Flashcards
Bioscience flashcards
Cards in this deck (62)
- 1What are the three general processes of urine formation?1. Glomerula filtration
2. Tubular reabsoption and secretion
3. Urine processing - 2Describe glomerula filtration. Why does it occur?1. Fluid is forced out of glomerulus (a tuft of capillaries) into the Bowman's capsule.
2. The filtrate then passes into the proximal convoluted tubule.
This occurs due to differences in the hydrostatic pressure (forces fluid out) and the oncotic pressures (keeping fluid in). - 3Name the areas of a nephron and their functions.Glomerulus - Filtration
Bowman's Capsule
Proximal tubule - reabsorption of protein, glucose, electrolytes.
Loop of Henle:
Ascending - permeable to ions
Descending - permeable to water
Distal tubule - reabsorption
Collecting duct - urine concentration - 4The permeability of the collecting duct to water is regulated by what?Anti-diuretic hormone and aldosterone.
- 5What is the method of action of anti-diuretic hormone (ADH)?Causes artery constriction and reabsorption of water in the collecting duct by inserting aquaporins (water pores) into the cell membrane.
- 6What is the method of action of aldosterone?Steroidal hormone.
Binds to mineralocorticoid receptor in collecting duct.
Increases production of sodium-potassium pumps and sodium protein channels.
Increases the osmotic pressure enhancing water absorption by ADH. - 7What are the three groups of diuretics? Where in the nephron do they act? Give an example of each.1. Loop diuretics - ascending Loop of Henle (which is permeable to ions) Eg. Furosemide
2. Thiazide diuretics - distal convoluted tubule (Think: D for diuretic = distal!) Eg. Chlorothiazide
3. Potassium-sparing diuretics - act on collecting duct. Eg. Spironolactone - 8What is particularly important to consider about loop diuretics?Furosemide toxicity - tinnitus, circulatory collapse, seizures.
Arrythmias due to hypokalemia.
Interactions with aminoglycoside abx - causing deafness. - 9What are some of the main indications for loop diuretics?CHF, ascities with oedema, renal failure, pulmonary oedema.
- 10What is the mechanism of action for potassium sparing diuretics? Give an example. What are some indications for use of a potassium sparing diuretic above thiazide/loop diuretics?Eg. Spironolactone
Competes with aldosterone (steroidal hormone increasing the number of sodium carrier proteins) to block mineralocorticoid receptor therefore reducing production of Na carrier proteins.
Indications: when hypokalemia is exceptionally harmful, eg. individuals taking digoxin or amiodarone.
HF, hyperaldosteronism (Conn's syndrome) - 11What are some adverse effects of diuretic therapy?Potassium loss can cause fatal arrythmia.
Drug interaction resulting in toxicity, eg. Digoxin
Hypo/hyperkalemia (high/low potassium)
Acidosis - 12Into which areas are the following hormone groups secreted? Endocrine Autocrine ParacrineEndocrine - released into the blood stream
Autocrine - acts on the same cell that secretes it
Paracrine - realeased into surrounding tissue - 13In regulation of BP, what is the second messenger? What is the target?Seond messenger - Calcium
Target - beta 1 adrenergic receptor - 14Targets tend to be receptors or enzymes. True or false?True!
- 15Which hormones are secreted by the posterior pituitary?Oxytocin and Anti-diuretic hormone (ADH)
- 16Which hormones are secreted by the anterior pituitary?Everything but oxytocin and anti-diuretic hormone! (ADH)
ACTH, thyroid stimulating hormone (FSH), gonadotrophic hormone etc. - 17What is Cushings' disease?Primary adrenal gland defect or excessive ACTH secretion.
- 18What is Addisons' disease?Hypoadrenocorticism
- 19What are the endocrine cell types of the pancreas? What is their function?Alpha cells - secrete glucagon
Beta cells - secrete insulin
Gamma cells - produce pancreatic peptide
Delta cells - secrete somatostatin - 20Glucose is stored as what?Glycogen
- 21When blood glucose is low, ______ is broken down by _______ to ______?Glycogen is broken down to glucose, by glucagon.
Think: when glucose is GONE - glucagon! - 22Blood pressure is controlled by a negative feedback mechanism. True or false?True!
Detected by baroreceptors (pressure receptors)
Renin --> Angiotensin --> Aldosterone system - 23Where is renin secreted from? In response to what?Renin is secreted by the kidneys in response to low BP or low serum sodium.
- 24Angiotensin II is converted to _____ by _____? ________ can stabilise blood pressure by preventing this.Angiotensin II is converted to aldosterone by angiotensin converting enzyme (ACE)
ACE inhinitors stabilise blood pressure by preventing aldosterone being produced and increasing BP. - 25Renin cleaves ______ to Angiotensin I?Angiotensinogen
- 26Where is angiotensin I converted to angiotensin II?In the lungs.
