bio 252

Question 1

4 types of intercellular communication

Answer 1

1. gap junctions through cytoplasm
2. neurotransmitters through synaptic cleft
3. paracrines through interstitial fluid
4. hormomes through the blood

Question 2

what are hormones traveling through blood important?

Answer 2

They illicit a systemic response, cell to cell communication, travel great distance.

Question 3

principles of hormone communication

Answer 3

1. hormones are released by endocrine glands (endocrine cells, neuroendocrine glands)
2. Picked up by blood
3. hormones travel throughout the body
4. hormones “diffuse” out of the capillaries
5. hormones stimulate “target cells”

Question 4

what is different about target cell capillary in hormone communication

Answer 4

target cell capillaries are fenestrated, basically look like windows where the hormone comes in. more surface area.

Question 5

endocrine system and communication

Answer 5

1. communication by hormones
2. releases hormones to blood
3. potentially widespread effect
4. slow response
5. long lasting

Question 6

what is a humeral stimulus?

Answer 6

where the hormone released in response to ion levels in the body, ex. parathyroid glands and calcium.

Question 7

neural stimulus

Answer 7

hormone release caused by neural input.

ex would be CNS releasing preganglionic sympathetic fibers, to medulla of adrenal gland to release epi.

Question 8

hormonal stimulus

Answer 8

a hormone release caused by another hormone (a tropic hormone). Ex. Anterior pituitary gland to release other hormones.

Question 9

function of hypothalamus

Answer 9

located in the third ventricle of the brain, controls water balance, thermoregulation, sex drive, childbirth and various autonomic functions. many functions executed by pituitary gland.

Question 10

how can hypothalamus exert control over pituitary gland.

Answer 10

nervous system signals and endocrine signals

Question 11

why is the pituitary gland divided into two parts?

Answer 11

anterior parts communicates via hormones, posterior part communicates through nervous system.

Question 12

the connection between hypothalamus and anterior pituitary gland?

Answer 12

vascular connection, still uses hormones but communication is through blood making it vascular. the system is called Hypothalamo-hypophyseal Portal System

Question 13

ADH antidiuretic hormone

Answer 13

stimulus - high blood osmolarity
messenger- ADH
response- increase water retention
increase thirst

Question 14

oxytocin

Answer 14

stimulus- neural stimulus (specifically during childbirth)
messenger- Oxytocin
response- smooth muscle contraction (uterus, reproductive ducts, and mammary glands) promotes emotional bonding.

Question 15

anterior pituitary hormones released when stimulated by hypothalamic hormones / trophic because their role is release other hormones.

Answer 15

Gonadotropin- releasing hormone
Thyrotropin- releasing hormone
Corticotropin- releasing hormone 
Prolactin- inhibiting hormone
Growth hormone- releasing hormone
growth hormone- inhibiting hormone (somatostatin)

Question 16

Anterior Pituitary gland exclusive hormones

Answer 16

FSH (follicle stimulating hormone) - stimulates secretion of ovarian sex hormones, development of ovarian follicles and sperm production.
LH (luteinizing hormone) - stimulated ovulation, stimulates corpus luteum to secrete progesterone & stimulates testes to secrete testosterone

Question 17

ACTH

Answer 17

Adrenocorticotropic hormone- stimulates adrenal cortex to secrete glucocorticoids

Question 18

PRL

Answer 18

Prolactin - afterbirth stimulates mammary glands to synthesize milk, enhances secretion of testosterone by testes.

Question 19

TSH

Answer 19

Thyroid Stimulation Hormone- stimulates secretion of thyroid hormone

Question 20

GH

Answer 20

Growth Hormone- stimulates mitosis and cellular differentiation.

Question 21

Growth Hormone (somatotropin) 
IGF - 1 (somatomedin)

Answer 21

sleep, exercise, low glucose, high protein, fasting between 12 to 16 hours, stress (good stress) like lifting
Direct (repairing tissue, bone, muscle, elevation of blood glucose & blood fatty acids) and indirect effects
(stimulating IGF *insulin growth factor) important mediator for growth in children to adolescence.

Question 22

GH & IGF cause our bodies to use…

Answer 22

fats for energy.. to avoid protein & glucose utilization for fuel preferred fuel
spare protein for repairs/growth…make proteins available for growth
and spare glucose…reduces use of carbs for glucose dependent organs bc of limited glycogen (glucose sparring effect) ex. like rbc’s, cns

Question 23

Lypolysis

Answer 23

Breakdown of fats into fatty acids for energy use

Question 24

Glycogenolysis

Answer 24

the breakdown of glycogen to produce glucose

Question 25

Gluconeogenesis

Answer 25

the use of fats/proteins to produce glucose

Question 26

Gigantism

Answer 26

GH hypersecretion during childhood or adolescence.

Epiphyseal plates are open and makes bones longer.

Question 27

Acromegaly

Answer 27

Post adolescent hypersecretion, thickening of bones & soft tissues epiphyseal plates are closed.

Question 28

Pituitary Dwarfism

Answer 28

GH hyposecretion - made rare since GH supplementation has become available