The Skeletal System and Muscular System Lecture Notes

Comprehensive practice questions covering the skeletal and muscular systems, including bone types, joint classifications, muscle tissues, and common injuries.

What are the two systems responsible for the movement of the human body?

The skeletal system and the muscular system.

What is the name of the internal skeleton found in humans?

An endoskeleton.

How many bones are in the human endoskeleton?

$206$ bones.

Why is bone considered a living tissue?

It contains blood vessels, nerves, and bone cells.

Which two minerals are responsible for the hardness of bone?

Calcium and phosphorus.

What are the two main types of bone tissue?

Compact bone and spongy bone.

Which part of the bone is responsible for forming bone marrow?

Spongy bone.

How is the vertebral column shaped?

It is an S-shaped spring.

What central structure is protected within the vertebral column?

The spinal cord.

How many separate bones called vertebrae make up the central supporting structure of the adult skeleton?

$26$ bones.

How many cervical (neck) vertebrae are in the vertebral column?

$7$.

How many thoracic (chest) vertebrae are in the vertebral column?

$12$.

How many lumbar (back) vertebrae are in the vertebral column?

$5$.

In adults, the sacrum consists of how many fused vertebrae?

$5$ fused vertebrae (counted as $1$ bone).

The coccyx consists of how many fused vertebrae in adults?

$3-5$ fused vertebrae (counted as $1$ bone).

What is the name of the fibrous cartilage that separates individual vertebrae?

Intervertebral discs.

What are the two primary functions of intervertebral discs?

Allowing slight movement in the vertebral column and cushioning the backbone against shock.

What are tendons?

Tough inelastic tissues that attach both ends of skeletal muscles to bones.

Which organ is encased and protected within the skull?

The brain.

Which internal organs are shielded by the rib cage?

The heart and lungs.

Where specifically are red and white blood cells produced?

In the red bone marrow of certain bones.

How do bones obtain iron for making hemoglobin?

Iron is obtained by the liver from the breakdown of old red blood cells and sent to the bones.

What is the definition of a joint?

A place where two adjacent bones meet.

What is another name for fixed or immovable joints?

Sutures.

What is an example of a fixed joint besides those in the skull?

Join between the sacrum and pelvic bones.

What is the clinical name for movable joints?

Synovial joints.

What are ligaments composed of?

Tough bands of fibrous tissue.

What is the function of the synovial membrane?

It lines the inside of the capsule and produces synovial fluid.

What is the purpose of synovial fluid?

It lubricates the joint, reducing friction between the two bones.

What material covers the ends of bones at a joint to act as a shock absorber?

Cartilage.

In which direction does a hinge joint allow movement?

In only one direction.

List four examples of hinge joints in the human body.

Elbow, knee, jaw, toes, and finger joints.

What defines a gliding joint?

A joint where bones slide across one another.

Where can gliding joints be found in the skeleton?

Between adjacent vertebrae and in the bones of the wrist and ankle.

What are the names of the first two vertebrae where a pivot joint is found?

The atlas and axis vertebrae.

Where in the body are ball and socket joints located?

At the shoulder and the hip.

What are the three types of muscle tissue found in the body?

Skeletal, cardiac, and smooth muscle.

Why is skeletal muscle referred to as voluntary muscle?

Because we are able to control its actions.

Why is skeletal muscle also called striped or striated muscle?

Due to alternating regions of light and dark fibers visible under a microscope.

Where is cardiac muscle exclusively found?

Only in the heart.

How does cardiac muscle differ from skeletal muscle regarding control and endurance?

It is involuntary and works continuously without becoming fatigued.

Where is smooth muscle typically found?

Within the lining of various organs such as the digestive organs, bladder, uterus, and blood vessels.

What is peristalsis?

The rhythmic contraction and relaxing of smooth muscle throughout most of the digestive tract.

Can muscles push a bone?

No, muscles pull on bone when they contract, but cannot push.

What are antagonistic pairs?

Pairs of muscles where one contracts while the other relaxes to produce movement.

In the forearm, which muscle acts as the flexor and which acts as the extensor?

The biceps is the flexor and the triceps is the extensor.

Approximately how many muscles are in the human body?

About $600$ muscles.

What is a fracture?

A broken bone.

What is a sprain?

The tearing of ligaments caused when a joint is forced beyond its degree of movement.

What causes osteoarthritis?

Cartilage wearing away, allowing bones to rub together, resulting in joint stiffness and pain.