MDS PREP
All of the following promote activation of muscle contraction EXCEPT
1. Binding of myosin to actin.
2. Opening of the sarcoplasmic reticulum Ca channel.
3. Ca2+ binding to troponin C.
4. Opening of Na channels.
Physiology
Answer: 1
Activation of muscle contraction is promoted by :
Opening of the sarcoplasmic reticulum Ca channel.
Ca2+ binding to troponin C.
Opening of Na channels
Ca2+ binding to the Ca2+-ATPase
What is the significance of the transport maximum for substances like glucose and phosphate?
1) It indicates the maximum amount that can be filtered by the glomerulus
2) It represents the maximum amount that can be actively reabsorbed by the tubules
3) It is the point at which the substance begins to be excreted in the urine
4) It is the point at which the substance becomes toxic to the body
Physiology
Answer: 2
Transport maximum indicates the maximum rate at which an active transport system can reabsorb a substance from the glomerular filtrate.
What is the primary function of vitamin D in the body?
1) Blood clotting
2) Bone formation and maintenance
3) Vision
4) Immune system function
The primary function of vitamin D in the body is bone formation and maintenance, as it helps regulate calcium and phosphate levels.
How does the skin color change in light-skinned patients with high serum bilirubin levels?
1) The skin turns yellow.
2) The skin turns green.
3) The skin turns blue.
4) The skin turns red.
In light-skinned patients with high serum bilirubin levels, the skin turns yellow due to the deposition of bilirubin.
MEAN CIRCULATING FILLING PRESSURE IS?
1. DIFFERENCE BETWEEN CENTRAL VENOUS PRESSURE AND CENTRAL ARTERIAL PRESSURE
2. MEAN ATRIAL PRESSURE
3. ARTERIALPRESSURE TAKEN JUST AT THE POINT WHEN HEART STOPS BEATING
4. DIFFERENCE BETWEEN SYSTEMIC AND PULMONARY ARTERIAL PRESSURE
Physiology
Answer: 3
Mean Circulating Filling Pressure (MCFP) is a concept used in cardiovascular physiology to describe the average pressure in the large veins and the right atrium when the heart is not actively pumping (i.e., during diastole or when the heart is stopped). It reflects the pressure that fills the heart and is influenced by the volume of blood in the circulatory system and the compliance of the vascular system.
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
What is the condition characterized by the lack of intrinsic factor, leading to vitamin B12 malabsorption?
1) Pernicious anemia
2) Celiac disease
3) Lactose intolerance
4) Crohn's disease
Physiology
Answer: 1
Pernicious anemia is caused by the lack of intrinsic factor, which leads to impaired vitamin B12 absorption and subsequent megaloblastic anemia.
What is the role of gastrin in the gastric phase of acid secretion?
1) It is released by the pancreas and stimulates acid secretion in the stomach
2) It is released by the duodenum and inhibits acid secretion
3) It is released by the stomach and stimulates acid secretion in response to food
4) It has no role in gastric acid secretion
Physiology
Answer: 3
Gastrin is released from G cells in the antral mucosa of the stomach in response to the presence of food. It stimulates the parietal cells of the stomach to secrete hydrochloric acid and intrinsic factor, contributing to the gastric phase of acid secretion.