Mr Allsop- Hormonal communication

Question 1

outline how the hormonal system differs from the nervous system

Answer 1

transmission in blood, wide spread responses, long- lasting response that can be permanent, slow transmission and response

Question 2

what are steroid hormones

Answer 2

lipids so they can pass through the bilayer and bind to receptors in the cytoplasm or nucleus

Question 3

what are non-steroid hormones

Answer 3

hydrophilic so cannot pass through the membrane and must bind to receptors on the cell surface membrane

Question 4

where is the pancreas located

Answer 4

upper abdomen behind the stomach

Question 5

what’s meant by the pancreas being an exocrine gland

Answer 5

releases enzymes from pancreatic duct into duodenum which is at the top of the small intestine

Question 6

what 3 digestive enzymes are produced in the pancreas

Answer 6

protease, amylase lipase

Question 7

how does the pancreas act as an endocrine gland

Answer 7

secretes insulin and glucagon into the bloodstream produced by the islets of Langerhans which are small regions of endocrine tissue

Question 8

what are alpha cells

Answer 8

produce and secrete glucagon

Question 9

what are beta cells

Answer 9

produce and secrete insulin

Question 10

under the microscope what are the darker regions of the pancreas

Answer 10

acini cells- produce and secrete digestive enzymes (exocrine)

Question 11

under a microscope what are the lighter bands of the pancreas

Answer 11

islets of Langerhans- circular structure that secretes and produces hormones (endocrine)

Question 12

how are alpha and beta cells distinguished

Answer 12

differential dye- some retains dye better
crystal violet added, iodine to fix dye
alpha cells- stained pink
beta cells- stained blue

Question 13

where are the adrenal glands located

Answer 13

2 small glands located on each kidney

Question 14

what are the two main structures of the adrenal glands

Answer 14

adrenal cortex- outer region that produces hormones vital for life
adrenal medulla- inner region - produces non-essential hormones

Question 15

what are glucocorticoids that the cortex produces

Answer 15

includes cortisol which helps regulate metabolism by controlling how body converts fats, proteins and carbohydrates to energy, blood pressure and corticosterone which helps with immune response- controlled by hypothalamus

Question 16

what are mineralocorticoids that the cortex produces

Answer 16

aldosterone which helps control blood pressure by maintaining balance of salt and water concentration in blood and other bodily fluids - release mediated by signals triggered by kidney

Question 17

what are androgens that the cortex produces

Answer 17

sex hormones- makes oestrogen and testosterone released by ovaries or testes but is important for women post-menopause

Question 18

what hormones are released from medulla and their roles

Answer 18

nor-adrenaline and adrenaline-only released when nervous system is stimulated.
adrenaline- increases heart rate so blood is delivers quickly to muscles and brain as well as raising blood glucose levels by converting glycogen into insulin
nor-adrenaline- widening of air passages, narrowing of blood vessels - works with adrenaline

Question 19

what is the typical blood glucose concentration

Answer 19

19 mg/cm3

Question 20

what is the structure of glucagon

Answer 20

coiled protein, (alpha helix)

Question 21

what is the structure of insulin

Answer 21

globular protein with 2 polypeptide chains

Question 22

what happens when blood glucose levels rise

Answer 22

detected by beta cells, which produce insulin
increased cellular respiration, conversion of glucose into glycogen (glycogenesis), absorption of glucose into cells and conversion of glucose to fat lowers blood glucose levels

Question 23

what happens when blood glucose levels are too low

Answer 23

detected by alpha cells, which produce glucagon
conversion of glycogen into glucose (glycolysis)
conversion of amino acids into glucose (gluconeogenesis)
uncontrolled quantity if glucose enters from intestine and blood glucose levels rise

Question 24

what is the process of insulin secretion

Answer 24

at normal blood glucose levels, potassium-chloride channels in plasma membrane of B cells are open and potassium diffuses out of cell = -70mv
when level increases glucose enters via glucose transporter
glucose is metabolised inside mitochondria, resulting in production of ATP, that binds to potassium channels causing them to close (ATP- sensitive potassium channels)
depolarisation occurs= -30mv
voltage- gated calcium channels open which causes secretory vesicles to release insulin they contain via exocytosis

