duc,
- Simple coiled tubular: Coiled:
- Simple branched tubular: bifurcate w/ short
- Simple acinar: bulbous or bottle-shaped
27
Compound Exocrine Glands
- Compound tubular: Tubules more or less coiled
- Compound acinar: bulbous, pear-shaped terminals
- Compound tubuloacinar: short tubules, have a number of acini along their sides and blind end
28
Example of Unicellular glands
Goblet cells, surface lining, glands of intestines, and respiratory tract
29
Derivatives of Ectoderm
1. Surface
- epidermis, hair, nails, cutaneous, mammary glands
- ant pit glands
- enamel of teeth
- internal ear
- corneal epithelium, lens of eye
2. Neuroectoderm
- neural crest: cranial/sensory gang & nerves, adrenal medulla, melanocytes, pharyngeal arch cartilages, head mesenchyme, Schwann cells
- neural tube: CNS, retina, pineal body, post pit gland
30
Mesoderm derivatives
- muscles of trunk and skeleton except skull
- dermis of skin
- connective tissue
- skull, dentin
Epithelium
- urogenital system including gonads, ducts, and accessory glands
- connective tissue and muscle of viscera and limbs
Mesothelium
-serous membranes of pleura, pericardium, peritoneum
Endothelium
- blood and lymph cells
- cardiovascular and lymphatic systems
- spleen
31
Derivatives of Endoderm
Respiratory
- trachea
- bronchi
- lungs
Alimentary canal
-GI tract
Extramural digestive gland
- liver
- pancreas
- urachus
- pharynx
-thyroid gland
Auditory tubes
- tympanic cavity
- pharyngotympanic tube
- tonsils
- parathyroid glands
32
Microvili Free surface
(striated border-more highly ordered/uniform-intestines
or brush border-kidney)
-slender, finger-like, cylindrical membrane bound cell processes.
-core of actin filaments in association w/ myosin I, that binds them to plasma memb of microvillus.
-anchored to vilin tip
-supported by Terminal Web underneath, made of spectrin, myosin II, tropomyosin for contractile ability.
-cross-linking bundle of 25-35 actin filaments of
proteins fascin and fimbrin
* 1-2 um long, 80-90 nm diameter
* glycocalyx-delicate branching filaments along luminal surface; terminal oligosaccharides of integral membrane proteins
* increase digestive and absorptive effieciency of epithelium
33
Stereocilia Free Surface
- tuft of long, slender processes
- nonmotile
- core bundles of actin microfilament, cross-linked by fimbrin.
- anchors to plasma membrane of stereocilia by erzin
- stem cross-bridging of alpha-actinin
- Function: -limited to epididymis, absorption
- ear hair cells, sensory
34
Kinocilia/Cillia Free surface
-specialized for transport of fluid or mucus along epithelial surfaces
-axoneme-core complex of longitudinal microtubules
-center: 2 single microtubules
-periphery: 9 doublet microtubules
(in one doublet, cilary dynein is attached on A-microtubule then connects to B-microtubule of adjacent doublet, then bound by nexin-uses ATP)
-base: basal body of nine short microtubule triplets
-7-10 um length, 0.2 cm diameter
35
Flagella Free Surface
- similar to cilia
| - 15-200 um
