Endocrine system

Question 1

Define sensitivity

Answer 1

Sensitivity is the ability of living organisms to respond or react to a stimulus

Question 2

What are some secondary effects of adrenaline secretion

Answer 2

• Hair erector muscles contract, producing goosebumps
• Increase rate of blood coagulation

Question 2

Name examples of endocrine glands

Answer 2

• Hypothalamus
• Pituitary gland
• Adrenal gland
• Pancreas

Question 3

What is the endocrine system

Answer 3

The endocrine system is a collection of endocrine glands that secrete hormones directly into the bloodstream to be carried towards target cells or organs

Question 3

Define a gland

Answer 3

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

Question 4

Define a hormone

Answer 4

A hormone is a chemical substance produced by an endocrine gland and carried by the blood to alter the activity of specific target organs and is then destroyed by the liver

Question 5

What are the characteristics of hormones

Answer 5

• Small, soluble molecules
• Effective in low concentrations
• Produced by 1 organ
• Secreted into and carried throughout body by the blood
• Target site is different from synthesised site
• Specific in action

Question 6

What stimuli can result in adrenaline secretion

Answer 6

• Stress
• Fear
• Anxiety
• Anger

Question 6

What are the main effects of adrenaline secretion

Answer 6

• Liver and muscles speed up breakdown of glycogen to glucose so blood glucose levels increase
• Liver increases metabolic rate so more energy is released in respiration
• Heart rate increases so oxygen and nutrients are carried to muscles faster
• Lungs increase rate and depth of ventilation to take in more oxygen
• Skin arterioles vasoconstrict so more blood can be channelled to muscles
• Pupils dilate to enhance vision

Question 7

What happens when blood glucose concentration increases beyond the norm

Answer 7

• Pancreas detects increase in blood glucose concentration and secretes more insulin into blood
• Blood transports insulin to body cells, liver and muscles
• Insulin promotes the uptake of glucose by almost all body cells and stimulates liver and muscles to convert excess glucose to glycogen
• Negative feedback sent to pancreas to prevent further corrective action once blood glucose concentration decreases to norm

Question 8

What happens when blood glucose concentration decreases below the norm

Answer 8

• Pancreas detects decrease in blood glucose concentration and secretes more glucagon into blood
• Blood transports glucagon to body cells, liver and muscles
• Glucagon stimulates liver and muscles to convert glycogen to glucose and increases the release of glucose from liver into blood
• Negative feedback sent to pancreas to prevent further corrective action once blood glucose concentration increases back to norm

Question 9

What endocrine disorder is marked by high blood glucose concentration

Answer 9

Diabetes mellitus

Question 10

What is type 2 diabetes

Answer 10

• Known as late-onset diabetes
• Caused by a decreased response to insulin in target tissues

Question 11

What is type 1 diabetes

Answer 11

• Known as early-onset diabetes
• Caused by islets of Langerhans in pancreas not producing enough insulin

Question 12

What are some signs of diabetes mellitus

Answer 12

• Persistently high blood glucose concentration
• Wounds difficult to heal
• Presence of glucose in urine

Question 13

How can type 2 diabetes be treated

Answer 13

Changes in lifestyle

Question 13

How can type 1 diabetes be treated

Answer 13

Insulin injections