Chapter 2 • Basic Exercise Science: Skeletal System

Question 1

What are the two divisions of the skeletal system?

Answer 1

1) Axial Skeleton

2) Appendicular Skeleton

Question 2

Which and how many bones make up the axial skeleton?

Answer 2

The skull, rib cage, and the vertebral column. Approximately 80 bones

Question 3

Which and how many bones make up the appendicular skeleton?

Answer 3

Upper & lower extremities as well as the shoulder and pelvic girdles. Approximately 126 bones.
Note: the pelvic girdle is often so suffered a component of both divisions and is a link between the two.

Question 4

The process of bone growth is called remodeling. What happens during this process?

Answer 4

It starts with resorption when the old bone tissue is broken down by osteoclasts. New bone tissue is then laid down during bone formation, this is done by osteoblasts.

Question 5

What are the 5 types of bones?

Answer 5

1) Long
2) Short
3) Flat
4) Irregular
5) Sesamoid

Question 6

What are the characteristics of long bones?

Answer 6

Long, cylindrical shafts with irregular or widened ends (i.e. humerus, femur)

Question 7

What are the characteristics of short bones?

Answer 7

Similar in length and width and appear somewhat cubical (carpals of the hand, tarsals of the feet)

Question 8

What are the characteristics of flat bones?

Answer 8

Thin and protective (scapulae)

Question 9

What are the characteristics of irregular bones?

Answer 9

Unique shape and function (i.e. vertebrae)

Question 10

What are the characteristics of sesamoid bones?

Answer 10

Small often round bones embedded in a joint capsule or in locations where a tendon passes over a joint (i.e. patella)

Question 11

What is the epiphysis (epiphyses)?

Answer 11

It’s the end of long bones mainly composed of cancellous (spongy) bone and houses most of the Ted marrow. It’s the primary site of bone growth and can be vulnerable to injury during growth periods.

Question 12

What is the diaphysis?

Answer 12

The shaft portion of the long bone, the principal role of this portion is support.

Question 13

What is the epiphyseal plate?

Answer 13

The region of the long bone connecting the diaphysis to the epiphysis. It’s made up of multiplying layers of cartilaginous cells stacked like columns of coins that move toward the diaphysis.

Question 14

What is the periosteum?

Answer 14

It is a tough fibrous membrane that coats the bone and contains nerves, blood vessels, and bone-producing cells. Its role in movement: provides point of attachment for tendons

Question 15

What is the medullary cavity?

Answer 15

A space that runs down the center of the diaphysis and contains fatty yellow marrow. It serves as an energy reserve.

Question 16

What is the articular (hyaline) cartilage?

Answer 16

It covers the ends of articulating bones and is a hard, white, shiny tissue that helps reduce friction in freely movable (synovial) joints with the help of synovial fluid. This is fundamiental for smooth joint action.

Question 17

What is the purpose of surface markings on bones?

Answer 17

They are necessary for increasing the stability in joints and provide attachment sites for muscles.

Question 18

What are the two categories of bone markings?

Answer 18

1) Depressions

2) Processes

Question 19

What are depressions?

Answer 19

Flattened or indented portions of the bone.

Question 20

What is a fossa?

Answer 20

A common depression.

Question 21

What is a sulcus?

Answer 21

Another form of a depression. It’s a groove in a bone that allows soft tissue (i.e. tendons) to pass through.

Question 22

What are processes?

Answer 22

Projections protruding from the bone to which muscles, tendons and ligaments can attach. Some common processes are called process, condyle, epicondyle, tubercle, and trochanter.

Question 23

Where is the condyle located?

Answer 23

On the inner and outer portions at the bottom of the femur (thigh bone) and top of the tibia (shin bone) to form the knee joint.

Question 24

Where are the epicondyles located?

Answer 24

On the inner and outer portions of the humerus to help form the elbow joint.

Question 25

Where are the tubercles located?

Answer 25

At the top of the humerus at the glenohumeral (shoulder) joint.

Question 26

Where are trochanters located?

Answer 26

At the top of the femur, they serve as attachment sites for the hip musculature. The greater trochanter is commonly called the hip bone

Question 27

What is the vertebral column?

Answer 27

The backbone or spinal column. It consists of a series of irregularly shaped bones called vertebrae and house the spinal cord.

