Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

A level Biology - Regular > Chapter 14 - Hormonal communication > Flashcards

Chapter 14 - Hormonal communication Flashcards

1
Q

What is an endocrine system ?
What are endocrine glands ?

A

Endocrine system is a system made up of endocrine glands
An endocrine gland is a group of specialised cells to secrete chemicals known as hormones DIRECTLY INTO THE BLOODSTREAM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

When are hormones secreted?

A

When glands are stimulated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

When can glands be stimulated ?

A

1) When there is a change in conc. of a substance
2) In response to another hormone or nerve impulse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How do hormones work ?

A
  • Secreted into the blood plasma
  • Transported all over the body and via the blood until it diffuses out and binds to specific receptors called target cells
  • Hormones will stimulate target cells to produce a response
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the two types of hormones ?

A

1) Steroid hormones
2) Non-steroid hormones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the features of steroid hormones ?

A
  • Lipid soluble
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How do steroid hormones work ?

A
  • Pass through lipid component of cell membrane and bind to steroid hormone receptors
  • Forms hormone-receptor complex
  • Complex acts as a transcription factor which facilitates transcription of a specific gene
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the features of non-steroid hormones ?

A

1) Protiens
2) Hydrophillic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How do non-steroid hormones work ?

A
  • Cannot pass directly through cell membrane
  • Bind to specific receptors on cell membrane of target cell
  • Triggers a cascade reaction mediated by chemicals called second messengers known as cAMP
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the differences of hormonal and nervous systems ?

A
  • Communication by nerves/hormones
  • Hormonal = slow
  • Nervous = fast
  • Hormonal = Travels everywhere
  • Nervous = Travels specific parts
  • Hormonal = Everlasting
  • Nervous = Temporary
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Where is the adrenal gland located ?
What is it made up of ?

A
  • Ontop of kidneys
    1. Adrenal cortex - Outer region
    2. Adrenal medulla - Inner region
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What do the adrenal cortex and adrenal medulla do ?

A
  1. Adrenal cortex = produces essential hormones like cortisol and aldostrone
  2. Adrenal medulla = Produces non essential hormones like adrenaline
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What controls the release of hormones from the Adrenal cortex ?

A
  • Production of hormones released by the cortex is controlled by hormones released by the pituitary gland
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the 3 main types of hormones released by the Adrenal Cortex ?

A

1) Glucorticaods I.E: Cortisol
2) Mineralocorticoids I.E: Aldosterone
3) Androgens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the features of Glucorticods ?

A

Example : - Cortisol
Function : - Helps regulate metabolism by controlling how body vconverts fats, proteins and carbs into energy also helps regulate blood pressure and cardiovascular functions during stress

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the features of mineralocorticoids ?

A

Example : - Aldosterone
Function : - Helps control blood pressure by maintaining balance between salt and water concentrations in the blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are androgens ?

A
  • Small amounts of male and female sex hormones
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

When is the Adrenal medulla stimulated ?

A
  • Hormones from adrenal medulla are released when symphatic nervous system is stimulated (Body is stressed)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the two main hormones released by Adrenal medulla ?

A
  1. Adrenaline
  2. Noradrenaline
20
Q

What are the features of Adrenaline ?

A
  • Increases heart rate; sends blood quickly to muscles
  • Increases blood-glucose conc. byb converting glycogen into glucose in the liver
21
Q

What are the features of Noradrenaline ?

A
  • Works with adrenaline to produce eddecrs (Increased heart rate)
22
Q

What are the two main roles of the pancreas ?

A
  1. Exocrine = Produces enzymes and releases them into the duodenum
  2. Endocrine = Produces hormones and releases them into blood
23
Q

What tissue carries out the pancreases exocrine functions ?

A

Pancreatic acini

24
Q

What do Pancreatic acini produce ?

A

Pancreatic juice (made up of digestive enzymes and pancreatic juices)

25
Q

Where do pancreatic juices go ?

A
  • Secreted into ducts which lead into pancreatic duct and then into duodenum
26
Q

What are the 4 main substances produces by pancreatic exocrine glands ?

A

1) Sodium hydrogencarbonate : - Neutralises acidic content in the stomach
2) Amylases : - Breaks starch into simple sugars
3) Tripsinagen : - Inactive but once active it tunes into trypsin and breaks down proteins into amino acids
4) Lipases : - Breaks lipids into fatty acids

27
Q

How does the pancreas act as an endocrine gland ?

