Bio220 Final Endocrine System

Front 1

Endocrine and nervous system differences

Back 1

Endocrine has a slower signal, the signal effects more things, lasts longer

Front 2

Endocrine and Nervous system similarities

Back 2

Both involved in maintaining homeostasis

i. Nervous systems allow responses to environmental stimuli
ii. Endocrine systems allow coordination of long-term body changes – molting in insects, puberty in humans.

Front 3

Endocrine system

Back 3

Composed of series of glands that release hormones into blood

Front 4

Tropic Hormones

Back 4

affect other endocrine tissues, and act as coordinating signals between endocrine glands and the nervous system and the endocrine system.

Front 5

Endocrine Hormones the other type

Back 5

other hormones can directly effect target tissue after transport in the blood stream and diffusino through the extracellular fluid

Front 6

Endocrine hormone types

Back 6

there are four types

i. Lipid soluble – steroids (another example we did not talk about: prostaglandins)
ii. Lipid insoluble – Amines (generally tyrosine-derived) and proteins

Front 7

Endocrine function in the pancreas

Back 7

endocrine tissue concentrated in clusters of cells known as islets of langerhans

alpha cells produce glucogen

beta cells produce insulin

Front 8

Role of Insulin

Back 8

Insulin reduces blood glucose in response to excess concentration

induces all cells except brain to take up glucose, which reduces glycogen breakdown by liver

Front 9

Role of Glycogon

Back 9

increases glucose levels by signaling the liver to increase the glycogen breakdown

Front 10

The control of the Endocrine system by the CNS what structures are involved

Back 10

Hypothalumus interacts with the pituitary gland

posterior pituitary:

(neurohypophysis) = neural tissue

Anterior Pituitary:

(adenohypophysis) = glandular tissue

Front 11

Hypothalamus function (anterior pit)

Back 11

Neurosecretory cells in hypothalamus regualte secretion by anterior pituitary (release neurohormones)

Produces both release and inhibiting hormones

Front 12

Hypothalamus funciont (posterior Pit)

Back 12

other neurosecretory cells produce ADH and oxytocin which are transported into the post pit via axons stored in the posterior pituitary

Front 13

ADH

Back 13

Targets kidneys, inhibits waterloss in response to an increase in osmolarity in the blood

Front 14

Oxytocin

Back 14

stiulates contraction of the uterus, release of milk from mammary, may affect mood and social interactions

Front 15

Adrenal Glands (stress response medulla)

Back 15

Located on the kidneys the medulla is the nueral origin

SNS signal induce release of epinephrine and norepinephrine in response to stress

Front 16

Short term stress resonse

Back 16

induce glycogen breakdown in liver increase glucose in blood

increase cardiac output

dialate bronchioles

iv. Increase blood supply to muscles and brain, reduce to skin, viscera

Front 17

Cortex of Adrenal Glands (responses)

Back 17

a. Responds to adrenocorticotropic hormone (ACTH) from ant pit – longer-term stress response than nor/epinephrine

Front 18

Cortex of Adrenal Glands (produces)

Back 18

b. Produces cortisol (and other glucocorticoids) and aldosterone (and other mineralocorticoids)
i. Aldosterone we have already studied – affects permeability of tubules in nephron
ii. Cortisol stimulates production of glucose from non-glycogen sources (like proteins and fats)
3. Cortex also secretes some steroid sex hormones

Front 19

how hormones get into target cell

Back 19

Signal gets into cell via transduction pathway.

starts by binding to receptor protein on cellular membrane

recepors are specific to signal molecules

2. Only expressed by those cells that need to respond to the specific signal (example, heart or liver response to epinephrine)

Front 20

G protein pathway

Back 20

i. Receptor changes shape across membrane when signal molecule binds;
ii. Conformational change results in binding of G-protein to receptor on cytoplasmic face of plasma membrane;
i. Receptor modifies conformation of G-protein by replacing GDP with GTP (guanosine triphosphate; analogous to ATP); G-protein with GTP bound activates target enzymes.