Endocrine System

Question 1

What is the classical definition of a hormone?

Answer 1

chemical substances produced by ductless glands and secreted into the blood supply to affect a tissue distant from the gland.
*now understood that hormones can be produced by single cells as well

Question 2

What is Epicrine signaling?

Answer 2

Hormones pass through gap junctions of adjacent cells without entering extracellular fluid

Question 3

what is neurocrine signaling?

Answer 3

hormones pass through synaptic clefts between neurons as do neurotransmitters; hormones can also be synthesized in a neuron and secreted directly into the blood from the axon (ex: oxytocin)

Question 4

What is paracrine signaling?

Answer 4

hormones diffuse through interstitial fluid(ex: prostaglandins)

Question 5

What is endocrine signaling?

Answer 5

hormones are delivered via the bloodstream (ex: growth hormone)

Question 6

what is exocrine signaling?

Answer 6

chemical substance is secreted to exterior of the body (ex: pheromones) or into the digestive tract (ex: somatostatin)

Question 7

What is Autocrine signaling?

Answer 7

when a cell is producing a hormone that is meant to affect that cell; the cell that it is producing (itself)

Question 8

What’s the difference between a Neurohormone and a Neurotransmitter?

Answer 8

a NT is meant to effect the next nerve cell in the chain; a NH is meant to effect cell types not part of the nervous system and often times are being secreted directly into the blood or put into organs/tissues that may be distant.

Question 9

What is interstitial fluid?

Answer 9

fluid between the cells, not to be confused with extracellular fluid, similar to plasma (no blood or urine)

Question 10

Describe amines

Answer 10

derived from amino acid tyrosine; includes things like thyroid hormones and adrenal cateocholamines

Question 11

Describe peptides

Answer 11

derived from peptides, polypeptides & proteins

Question 12

Describe steroids

Answer 12

derived from cholesterol; includes things like estradiol, testosterone, cortisol, and progesterone

Question 13

describe prostaglandins

Answer 13

derived from arachidonic acid; includes things like PGF2

Question 14

Where is the hypothalamus located and what borders it?

Answer 14

at the base of the brain; bordered by the optic chiasma, mammillary bodies, thalamus, and sphenoid bone

Question 15

how much does the hypothalamus weigh?

Answer 15

5-10 g in humans (1/300th of the total brain weight)

Question 16

What does the hypothalamus control?

Answer 16

sexual cycles, pregnancy, lactation, growth, stress Reponses, temperature regulation, water balance, sleep, emotional reactions, etc.

Question 17

what is the Hypoglamic nuclei?

Answer 17

region of the hypothalamus that is controlling one aspect of the body and the nerves there will communicate with the pituitary for hormonal secretion.

Question 18

Pituitary=?

Answer 18

Hypophysis

Question 19

Anterior Pituitary=?

Answer 19

Adenohypophysis

Question 20

Posterior Pituitary=?

Answer 20

Neurohypophysis

Question 21

Where is the pituitary located?

Answer 21

in the sella tunica at the base of the brain

Question 22

Where is the Sella tunica located?

Answer 22

in the sphenoid bone. Sella tunica is a cavity within the sphenoid bone. DO NOT CONFUSE THESE

Question 23

How is the pituitary connected to the brain?

Answer 23

via the hypothalamus and the portal blood supply

Question 24

What is the pars distalis?

Answer 24

The principle part of the pituitary gland

Question 25

What hormone do somatotropes release?

Answer 25

Growth Hormone

Question 26

What hormone do corticotropes release?

Answer 26

corticotropin releasing hormone

Question 27

what hormone do mammotropes release?

Answer 27

prolactin

Question 28

what hormone do thryotropes release?

Answer 28

thyroid stimulating hormone

Question 29

What hormones do gonadotropes release?

Answer 29

LH and FSH

Question 30

What hormone is released from the pars intermedia?

Answer 30

Melanocyte stimulating hormone

Question 31

What is the pars tuberalis?

Answer 31

layer of cells surrounding the neural stalk with no known function

Question 32

What is the name of the portal system that carries hormones from the hypothalamus to the pituitary?

Answer 32

Hypothalamo-hypophyseal portal system

Question 33

What are some characteristics of the Hypothalamo-Hypopphyseal portal system?

Answer 33

1) allows rapid response
2)little dilution of peptide hormones
3)peptide hormones have short 1/2 life

Question 34

What is the function of growth Hormone?

Answer 34

regulates growth, metabolism; acts on liver to cause production of somatomedins and somatomedin binding proteins

Question 35

What is the function of adrenocorticotrophic hormone?

Answer 35

stimulates adrenal cortex to release cortisol and aldosterone, involved in metabolic regulation

Question 36

What is the function of gonadotrophic hormones

Answer 36

follicle stimulating hormone; stimulates follicular growth in the ovary
Luteinizing hormone; stimulates ovulation and growth of corpora lutea

Question 37

what is the function of thyroid stimulating hormone?

Answer 37

stimulates release of thyroxine from thyroid gland

Question 38

What is the function of prolactin?

Answer 38

stimulates mammary development and lactation

Question 39

what is the function of beta-lipotrophin?

Answer 39

secreted by corticotropes; involved in pain relief

Question 40

Define posterior pituitary gland

Answer 40

an outgrowth of the hypothalamus and contains the terminal axons from two pairs of nuclei

Question 41

what does the supraoptic portion of the posterior pituitary do?

Answer 41

secretes antidiuretic hormone

Question 42

what does the paraventricular portion of the posterior pituitary gland do?

Answer 42

secretes oxytocin

Question 43

what does ADH do?

Answer 43

regulates reabsorption of water in the kidney

Question 44

what does oxytocin cause?

Answer 44

milk ejection reflex