Lab Quiz 1: Endocrinology

Question 1

Hypothalamus functions

Answer 1

1) regulating body temperatures
2) Maintaining Daily Physiological Cycles
3) Controlling Appetite
4) Managing of sexual behavior/reproductive cycling
5) regulating emotional responses

Question 2

How does the hypothalamus succeed in regulating important functions?

Answer 2

• communicates with the pituitary gland via releasing hormones and neurological signals
• in response, the pituitary then produces and releases hormones into the blood stream which travel to target organs throughout the body
• these hormones then affect a change in the function of that target organ, often that change is to stimulate the target organ to produce a hormone

Question 3

Example of hypothalamic pituitary target organ axis specific to reproduction

Answer 3

1) the hypothalamus releases gonadotropin releasing hormone (GnRH)
2) GnRH travels to the anterior pituitary gland which stimulates the release of FSH and LH
3) FSH and LH travel to the testis where they stimulate the production of testosterone (LH) and stimulate sperm production and development (FSH)
4) the presence of testosterone then signals the hypothalamus that it can stop making GnRH

Question 4

How do releasing hormones differ in their pathway

Answer 4

• some releasing hormones trigger the anterior pituitary while other hormones are sent straight from the hypothalamus to the posterior pituitary where they are then released

Ex: Posterior- oxytocin and antidiuretic hormone (ADH)

Question 5

Four primary structures of the pituitary

Answer 5

1) anterior pituitary
2) posterior pituitary
3) infundibulum
4) sella turcica

Question 6

Anterior pituitary

Answer 6

• develops from the same tissue as the roof of the mouth, so it is not neural origin
• therefore, the hypothalamus communicates with it via releasing hormones which trigger its endocrine action
• these releasing hormones travel via the portal system

Question 7

Posterior Pituitary

Answer 7

• develops from neural tissue, so hormones that are made in the hypothalamus can travel to the posterior pituitary neural connections to be released

Question 8

Infundibulum

Answer 8

• the attachment between the hypothalamus and the pituitary

Question 9

Sella turcica

Answer 9

• latin for turkish seat
• a saddle shaped depression in the body of the sphenoid bone of the human skull and of skulls of other hominids including chimpanzees, orangutans and gorillas

Question 10

Pars intermedia

Answer 10

• the dividing line between the two tissue types of the posterior and anterior pituitary glands

Question 11

Neurohypophysis

Answer 11

• pars nervosa

- anterior pituitary

Question 12

Adenohypophysis

Answer 12

• pars distalis

- anterior pituitary gland

Question 13

Rat example what hormone were they injected with and why

Answer 13

• since the only groups affected by the hormone injection were the intact rats, not castrated
• we can assume that luteinizing hormone was injected because this would only affect rats with testis
• if testosterone was injected all of the rats would have been affected