5.1.4 Hormonal Communication

Question 1

Role of endocrine gland

Answer 1

Region of tissue known as islets of langerhans- made up of alpha and beta cells

Question 2

Alpha cells

Answer 2

Produce and secrete glucagon

Question 3

Beta cells

Answer 3

Produce and secrete insulin

Question 4

Histology of pancreas

Answer 4

Islets of langerhans appear lightly stained and are large and spherical
Pancreatic Acin appear darker stained and small Berry like clusters
Alpha cells are large and more numerous

Question 5

How to increase blood glucose concentration

Answer 5

Diet
Glycogenolysis-glycogen to glucose
Gluconeogenesis-the production of glucose from non carbohydrate sources

Question 6

Decreasing blood glucose concentration

Answer 6

Respiration

Glycogenlysis-production of glycogen

Question 7

How does insulin lower blood glucose concentration

Answer 7

Increasing rate of absorption of glucose by cells
Increasing respiratory rate of cells
Increasing the rate of glyocgenesis
Increasing rate of glucose conversion to fat
Inhibiting the release of glucagon

Question 8

How does glucagon raise blood glucose concentration

Answer 8

Glycogenolysis-the liver breaks down its glycogen store into glucose
Reducing the amount of glucose absorbed by the liver cells
Increasing gluconeogenesis-conversion of amino acids and glycerol into glucose

Question 9

How insulin secretion is controlled

Answer 9

When blood glucose concentration is high , this is detected by B cels and insulin is released

1. At normal blood glucose level, K+ channels are open and K+ ions diffuse out of cell
2. When blood glucose increase glucose enters cel
3. Glucose is metabolised in mitochondria forming ATP
4. ATP binds to K+ channels causing them to close
5. Goes to -30mV and depolarisation occurs
6. Ca2+ ions enter, insulin seceretory vesicles move out

Question 10

How does cell signalling occur

Answer 10

Through one cel releasing a chemical which has an effect on another cel, known as a target cell

Question 11

What is an endocrine gland?

Answer 11

Specialise in secreting chemicals

Question 12

Where are adrenal glands located?

Answer 12

On top of the kidneys

Question 13

Structure of adrenal glands?

Answer 13

Adrenal cortex- produces hormones that are vital to life

Adrenal medulla- produces non essential hormones such as adrenaline and noradrenaline

Question 14

Hormones produced by cortex

Answer 14

Glucocortioids- regulate metabolism by controlling how body converts fats, proteins, carbs to energy
Mineralcortioids- helps control blood pressure, by salt and water concentration
Androgens- small amounts of male and female hormones

Question 15

Hormones produced by medulla

Answer 15

Adrenaline causes increase HR,Blood glucose and glycogen conversion to glucose
Noradrenaline- works with adrenaline

Question 16

Difference between type 1 and type 2 diabities

Answer 16

type 1- unable to produce insulin, B cells do not produce it

type 2- cannot effectively use insulin and control their blood sugar levels