Brainscape's Knowledge GenomeTM

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


See full index

Medicine - Year 1 > Block 1 - Foundations of Medicine - Week 4 > Flashcards

Block 1 - Foundations of Medicine - Week 4 Flashcards

1
Q

Why is sigalling needed

A

Cognition, development, growth, homeostasis, infections, injury, movement

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

Give 10 examples of chemical and electrical signals

A

Amino acids, cytokines, gases, growth factors, hormones, ions, light, neurohormones, neurotransmitter, peptides

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

What are neurohormones

A

Hormones released by neurones

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

How do target cells produce responses

A

Signal transduction pathway

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

4 examples of short range signalling

A

Direct, intacrine, autocrine, juxtacrine

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

What happens during direct signalling?

A

GAP JUNCTIONS

Adjacent cells have channel proteins which join them together

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

What happens during intacrine signalling?

A

The ligand binds to a receptor on the cell nucleus to regulate intracellular function

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

What happens during autocrine signalling?

A

Cell secretes a substance which binds to the cell membrane of the cell which secreted it

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

What happens during juxtacrine signalling?

A

A protein on the outside of the cell triggers a response on a neighbouring cell which has physical contact

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

What is medium-range signalling called?

A

Paracrine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Define neuron

A

Nerve cell

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

Define nerve

A

Enclosed bundle of axons in the PNS

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

What is the difference between a multipolar, bipolar and unipolar nerve

A

Multipolar: many dendrites; one axon
Bipolar: 1 dendrite; 1 axon
Unipolar: bipolar but cell body in another place

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the roles of neuroglia?

A 
Supports, insulates  and supplies nutrients to neurones
Kills dead neurones
Regulate extracellular space
Immune response
Moderates neurotransmission
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the endoneurium?

A

Connective tissue which surrounds each nerve fibre

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

What is the fasciculus?

A

bundles of nerve fibres surrounded by a layer of connective tissue called the perineum

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

What is the epineurium?

A

Layer of connective tissue which surrounds each nerve

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

Define tract

A

Bundle of axons in the CNS

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

5 roles of the cerebral cortex

A

Emotions, memory, motor control, sensory input and voluntary movements

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

What are the 6 lobes of the cerebral cortex and their roles?

A

Frontal: Cognitive thinking, decision making and planning
Parietal: Spacial awareness and interaction
Temporal: Hearing
Occipital: Vision
Cerebellum: Memory

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

What happens in Myasthenia Gravis?

2 symptoms

A

Antibodies against Ach receptors block Ach binding

Weak muscles and droopy eyes

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

What happens in Lambert-Eaton Myasthenic syndrome?

1 symptom

A

Antibodies against calcium channels prevent Ach release

Weak muscles

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

What is the difference between long and short term cell signalling?

A

Short term: Modification and release of proteins which are already there
Long term: Transcription factors are altered permanently to synthesise new molecules

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

How do ligand gated ion channels work?

A

Let the ions into the cell through gated pores

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Give 3 examples of effector proteins which are activated by the receptor and protein cascade

A

Cytoskeletal proteins
Gene regulatory proteins
Metabolic enzymes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Give 4 examples of second messengers

A

Calcium
Cyclic nucleotides
Lipids
Phosphoinositols

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What happens in a protein cascade?

A

Successive phosphorylation of specific proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

How are cyclic nucleotides formed?

A

ATP + adenylate cyclase –> cAMP

cAMP –> 5’AMP (phosphodiesterase)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

How are phosphoinositols and lipids formed?

A

Phosphatinfdyl inostiol (PI) –> PIP –> PIP2 –> DAG and IP3

DAG and IP3 are examples of phosphoinositols and lipids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

How does phosphorylation occur?

A

By the action of a protein kinase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What are the two types of kinases and their roles?

A

Kinases that phosphorylate serine and threonine

Kinases that phosphorylate tyrosine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What can ATP work as?

A

A second messenger

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

How are molecules turned off?

A

Protein phosphates form ATP from ADP which removes the phosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Explain how the G-protein coupled receptor works

A

The ligand binds to the G-protein receptor which causes a conformational change in the G-protein

GDP which is attached to the G-protein falls off and is replaced by GTP - this is attached to a phosphate which causes downstream signalling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Explain how the G-protein is a trimeric protien

A

Monomeric small molecular weight ATPases:
Single GDP/GTP binding proteins

Heterotrimeric G proteins:
Alpha causes phosphorylation by activating second messengers
Beta and Gamma separate from the alpha subunit and cause stimulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What are the three classes of G protein?

