Free Medical Doctor General Questions and Answers

Question 1

Which spinal canal segment will exhibit secondary curves with a concavity that is reversed?

Accepted Answer

Cervical

Answer

The vertebral column has four natural curves: two primary (thoracic and sacral) and two secondary (cervical and lumbar). Primary curves are concave anteriorly (kyphotic), while secondary curves are concave posteriorly (lordotic). Therefore, the cervical segment, being a secondary curve, exhibits a lordotic curve, meaning its concavity is reversed compared to the primary curves, presenting anteriorly.

Question 2

Which of the following enables communication between the cytoskeleton and the extracellular matrix across the cell membrane?

Accepted Answer

Integrins

Answer

Integrins are transmembrane receptor proteins that play a crucial role in cell adhesion and communication. They link the cell's cytoskeleton (specifically actin filaments) to components of the extracellular matrix (ECM), such as collagen, fibronectin, and laminin. This connection allows cells to sense and respond to their environment, influencing cell migration, differentiation, and survival.

Question 3

Which of the following describes how goblet cells and enteroendocrine cells are different?

Accepted Answer

The direction of release of secretion

Answer

Both goblet cells and enteroendocrine cells originate from crypt stem cells and use exocytosis to release their secretory products. However, their direction of secretion differs significantly. Goblet cells secrete mucus onto the apical surface into the intestinal lumen, while enteroendocrine cells secrete hormones into the basolateral side, which then enter the bloodstream to act on distant targets.

Question 4

The Papez circuit's implicated nucleus is?

Accepted Answer

Anterior nucleus of thalamus

Answer

The Papez circuit is a neural pathway involved in emotion and memory, particularly the formation of long-term memories. Key structures in this circuit include the hippocampus, fornix, mammillary bodies, mammillothalamic tract, anterior nucleus of the thalamus, cingulate gyrus, and entorhinal cortex. The anterior nucleus of the thalamus serves as a crucial relay station within this circuit.

Question 5

The synthesis of these substances occurs in the agranular endoplasmic reticulum:

Accepted Answer

Lipid

Answer

The agranular (smooth) endoplasmic reticulum (SER) is primarily involved in the synthesis of lipids, including phospholipids, cholesterol, and steroid hormones. It also plays roles in detoxification of drugs and poisons, and storage of calcium ions. In contrast, the granular (rough) endoplasmic reticulum, with its ribosomes, is responsible for protein synthesis and modification.

MD - Doctor of Medicine Practice Test

MD - Doctor of Medicine Practice Test

Free Medical Doctor General Questions and Answers