which parts of the heart are separated by the mitral valve

HESI A2

Anatomy HESI A2

1. Which parts of the heart are separated by the mitral valve?

A. Left atrium and right atrium
B. Right atrium and right ventricle
C. Left ventricle and right ventricle
D. Left atrium and left ventricle

Correct answer: D

Rationale: The mitral valve, also known as the bicuspid valve, separates the left atrium and the left ventricle of the heart. Its primary function is to prevent the backflow of blood from the left ventricle to the left atrium during the heart's contraction. Therefore, option D, 'Left atrium and left ventricle,' is the correct answer. Choices A, B, and C are incorrect because they do not represent the parts separated by the mitral valve.

2. Which type of muscle tissue is found in the walls of hollow organs?

A. Skeletal muscle
B. Cardiac muscle
C. Smooth muscle
D. Striated muscle

Correct answer: C

Rationale: Smooth muscle tissue is found in the walls of hollow organs such as the intestines, blood vessels, and bladder. It contracts involuntarily, allowing for functions like peristalsis in the intestines and regulation of blood flow in blood vessels. Skeletal muscle (Choice A) is attached to bones, cardiac muscle (Choice B) is found in the heart, and striated muscle (Choice D) refers to both skeletal and cardiac muscles due to their striped appearance, but neither of these types are typically found in the walls of hollow organs.

3. What is the function of parathyroid hormone?

A. Increasing energy levels
B. Stimulating cell reproduction
C. Speeding up metabolism
D. Activating vitamin D

Correct answer: D

Rationale: The correct answer is D. Parathyroid hormone plays a crucial role in activating vitamin D. This activation occurs in the kidneys, where parathyroid hormone stimulates the conversion of inactive vitamin D to its active form. Active vitamin D is essential for maintaining proper levels of calcium and phosphorus in the body, which are important for bone health and other physiological functions. Choices A, B, and C are incorrect because parathyroid hormone is not involved in increasing energy levels, stimulating cell reproduction, or speeding up metabolism. Its primary function is related to calcium and phosphorus homeostasis through the activation of vitamin D.

4. The motor cortex helps the brain by monitoring and controlling the body's movement. Where is the motor cortex located within the brain?

A. Back of the head
B. Top middle portion of the parietal lobe
C. Front portion of the parietal lobe
D. Around the auditory cortex

Correct answer: C

Rationale: The correct answer is C: Front portion of the parietal lobe. The motor cortex is located in the frontal lobe, specifically in the front portion of the parietal lobe. It is responsible for planning, controlling, and executing voluntary movements. Choices A, B, and D are incorrect as the motor cortex is not located at the back of the head, top middle portion of the parietal lobe, or around the auditory cortex.

5. What type of joint is found at the elbow?

A. Ball and socket
B. Hinge
C. Pivot
D. Saddle

Correct answer: B

Rationale: The correct answer is B: Hinge. A hinge joint, such as the one found at the elbow, allows for movement primarily in one plane, enabling flexion and extension similar to the movement of a door hinge. This joint structure permits bending and straightening of the arm, controlling the range of motion in a specific direction. Choices A, C, and D are incorrect. A ball and socket joint allows for multi-axial movement like the hip joint, a pivot joint allows for rotation around an axis like the joint between the first and second cervical vertebrae, and a saddle joint allows for movement in two planes at right angles to each other like the joint at the base of the thumb.