CONTROL OF BLOOD GLUCOSE

Question 1

What is homeostasis?

Answer 1

the body’s way of keeping things balanced inside, even when things change outside so the body can function properly

Question 2

Examples of homeostasis?

Answer 2

*Blood glucose homeostasis

*Blood oxygen content homeostasis

*Core body temperature homeostasis.

*The volume of body water homeostasis

Question 3

what is the control of blood glucose an example of?

Answer 3

a Negative feedback system

Question 4

What happens when the blood glucose level increases?

Answer 4

1-Detected by
B cells in the islets of Langerhans

2-B cells secrete insulin into the blood

3-Insulin detected by receptors on liver and muscle cells

4-Liver and muscle cells remove glucose from the blood and convert glucose to glycogen

5-blood glucose levels decline
and the stimulus to release insulin is diminished

Question 5

What happens when the blood glucose level decreases?

Answer 5

1-Detected by a cells in the islets of Langerhans

2-a cells secrete glucagon into the blood

3-Glucagon detected by receptors on liver cells

4-Liver cells convert glycogen to glucose and release glucose into the blood

5-Glucose levels rise and stimulus for glucagon stops

Question 6

What type of glands do pancreas have and their function?

Answer 6

• Exocrine function - secretes digestive enzymes into the pancreatic duct
• Endocrine function - secretes hormones
  (insulin and glucagon) directly into the
  blood

Question 7

What is the exocrine function of the pancreas?

Answer 7

1-Pancreatic cells surround
small tubules which drain into the pancreatic duct

2-Pancreatic cells produce
pancreatic juice which is
made up of:
* Amylase (a carbohydrase)
* Trypsinogen (an inactive
protease)
* Lipase

Question 8

What is the enodcrine function of the pancreas?

Answer 8

1-Hormones are secreted from the cells in the
islets of Langerhans

2-α cells (least abundant in humans) manufacture
and secrete the hormone glucagon

3- β cells (most abundant in humans) manufacture
and secrete the hormone insulin

4- These hormones are released directly into the
blood – This is the ENDOCRINE FUNCTION

Question 9

What is GLYCOGENOLYSIS?

Answer 9

The breakdown of glycogen

Question 10

What is GLUCONEOGENISIS?

Answer 10

The production of new glucose from sources other than carbohydrates in the kidneys and liver

Question 11

What is glycogenesis?

Answer 11

the formation of Glycogen from Glucose.

Question 12

How do beta cells act and what is the response?

Answer 12

1-act as receptors that detect a rise in blood glucose

2-When the rise is detected they secrete insulin into the blood plasma

Question 13

How do alpha cells act and what is the response and Whats the result ?

Answer 13

1-Alpha cells act as receptors that detect a fall in blood glucose level.

2-When a fall is detected they secrete the hormone glucagon into the blood
plasma

3-Glucagon binds to glycoprotein receptors in LIVER.

The result:
1-An enzyme is activated that converts glycogen to glucose (GLYCOGENOLYSIS).

2- There is an increase in the conversion of amino acids
and glycerol into glucose (GLUCONEOGENESIS)

Question 13

What’s the effect of insulin on target cells and what’s the result?

Answer 13

1. Vesicles containing glucose carrier proteins are stimulated to move to,
   and fuse with the cell membrane.
2. More glucose is taken up by the cell.
3. Enzymes that convert glucose to glycogen (and fat) are activated.

The Result:
increased rate of conversion of glucose to glycogen (glycogenesis) in the liver and muscles and the blood sugar level falls

Question 14

whats adrenaline?

where is it produced?

Answer 14

1-hormone that increases blood sugar levels

2-adrenal glands (above kidneys)

Question 15

how does adrenaline raise blood glucose?

Answer 15

1- Activating an enzyme that causes the breakdown of glycogen into glucose in the liver.

2-Inactivating an enzyme that synthesizes glycogen from glucose.

Question 16

other roles of adrenaline?

Answer 16

• Increases metabolic rate
• Prepares the body for activity
• Is an amino acid derivative
• Cannot enter the target cell

Question 17

What is type 1 diabetes?

how can it be controlled?

Answer 17

The body is not able to produce its own insulin. This is thought to be caused by the immune system attacking the insulin-producing beta cells

with regular insulin injections
and the careful management of diet and exercise.

Question 18

What’s type 2 diabetes?
How can it be controlled?

Answer 18

don’t make enough insulin
or don’t make insulin that the body can use properly. This condition is caused by receptors on the body cells losing their responsiveness to insulin or an inadequate supply of insulin
from the pancreas

controlled by careful regulation of
diet and exercise

Question 19

What is hyperglycemia?

What are the symptoms?

Answer 19

the blood glucose concentration
becomes too high. This can lower the water potential of the blood, which can create osmotic problems that can cause dehydration

thirst, frequent urination,
glucose in the urine and ultimately coma.

Question 20

What is hypoglycemia?

What are the symptoms?

Answer 20

occurs when the blood glucose
concentration becomes too low. This can occur when there is no store of glycogen. It can result in cells being deprived of energy

nausea, loss of concentration
and ultimately coma