B5 Endocrine System/Thermoregulation

Question 1

Endocrine System

Answer 1

Secretes hormones into the body through various glands

Question 2

Hormones

Answer 2

Chemical molecules directly released into the blood.

Question 3

Name every gland and the hormones they produce

Answer 3

Pituatary gland- ADH helps control blood water levels by producing urine in the kidney. HGH helps with growth in childhood and puberty. It goes to all tissues
Thyroid-Thyroxine into numerous tissues to control rate of metabolism
Adrenal Gland-Releases adrenaline into the vital organs that get the body ready for action.
Testes-Releases testoterone. Which helps with male puberty and muscle growth. Male reproductive organs are the target.
Pancreas-Releases the hormone insulin to liver to control glucose levels
Ovaries-Produce oestrogen controls puberty and menstrual cycle. Progesterone maintains lining of the womb. Targets ovaries and uterus.

Question 4

4 differences between endocrine and nervous system

Answer 4

Nervous-Fast action
Acts for a Short time
Precise area
Travels via electrical impulses
Endocrine-Slower action
Acts for a long time
More general area
Via blood

Question 5

Definition

Homeostasis

Answer 5

The regulation of conditions in the body to maintain a stable internal enviroment

Question 6

Negative feedback

Answer 6

A change in the body that triggers a response to counteract the change to maintain a stable internal enviroment.

Question 7

Explain what occurs when the body is too hot

Answer 7

Temperature receptors detect body is hot so must cool down. The thermoregulatory centre recevies information and coordinates a response. This triggers effectors immediatley. Sweat is produced by sweat glands and evaporates from the skin. This transfers energy to the enviroment. In vasodilation the blood vessels supplying the skin dilate so more blood flows close to the surface of the skin. This allows energy to transfer to the enviroment from the skin

Question 8

Explain what occurs when the body is too cold

Answer 8

Temperature receptors detect body is cold so must warm up. The thermoregulatory centre recevies information and coordinates response. This triggers effectors immediatley. Hairs stand on end to trap an insulating layer of air. No sweat produced. Vasoconstriction Blood vessels supplying skin capillaires constrict to close off the skins blood supply. When cold you shiver. This needs respiration which releases energy in the form of heat to warm up the body.

Question 9

When is adrenaline released and what does it do

Answer 9

In stressful or scary situations. It get the body ready for fight or flight by increasing the supply of oxygen and glucose to cells so increases heart rate