Why Are Hormones Important?

Question 1

Autocrine

Answer 1

Released by cells & have a local effect on same cells type from which chemical signals were released.

Question 2

Paracrine

Answer 2

Released by cells & affect other cell types locally without being transported in the blood.

Question 3

Neurotransmitter

Answer 3

Produced by neurons & secreted into extracellular spaces by presynaptic nerve terminals; travels short distances, influences post-synaptic cells.

Question 4

Hormone Secretion: Acute

Answer 4

Sudden release of hormones due to stimulus (eg. adrenaline in response to stress).

Question 5

Hormone Secretion: Chronic

Answer 5

Small variations over a long period of time (eg. thyroid hormones).

Question 6

Episodic

Answer 6

Oestrogen or progesterone produced during menstrual cycle.

Question 7

Why do target cells respond to a hormone?

Answer 7

The target cells have the correct receptor to respond to the hormone.

Question 8

AP Hormones

Answer 8

FSH, LH, ACTH, thyroid hormone, prolactin, GH, MSH.

Question 9

PP Hormones

Answer 9

ADH, oxytocin.

Question 10

Tropic Hormones

Answer 10

Stimulate secretion of other hormones from target tissues.

Question 11

Non-Trophic Hormones

Answer 11

Initiates an effect from a target tissue.

Question 12

Hormone Secretion from PP

Answer 12

Stimuli causes neurons in hypothalamus to increase or decrease AP frequency. APs conducted along neurons from hypothalamus to PP. Axon terminals of these neurons store hormones which are secreted into circulatory system to the target tissue.

Question 13

Hormone Secretion from AP

Answer 13

Stimuli within NS regulates secretion of releasing hormones from neurons in hypothalamus. Releasing hormones pass to AP, stimulating release of hormones from AP. These travel in the bloodstream to reach target tissue. Target tissue may be another gland.

Question 14

Thyroid Gland

Answer 14

Highly vascular. Only gland that stores its own hormones. Its hormones increase rate of metabolism.