Question 25

what are some symptoms of diabetes and why

Answer 25

glucose in urine/ excess need to wee/drink- trying to get rid of glucose hunger/loss weight- no nutrition as being washed away tiredness- glucose is respiratory substrate of ATP - none blurred vision- damage organs

Question 26

what are some advantages of using bacteria to make insulin rather than cows/pigs

Answer 26

pure form- less likely to get allergic reaction high quantities produced cheaper costs no religious/ethical concerns

Question 27

what is type one diabetes

Answer 27

autoimmune disease where the B cells are destroyed so don't produce insulin

Question 28

what is the cause of type 1 diabetes

Answer 28

autoimmune/ inherited

Question 29

what are treatments of type 1 diabetes

Answer 29

inject insulin, transplant, stem cells

Question 30

what is type 2 diabetes

Answer 30

target cells no longer respond to insulin

Question 31

what are some causes of type 2 diabetes

Answer 31

poor diet- sugary etc. reduced exercise old age glycoprotein insulin receptor malfunctions

Question 32

what are some treatments of type 2 diabetes

Answer 32

improve diet, more exercise, medication, insulin injection

Question 33

what is meant by coordinated responses

Answer 33

responses to environmental changes through coordination of endocrine and nervous system

Question 34

outline how the flight or fight response is coordinated

Answer 34

the hypothalamus activates the sympathetic nervous system which not only activates glands and smooth muscle but also stimulates the adrenal medulla to release nor-adrenaline and adrenaline into the bloodstream simultaneously the adrenal-cortical system is activated by releasing CRF the pituitary gland then releases hormone ACTH that arrives at adrenal cortex and releases approx. 30 hormones

Question 35

what the purpose of pupils dilating

Answer 35

taken in as much light for better vision

Question 36

what the point of arterioles in the skin contracting

Answer 36

more blood to major muscle groups, brain, heart

Question 37

what is the point of blood glucose levels increasing

Answer 37

increases respiration to provide energy for muscle contraction

Question 38

what is the point of smooth muscle of airways relaxing

Answer 38

allow more oxygen into lungs

Question 39

what is the point of non-essential systems shutting down

Answer 39

focus resources on emergency functions

Question 40

what are some long term effects of continued stress

Answer 40

diabetes, pressure on cardiovascular system, low immune system

Question 41

how does adrenaline trigger glycogenolysis in liver cells

Answer 41

adrenaline is a non-steroid hormone so binds to bilayer as a first messenger this causes adenyl cyclase to be activates and converts ATP to cAMP which is a secondary messenger that phosphorylates protein kinases that activate all the enzymes involved in glycogenolysis

Question 42

what is the basic purpose of adrenaline

Answer 42

to tell the liver to break down glycogen into glucose

Question 43

Approximately how many times does the heart beat a minute?

Answer 43

70.

Question 44

What is the function and structure of the medulla oblongata?

Answer 44

Controls heart rate - controlled by autonomic nervous system. ## Footnote Two centres - one that increases heart rate, one that decreases.

Question 45

How is heart rate increased?

Answer 45

Sympathetic nervous system by accelerator nerve.

Question 46

How is heart rate decreased?

Answer 46

Parasympathetic nervous system - vagus nerve.

Question 47

What are baroreceptors?

Answer 47

Pressure detectors that detect changes in blood. ## Footnote Found in aorta, vena cava, carotid arteries (neck).

Question 48

What are chemoreceptors?

Answer 48

Detect changes in levels of chemicals in blood. ## Footnote Found in aorta, carotid arteries and medulla.

Question 49

What happens when blood pressure increases?

Answer 49

Baroreceptors detect change and send impulse to medulla oblongata to decrease heart rate by passing impulse along parasympathetic neurones (vagus nerve) to SAN.

Question 50

What happens when there is a high carbon dioxide concentration in the blood?

Answer 50

Chemoreceptors send impulse to medulla oblongata which travels down sympathetic neurones (accelerator nerves) to increase heart rate - get rid of waste product by transporting it to lungs for exhalation.

Question 51

How do hormones control heart rate?

Answer 51

Adrenaline and nor-adrenaline increase frequency of contraction produced by SAN, speeding up heart rate.