A

Gq: Phospholipase C
Gi: Adenylate cyclase and cAMP cause a NEGATIVE effect downstream
Gs: Adenylate cyclase and cAMP cause a POSITIVE effect downstream

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is the difference between muscarinic and nicotinic receptors?

  • receptor
  • location and function
A

Muscarinic: GPCR; decreases heart contraction and increases secretion of salivary glands
Nicotinic: Ion channels; increases skeletal muscle contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What are the two classes of kinase linked receptors?

A

Intrinsic tyrosine kinase activity receptors

Tyrosine kinase linked receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What is the downstream signalling cascade for kinase receptors?

A

MAP kinase kinase kinase –> MAP kinase kinase –> MAP kinase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Explain how intrinsic kinase linked receptors work

What is the difference between tyrosine kinase activity receptors and tyrosine kinase linked receptors

A

Ligand causes dimerisation and phosphorylation which causes downstream signalling
Activity: Transmembrane protein with a domain in the cell
Linked: Single pass transmembrane protein bound to the kinase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What are tyrosine kinase activity receptors for?

A

Receptors for growth factors and insulin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What are tyrosine kinase linked receptors for?

A

Receptors for interferons, interleukins and growth hormones

43
Q

Define drug

A

Man-made molecule found inside/outside the body which exerts a biochemical physiological effect on the organism which affects its function

44
Q

Define receptor

A

Protein molecule that recognises and responds to endogenous chemical signals

45
Q

Define endogenous

A

Inside the cell

46
Q

Define drug targets

A

Marcomolecules which drugs interact with

47
Q

How do drugs bind to their receptors?

A

Drugs are ionic so will align the charges on the receptor causing a conformational change in the protein structrue which changes the way that it works

48
Q

What is the timecourse?

What decreases it?

A

The time taken for the drug to bind to its receptor

Higher temperature of interstitial fluid = increased kinetic energy and decreased time

49
Q

Define specificity

A

The degree to which the effects of a drug are due to one pharmacological action

50
Q

Define affinity

A

The strength of the non-covalent bonds between drug and receptor are measured by Kd of the drug receptor complex

51
Q

Define Kd

A

The concentration when half the drug is bound to the receptor at equilibrium
Drug binding is proportional to drug effect
50% response rate = 50% of the drug bound

52
Q

Define pharmacodynamics

A

The study of drug-receptor interactions

53
Q

Why is the dose-response relationship graph ‘s’ shaped?

A

The majority of drug change is at small concentrations so the graph is a ‘log’

54
Q

Define potency

What 2 things does it depend on?

A

The drug dose needed to produce a specific effect of a given intensity
It depends on efficacy and affinity

55
Q

Define efficacy

A

Emax

The maximum response achievable from a drug in the target system

56
Q

What happens to Kd if you have a drug with a higher affinity

A

Drugs with a higher affinity need less drug to get 50% binding

57
Q

Which state of receptor does the agonist, inverse agonist and antagonist work on?

A

Agonist: Active state
Inverse agonist: Inactive state
Antagonist: Inactive and active state

58
Q

What do drugs target if they bind to ligand-gated ion channels?

A

Brain

Cardiac and skeletal muscle

59
Q

What do drugs target if they bind to G-protein coupled receptors?

A

Alter levels of secretion

60
Q

What do drugs target if they bind to receptor kinases?

A

Alter duplication, growth and maturation

61
Q

What do drugs target if they bind to nuclear receptors?

A

Transcription and translation

62
Q

Define pharmacokinetics

A

Process by which the drug enters the body and becomes bio-available so it can bind to the receptor and create cellular change

63
Q

What are the 4 stages of how drugs work?

A

Absorption - Distribution - Metabolism - Excretion

64
Q

Define drug absorption

A

The mechanism of accumulation of the drug into the body compartment that you want it to be in

65
Q

Define haematically sealed

A

Airtight

66
Q

What two states can drugs be in?

What does it depend on?

A

Acid or base

Differences in IONISATION

67
Q

What is pKa?

A

log[H+] that gives 50% of H+ bound to the drug molecule

68
Q

Is a drug ionised when pH = pKa?

A

No

69
Q

Define volume of distribution
What does it quantify?
What are its units?

