MDS PREP
In which part of the nephron does the reabsorption of glucose and amino acids primarily occur?
1) Proximal Convoluted Tubule (PCT)
2) Loop of Henle
3) Distal Convoluted Tubule (DCT)
4) Collecting Duct
The reabsorption of glucose and amino acids primarily occurs in the Proximal Convoluted Tubule (PCT), where these nutrients are actively transported back into the bloodstream.
What is the osmolarity of the tubular fluid leaving the ascending limb of the loop of Henle?
1) 300mOsm/L
2) 100mOsm/L
3) 1200mOsm/L
4) 50mOsm/L
The osmolarity of the tubular fluid leaving the ascending limb of the loop of Henle is 100mOsm/L, as it is impermeable to water and reabsorbs solutes.
What is the effect of vitamin E deficiency on cell membranes?
1) Increased fluidity
2) Decreased fluidity
3) No change in fluidity
4) Unknown
Vitamin E deficiency can lead to decreased fluidity of cell membranes, making them less flexible and more prone to damage.
Diabetic insipidus is due to the lack of
1 Insulin
2 Angiotensin.
3 Aldosterone.
4 A.D.H.
Physiology
Answer: 4
Diabetic insipidus is due to the lack of 4. A.D.H. (Antidiuretic hormone).
Explanation:
Diabetic insipidus (DI) is a condition characterized by the production of large
volumes of dilute urine due to the lack of the antidiuretic hormone (ADH) or the
body's inability to respond to it. It is different from diabetes mellitus, which
involves problems with insulin and blood sugar regulation.
1. Insulin: Insulin is a hormone produced by the pancreas that plays a critical
role in regulating blood sugar levels. A deficiency or resistance to insulin
leads to diabetes mellitus, not diabetic insipidus. Diabetes mellitus is
characterized by hyperglycemia (high blood sugar) and increased thirst and urine
production due to the inability of the kidneys to reabsorb glucose properly.
2. Angiotensin: Angiotensin is a hormone system that plays a role in the
regulation of blood pressure and fluid balance. It is involved in the
renin-angiotensin-aldosterone system (RAAS). While it is crucial for maintaining
blood pressure, it is not directly related to the pathophysiology of diabetic
insipidus.
3. Aldosterone: Aldosterone is a mineralocorticoid hormone produced by the
adrenal glands. It helps regulate sodium and potassium levels in the body, which
in turn affects fluid and blood volume. While it is essential for electrolyte
and fluid balance, it does not cause diabetic insipidus when lacking.
4. Antidiuretic hormone (ADH): ADH is a hormone produced by the hypothalamus and
stored in the posterior pituitary gland. It acts on the kidneys to increase
water reabsorption, which leads to the production of concentrated urine. In
diabetic insipidus, there is either a deficiency of ADH or the kidneys fail to
respond to it adequately. This results in the kidneys being unable to reabsorb
enough water, leading to the production of large volumes of dilute urine and
increased thirst.
There are two main types of diabetic insipidus: central and nephrogenic. Central
DI occurs when the pituitary gland does not produce enough ADH, while
nephrogenic DI results from the kidneys' inability to respond to ADH. Both types
lead to an imbalance in water regulation and can cause symptoms such as polyuria
(excessive urine production), polydipsia (excessive thirst), and dehydration if
not managed properly.
To treat diabetic insipidus, the underlying cause must be addressed. If it is
central DI, synthetic ADH (desmopressin) is administered to replace the missing
hormone. If it is nephrogenic DI, the treatment focuses on addressing the
kidney's response to ADH and managing symptoms such as maintaining fluid intake
and sometimes medications to reduce urine output.
The increased venous return to the heart causes:
1. End diastolic volume increase
2. End systolic volume decrease
3. Decrease stroke volume
4. Decreased isovolumetric ventricular contraction.
Physiology
Answer: 1
The increased venous return to the heart causes End diastolic volume increase
MCQ: The primary site of absorption for:
1) Calcium - Jejunum
2) Iron - Jejunum
3) Vitamin B12 - Duodenum
4) All of the above
The primary site of absorption for calcium, iron, and vitamin B12 is the jejunum, making the answer "All of the above" correct.
What is the primary site of bilirubin deposition in tissues during jaundice?
1) The liver
2) The spleen
3) The skin and sclera
4) The pancreas
The primary site of bilirubin deposition in tissues during jaundice is the skin and sclera, leading to yellowing.
In which part of the nephron does the majority of glucose reabsorption occur?
1) Loop of Henle
2) Proximal convoluted tubule
3) Distal convoluted tubule
4) Collecting duct
The majority of glucose reabsorption occurs in the proximal convoluted tubule, where glucose is actively transported back into the bloodstream.