Physiology wk2 Flashcards

1
Q

what is neuroendocrinology

A

the combination of the nervous system + endocrine system

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

what does the nervous system do

A

uses neurotransmitters to relay messages from one nerve tissue to another, or nerve to a tissue

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

how do hormones act

A

they are released into the blood by endocrine glands, they then bind to specific receptors to exert effect

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

what affects the effect of hormones on a tissue

A

plasma concentration, it alters their access to target tissue by either allowing greater access or restricts it

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

what is plasma concentration determined by

A

Rate of secretion of hormones from endocrine gland
Rate of metabolism/excretion of hormone
Quantity of the transport protein
Changes in plasma volume

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

what two types of influence do endocrine glands cause

A

they can either interfere or reinforce

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

what does the magnitude of effect depend upon

A

Concentration of hormones
Number of target receptors
Affinity of receptor to hormone
plasma concentration/volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is down-regulation

A

decrease in receptors in response to high concentration of hormone

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

what is up-regulation

A

increase in receptor number in response to low concentration of hormone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is the mechanism of steroid hormone action

A
  1. Hormone passes through membrane
  2. Hormone binds to receptor protein in cytoplasm/nucleus
  3. Hormone-receptor complex binds to hormone response element on DNA regulating gene transcription
  4. Protein synthesis
  5. Change in protein synthesis is cellular response
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what are the steps of glucose membrane transport mechanism

A

1.Insulin binds to the extracellular domain of the alpha-subunit of insulin receptor
2.The beta-subunit of one insulin receptor phosphorylates the other, allowing insulin response proteins to be activated
3.Phosphorylated insulin response proteins activate glycogen synthase
4.Glycogen synthase converts glucose into glycogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is the hypothalamus

A

this is the sector of the brain that controls secretion of the pituitary glands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what hormones does the anterior pituitary gland secret

A
  • Adrenocorticotropic hormone (ACTH)
  • Follicle-stimulating hormone (FSH)
  • Luteinizing hormone (LH)
  • Melanocyte-stimulating hormone (MSH)
  • Thyroid-stimulating hormone (TSH)
  • Growth hormone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what hormones does the posterior pituitary gland secret

A

*Oxytocin
*Antidiuretic hormone (ADH) – reduces water loss from the body, release is caused by high plasma osmolality and low plasma volume

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

what does aldosterone do

A

helps to regulate your blood volume/pressure by managing levels of Na and K in blood

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

how is aldosterone activated

A
  1. low plasma volume and blood pressure
  2. secretes renin at the kidney
  3. activates ANGIOTENSIN 1
  4. acted on by ACE (angiotensin converting enzyme)
  5. activates ANGIOTENSIN 2
  6. triggers aldosterone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is the definition of bioenergentics

A

the flow and exchange of energy within a living system, conversion of substance into useable energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is the definition of metabolism

A

the sum of all chemical reactions within the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what are the two types of metabolism

A

anabolic - synthesis of molecules
catabolic - breakdown of molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what does endergonic mean

A

requires energy to be added to the reactants (pushing a ball up a hill)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what does exergonic mean

A

this releases energy (pushing a ball down a hill)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what is special about coupled reactions

A

they use the liberation of energy from an exergonic reaction to drive and endergonic reaction
oxidation-reduction reactions are always coupled

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what is oxidation

A

the removal of an electron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what is a reduction reaction

