Homeostasis
Thermoregulation
Regulation of blood glucose
Excretion
The Nephron
100
What is homeostasis
The maintenance of a constant internal environment
100
The _____________ is a part of the brain that keeps internal temperature constant.
Hypothalamus
100
The control of blood glucose concentration is carried out by the ___________________ and the ________________.
Pancreas, Liver
100

What is excretion?

The removal of metabolic waste products (e.g urea & carbon dioxide) from the body.  These materials are toxic if left to accumulate in the body.

100

What is a nephron? How many does each kidney have?

They are tiny tubules in a kidney, in which urine is produced. The kidney contains thousands of these

200
Give two reasons why homeostasis is important
1. keeps your cells working efficiently 2. keeps a constant temperature of 37 degreees celsius (which helps enzymes to work at the optimum rate) 3. keeps a constant amount of water so cells are not damaged by absorbing or losing to much water by osmosis 4. keeps a constant concentration of glucose so that there is always enough fuel for respiration
200
What is vasoconstriction?
Vasoconstriction is when the arterioles that supply the blood capillaries near to surface of skin become narrower, or constricted.
200

Name the two hormones and their function that are secreted by the pancreas.

Insulin - stimulates the liver to store excess glucose as glycogen Glucagon - stimulates the liver to break down stored glycogen and release glucose.

200

Name one metabolic waste product that must be removed from the body and where it is removed from

Carbon Dioxide - lungs

Urea - kidneys (urine)

200
In what stage is water, urea, salts and glucose forced into the Bowman's capsule?
Ultrafiltration
300
what is the difference between homeotherm and poikilotherm?
Homeotherms are warm blood and keep their body temperature constant Poikilotherms are cold blooded and cannot control their body temperature.
300

How does vasoconstriction conserve heat?

Vasoconstriction of arterioles under the skin.  Shunt vessel dilate.  Less blood flows to the capillaries on the surface of the skin.  Less heat loss via conduction, convection and radiation 

300

Describe what happens to your blood glucose concentration, pancreas and liver after eating a meal which provides a lot of glucose.

Your blood glucose concentration will rise, which causes the Islets of Langerhans in the pancreas to release insulin which stimulates the liver to store excess glucose as glycogen. The blood glucose concentration will then go back down to normal.

300

What happens to the nitrogenous waste that is produced in our body

It is sent to the liver to be deaminated into urea

300
During the selective reabsorption stage, what substances are reabsorbed by into the blood capillary, and in what quantity?
Glucose - 100% Water and Salts -2/3
400
State two advantages and one disadvantage of being a homeotherm
1. enzymes can always work efficiently if body temperature is always 37 degrees celsius 2. metabolism can keep going, even when it is cold outside. so they can always be active Disadvantage: have to eat far more food than poikilotherms.
400

Other than vasoconstriction, how does the human body generate or save heat?

Muscles work: muscles in some parts of the body contract and relax very quickly to generate heat. Metabolism may increase: the speed of chemical reactions such as respiration may increase. this also releases more heat

400
Why is it important to maintain the amount of glucose in our body?
Keeping a constant concentration of glucose means that there is always enough fuel for respiration. But make sure that it doesn't get to high and cause hyperglycemia and affect the concentration gradients across the cells.
400

What is deamination?

The breakdown of excess amino acids to form urea and a carbohydrate. The amino group (-NH2) group forms urea,) while the (-CHO) group forms the carbohydrate.

400
The ascending loop of Henle is permeable to ______________.
What is salts
500

What is the function of the adipose tissue?

This is made up of cells which contain large drops of oil. This layer helps to insulate your body and also acts as an energy reserve.

500
Name and describe two ways that the body can lose heat.
Sweating: the sweat lies on the surface of the hot skin. the water in it then evaporates, taking heat from the skin with it, thus cooling the body. Vasodilation: the arterioles supplying the capillaries near the surface of the skin get wider. because a lot of blood is near the surface of the skin, heat is readily lost from the blood into the air.
500
A person with diabetes is suffering from low blood glucose concentration and is feeling very faint. How does our body normally handle low glucose concentration in our blood, and how must a person with diabetes handle this situation.
Normally, the body produces glucagon which stimulates te liver to break down glycogen and release glucose back into the blood. Someone with diabetes will need to eat high glucose foods to boost up the glucose levels
500

Name three functions of the liver

1. converts excess amino acids into urea and carbohydrates 2. controls the amount of glucose in the blood 3. stores carbohydrates as glycogen 4. makes bile 5. breaks down old red blood cells breaks down harmful substances such as alcohol 6. stores vitamins A, B, D, E and K 7. stores potassium

500

Name the 6 different parts of a nephron

Glomerulus, Bowman's capsule, proximal convoluted tubule, distal convoluted tubule, loop of Henle, collecting duct

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