Endocrinology Chapter 1 Part 1

Question 1

Fx of endocrine system

Answer 1

Compliments and augments the function of the central nervous system in response to internal and external stimuli

Question 2

why are endocrine responses slower than neural effects? (3)

Answer 2

1. Hormones are released from specific endocrine cells
2. Hormones must cross extracellular space + capillary wall –> blood –> transport to target tissue
3. Horses cross capillary wall + intercellular space again to reach target tissue

Question 3

why is the ‘endocrine system’ different to other body systems?

Answer 3

made of organs that are positioned throughout the body

Question 4

what is an endocrine organ?

Answer 4

tissue that secretes a hormone directly into a vascular system

Question 5

what is considered a hormone?

Answer 5

any secretory substance that has a regulatory function

Question 6

local hormones vs general hormones

Answer 6

L = specific local effect
G = others

Question 7

describe local hormones

Answer 7

1. travel short distance
2. usually only small amount in general circulation
   eg gastrin of GI (pancreas area only)

Question 8

Describe general hormones

Answer 8

• secreted by specific endocrine glands

Question 9

epinephrine and norepinephrine

• release Lx
• Fx

Answer 9

RLx = adrenal medulla 
Fx = Sympathetic

Question 10

Testosterone
RLx
Ax

Answer 10

RLx = Leydig cell
Ax = testies, epididymis, penis, prostate, and other accessory glands, brain, hair, skin and muscles.

Question 11

target tissues

Answer 11

the only tissue which have the specific receptors to bind to a specific hormone.

eg adrenocorticotrophin from the anterior pituitary (adenohypophysis) specifically stimulates the adrenal cortex, causing secretion of the adrenocortical hormones.

Question 12

how are hormones transported usually? Why?

Answer 12

in blood
bound to carrier molecules (usually proteins)
protecting the hormone from premature degradation or protect the organism from over exposure to high concentrations of ‘free’ hormone

Question 13

list the four basic types of hormone

Answer 13

1. steroid hormones
2. Protein, polypeptide and amino acid hormones
3. Hormones with the amino acid tyrosine
4. hormones consisting of several unique fatty acid having hormone- like properties

Question 14

Explain steroid hormones

Answer 14

• structure = similar to cholesterol (most times a derived from cholesterol)
• neutral lipid characteristics
• secreted by steroid-secreting cells

Question 15

characteristic of the steroid-secreting cell

Answer 15

• neutral lipid characteristics
• pale or vacuolated cytoplasm
• lipid precursors of steroid synthesis are able to be shown by lipid stains
• large mitochondria (contain enzymes for steroidogenesis
• abundant smooth ER (for lipid biosynthesis and intracellular transport

Question 16

Steroid hormones are secreted by:

Answer 16

a) the adrenal cortex (cortisol and aldosterone)
b) the ovaries (oestrogen and progesterone)
c) the testes (testosterone)
d) the placenta (oestrogen and progesterone)

Question 17

Protein, polypeptide and amino acid hormones

Answer 17

Hormones which are either proteins, peptides or derivatives of these

Question 18

where are protein hormones secreted

Answer 18

and modified
–> peptides, polypeptides, proteins, glycoproteins, halogenated peptides, indolamines and catecholamines

characteristics

• dense staining cytoplasm (secretory granules and/or ribosomes)
• well developed rER
• mitochondria
• lysosomes

Question 19

Hormones which are either proteins, peptides or derivatives of these: (2)

Answer 19

peptides containing eight amino acids

• posterior pituitary hormones
• antidiuretic hormone
• oxytocin

large peptides

• insulin
• glucagon
• parathormone (controls calcium levels in blood)

Question 20

list the hormones with amino acid tyrosine

Answer 20

a) Thyroid hormones (thyroxine and triiodothyronine)

b) Adrenal medulla (epinehprine and norepinephrine).

Question 21

4. Hormones consisting of several unique fatty acids having hormone-like properties

Answer 21

prostaglandins.

Question 22

list 5 characteristics of endocrine organs

Answer 22

a) secretory cells of epithelial origin
b) absence of drainage ducts
c) sparse supporting framework
d) generous vascularity
e) intimate association with blood vascular or other transport mechanism

Question 23

List the three types of endocrine organs that may be recognised

Answer 23

1. Discrete organs of a primary endocrine nature
2. Organs that combine major endocrine with other important related functions
3. Organs with a quite different primary function but which include an unobtrusive endocrine component

Question 24

list the 5 discrete endocrine organs

Answer 24

a) hypophysis
b) epiphysis
c) thyroid
d) parathyroid
e) adrenal glands

Question 25

list the 4 organs that combine important related fx with major endocrine componet

Answer 25

a) pancreas b) testes

c) ovaries d) placenta

Question 26

List the two organs whose primary fx is quite different, with an unobtrusive endocrine component

Answer 26

1. kidneys

2. GI tract`

Question 27

dividing endocrine glands by morphology 4 ways

Answer 27

1. follicular endocrine glands (completely enclosed small sacs, containing fluid)
   - eg thyroid gland
2. cell masses or cords
   - eg. pituitary, intertubular tissue of testis
3. solitary endocrine cells
   - eg. mucous membrane or digestive tract
4. Neuronic endocrine cells
   - eg. hypothalamus, pineal

Question 28

list 4 general fx of hormones

Answer 28

1. Reproduction
2. Growth and development
3. Maintainance of internal
   environment
4. Energy production,
   utilization and storage.