01 - Homeostasis And Energy

Question 1

What is homeostasis?

Answer 1

The ability of the body to maintain relatively stable internal conditions even when the environment and/ or the the activity of the person is changing

Question 2

Most organ systems are involved in homeostatic mechanisms, true or false?

Answer 2

True

Question 3

What are the parameters that are controlled?

Answer 3

Temperature 
Concentration of nutrients in blood
Heart rate
Blood pressure
Waste removal

Question 4

What is the homeostatic state of the body controlled by?

Answer 4

The neural and endocrine systems

Question 5

What do the homeostatic control systems involve?

Answer 5

>Receptors
>Stimuli
>Control centre
>Effector
>Reflex
>Negative feedback
>Positive feedback

Question 6

What is negative feedback?

Answer 6

Response to a given stimulus which, causes an increase in output

Question 7

In negative feedback what does the increase in output itself do?

Answer 7

It turns off (or down) the effect of the original stimulus

Question 8

What is positive feedback?

Answer 8

Response causes an increase in the afferent signal so the response becomes stronger until the stimulus is removed

Question 9

What is an example of positive feedback?

Answer 9

Uterine muscle contraction intensified by the release of the hormone oxytocin until the baby is born

Question 10

What is the primary hormonal control made of?

Answer 10

Insulin and Glucagon

Question 11

Islets of Langerhans contain the cells that secrete what?

Answer 11

Glucagon

Insulin

Question 12

What are glucagon cells in islets in Langerhans cells?

Answer 12

Alpha cells, 20% of cells

Question 13

What are insulin in Langerhans cells?

Answer 13

Beta cells, 70% of cells

Question 14

How many amino acid peptide is insulin?

Answer 14

51

Question 15

How many chains of what kind of bridge do insulin cells have?

Answer 15

2 chains of s-s bridges

Question 16

What is insulin secretion stimulated by?

Answer 16

Rising blood concentration, amino and fatty acid levels and parasympathetic neural action

Question 17

What do insulin cells do?

Answer 17

Lower blood glucose concentration and promotes protein synthesis and fat storage

Question 18

How do insulin cells lower blood glucose?

Answer 18

By enhancing glucose uptake by cells, particularly muscle and fat cells

By inhibiting glyconeogenesis - conversion of amino acids or fats into glucose

Question 19

How many amino acid peptide does glucagon have?

Answer 19

29

Question 20

What type of cells are glucagon cells?

Answer 20

Alpha cells of pancreatic islet

Question 21

What is glucagon’s secretion increase stimulated by?

Answer 21

Increased in response to low glucose concentration of the blood, also sympathetic neural activation, and increased amino acid concentration

Question 22

What is decreased secretion of glucagon stimulated by?

Answer 22

High glucose concentration, insulin and somostatin

Question 23

What are glucagon’s primary target?

Answer 23

Liver cells

Question 24

How does glucagon raise blood glucose?

Answer 24

• Stimulates glycogenolysis (breakdown of glycogen to glucose)
• Stimulates gluconeogenolysis (synthesis of glucose from lactic acid and from non-carbohydrate molecules)
• Stimulates the release of glucose into blood stream