Glands

Question 1

Glands can be classified based on

Answer 1

# of cells in a gland 
relationship to the surface lining and surrounding tissues

Question 2

Describe the difference between unicellular and multicellular glands

Answer 2

unicellular
-specialized cells scattered throughout an epithelium
-goblet cells–> respiratory, digestive, urinary tract
Multicellular
-composed of more than one cell
-varying degrees of complexity

Question 3

Exocrine glands secrete product?

Answer 3

directly onto a surface or through epithelial ducts that are connected to the surface (gut lumen, skin surface)

Question 4

Describe characteristics of endocrine glands in mammals

Answer 4

-ductless gland system
-high vascularity allows for increased blood flow
-functionally related to nervous system
-

Question 5

Compare the endocrine and nervous system in terms of:

specificity, speed and response time

Answer 5

E= broad, slower, prolonged response
N= specific, fast, short response

Question 6

Describe the different arrangements of the endocrine gland

Answer 6

follicles- thyroid
cords- adrenal
nests or clumps - parathyroid

Question 7

The pituitary gland develops from which two structures

Answer 7

Rathke’s pouch- ectodermal evagination of the developing guy (oropharynx)
Neuroectodermal downgrowth of the diencephalon

Question 8

What is the cleft in the pituitary gland called?

Answer 8

hypophyseal cleft

Question 9

What are the 3 areas within the adenophysis (endocrine control)

Answer 9

Par distalis
pars intermedia
-adjacent to neurophysis 
pars tuberalis 
-adjacent/surrounding infundibular stalk

Question 10

What is the infundibular stalk?

Answer 10

reminent from down growth during production

Question 11

What is the hypothalamohypophseal tract?

Answer 11

will see nerve processes within the infundibular stalk that are neurons from the hypothalamus

Question 12

How does communication between hypothalamus and anterior pituitary work?

Answer 12

Parvocellular neurons
-neurosecretory cells secrete trophic hormones (releasing factors/hormones) into the hypophyseal portal system of adenohypophysis

Question 13

Pars distalis

Answer 13

distal part of anterior lobe

• major portion of adenophypohysis
• cells arranged into cords/clusters
• Many capillaries and sinusoids

Question 14

Chromophiles

Answer 14

like stain

acidophils- red/pink
-pink colour= acidophils produce peptide hormones

Basophils -blue/purple
-glycoproteins produced by these cells that’s why cytoplasm looks purple

Question 15

Chromophobes

Answer 15

we hate stain

Question 16

Functional cell types identified with PAS-OG

Answer 16

Acidophils

• somatotroph- secrete growth hormone
  - medium, oval/angular, orange cytoplasm prominent nucleoli
• mammotroph- secrete prolactin
  - large, polygonal/angular, purple-pink cytoplasm

Basophils

• gonadotrophs– secrete FSH and LH
  - large, round, granular deep purple black cytoplasm
• thyrotrophs
  - small,angular, oval nucleus, very dense deep purple-black

Question 17

Pars intermedia

Answer 17

• narrow band
• close association with pars nervosa
• hypophyseal cleft separates from pars distalis
• basophilic cells arranged in layers
• most are melanotrophs- melanocyte stimulating hormone

Question 18

Pars tuberalis

Answer 18

• collar around infundibular stalk
• basophillic cells are arranged in clusters/rosettes
• many veins/venules
• gonadotrophs

Question 19

Magnocellular neurons

Answer 19

• peptidergic neurosecretory cells
• terminate within neurohypophysis–> herring body
• ADH, oxytocin

Question 20

Pars nervosa

Answer 20

zones of the infundibular stalk
herring bodies
pituicytes (glial cells of pituitary)

Question 21

Is it easier or harder to see a herring with H&E?

Answer 21

difficult to see herring body

-easier to see with trichome

Question 22

Thyroid and parathyroid

Answer 22

Bi-lobed in most mammalian species
In general, lobes are connected by the isthmus (also glandular)
Function is essential to normal growth and development

Question 23

What is the functional unit of the thyroid?

Answer 23

Follicle

Question 24

What structure of the thyroid can be very thick in ruminants

Answer 24

CT capsule with trabeculae and septa

Question 25

Follicular cells within the thyroid are

Answer 25

- epithelial cells that form the follicles - simple cuboidal secretory cells - microvilli on apical surface (hard to see) - lumen of the follicle filled with colloidal substance (T3 and T4) - homogenous eosinophillic material - may see vacuoles

Question 26

Parathyroid gland

Answer 26

``` embedded in the thyroid Capsule surrounds the parathyroid -extends within the parathyroid to form trabeculae/septa (white arrows) -dense irregular CT -highly vascularized Chief cells (principal cells) -compose majority of the parathyroid -deeply basophilic and uniform cuboidal secretory cells -parathyroid hormone (PTH) ```

Question 27

Oxyphils are common in?

Answer 27

humans, horses, large ruminants | -no known secretory role

Question 28

What are the 2 regions of the adrenal gland

Answer 28

cortex and medulla | -the adrenal glands are encapsulated by CT

Question 29

Function of the cortex

Answer 29

steroids - mineralocorticoids- zona glomerulus - aldosterone - glucocorticoids- zona fasiculata- cortisol - Zona reticularis- sex hormones estrogen and androgen

Question 30

Function of the medulla

Answer 30

catecholamines - epinephrine (adrenalin) - norepinephrine (noradrenalin)

Question 31

Zona glomerulosa/arcuata

Answer 31

first layer under the capsule species difference in cell arrangement -glomerulosa- ruminants, pig (clusters or cords with glomerular appearance) -arcuata- horses, dog (columnar cells arranged in arches) Zona intermedia -prominent in horses, ruminants -transitional zone to undifferentiated cells between z.glomerulosa and z.fasiculata

Question 32

Zona fasiculata

Answer 32

- most extensive - spongiocytes - may appear vacuolated - cuboidal or polyhedral in shape - arranged in regular rows/cords - cords radiate away from medulla

Question 33

Zona reticularis

Answer 33

- innermost layer adjacent to the medulla - cells are smaller and arranged in interlacing anastomising cords - may see sinusoids

Question 34

Medulla H&E

Answer 34

cells in groups, cords stellate with round nucleus faint basophilic cytoplasm

Question 35

Chromaffin reaction in the medulla

Answer 35

K2Cr2O7- potassium dichromate oxidizes catecholamines- brown call chromaffin cells