Endocrine System

Question 1

Why are communication systems important

Answer 1

They help to maintain a constant internal environment and help an organism survive

Question 2

Define sensitivity

Answer 2

The ability of living organisms to respond or react to a stimulus

Question 3

How are stimulus detected and transmitted

Answer 3

Stimulus is detected by a receptor, transmitted by a means of nerve impulses or hormones and an effector brings about a response

Question 4

Define glands

Answer 4

A gland is a group of cells that produces and secretes chemicals for release, such as enzymes or hormones

Question 5

Define endocrine system

Answer 5

A collection of endocrine glands that secrete hormones directly into the bloodstream to be carried towards target cells or organs. Large number of blood capillaries surrounds endocrine glands

Question 6

Define hormone

Answer 6

A chemical substance produced by an endocrine gland, carried by the blood, which alters the activity of one or more specific target organs and is then destroyed by the liver

Question 7

Characteristics of hormones

Answer 7

Small, soluble, Effective in low concentration, Produced by one organ, Secreted into and carried to all parts of the body by blood, Target site different from site where it is synthesised, specific(only organs with specific receptors will respond to hormone)

Question 8

What gland produces adrenaline

Answer 8

Adrenal glands(above the kidneys)

Question 9

How does adrenaline stimulate liver and muscles

Answer 9

Speed up breakdown of glycogen into glucose to increase blood glucose levels

Question 10

How does adrenaline stimulate liver

Answer 10

Increases metabolic rate to release more energy by tissue respiration

Question 11

How does adrenaline stimulate the heart

Answer 11

Increases rate of heartbeat and cause a rise in blood pressure so oxygen and glucose can be carried faster to muscles

Question 12

How does adrenaline stimulate the lungs

Answer 12

To increase the rate and depth of ventilation to take in more oxygen

Question 13

How does adrenaline stimulate the arterioles in the skin

Answer 13

To constrict, causing paleness, channeling more blood to the muscle

Question 14

How does adrenaline stimulate the pupils

Answer 14

To dilate, enhancing vision

Question 15

What are two other effects of adrenaline secretion

Answer 15

To stimulate the contraction of hair erector muscle and increase in rate of blood coagulation

Question 16

When blood glucose is not at norm, what organ secretes hormones

Answer 16

Pancreas

Question 17

What hormones are secreted when blood glucose increases/decreases norm

Answer 17

Insulin/glucagon

Question 18

What is purpose of insulin

Answer 18

Blood transports insulin to body cells, liver and muscles to promote uptake of glucose by almost all body cells, especially liver, muscle and adipose tissue. Stimulates liver and muscle to convert excess glucose into glycogen

Question 19

What is purpose of glucagon

Answer 19

Blood transports glucagon to liver and muscles, glucagon stimulates liver and muscles to convert glycogen to glucose. Increase the release of glucose into blood from liver

Question 20

What causes type 1 diabetes

Answer 20

Deficiency of insulin, where islets of Langerhans in pancreas cannot produce sufficient insulin

Question 21

What causes type 2 diabetes

Answer 21

Decreased response to insulin in target tissues. It occurs later in a person’s life and is known s late-onset diabetes.

Question 22

What are some signs of diabetes mellitus

Answer 22

1. Persistently high blood glucose level
2. Slow or difficult healing of wounds
3. Presence of glucose in urine, especially after meal

Question 23

Why can glucose be found in urine of diabetic patients

Answer 23

Elevated blood glucose exceeds reabsorption capacity of the kidneys, causing glucose to remain in the filtrate.

Question 24

Why are diabetic patients normally thirsty

Answer 24

More glucose is concentrated in the urine, water potential in filtrate decreases, less water leaves the filtrate by osmosis, resulting in more water excreted with urine and resulting in excessive volumes of urine

Question 25

Two similarities in nervous and hormonal coordination

Answer 25

Both provide pathways of communication within the body to coordinate various activities and involve the transmission of messages to the effectors

Question 26

Difference in nervous and hormonal coordination by nature of message

Answer 26

Nervous: Nerve impulses(electrical) and neurotransmitters(chemical)
Hormonal: Hormones(chemical)

Question 27

Difference in nervous and hormonal coordination by route of transmission

Answer 27

Nervous: Along neurones
Hormonal: In the bloodstream

Question 28

Difference in nervous and hormonal coordination by rate of transmission

Answer 28

Nervous: Rapid
Hormonal: Relatively slow

Question 29

Difference in nervous and hormonal coordination by areas affected

Answer 29

Nervous: Restricted to structures linked to related neurones
Hormonal: Over many parts of the body

Question 30

Difference in nervous and hormonal coordination by duration of effect

Answer 30

Nervous: Generally short-lived
Hormonal: Generally long lasting