A
  • Releases insulin and glucagon to control blood glucose conc.
28
Q

How are Islets of langerhans differentiated from pancreatic acini ?

A

Islets = Light stain, Sphere
Pancreatic acini = Dark stain, Small berry-like pyramidal

29
Q

What do islets of langerhans have and what do they produce ?
How are they differentiated ?

A

Alpha cells - Glucagon - Pink stain
Beta cells - Insulin - Blue stain

30
Q

What are the 3 main things that cause a rise in blood glucose concentration ?

A

1) Diet
2) Glycogenolysis - Breakdown of glycogen stores into glucose molecules released into bloodstream
3) Gluconeogenesis - Production of glucose from non-carbohydrate sources

31
Q

What are the 2 main things that cause a decrease in blood glucose concentration ?

A

1) Respiration - Glucose is used in resp.
2) Glycogenesis - Production of glycogen from glucose when blood-glucose conc. is too high

32
Q

What is the role of insulin ?

A

When blood-glucose concentration increases too high beta cells release insulin

33
Q

How is an increase in blood-glucose concentration detected by the body ?

A
  1. Body cells bind to insulin receptors (glycoproteins)thereby causing a conformation change in tertiary structure
  2. This causes the channel to open thereby more glucose enters the cell
34
Q

How is insulin released to control glucose conc. ?

A
  1. Cell surface membrane has K+ and Ca2+ channels
  2. K+ channels are open and K+ flows out leading to -70mV charge
  3. When blood-glucose conc increases the glucose moves into the cell via GLUT transporter proteins
  4. Glucose is matabolised to produce ATP via glucokinase
  5. ATP closes K+ channels and this alters P.D. (-30mV)
  6. This change in p.d. causes Ca2+ channels to open the influx of Ca2+ causes the vesicles of insulin to fuse with cell membrane thereby releasing insulin via exocytosis
35
Q

How does insulin reduce blood-glucose conc. ?

A
  1. Increase rate of absorbtion of glucose by cells
  2. Increases respiratory rate of cells
  3. Increases rate of glycogenesis
  4. Inhibits the release of glucagon from alpha cells
36
Q

What is the role of Glucagon ?

A

Raises blood glucose concentration by releasing glucagon directly into the bloodstream

37
Q

What are the 3 main ways glucagon raises blood-glucose conc. ?

A
  1. Glycogenolysis - Liver breaks fown glycogen into glucose
  2. Reduces the amounf of glucose absorbed into the liver
  3. Increases gluconeogenesis - Conversion of amino acids and glycerol into glucose
38
Q

What are the features of type 1 diabetes ?

A
  • Beta cells unable to produce insulin
  • Autoimmune response
  • Genetic
  • Early diagnosis
39
Q

What are the features of type 2 diabetes ?

A
  • Unable to use insulin
    Could be because :
    1. Patients beta cells do not produce enough insulin
    2. Patients body cells do not respond properly hence lose their responses to insulin
  • Result of excess body weight
40
Q

What are the treatments for type 1 diabetes ?

A
  • Controlled via regular injections
  • If too much is injected hypoglycaemia will be experienced resulting in unconsciousness
  • If too little is administered then hyperglycaemia will be experienced resulting unconsciousness
41
Q

What are the treatments for type 2 diabetes ?

A
  • Diet and exercise
  • Drugs that stimulate insulin production or slow down insulin production
42
Q

What are the benefits of making Insulin from Genetically modified bacteria ?

A
  • Human insulin produced in a pure form (less likely to be allergic to)
  • Produced in larger quantities
  • Cheaper production
  • Religious and ethical issues can be overcome
43
Q

What are the advantages of using stem cell treatment for diabetes ?

A
  • Donor availability is not an issue as an unlimited number of Beta cells are produced
  • Reduced likelihood of rejection
  • No longer require regular insulin injections
44
Q

What do the graphs look like between someone with type 1 diabetes and without after each has swalled a glucose tablet ?

A
45
Q

Why can Adrenaline not pass through the cell membrane ?

A
  • It is hydrophillic
46
Q

How does Adrenaline work in a fight or flight response ?

A

1 - Adrenaline approached receptor site
2 - Adrenaline fuses to receptor site; activates enzume Adenyl cyclase inside the membrane that was inactive
3 - Activated enzyme then converts ATP to cAMP which acts as a second messenger
4 - cAMP levels increase which activates specific enzymes called protein kinases which phosphorylate; activate other enzymes
5 - This triggers the conversion of glycogen into glucose which can increase rate of respiration

A level Biology - Regular (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions