which feature of the ear is most medial

HESI A2

Anatomy HESI A2

1. Which feature of the ear is most medial?

A. Pinna
B. Tympanic membrane
C. Cochlea
D. Outer canal

Correct answer: B

Rationale: The tympanic membrane, also known as the eardrum, is the most medial feature in the ear. It separates the outer ear from the middle ear and serves as a barrier that vibrates in response to sound waves, transmitting vibrations to the middle ear ossicles. The pinna, cochlea, and outer canal are located more laterally in the ear anatomy. The pinna is the visible part of the ear located on the lateral side of the head, the cochlea is a spiral-shaped structure in the inner ear responsible for hearing, and the outer canal refers to the external auditory canal leading to the eardrum.

2. What is the function of amylase?

A. Breaking down starch
B. Digesting fat
C. Breaking down protein
D. Absorbing water

Correct answer: A

Rationale: The correct answer is A: Breaking down starch. Amylase is an enzyme that specifically functions to break down starch into smaller sugar molecules such as maltose and glucose. This process is essential for the digestion and absorption of carbohydrates in the body. Choices B, C, and D are incorrect because amylase does not digest fat, break down protein, or absorb water; its primary function lies in starch digestion.

3. Which type of muscles are involved in peristalsis?

A. Smooth muscles
B. Cardiac muscles
C. Skeletal muscles
D. Epaxial muscles

Correct answer: A

Rationale: Peristalsis is a coordinated, wave-like muscular contraction that propels food and other materials through the digestive tract. Smooth muscles are responsible for this movement in the gastrointestinal tract, providing the involuntary contractions needed for peristalsis to occur. Skeletal muscles, cardiac muscles, and epaxial muscles are not directly involved in peristalsis. Cardiac muscles are found in the heart and are responsible for its contraction. Skeletal muscles are attached to bones and control voluntary movements. Epaxial muscles are located along the vertebral column and are involved in the movement and stabilization of the spine.

4. Which part of the respiratory system is in the upper respiratory tract?

A. Bronchioles
B. Alveolar ducts
C. Alveoli
D. None of the above

Correct answer: D

Rationale: The upper respiratory tract includes structures such as the nose, nasal cavity, pharynx, and larynx. These structures are responsible for filtering, warming, and humidifying the air. The lower respiratory tract comprises the trachea, bronchi, bronchioles, alveolar ducts, and alveoli. Bronchioles, alveolar ducts, and alveoli are all part of the lower respiratory system, involved in gas exchange. Therefore, the correct answer is 'None of the above' as none of the listed options are part of the upper respiratory tract.

5. The corpus callosum facilitates communication between which brain structures?

A. the left and right brain
B. the skeletal and neural systems
C. the brain and spinal cord
D. the thalamus and hypothalamus

Correct answer: A

Rationale: The corpus callosum is a structure in the brain that enables communication between the two hemispheres. It allows for the transfer of various types of information, such as motor, sensory, and cognitive, between the left and right brain hemispheres, aiding in overall brain function and integration of tasks. Choices B, C, and D are incorrect as they do not involve the specific brain structures connected by the corpus callosum.