Question 1

Which muscle is primarily responsible for elevating the eyebrows and wrinkling the forehead?

Accepted Answer

Frontalis

Question 2

A patient presents with difficulty chewing due to impaired elevation of the mandible. Which muscle is most likely affected?

Accepted Answer

Masseter

Question 3

Which of the following muscles is NOT part of the quadriceps femoris group?

Accepted Answer

Biceps femoris

Question 4

During muscle contraction, which region of the sarcomere shortens?

Accepted Answer

The I band

Question 5

Which step of the cross-bridge cycle requires ATP?

Accepted Answer

Detachment of myosin from actin

Question 6

A muscle fiber is exposed to acetylcholine, resulting in sodium influx. What is the effect on membrane potential?

Accepted Answer

Depolarization

Question 7

Which equation best represents the calculation of membrane potential using ion concentrations?

Accepted Answer

$$V_m = \frac{RT}{F} \ln \left( \frac{[K^+]_{out}}{[K^+]_{in}} \right)$$

Question 8

Which structure is specialized for rapid transmission of action potentials along a neuron?

Accepted Answer

Myelin sheath

Question 9

Which glial cell is responsible for forming the blood-brain barrier?

Accepted Answer

Astrocyte

Question 10

A neurotransmitter binds to an ionotropic receptor that allows $$Cl^-$$ ions to enter the postsynaptic neuron. What is the likely effect?

Accepted Answer

IPSP (inhibitory postsynaptic potential)

Question 11

Which muscle is responsible for flexion of the forearm at the elbow?

Accepted Answer

Brachialis

Question 12

Which process provides the fastest source of ATP for muscle contraction?

Accepted Answer

Creatine phosphate system

Question 13

Which muscle is involved in abduction of the thigh at the hip?

Accepted Answer

Gluteus medius

Question 14

Which neurotransmitter is most associated with excitatory synaptic transmission in the CNS?

Accepted Answer

Glutamate

Question 15

Which of the following best describes the difference between white matter and grey matter in the CNS?

Accepted Answer

White matter contains myelinated axons; grey matter contains neuron cell bodies

Question 16

Which muscle is responsible for plantar flexion of the foot?

Accepted Answer

Gastrocnemius

Question 17

Which equation represents the relationship between force, muscle cross-sectional area, and muscle tension?

Accepted Answer

$$F = \sigma \cdot A$$

Question 18

Which type of neuron is most commonly found in sensory pathways of the PNS?

Accepted Answer

Pseudo-unipolar neuron

Question 19

Which muscle is responsible for lateral rotation of the thigh?

Accepted Answer

Sartorius

Question 20

Which statement best explains why action potentials only travel in one direction along an axon?

Accepted Answer

The absolute refractory period prevents backward propagation

Muscular System and Introduction to the Nervous System: Study Guide

Study Guide - Practice Questions