Homeostasis & Excretion

Question 1

Why is homeostasis important?

Answer 1

Conditions in the body must be constantly controlled because cells rely on the body’s enviorment to live and function.
In the wrong body conditions certain processes and protein wont function properly.

Question 2

What are tissue fluids?

Answer 2

It surrounds the cells of the body, forming a pathway for the transfer of nutrients between the blood and the cells.

Question 3

What is the job of the kidneys?

Answer 3

The kidneys filter waste and excess fluid from the blood.

Question 4

What does the renal artery do?

Answer 4

Carries a large volume of blood from the heart to the kidneys.

Question 5

What does the renal vein do?

Answer 5

Inside the kidneys, blood is filtered and the “clean blood” passes out through each renal vein to the vena cava.

Question 6

What is the cortex?

Answer 6

Dark outer region.
Contains microscopic tubes that are filtering units, called nephrons.

Question 7

Whats the medulla?

Answer 7

Middle layer of kidney.
Regulates concentration of the urine. The urine flows from the collecting ducts into the pelvis.

Question 8

Whats the pelvis in the kidneys?

Answer 8

The pelvis connects to the ureter to the bladder.

Question 9

Whats a nephron?

Answer 9

Filtering unit of the kidney, the structure that produces urine in the process of removing waste and excess substances from the blood.

Question 10

What is the Bowmans capsule?

Answer 10

At the start of a nephron is a hollow cup of cells called the Bowman’s Capsule.
It surrounds a ball of blood capillaries called glomerulus. Here is where blood is filtered.

Question 11

How does the Bowmans capsule work?

Answer 11

Small molecules from the blood pass freely into Bowman’s space, but as long as the kidney filter is working normally, cells and large proteins stay in the blood.

Question 12

Whats the loop of henle?

Answer 12

Part of a nephron.
Is involved with concentrating fluid in the tubule by causing more water to be reabsorbed.

Question 13

Whats an endotherm?

Answer 13

An endotherm uses heat from chemical reactions in its cells to warm its body. It then regulates its heat loss by sweating and/or blood flow through the skin.

Question 14

Whats the epidermis?

Answer 14

The outer layer of he skin.

Question 15

Whats the hypodermis?

Answer 15

A layer of the skin that consists of fatty tissue, which insulates the body against heat loss and is a store of energy.

Question 16

Whats the dermis?

Answer 16

The middle layer of skin, the location of sweat glands, many blood vessels and hair follicles.

Question 17

What are capillary loops?

Answer 17

Blood flows through these loops, radiating heat to the outside, and cooling the body down.

Question 18

Whats vasodilation?

Answer 18

If the body is too hot, arterioles leading to the capillary loops dilate. This increases the blood flow to the skins surface and is called vasodilation.

Question 19

Whats vasoconstriction?

Answer 19

In cold conditions the opposite happens, the arterioles leading to the surface constrict and blood flow to the surface of the skin is reduced so less heat is lost.
This is vasoconstriction.