Modules 3 and 4

Question 1

What are the three systems focused on in Module 3?

Answer 1

Skeletal, muscular, and nervous systems

Question 2

What types of muscle tissue are briefly discussed?

Answer 2

Cardiac, smooth, and skeletal muscle

Question 3

What is osseous tissue?

Answer 3

A type of connective tissue that makes up bones

Question 4

What is the primary function of cartilage in bone growth?

Answer 4

Provides a template for bone development

Question 5

What are the two main types of bone tissue?

Answer 5

• Compact bone
• Spongy bone

Question 6

What are the structural features of compact bone?

Answer 6

• Osteon (Haversian system)
• Central canal
• Osteocytes in concentric lamellae

Question 7

What is the periosteum?

Answer 7

Fibrous membrane covering the outer surface of bone

Question 8

What is the medullary cavity filled with?

Answer 8

Marrow

Question 9

What are the two types of bone marrow?

Answer 9

• Red marrow
• Yellow marrow

Question 10

What is the role of osteoblasts?

Answer 10

Cells that form new bone matrix

Question 11

What do osteoclasts do?

Answer 11

Resorb bone

Question 12

What is the epiphyseal plate?

Answer 12

Growth plate made of hyaline cartilage

Question 13

What is intramembranous ossification?

Answer 13

Bone develops directly from sheets of mesenchymal connective tissue

Question 14

What is endochondral ossification?

Answer 14

Bone develops by replacing hyaline cartilage

Question 15

What is the nutrient artery’s function?

Answer 15

Provides nourishment to the bone

Question 16

What happens during bone remodeling?

Answer 16

Resorption of old bone and laying down of new bone

Question 17

What are the characteristics of skeletal muscle cells?

Answer 17

• Striated appearance
• Multinucleated cells

Question 18

What distinguishes cardiac muscle tissue?

Answer 18

Single nucleus and striated appearance with less parallel striations

Question 19

What is the role of calcium homeostasis in bone health?

Answer 19

Essential for bone development, growth, and maintenance

Question 20

Fill in the blank: The _______ is a thin layer of cartilage covering an epiphysis.

Answer 20

[articular cartilage]

Question 21

True or False: Smooth muscle tissue has a striated appearance.

Answer 21

False

Question 22

What are lacunae in bone tissue?

Answer 22

Small spaces occupied by bone or cartilage cells

Question 23

What is the function of canaliculi?

Answer 23

Channels that house cytoplasmic extensions of osteocytes for communication

Question 24

What is the significance of the epiphyseal line?

Answer 24

Remnant of the epiphyseal plate after growth is completed

Question 25

What is trabecular bone?

Answer 25

Type of spongy bone with a lattice-like matrix

Question 26

What initiates the transformation of perichondrium into periosteum?

Answer 26

Penetration of capillaries into cartilage

Question 27

What is a secondary ossification center?

Answer 27

A region where bone growth occurs during development.

Question 28

What is bone remodeling?

Answer 28

The process of maintenance of bones throughout a lifetime.

Question 29

What role do osteoclasts play in bone remodeling?

Answer 29

They break down the bone matrix.

Question 30

What do osteoblasts do?

Answer 30

They release calcium into the body and create new osteocytes and matrix.

Question 31

How does the body balance calcium levels?

Answer 31

By depositing calcium in bones when levels are high and releasing it when levels are low.

Question 32

What is hypercalcemia?

Answer 32

A condition where blood calcium levels are too high.

Question 33

What is hypocalcemia?

Answer 33

A condition where blood calcium levels are too low.

Question 34

What happens when blood calcium levels are too high?

Answer 34

The thyroid gland releases calcitonin, inhibiting osteoclast activity and stimulating calcium uptake by bones.

Question 35

What does parathyroid hormone (PTH) do?

Answer 35

Stimulates osteoclast proliferation and bone resorption when calcium levels are low.

Question 36

What are the layers surrounding a skeletal muscle?

Answer 36

Epimysium, perimysium, and endomysium.

Question 37

What is the smallest unit of muscle contraction?

Answer 37

The sarcomere.

Question 38

What proteins make up myofilaments?

Answer 38

* Actin * Myosin

Question 39

What triggers the release of calcium ions in muscle contraction?

Answer 39

The arrival of an action potential at the T-tubules.

Question 40

What is the function of the sarcoplasmic reticulum?

Answer 40

It serves as a reservoir for calcium ions in muscle cells.

Question 41

What initiates the excitation of muscle fibers?

Answer 41

The release of acetylcholine (ACh) at the neuromuscular junction (NMJ).

Question 42

What occurs when ACh binds to its receptor?

Answer 42

A channel opens, allowing positively charged ions to enter the muscle fiber, causing depolarization.

Question 43

What is the role of T-tubules in muscle contraction?

Answer 43

They carry the action potential into the interior of the muscle cell.

Question 44

What is cross-bridge formation?

Answer 44

The attachment of myosin heads to actin during muscle contraction.

Question 45

What is the power stroke in muscle contraction?

Answer 45

The movement of the myosin head that pulls actin toward the center of the sarcomere.

Question 46

What happens when ATP binds to the myosin head?

Answer 46

It causes the cross-bridge to detach from actin.

Question 47

What is the sliding filament theory?

Answer 47

The process where thin filaments slide past thick filaments during muscle contraction.

Question 48

What marks the boundaries between sarcomeres?

Answer 48

Z discs.

Question 49

What is the significance of the H zone in a sarcomere?

Answer 49

It is the area where only thick filaments are present.

Question 50

Fill in the blank: The _______ is the plasma membrane of a muscle cell.

Answer 50

sarcolemma

Question 51

True or False: Calcium is produced by biological processes.

Answer 51

False