wk 6.1 HPA-Axis and Hormone Regulation

Question 1

What is the role of the Endocrine system?

Answer 1

-Control system of the body
-Long term regulation and adjustment ofhomeostatic mechanisms and a variety ofbody functions

Question 2

What are endocrine functions?

Answer 2

*Pituitary
*Parathyroid
*Thyroid
*Adrenal

Question 3

What are the main endocrine glands?

Answer 3

• Pineal
  *Thymus
  *Pancreas
  *Testis / Ovaries

Question 4

What are the endocrine cells?

Answer 4

Kidney
* Heart
* Stomach
* Small intestine
* Liver Hypothalamus

Question 5

What are hormones?

Answer 5

• Can be released from more than one type of cell
• Can have more than one type of effect
• Can be permissive
• Can be synergistic
• Can be antagonistic

Question 6

What are target Organs

Answer 6

Can have receptors for more than one hormone
* Different cell types can respond differently to the same hormone
* The endocrine cell can be its own target cell
* The target has a physiological response or releases another hormone in the pathway

Question 7

What are the diverse structures of Hormones

Answer 7

Amino acid
– peptides
– proteins
– Steroids

Question 8

What is circulating hormones

Answer 8

Pass from the secretory cells that makes them into interstitial fluid and blood. Act on distant tissues.Linger in blood for minutes tohours. They are inactivated by theliver and excreted by the kidneys

Question 9

What is local hormones?

Answer 9

Act on targecells close to release sites. Do notfirst enter blood stream e.g.Macula densa. Paracrine(para=beside) act on neighboringcell

Question 10

1.What are hydrophilic hormones?
2. Give example?

Answer 10

• Non-Steroid hormones / peptide(small proteins)
• Water soluble – can’t cross theplasma membrane
• Circulate in the ‘free’ active form
• Can be stored
• Work quickly - are activated anddeactivated quickly

2.Insulin, Epinephrine,

Question 11

1.What are hydrophobic hormones?
2. Give example?

Answer 11

• Steroid Hormones / Lipids
• Fat soluble – pass through theplasma membrane
• Circulate in the ‘bound’ inactiveform
• Cannot be stored
• Work slowly - are activated anddeactivated slowly
• Secreted from Adrenal cortex,testes, ovaries and placenta.

2.Testosterone, Estrogens

Question 12

Why are hormones important?

Answer 12

1.Control the wake-up cycle and the biological rhythms

2. Regulate the activity of the reproductive cycle.
3. Induce or suppress the cell cycle (mitosis, meiosis apoptosis)
4. Regulate metabolism and cell biochemistry.
5. Control hunger and thirst
6. Responsible for mood swings
7. Activate or inhibit the immune system
8. Prepare for mating, fleeing, fighting and coping
9. Prepares body for e.g. birth, puberty, parenting and menopause.
10. Stimulate or inhibit growth

Question 13

1.What is the role of the Pituitary Gland?
2. Where is it located?
3. How does it increase or decrease?

Answer 13

1.controls the functions of numerous other endocrine glands

2.beneath the Hypothalamus

3.Increases in size during pregnancy and size decreaseswith age

Question 14

What are the 5 main endocrine cell types of the anterior pituitary gland?

Answer 14

– Gonadotroph
– Lactotroph
– Somatotroph
– Corticotroph
– Thyrotroph

Question 15

What are the inhibiting hormones?

Answer 15

• Somatostatin (AKA Growth HormoneInhibiting Hormone)
• Prolactin Inhibiting Hormone PIH (Dopamine)

Question 16

How does the hormonal stimuli work?

Answer 16

-Hormones from the hypothalamus are secreted e.g the Gonadotropin releasing hormone(Gn-RH)

-Gn-RH arrives at the Anterior pituitary gland

-Anterior pituitary gland releases FSH and LH

-FSH and LH arrive at the ovaries and controlsthe menstrual cycle

Question 17

How does neural stimuli work?

Answer 17

• stressful environment
  -The CNS starts the fight or flight response
  -CNS stimulates the adrenal medulla to release adrenaline
  -Adrenaline travels in the blood to many target organs
  -Flight or flight response isstrengthened andincreased in duration