Professor Mohankumar’s Lectures Flashcards
What is blood made up of?
Plasma
Buffy coat
Erythrocytes
What is plasma made up of?
90% water
10% soluble components e.g
-Plasma proteins
-Nutrients - glucose, cholesterol
-Gases - CO2, O2
-Electrolytes
What is the process of forming blood cells
Haematopoiesis
Where does haematopoiesis occur?
In red bone marrow
What does the buffy coat contain?
White blood cells
Leukocytes
Thrombocytes
What is the term for deficiency?
Penia
What is the term for excess?
Philia
How is erythropoiesis regulated
Negative feedback loop:
The kidney senses low O2 in renal artery triggering the release of erythropoietin (EPO) which stimulates bone marrow to produce erythrocytes. Erythrocytes increase O2 resulting in the decrease of EPO
What are the symptoms of dwarfism
Anxiety, depression, poor muscle tone, impaired hair growth, increase adipose tissue, decreased lean body mass
What are the symptoms of Gigantism/acromegaly
Enlarged hands/feet, headaches, blurred vision, glucose intolerance (diabetes), hypertension, coarsening of face
What are the symptoms of Graves’ disease (hyperthyroidism)
Weight loss, sweating, heat intolerance, goitre, nervousness
What are the symptoms of Primary hyperaldosteronism (Conn’s syndrome)
Hyper secretion of aldosterone, low blood potassium levels, high blood sodium levels
What are the symptoms of excess cortisol (cushing’s syndrome)
Buffalo hump, obesity, high blood pressure/sugar, cognitive difficulties, stretch marks
What is grave’s disease?
Hyperthyroidism - over production of thyroid hormones
What is conn’s syndrome?
Hyperaldosteronism - too much aldosterone
What is Cushing’s syndrome?
Hypersecretion of cortisol
What are the symptoms of low ADH
Diabetes insipidus - polyuria and polydipsia, inadequate release of ADH
What is Addison’s disease
Hyposecretion of cortisol
What are the effects of Hyposecretion of cortisol (Addison’s)
Darkening of skin, hair loss, decreased appetite, weight loss
A drug is something that…
Has a defined chemical structure
Prompts physiological response
Is specific
Pharmacodynamics is…
What the drug does to the body
Pharmacokinetics is…
What the body does to the drug
What barriers do drugs experience
ADME:
Absorption in the GI tract
Distribution, may not get past blood brain barrier
Metabolism
Excretion
What does adrenaline do to the heart
Activates the sympathetic NS and increases heart rate as well as force of contraction (beta 1 receptor)
What does adrenaline do to the lungs?
Relaxes airway and dilates smooth muscles, higher gas exchange (beta 2)
The drug must act on the right target and the target gives the right site for it to bind and release the drugs effect
Drugs targeting enzymes can be inhibitors or substrates
What is the difference between competitive and non competitive enzymes?
Competitive directly compete for the space in the active site
Non-competitive binds to another part of the enzyme and changes the shape of the actual active site
What do the transporters on synapses do?
They recycle the neurotransmitters by putting them back into the presynaptic cleft
What does cocaine do?
They block the transporters on the membrane which stops the neurotransmitters from being recycled back into the pre synaptic cleft which means more neurotransmitters bind to the receptors
What are the key types of receptors
Nuclear receptor
Ligand gated ion channels
Catalytic receptors
G-protein coupled receptors
What is an agonist in pharmacology?
A drug which acts on the same binding site which prompts a similar response to a neurotransmitter
What is an antagonist in pharmacology?
A drug which acts on the same binding site, which stops more neurotransmitters and agonists from binding to the receptor which decreases the response
What is affinity in pharmacology?
How well the drug/ligand binds to it’s receptor
What is efficacy in pharmacology?
Once something is bound, it’s how well a drug/ligand activates the receptors, or how much of a conformational change there is
What must agonists have in a pharmacological sense, to be good drugs?
Good affinity and efficacy
What would make a good antagonist drug in a pharmacological way?
It only has good affinity, does not prompt a response from the receptor. Antagonist blocks the agonist response
Equilibrium dissociation constant is the empirical measurement of affinity measure
What dies kD defined as
The concentration of drug required to occupy 50% of receptors (measure of drug affinity)
Lower kD means the drug has…
A stronger affinity to receptors
10-3 milimolar 10-6 micromolar 10-9 nanomolar
Potency is…
The strength of the biological response
Efficacy is…
How well a drug can activate a receptors
Full agonists are…
Agonists which produce a 100% response in a receptor
Partial agonists are
Agonists which produce less than 100% response
Non competitive agonists can be either…
Allo - different
Steric - Binding site
If the antagonist is reversible and competitive, by increasing the agonist the effect of the antagonist is minimised
A full agonist is when it gets a maximum response (Rmax/100%)
What is occupancy?
The binding of an agonist/antagonist to a receptor
Ligands are often
Peptides or proteins
A drug has to be unionised because…
It must be neutral to pass through a plasma membrane
The liver is the metabolic hub, but how does it help in association with the GI?
It acts as the area which separates bacteria, toxins, drugs and food as the GI just absorbs everything. The liver acts as the barrier. When it goes through the liver this is known as the first pass.
Oral drug route
Gut -> liver -> Kidney -> site of action
Drug metabolising enzymes in the liver include…
Cytochromes P450
Alcohol dehydrogenase
Esterases
The liver and the enzymes in it turn drug molecules to polar molecules so they can be excreted
If you increase the metabolic activity of an enzyme the drug will be metabolised quicker so the drug isn’t available for as long in the body
Drug metabolism is a two step process
Phase 1 - oxidation, reduction, hydrolysis
(NADPH + O2 required)
Phase 2 - Conjugation, adding polar groups
(OH, NH2, COOH)
The higher the concentration of drug the higher the elimination
What are the layers of the GI tract?
Lumen - epithelial tissue
Mucosa - thin layer epithelial tissue, secretes enzymes, mucus and hormones
Submucosa - thick layer connective tissue, has blood cells, lymphatic vessels, nerves and glands which aid in peristalsis
Circular muscle layer - blood vessels and nerves for innervation
Longitudinal muscle layer - Peristalsis (involuntary)
Serosa - thin connective tissue with blood + lymphatic vessels. Secretes serous fluid which grant lubricated sliding movement between surfaces