A

the gaining of an electron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
what do enzymes do
lower activation energy by providing an alternative pathway to accelerate chemical reactions
26
what are the 4 main type of enzymes and what do they do
Kinase – adds Pi Dehydrogenases – remove hydrogen atoms Oxidases – catalyse oxidation-reduction reactions involving o2 Isomerases – rearrangement of the molecules structure
27
what factors affect enzymes activity
temp pH substrate availability
28
brief summary of glycolysis
glucose is phosphorlayted into pyruvate to go to krebs, H+ ions taken up by NAD rate limiting enzyme - phosphofructokinase
29
brief summary of anaerobic glycolysis
glucose is phosphorylated into pyruvate, no O2 available to take up H+ ions, they bond with pyruvate to form lactate rate limiting - lactate dehydrogenase
30
brief summary of krebs
pyruvate into acteyl coa, this is oxidised to form atp but more importantly FADH and NADH fro ETC rate limiting enzyme - isocitrate dehydrogenase
31
breif summary of ETC
electrons shot into inter-membrane space to create a gradient, come back down gradient making energy, o2 as last electron acceptor to form h20 rate limiting enzyme - cytochrome oxidase
32
what is an oxygen deficit
when we use anaerobic pathways to make energy as oxygen supply cant meet demand at start of exercise
33
what does o2 deficit lead to
EPOC - excess post exercise oxygen consumption
34
what happens in the rapid phase of epoc
resynthesis of pc replenish muscle myoglobin and haemoglobin o2 stores
35
what happens in slow phase of epoc
* Elevated HR and breathing increases * Elevated body temp to increase metabolic rate * Elevated blood levels of epinephrine and norepinephrine to increase metabolic rate * Conversion of lactic acid to glucose - cori cycle
36
why do endurance trained have less o2 deficit
* Greater regional blood flow * Increased cellular adaption/efficiency * Increased mitochondrial volume
37
How do you calculate RER
vCO2 divided by vO2
38
what does RER tell us
tells us how hard they're working and thus what substrate they're using to provide energy. RER = 0.7 = FATS RER = 1.0 = CHO
39
what factors affect what fuel we use
exercise intensity exercise duration
40
what is beta oxidation
the process of converting FFA into acetyl coA
41
at what intensities do we use what fuels
lower intensity and duration we use fats, as we increase both we use CHO due to more recruitment of fast twitch fibers that use glycolytic enzymes due to high epinephrine that stimulates glycolysis
42
what happens over a long duration event in terms of fuels
at first we will use CHO stores as it's more energy efficient to break these down, however as time goes on and these run out we will switch to fats as fuels due to increased lipolysis stimulatedby high levels of epinephrine, norepinephrine and glucagon
43
what is the lactate threshold
when blood lactate levels reach 4mmol/L, occurs at around 60% of vO2 max. Also called OBLA
44
possible reasons for lactate threshold
lower muscle oxygen accelerated glycolysis recruitment of fast twitch fibers reduced rate of lactate removal from the blood
45
what is the lactate shuttle
where lactate is produced in the muscle and transported to the liver to go through the Cori cycle
46
what causes DOMS
due to microscopic tears in muscle fibers leading to inflammation and edema (NOT DUE TO LACTIC)
47
name the endocrine glands
* Hypothalamus and pituitary glands * Thyroid and parathyroid * Adrenal glands * Pancreas * Testes and ovaries
48
how is plasma glucose maintained through fasting or exercise
1. Mobilization of glucose from liver glycogen stores 2. mobilization of FFA from adipose tissue 3. gluconeogenesis from amino acids, lactic acid and glycerol 4. blocking the entry of glucose into cells
49
what hormones control permissive or slow acting processes
thyroxine cortisol GH
50
what hormones control fast acting processes
epinephrine norepinephrine insulin glucagon
51
what do thyroid hormones do
influences the number of receptors on the surface increases the affinity of receptor to the hormone
52
what does T3 do
enhances the effect of epinephrine to mobilize FFA from adipose tissue
53
what does growth hormone do
* Increases amino acid take up and protein synthesis * Spares plasma glucose – reduces use of plasma glucose, increases gluconeogenesis, mobilizes fatty acids from adipose tissue
54
what does cortisol do
* Steroid hormone derived from cholesterol and secreted from adrenal cortex * Stimulated by stress (adrenocorticotropic hormone) and exercise * Contributes to maintenance of plasma glucose * Conc peaks in the morning and drops throughout the day * Proportional to increase in exercise intensity – mediated through slow process fo DNA transcription and translation to protein synthesis, thus may be related to tissue damage
55
what does the word catecholamines refer to
adrenalin (epinephrine/norepinephrine)
56
what effect can e/ne have upon tissues
increases all: hr glycogenolysis lipolysis vasodilation vasoconstriction
57
what happens to NE and E during exercise
it increases however in endurance exercise it causes a rapid decrease to a fixed intensity bout
58
what does the pancreas do
* Controls both exocrine and endocrine functions * Secretes counter-regulatory hormones from the ilses and Langerhans * Insulin from beta-cells * Glucagon from alpha-cells
59
what happens to conc of insulin during moderate intensity exercise
drops by 50% to favour glucose breakdown from the liver and FFA from adipose tissue
60
what is the main stimulus for change in insulin and glucagon
plasma glucose levels
61
why does FFA oxidation lower during exercise
* High levels of lactic * Elevated H+ conc and inhibits HSL * Inadequate blood flow to adipose tissue * Insufficient albumin to transport FFA in plasma epinpehrine stimulates glycolysis fast twitch fiber recruitment and use of more glycolytic vs lipolytic enzymes