Internal Regulation ( + Textbook Chapter 9 )

Question 1

Where is the hypothalamus located?

Answer 1

In the midbrain, below the thalamus.

Question 2

Define:

Neuroendocrinology

Answer 2

The branch of physiology that deals with the connection between the nervous system and the endocrine system.

Ernst and Berta Scharrer are considered pioneers in this field.

Question 3

What are the THREE main regions of the hypothalamus?

Answer 3

• Posterior
• Middle
• Anterior

There are large numbers of subnuclei and subregions associated with the hypothalamus.

Question 4

What is the overarching function of the hypothalamus.

Answer 4

Internal regulation

Question 5

List:

SIX examples of important functions carried out by the hypothalamus.

Answer 5

• Temperature control
• Thirst (fluid balance)
• Biorhythms (via SCN)
• Hunger
• Sexual behaviour
• Aggression

The last two are more complex behaviours and may be induced or repressed by activation of certain subregions.

Question 6

Which key brain structure is directly controlled by the hypothalamus?

Answer 6

The pituitary gland.

It is made up of an anterior and posterior section.

Question 7

What are the TWO major neurohormones of the posterior pituitary gland?

Answer 7

• Vasopressin
• Oxytocin

Question 8

What function does vasopressin excreted by the posterior pituitary gland serve?

Answer 8

It has roles in homeostatic regulation of salt levels and blood pressure.

Question 9

What function does oxytocin excreted by the posterior pituitary gland serve?

Answer 9

It has roles in social bonding and milk production.

Question 10

List:

SIX major neurohormones excreted by the anterior pituitary.

Answer 10

• GH (growth hormone)
• ACTH (adrenocorticotropic hormone)
• TSH (thyroid-stimulating hormone)
• FSH (follicle-stimulating hormone)
• LH (luteinising hormone)
• Prolactin

Question 11

List:

TWO distinctions of hormones compared to neurotransmitters.

Answer 11

• Slower acting.
• Can reach all tissues connected to blood supply.

But, like neurotransmitters, hormones can only initiate an effect upon cells with the appropriate receptors.

Question 12

Define:

Neurohormone

Answer 12

Chemical messengers that are produced and secreted by neuroendocrine cells.

Question 13

What is the overarching effect of neurohormones secreted by the anterior pituitary?

Answer 13

To stimulate endocrine cells to release hormones.

The anterior pituitary operates via a system of portal veins.

Question 14

True or False:

The average person can live up to a month without food, but only around a maximum of one week without water.

Answer 14

True

Question 15

What are the TWO types of thirst?

Answer 15

• Osmotic
• Hypovolemic

The detection and response for these thirst types differ from each other.

Question 16

Which type of thirst is characterised by high [ion]:[water]?

Answer 16

Osmotic thirst

Question 17

Which type of thirst is characterised by low water levels?

Answer 17

Hypovolemic thirst

This tends to occur during excessive sweating or blood loss.

Question 18

What is the neurohormone vasopressin also known as?

Answer 18

Antidiuretic hormone (ADH).

Its release and effect causes increased water absorption from the kidneys (i.e. water retention).