ENDOCRINE SYSTEM Session 10

Question 1

What are gonads and what do they produce ?

Answer 1

• the male testes and female ovaries
• they produce hormones

Question 2

What are the testes and ovaries controlled by ?

Answer 2

• Hypothalamus and the pituitary

Question 3

What does the testes and ovaries produce ?

Answer 3

• testes : produce androgens such as testosterone
• Ovaries : produce estrogen and progesterone

Question 4

what causes an increase amount of testosterone starting at puberty ?

Answer 4

• Because of gonadotropic hormones ( FSH , LH) the testes begin to release increased amounts

Question 5

What does testosterone stimulate ?

Answer 5

• Stimulates the growth of the penis and the testes

Question 6

What does estrogen stimulate and where else is estrogen necessary for ?

Answer 6

• Estrogen secreted at puberty stimulates the growth of the uterus , vagina and breasts .
• Estrogen is necessary for egg maturation

Question 7

Where is the Thymus located and when does it peak capability ?

Answer 7

• It is located beneath the sternum
• reaches its largest size and is most active during childhood

Question 8

What does thymosins cause ?

Answer 8

• Causes lymphocytes T to mature

Question 9

Where is the Pineal gland located and what does ir produce and regulate ?

Answer 9

• Located in the brain
• Regulates daily sleep - wake cycle
• Produces melatonin , primarily at night

Question 10

When are Erythropoietin (EPO) secreted , how is it produced and what does it stimulate ?

Answer 10

• Mainly secreted by the kidneys in response to a low oxygen blood level
• Stimulates red blood cell formation in the red bone marrow
• produced in adult by interstitial fibroblasts in the kidney and produced in perisinusodial cells in the liver.

Question 11

How are leptin produced and what do they do ?

Answer 11

• Produced in the adipose tissue
• Acts on hypothalamus and it signals satiety ( fullness )

Question 12

What does the atrial natriuretic hormone do and where is it produced ?

Answer 12

• produced in the heart
• acts on kidney to decrease blood volume/pressure

Question 13

How are prostaglandins produced and what do they do ?

Answer 13

• They are made from arachidonate , a fatty acid
• since they are produced by damage tissues , they cause pain
• For example in the uterus , it causes muscles to contract (cramps)

Question 14

What controls the internal environment in our bodies ?

Answer 14

• The endocrine and nervous systems work together to control the internal environment

Question 15

What are some differences in the nervous system and endocrine system in terms of speed of signal.

Answer 15

• They both use chemical signals
• They nervous system uses neurotransmitters and is faster than the endocrine system
• The endocrine system takes time to deliver hormones and it takes time for cells to respond

Question 16

what is the neuroendocrine system ?

Answer 16

• A combination of the two systems
• the hypothalamus bridges the regulatory activities of the nervous and endocrine systems