Question 1

Which of the following best describes the process of intramembranous ossification as depicted in the first image?

Accepted Answer

Bone develops directly from a fibrous membrane, forming flat bones such as the clavicle and cranial bones.

Question 2

During endochondral ossification (see the second image), what is the correct sequence of events?

Accepted Answer

Formation of bone collar, cavitation of cartilage, invasion by periosteal bud, formation of medullary cavity, ossification of epiphyses.

Question 3

Based on the third image, what is the primary difference between bone growth and bone remodeling?

Accepted Answer

Bone growth involves the lengthening of bone via the epiphyseal plate, while bone remodeling involves the resorption and deposition of bone throughout life.

Question 4

Referencing the fourth image, which hormone is primarily responsible for increasing blood calcium levels when they fall below normal?

Accepted Answer

Parathyroid hormone (PTH)

Question 5

In the context of bone fracture repair (see the fifth image), what is the correct order of the healing process?

Accepted Answer

Hematoma formation, fibrocartilaginous callus formation, bony callus formation, bone remodeling

Question 6

According to the sixth image, which structure marks the boundary of a sarcomere in skeletal muscle?

Accepted Answer

Z disc

Question 7

What happens to the H zone and I band during a muscle contraction, as shown in the seventh image?

Accepted Answer

The H zone disappears and the I band shortens.

Question 8

Based on the eighth image, what is the role of acetylcholinesterase at the neuromuscular junction?

Accepted Answer

It degrades acetylcholine in the synaptic cleft, terminating the signal.

Question 9

Referencing the tenth image, what is the primary ion responsible for depolarization during an action potential in muscle fibers?

Accepted Answer

Sodium (Na+)

Question 10

According to the eleventh image, what is the sequence of ion channel activity during an action potential?

Accepted Answer

Na+ channels open, then K+ channels open, then both close.

Question 11

In the context of muscle contraction (see images 12–15), what is the role of calcium ions ($$\mathrm{Ca$$^{2+}$$}$$)?

Accepted Answer

They bind to troponin, causing tropomyosin to move and expose active sites on actin.

Question 12

Based on the cross-bridge cycle (image 15), what event causes the detachment of the myosin head from actin?

Accepted Answer

Binding of ATP to the myosin head

Question 13

According to the motor unit diagram (image 16), what is the functional significance of motor units being spread throughout a muscle?

Accepted Answer

It ensures that a single motor unit causes a weak contraction of the entire muscle.

Question 14

Based on the muscle twitch myogram (image 17), what occurs during the latent period?

Accepted Answer

Excitation-contraction coupling events occur before contraction begins.

Question 15

Referencing the graded muscle response images (images 18–20), what is the physiological basis for fused (complete) tetanus?

Accepted Answer

Stimuli are delivered at a high frequency, preventing any relaxation between contractions.

Question 16

According to the recruitment diagrams (images 21–22), what is the size principle in muscle contraction?

Accepted Answer

Motor units with larger fibers are recruited as stimulus intensity increases.

Question 17

Based on the isotonic and isometric contraction images (images 23–26), what distinguishes an isometric contraction from an isotonic contraction?

Accepted Answer

Isometric contraction develops tension without changing muscle length, while isotonic contraction changes muscle length to move a load.

Question 18

Referencing the energy pathway diagrams (images 27–28), which pathway provides the fastest but shortest duration of ATP supply for muscle contraction?

Accepted Answer

Direct phosphorylation of ADP by creatine phosphate

Mini-Textbook Study Notes: Skeletal System, Muscular System, and Nervous System

Study Guide - Practice Questions

Study Guide - Flashcards