MDS PREP
What is the primary function of Secretin?
1) Stimulating the release of insulin
2) Increasing bicarbonate secretion in the pancreas
3) Promoting gastrin release
4) Activating the secretion of pepsinogen in the stomach
The primary function of Secretin is to increase bicarbonate secretion in the pancreas, helping to neutralize gastric acid in the duodenum.
What is the role of the cholinergic system in the regulation of urinary bladder function?
1) Contraction of the detrusor muscle and relaxation of the trigone
2) Relaxation of the detrusor muscle and contraction of the trigone
3) Contraction of the urethral sphincter
4) Contraction of the urethral sphincter and relaxation of the detrusor muscle
The parasympathetic nervous system, which is cholinergic, stimulates the detrusor muscle of the urinary bladder to contract and the trigone muscle to relax, facilitating micturition (urination). This is mediated by the activation of muscarinic M3 receptors.
What is the primary method by which Secretin increases the secretion of bicarbonate by duct cells?
1) By increasing intracellular calcium levels
2) By increasing intracellular cyclic AMP (cAMP) levels
3) By stimulating the sympathetic nervous system
4) By activating the release of aldosterone
Secretin increases the secretion of bicarbonate by duct cells primarily by increasing intracellular cyclic AMP (cAMP) levels.
In the presence of antidiuretic hormone (ADH), which part of the nephron becomes highly permeable to water?
1) Proximal Convoluted Tubule (PCT)
2) Loop of Henle
3) Collecting Duct
4) Afferent Arteriole
In the presence of antidiuretic hormone (ADH), the collecting duct becomes highly permeable to water, allowing for increased water reabsorption and concentrated urine.
Which of the following is NOT an action of bile salts?
1) Emulsification of fat
2) Facilitation of fat absorption
3) Neutralization of stomach acid
4) Conjugation of bile acids
Physiology
Answer: 3
Bile salts are involved in the emulsification and absorption of fat, not in neutralizing stomach acid.
Elevation of aldosterone, in blood results in
1 Low 'Na' and low 'K' in urine
2 High 'Na' and high 'K' in urine
3 High 'Na' and low 'K' in urine
4 Low 'Na' and high 'K' in urine
Physiology
Answer: 2
Elevation of aldosterone, in blood results in High 'Na' and high 'K' in urine resulting in acidic urine and body alkalosis
What is the primary action of endorphins on the body?
1) Inhibition of pain
2) Stimulation of growth
3) Regulation of mood and emotions
4) Increased blood pressure
E. Regulation of sleep-wake cycle
Endorphins, particularly ?-endorphin, are opioid peptides that act as natural painkillers. They are released during stress and pain and bind to opioid receptors in the brain and spinal cord to inhibit the transmission of pain signals. While they do have secondary effects on mood and stress response, their primary function is pain inhibition.
What is the primary effect of thyroid hormones on cardiac output?
1) Decrease in heart rate and stroke volume
2) Increase in heart rate and stroke volume
3) Decrease in heart rate and decrease in stroke volume
4) Increase in heart rate and increase in stroke volume
Answer: 4) Increase in heart rate and increase in stroke volumeExplanation: Thyroid hormones, such as thyroxine (T4) and triiodothyronine (T3), enhance the effects of catecholamines on the cardiovascular system, leading to increased heart rate and stroke volume. This results in a higher cardiac output, which is essential for meeting the increased metabolic demands during stress or exercise.