A

Theoretical volume that the total administered drug would have to occupy (if it was uniformly distributed) to provide the same concentration as it currently is in blood plasma
Quantifies drug ability to pass through lipid membranes
(mls)

70
Q

What is the vd of a:

  • Very ionised drug?
  • Lipophilic drug?
  • Drug bound to globulin?
A
  • Very ionised drug: Low as it will stay in the plasma
  • Lipophilic drug: High as it will not stay in the plasma
  • Drug bound to globulin: High as the dose is higher
71
Q

Define drug metabolism

A

Chemical alteration of a drug into its inactive form

72
Q

7 ways that the liver metabolises drugs

What does it require?

A

Condensation, conjugation, hydration, hydrolysis, isomerisation, oxidation and reduction
High energy

73
Q

When is a prodrug useful?

A

If you cannot make a drug with the right pKa for absorption

74
Q

Why do you need to be careful about increasing dosage due to the first pass effect?

A

Some people’s livers work better than others due to the environment (e.g. alcohol) or genetics

75
Q

How many cytochrome p450 enzyme gene families are there?

How do they differ?

A

74 gene families differing in their gene families and specificity of reactions

76
Q

Which genes are involved in drug metabolism?

A

CYP1, CYP2, CYP3

77
Q

How do cytochrome p450 enzymes work?

A

They have a haem group which exchanges electrons causing oxidation and reduction

78
Q

Where are the electrons supplied from for oxidation and reduction by P450’s?

A

Supplied from a flavoprotein which supplies electrons from NADPH to CYP450

79
Q

Define induction

A

Decreased plasma drug concentration

1 drug increases CYP450 so the concentration of the other drug decreases –> decreased therapeutic effect

80
Q

Define inhibition

A

Increased plasma drug concentration

1 drug decreases CYP450 so the concentration of the other drug increases –> toxicity

81
Q

What is phase 2 metabolism

A

Molecules are conjugated to make them more soluble and ionic so they can be excreted in the bile or urine

82
Q

What happens during glucuronidation?

A

A protein in the liver changes the drug shape

83
Q

What does adding amino acids do?
What amino acids are added? (2)
Why is this dangerous in neonates?

A

Changes the drug shape
e.g. lutamine and glycine
Slower in neonates

84
Q

What does adding sulphate esters do?

A

Makes the drug more polar

85
Q

How is aspirin metabolised?

A

Aspirin –> Salicyclic acid –> Glucononide

86
Q

4 roles of the kidney

A

Conserve salt and water
Control pH
Drug excretion
Regulates fluid volume and electrolytes

87
Q

What is Cp?

A

The concentration of drug in blood plasma

88
Q

What do you assume that Cp relates to?

A

The drug concentration in the active tissues

89
Q

What does the target concentration strategy use?

A

Therapeutic drug monitoring

90
Q

What happens during therapeutic drug monitoring?

A

Guess the dose based on the patients size, lifestyle, fat:muscle ratio and adjust the dose accordingly

91
Q

When is therapeutic drug monitoring used?

A

For toxic drugs in hospitals

92
Q

3 things that alter Tmax

A

1st pass effect
Absorption rate
Metabolism

93
Q

Define Kabs

A

A rate constant that governs the transfer of drug to the central compartment
Proportional to the amount of drug still unabsorbed

94
Q

How will Cp decline after absorption is complete?

A

At the same t 1/2

95
Q

What does the single compartment model assume?

A

The body is one compartment

Once the drug enters the body, it reaches every compartment

96
Q

What is the equation for the single compartment model?

A

Initial drug concentration (C0) = Drug mass (Q) / Vd

97
Q

How can you estimate C0 and plasma concentration?

A

Extrapolate the semi log plot of Cp over time to zero

98
Q

What elimination half life (t 1/2)

A

The time taken for Cp to fall by 50%

99
Q

What 3 things does elimination half life predict?

A
  • How long the drug will be in the system at a pharmacologically active level
  • What will happen after the drug has been administered before it reaches a steady state ( when administration = metabolism)
  • What will happen when Cp falls to zero (when another dose is needed)
100
Q

3 criticisms of the single compartment model

A
  • Assumes rates of absorption, metabolism and secretion are directly proportional to drug concentration
  • Doesn’t look at other compartments
  • Oversimplified
101
Q

What does the two compartment model assume?

A

There is a central compartment and a peripheral compartment which drugs enter via the plasma

102
Q

What are the two phases on the Cp timecourse if you are looking at the two compartment model?

A

Fast phase: Transfer between central (plasma) and peripheral (tissue) compartments
Slow phase: Estimates half life

103
Q

How is the fast and slow phase found?

A

Experimentally

104
Q

When is the fast and slow phase similar?

A

When metabolism is fast

Medicine - Year 1 (20 decks)

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