Module 5.1.4 - Hormonal communication

Question 1

What are features of the hormonal system?

Answer 1

• transmission in blood
• slow transmission
• widespread response
• long lasting response
• may be permanent
• slow responses

Question 2

What does the endocrine system do?

Answer 2

Reacts to change and uses hormones to bring about a response

Question 3

What are the 2 hormone types?

Answer 3

Steroid hormones
Non-steroid hormones

Question 4

What are steroid hormones?

Answer 4

Lipid soluble, pass through lipid soluble component of cell membrane and bind to receptors in cytoplasm or nucleus

Question 5

What are non-steroid hormones?

Answer 5

Hydrophilic, cant pass directly through cell membrane, must bind to receptors on cell surface membrane instead

Question 6

What are the adrenal glands?

Answer 6

2 small glands on top of each kidney, stress glands

Question 7

What are the inside/outside tissues of adrenal glands made of?

Answer 7

Outside - gland tissue
Inside - nerve tissue

Question 8

What is the inside and outside of the adrenal glands called?

Answer 8

Outside - cortex
Inside - medulla

Question 9

What neurotransmitters does the medulla produce?

Answer 9

• adrenaline
• noradrenaline

Question 10

What hormones does the cortex produce?

Answer 10

Androgens - sex hormone, makes oestrogen, particularly post menopause
Mineralocorticoids - aldosterone, regulates blood pressure and osmotic balance
Glucocorticoids - cortisol, regulates metabolic rate

Question 11

What does the cortex secrete?

Answer 11

Steroid functions

Question 12

What does the medulla secrete?

Answer 12

Neural function

Question 13

Where is the pancreas found?

Answer 13

Behind stomach and in upper abdomen

Question 13

What are parts of the pancreas?

Answer 13

Gallbladder, body, head, tail, duodenum

Question 14

What does exocrine mean?

Answer 14

Releases enzymes into duodenum, such as lipase, amylase, protease
Gland has ducts to allow cells to secrete their products onto surface of target cells

Question 15

What does endocrine mean?

Answer 15

Insulin and glucagon, produce chemicals (hormones) that regulate blood sugar
Glands don’t have duct system and releases products into bloodstream

Question 16

What are Islets of Langerhans?

Answer 16

• small regions of endocrine tissue responsible for producing insulin and glucagon, lightly stained, larger spherical clusters
• alpha cells produce and secrete glucagon
• beta cells produce and secrete insulin

Question 17

What happens when staining Islets of Langerhans?

Answer 17

• use differential staining technique
• beta cell stained blue
• alpha cells stained pink

Question 18

What is glycogenesis?

Answer 18

Glucose -> glycogen

Question 19

What is glycogenolysis?

Answer 19

Glycogen -> glucose

Question 20

What is gluconeogenesis?

Answer 20

Amino acids - > glucose

Question 21

How do high blood glucose levels go back to normal?

Answer 21

• increase is detected by beta cells in pancreas
• insulin is produced which increases respiration
• glucose is converted to glycogen and fats
• glucose is absorbed
• blood glucose levels fall back to normal

Question 22

What is the normal blood glucose level?

Answer 22

90mg 100cm-3

Question 22

How do low blood glucose levels go back to normal?

Answer 22

• fall detected by alpha cells in pancreas
• glucagon produced
• glycogen and amino acids converted into glucose
• uncontrolled quantity of glucose enters from intestine

Question 23

Why does diabetes happen?

Answer 23

Pancreas doesn't produce enough insulin or the body can't effectively respond to insulin produced

Question 24

What are the symptoms of diabetes?

Answer 24

- high glucose conc - glucose in urine - excessive need to urinate - excessive thirst - constant hunger - weight loss - blurred vision - tiredness

Question 25

Why is human insulin used?

Answer 25

Pure form, less likely to cause allergic reactions, high quantities produced, cheaper, no religious/ethical concerns over animal products

Question 26

What is type 1 diabetes?

Answer 26

Autoimmune disease where body attacks beta cells in pancreas - no insulin produced as a result

Question 27

What is type 2 diabetes?

Answer 27

Condition based on lifestyle/diet - beta cells in pancreas don't produce enough insulin or not sensitive to insulin - glycoprotein insulin receptor malfunctioning - overweight - high carb diet

Question 28

What are some treatments for type 1 diabetes?

Answer 28

- insulin pump/injections - pancreas transplant - stem cell therapy - glucose drinks/sweets - balanced diet

Question 29

What are some treatments for type 2 diabetes?

Answer 29

- exercise - drugs - insulin injections - regular carb intake

Question 30

How does the endocrine system respond to change?

Answer 30

- hypothalamus activates adrenal cortical system by releasing CRF - pituitary gland secretes ACTH hormone - ATCH arrives at adrenal cortex and releases around 30 hormones

Question 30

How does the body respond to environmental changes?

Answer 30

Nervous and endocrine systems

Question 31

What is the main response of adrenaline?

Answer 31

- to trigger liver cells to undergo glycogenolysis - glucose released into bloodstream - adrenaline is hydrophilic son cant pass through cell membranes - adrenaline binds with receptors on surface of liver cell membrane - trigger chain reaction inside cell

Question 31

How does the neuronal system respond to change?

Answer 31

- hypothalamus activates sympathetic nervous system - actives adrenal medulla which releases noradrenaline and adrenaline into bloodstream - impulses activates glands and smooth muscle

Question 32

What is the action of adrenaline process?

Answer 32

1. hormone adrenaline approaches receptor site and activates adenyl cyclase 2. adrenaline fuses to receptor site, activates enzyme inside cell 3. activated enzyme converts ATP to cyclic AMP which acts as a second messenger that activates other enzymes that convert glycogen to glucose

Question 33

What is the average human heart beat a minute?

Answer 33

70 times a minute at rest

Question 34

What is heart rate controlled by?

Answer 34

Controlled by medulla oblongata in automatic nervous system

Question 35

What is the medulla oblongata?

Answer 35

- 2 centres linked by sinoatrial node in heart by motor neurone - impulses sent through sympathetic NS to increase heart rate by accelerator nerve - impulses sent through parasympathetic NS to decrease heart rate by Vagus nerve

Question 36

What are baroreceptors?

Answer 36

- detect changes in blood pressure - in aorta, vena cava and carotid arteries

Question 37

What are chemoreceptors?

Answer 37

- detect changes in levels of particular chemicals, pH - in aorta, carotid artery and medulla

Question 38

How do baroreceptors react to blood pressure increasing and decreasing?

Answer 38

- too high, impulses sent to medulla, parasympathetic neurones to SAN which decreases heart rate to normal levels - too low, impulses sent to medulla, sympathetic neurones to SAN which increases heart rate to normal levels

Question 39

What is hormonal control?

Answer 39

- fluctuates heart rate - adrenaline and noradrenaline increases frequency of impulses produced by SAN - speeds up heart rate

Question 40

What is the process of chemoreceptors

Answer 40

1. increased muscular/metabolic activity 2. more CO2 is produced by tissues from increased respiration 3. blood pH is lowered 4. centre in medulla oblongata that speeds heart rate, increases frequency of impulses to SAN via sympathetic nervous system 5. SAN increases heart rate 6. increased blood flow removes CO2 faster 7. CO2 level returns to normal