$$ \text{PTH} \rightarrow \text{Osteoclast activity} \rightarrow \text{Increase in blood Ca}^{2+} $$

Question 1

Which of the following best describes the difference in structure between compact bone and spongy bone?

Accepted Answer

Compact bone is composed of tightly packed osteons (Haversian systems), while spongy bone contains trabeculae arranged in a lattice.

Question 2

A patient presents with a fracture. Which of the following lists the correct sequence of major steps in the repair of a bone fracture?

Accepted Answer

Formation of a hematoma, fibrocartilaginous callus, bony callus, and bone remodeling.

Question 3

Which hormone increases blood calcium levels by stimulating osteoclast activity?

Accepted Answer

Parathyroid hormone (PTH)

Question 4

During muscle contraction, what happens to the sarcomere?

Accepted Answer

The I band shortens, the A band remains the same, and the H zone disappears.

Question 5

Which molecule is produced during anaerobic respiration in muscle cells, resulting in oxygen debt?

Accepted Answer

Lactic acid

Question 6

A long bone grows in length primarily through which process?

Accepted Answer

Endochondral ossification at the epiphyseal plate

Question 7

Which of the following best describes the function of synovial fluid?

Accepted Answer

It lubricates the joint, reducing friction between articular surfaces.

Question 8

Which of the following is NOT a function of bone tissue?

Accepted Answer

Production of hormones

Question 9

Which of the following substances is NOT normally stored in bone tissue?

Accepted Answer

Potassium

Question 10

A muscle fiber receives a signal from a motor neuron. Which event occurs first at the neuromuscular junction?

Accepted Answer

Release of acetylcholine into the synaptic cleft

Question 11

Which of the following best describes the all-or-none principle as it relates to muscle cell contraction?

Accepted Answer

A muscle fiber contracts completely or not at all when stimulated above threshold.

Question 12

Which of the following is a characteristic of fast twitch muscle fibers?

Accepted Answer

Rapid contraction, low resistance to fatigue, and fewer mitochondria

Question 13

Which equation best represents the regulation of blood calcium concentration involving parathyroid hormone (PTH)?

Accepted Answer

$$ 	ext{PTH} ightarrow 	ext{Osteoclast activity} ightarrow 	ext{Increase in blood Ca}^{2+} $$

Question 14

Which of the following best describes the function of myoglobin in muscle cells?

Accepted Answer

It binds oxygen for use during muscle contraction.

Question 15

Which of the following is a real-life example of an isometric muscle contraction?

Accepted Answer

Holding a plank position

Question 16

Which of the following best describes the structure of a synovial joint?

Accepted Answer

Bones joined by a fluid-filled cavity surrounded by a joint capsule

Question 17

Which of the following is the correct sequence of events leading to muscle fiber contraction, starting at the neuromuscular junction?

Accepted Answer

Acetylcholine release, depolarization, calcium release, actin slides over myosin

Question 18

Which of the following best describes the function of the sarcoplasmic reticulum in muscle cells?

Accepted Answer

It stores and releases calcium ions during muscle contraction.

Question 19

Which of the following is a major function of red bone marrow?

Accepted Answer

Production of blood cells

Question 20

Which of the following best describes the difference between troponin and tropomyosin?

Accepted Answer

Troponin binds calcium and regulates tropomyosin's position on actin.

BI 121 Unit #3 Study Guide – Step-by-Step Guidance for Skeletal, Joint, and Muscular System Questions

Study Guide - Practice Questions