histo- b1 (foundation)

Question 1

2 classifications of glands

Answer 1

endocrine: release their products into the bloodstream
- done later in 2nd year

exocrine: release their products onto an epithelial surface (either directly or through a duct)

Question 2

3 further classifications of exocrine glands + examples in each

Answer 2

1. On basis of morphology of duct & secretory portion
   - simple & compound glands
2. Nature of secretory product
   - mucous, serious, mixed
3. Mode of secretion
   - holocrine, apocrine, merocrine/ecrine

Question 3

classification of exocrine glands: morphology of duct & secretory portion

Answer 3

simple (can be straight or branched) & compound glands (branched duct system) → simple glands further divided into simple tubular, simple acing (alveolar), simple branched acinar

compounds glands further divided into → compound tubular, compound acing, compound tubuloacinar glands

Question 4

simple glands + further classifications & examples

Answer 4

simple glands: have unbranched ducts
(its all one duct that can have multiple branches but not multiple ducts)

further classifications
simple tubular glands: can be
- straight (ex. intestinal glands)
- branched (ex. principal glands of stomach & endometrial glands of uterus)
- coiled (ex. sweat glands*)

simple acinar (alveolar) glands: have sac-like secrecy portion & not very common in the body
- ex. urethral glands in penile part of urethra

simple branched acinar gland: ex. sebaceous gland of skin

Question 5

compound glands + further classifications & examples

Answer 5

have a branched duct system, classified on shape of their secretory units

compound tubular glands: secretory portions are tube like
- brunner glands of duodenum

compound acinar glands: secretory portion is sac like
- exocrine pancreas

compound tubuloacinar glands: both tubular & acinar secretory units
- submandibular salivary gland

Question 6

nature of secretory product classifications + examples

Answer 6

mainly applies to merocrine glands

mucous glands: secrete mucus
- ex. pyloric glands of stomach

serous glands: secrete watery, enzyme rich fluid
- ex. parotid gland

mixed glands: contain both mucous & serous acini
- sublingual & submandibular salivary glands

these are the ones you need to be able to differentiate under the microscope

Question 7

classification on mode of secretion, further classifications + examples

Answer 7

holocrine glands: entire secretory cell is destroyed & becomes part of secretion
- only ex. in body are the sebaceous glands

apocrine glands: portion of apical cytoplasm containing secretory product is pinched off
- special sweat glands of axilla & perineal region

merocrine/ecrine glands: secretory product released via exocytosis or without any loss of cytoplasm
- ex. salivary, lacrimal, intestinal glands

Question 8

3 specializations of the apical cell surface UQ

Answer 8

apical cell surface = outermost surface of a cell

1. Microvilli: plasma membrane covered cytoplasmic extensions that can only be seen with electron microscope
   - form striated border when they’re densely packed (like striated border in intestines or brush border in kidneys)
   - function: increase surface area of the cell in correlation with an absorptive function
2. Sterocilia
3. Cilia (*these 2 discussed separately)

Question 9

Stereocilia UQ

Answer 9

thin, hair like structures that appear to resemble cilia but are incapable of movement

present in: epithelial lining of duct of epididymis and vas deferens, on neuroepithelial cells of the inner ear

function: in epidydimis & vas deferens = increases mucosal surface area to facilitate reabsorption of the fluid that leaves the testes

• in ear = function in nerve signal generation (completely diff function)