- 27What is aldosterone?A steroidal hormone that causes sodium retention.
- 28What is conductive tisssue?Specialised muscle (less elastic than myocardium) that has the ability to automatically generate an electrical impulse.
- 29What is stroke volume?Volume of blood ejected from each ventricle on each contraction.
- 30What is cardiac output?Volume of blood ejected by the heart in one minute.
- 31What is the equation of cardiac output?Cardiac output = stroke volume x heart rate
CO = SV x HR - 32How many pairs of chromosomes do humans have?23
- 33What are the nitrogenous bases in RNA?A C U G
Uracil replaces T - 34What is transcription?DNA -----> RNA
RNA polymerase reads the DNA template strand to make mRNA. - 35What is translation?RNA -----> protein
mRNA attaches to ribosome. Ribosome reads mRNA and tRNA transports corresponding amino acids to create complementary base pairs. - 36Define genotype and phenotype?Genotype - genetic make-up, inherited from parents. Alterations occur at conception.
Phenotype: observable characteristics determined by genotype and environment (phenotypic polymorphisms etc.) - 37What is an allele?Genes that contain different descriptive data about the same trait, eg. eye colour, blood group, height.
- 38What is co-dominance?When two alleles are equally dominant. Eg. blood group - A & B forming group AB.
- 39What is incomplete codominance?Pink flowers!
One allele is not completely expressed over another, resulting in a third phenotype.
Eg. red & white flowers - pink flowers. - 40Give an example of a genetic disorder that occurs at the result of a point mutation?Cystic fibrosis
Sickle cell anaemia
Long QT - 41How many chromosomes does a daughter cell produced by meiosis have? Are they haploid or diploid cells? Where does meiosis occur?23 chromosomes (haploid)
In reproductive cells/gonadal. - 42Define oncotic pressure.A gradient caused by unequal distribution of macromolecules (eg. proteins & peptides) across a membrane.
- 43Define homeostasis.Maintenance of a constant internal environment.
- 44What is diffusion? Is this an active or passive process? (Does it require energy?)Diffusion is the movement of solute from a high concentration to a lower concentration.
It is passive, going with the concentration gradient and therefore does NOT require energy. - 45What are factors that cause fluid extravasation?Increased BP.
Blocked lymph drainage
Inflammation
Liver failure - 46What are factors that cause fluid retention?Hypernatremia (high sodium)
Renal failure - 47Give an example of a positive feedback mechanism?Childbirth - oxytocin/muscle contractility
- 48Define agonist and antagonist drugs.Agonist - drug with a high affinity and high intrinsic activity.
Antagonist - drugs with a high affinity but no intrinsic activity. - 49What are the two kinds of antagonist? What do they do?Competitive antagonist - compete for the same receptor as the agonist.
Non-competitive antagonist - bind somewhere other than the natural ligand site and incapacitate receptor. - 50What is the role of the golgi apparatus?To produce and mature proteins in collaboration with the endoplasmic reticulum.
- 51Give examples of amine hormones?Catecholamines
Thyroid hormone - 52The CNS exerts rapid control via impulses and neurotransmitters. True or false?True!
- 53Calcium is not a secondary messenger. True or false?False.
Calcium is a secondary messenger. - 54Give an example of an adrenal steroid/mineralocorticoid steroid?Aldosterone!
- 55What are islets?Pancreatic cells that are richly vascular so that hormones secreted have rapid access to circulation.
- 56Glucagon is secreted in response to hypoglycemia. True or false?True.
- 57What is diabetes mellitus?Beta cell disease. (Pancreatic beta cells secrete insulin.)
Type 1 = no secretion of insulin.
Type 2 = insufficient or resistance to secreted insulin. - 58Dendrites conduct nerve impulses ________ the cell body. Axons conduct nerve impulses _______ from the cell body. Towards, away.Dendrites conduct nerve impulses TOWARDS the cell body.
Axons conduct nerve impulses AWAY from the cell body. - 59Schwann cells facilitate _________ conduction.Saltatory conduction.
- 60What are the functions of: Bronchi Alveoli NoseBronchi - regulates airflow by regulating diameter.
Alveoli - remove foreign bodies from air, gaseous exchange surface.
Nose - filters and moisturises air. - 61What are the functions of the two types of alveolar cells?Type 1 - main respiratory surface (gas exchange)
Type 2 - inflammation response, secrete surfactant and clear alveolar sac. - 62What is FEV1?The measure of air volume forcefully blown out in one second.