5.4 Hormonal Communication

Question 1

Define endocrine system

Answer 1

A communication system that uses hormones as signalling molecules

Question 2

Define hormones

Answer 2

• Molecules (proteins or steroids) that are released by endocrine glands directly into the blood
• They act as messengers

Question 3

Define target cells

Answer 3

• cells that possess a specific receptor on their plasma membrane
• Many similar cells together form a target tissue

Question 4

Define adrenal cortex

Answer 4

The outer layer of the adrenal gland

Question 5

Define adrenal gland

Answer 5

One of a pair of glands lying above the kidneys

-release adrenaline and a number of other hormones (corticoids such as aldosterone)

Question 6

Define adrenaline

Answer 6

A hormone released from the adrenal glands

-stimulates the body to prepare for fight to flight

Question 7

Define adrenal medulla

Answer 7

The inner layer of the adrenal gland

Question 8

Define beta cells

Answer 8

Cells found in the islets of Langerhans that secrete the hormone insulin

Question 9

Define glucagon

Answer 9

a hormone that causes an increase in blood glucose concentration

Question 10

Define insulin

Answer 10

the hormone, released from the pancreas, that causes blood glucose levels to go down

Question 11

Define diabetes mellitus

Answer 11

A condition in which blood glucose concentrations cannot be controlled effectively

Question 12

Define stem cells

Answer 12

Unspecialised cells that have potential to develop into any type of cell

Question 13

What type of glands are endocrine glands

Answer 13

Ductless, hormones are released directly into the capillary

Question 14

Example of non steroid hormones

Answer 14

• Adrenaline
• Insulin
• Glucagon

Question 15

Examples of steroid hormones

Answer 15

• oestrogen

- testosterone

Question 16

Describe steroid hormones

Answer 16

• lipid soluble (can go through plasma membrane)
• can get to cells nucleus
• can affect DNA

Question 17

Describe non-steroid hormone

Answer 17

• cannot pass through membrane

- known as first messenger

Question 18

What do many non steroid hormones act via?

Answer 18

G protein in the membrane

-activates an effector molecule

Question 19

What is a common effector molecule?

Answer 19

• adenyl cyclase

- converts ATP to cyclic AMP and cAMP is the second messenger

Question 20

What may a second messenger do?

Answer 20

• Act directly on another protein

- Initiate a cascade of enzyme controlled reactions

Question 21

Three layers of adrenal cortex

Answer 21

• Zona glomerulosa - outermost layer (secretes mineralocorticoids)
• Zona fasciculata - secretes glucocorticoids
• Zona reticularis - secretes molecules that make sex hormones

Question 22

Example of mineralocorticoids

Answer 22

Aldosterone

Question 23

Example of glucocorticoids

Answer 23

Cortisol

Question 24

What hormones are derived from cholesterol

Answer 24

Steroid hormones produced in 3 zones

Question 25

What do mineralocorticoids do?

Answer 25

help control the concentration of sodium and potassium in the blood maintain blood pressure

Question 26

What does aldosterone do?

Answer 26

Acts on distal tubules and collecting duct - increases Na - decreases reabsorption of of K - increases water retention - increases blood pressure

Question 27

What do glucocorticoids do?

Answer 27

Control metabolism of carbohydrates, fats and proteins in the liver

Question 28

What does cortisol do?

Answer 28

Stimulates the production of glucose from stored compounds | Released in response to stress or low blood glucose

Question 29

What do androgen precursors do?

Answer 29

Taken up by ovaries or testes and converted into sex hormones, regulate production of gametes

Question 30

What are the main functions of the adrenal medulla?

Answer 30

Producing noradrenaline and adrenaline

Question 31

What is adrenaline not?

Answer 31

A steroid hormone

Question 32

What does adrenaline do?

Answer 32

- Relax smooth muscle in bronchioles - Increases stoke volume of heart and heart rate - Vasoconstriction (higher blood pressure) - Stimulating glycogen to glucose - Dilating pupils - Increasing mental awareness - Inhibiting gut action - Cause body hair to stand erect

Question 33

What are the main secretions of the pancreas?

Answer 33

- Pancreatic juices containing enzymes which are secreted into the small intestine - Hormones which are released into the islets of Langerhans

Question 34

What is the exocrine function of the pancreas?

Answer 34

Synthesise and release digestive enzymes into duodenum

Question 35

What does fluid from the pancreatic duct contain?

Answer 35

pancreatic amylase trypsinogen lipase hydrogen carbonate to make it alkaline

Question 36

What do alpha cells in the pancreas secrete?

Answer 36

glucagon

Question 37

What do the beta cells in the pancreas secrete?

Answer 37

insulin

Question 38

What do the islets of Langerhans contain?

Answer 38

Alpha and beta cells

Question 39

What are acini?

Answer 39

small groups of exocrine cells | (the lumen of them are branches of the pancreatic duct) they are grouped into lobules

Question 40

Where does the pancreatic duct go?

Answer 40

First part of small intestine | duodenum

Question 41

What is the duodenum?

Answer 41

The first part of the small intestine

Question 42

What does pancreatic amylase do?

Answer 42

amylase to maltose

Question 43

What does trysinogen do?

Answer 43

Converted do trypsin in duodenum

Question 44

What is glycogenesis?

Answer 44

Conversion of glucose to glycogen (less glucose)

Question 45

What is glycogenolysis?

Answer 45

Breakdown of glycogen to glucose (more glucose)

Question 46

What is gluconeogenesis?

Answer 46

Synthesis of glucose from sources that are not carbohydrate (e.g. amino acids and fats) (more glucose)

Question 47

Consequences of hypoglycemia

Answer 47

``` Reduced delivery of glucose impairment of brain function seizures tiredness confusion ```

Question 48

Consequences of hyperglycemia

Answer 48

Organ failure lower blood water potential osmotic problems and dehydration

Question 49

What cells detect too high blood glucose?

Answer 49

Beta cells

Question 50

Type 1 diabetes

Answer 50

Result of autoimmune response Beta cells attacked Can’t make insulin

Question 51

Type 2 diabetes

Answer 51

Not enough insulin Responsiveness to insulin decreases Obesity Lack of exercise and family history

Question 52

What are the endocrine functions of the pancreas?

Answer 52

hormones from islets of Langerhans into blood

Question 53

What do alpha cells secrete?

Answer 53

Glucagon

Question 54

What do beta cells secrete?

Answer 54

Insulin (and manufacture it)

Question 55

How do our bodies get rid of glucose in the blood?

Answer 55

Beta cells release insulin Insulin binds to receptor which is attached to TYROSINE KINASE This induces phosphorylation of inactive enzymes to enzyme cascade Vesicle containing glucose transporter proteins binds yo membrane and glucose enters cells

Question 56

Target cells of glucagon

Answer 56

Hepatocytes

Question 57

What cells detect low blood glucose?

Answer 57

alpha cells

Question 58

What cells detect high blood glucose?

Answer 58

beta cells

Question 59

Which hormone is released when blood glucose is low?

Answer 59

Glucagon

Question 60

Type 1 diabetes treatments

Answer 60

``` Insulin injections insulin pump islet cell transplantation pancreas transplantation possibly stem cells ```

Question 61

Type 2 diabetes treatments

Answer 61

``` changes in lifestyle weightloss regular exercise match carbohydrate intake and use medication severe cases = insulin injections ```

Question 62

Why is e coli better than pigs?

Answer 62

``` exact copy, faster acting more effective less of a chance of developing tolerance less of a chance of rejection lower risk of infection cheaper to make manufacture is more adaptable to demand fewer ethical/ moral concerns ```