Question 28

What are the five categories the vertebral column are divided into?

Answer 28

1) Cervical vertebrae/spine (C1-C7) 7 vertebrae that form a flexible framework and provide support and motion for the head.
2) Thoracic vertebrae/spine (T1-T12) 12 vertebrae that move with the ribs to form the rear anchor of the rib cage.
3) Lumbar vertebrae/spine (L1-L5) 5 vertebrae that are the largest in the spinal column and support most of the body’s weight and are attached to many of the back muscles
4) Sacrum is a triangular bone located just below the lumbar vertebrae. Consists of 4-5 bones as a child that fuse together in adulthood
5) Coccyx/Tailbone is the bottom of the spinal column. Consists of 4-5 bones that fuse together in adulthood. Many muscles connect to this bone.

Question 29

What are the three major curvatures of the adult human spine?

Answer 29

1) Posterior cervical curvature: posterior concavity of the cervical spine
2) Anterior thoracic curvature: posterior convexity of the thoracic spine
3) Posterior lumbar curvature: posterior concavity of the lumbar spine

Question 30

How are joints formed?

Answer 30

They are formed by one bone that articulates with another bone

Question 31

How are joints categorized?

Answer 31

By their function (the way they move) and their structure

Question 32

What is arthrokinematics?

Answer 32

Joint motion

Question 33

What are synovial joints?

Answer 33

The most common joints associated with human movement. They are held together by a joint capsule and ligaments.

Question 34

What are the different types of synovial joints?

Answer 34

1) Gliding (plane)
2) Condyloid (condylar or ellipsoidal)
3) Hinge
4) Saddle
5) Pivot
6) Ball and socket

Question 35

What is a gliding joint?

Answer 35

A non-axial joint that has the simplest movement of all joints (back and forth). i.e carpals of the hand

Question 36

What is a condyloid joint?

Answer 36

Those where the condyle of one bone fits into the elliptical cavity of another to form a joint. Movement occurs in one plane (flexion and extension in the sagittal plane) with minimal movement in the others (rotation in the transverse plane; adduction and abduction in the frontal plane). i.e. the wrist between the radius and carpals and the joints of the fingers (metacarpophalangeal)

Question 37

What is a hinge joint?

Answer 37

A uniaxial joint that allows movement predominantly in one plane of motion, the sagittal plane. i.e. elbow, toe (interphalangeal)

Question 38

What is a saddle joint?

Answer 38

One bone looks like a saddle with the articulating bone straddling it like a rider. Only found in the carpometacarpal joint in the thumb. Allows movement in two planes of motion (flexion and extension in the sagittal plane; adduction and abduction in the frontal plane) with some rotation to produce circumduction (circular motion)

Question 39

What are pivot joints?

Answer 39

They allow movement in predominantly one plane of motion (rotation, pronation, and supination in the transverse plane). Found in the atlantoaxial joint at the base of the skull and the proximal radioulnar joint at the elbow.

Question 40

What are ball and socket joints?

Answer 40

They are the most mobile of the joints and allow movement in all three planes. i.e. shoulder and hip

Question 41

What are nonsynovial joints?

Answer 41

They are joints that have no joint cavity, connective tissue or cartilage and exhibit little to no movement. i.e. sutures of the skull, the distal joint of the tibia and fibula, and the symphysis pubis (pubic bones)

Question 42

What are the functions of joints?

Answer 42

1) Allows for motion and movement

2) Provide stability

Question 43

Are all joints in the human body linked together?

Answer 43

Yes, it implies that movement of one joint directly affects the movement of others.

Question 44

What are ligaments?

Answer 44

Primary connective tissue that connects bones together and provides stability, input to the nervous system (proprioception), guidance, and the limitation of improper joint movement.

Question 45

What are ligaments made of?

Answer 45

They are primarily made of collagen (a protein) with varying amounts of elastin (another protein)

Question 46

What does collagen do for ligaments?

Answer 46

They are situated in a parallel fashion to the forces that are placed on the ligament and provide the ligament with the ability to withstand tension (tensile strength)

Question 47

What does elastin do for ligaments?

Answer 47

It gives a ligament some flexibility or elastic recoil to withstand the bending and twisting it has to endure.

Question 48

What is one characteristic of ligaments and what is the result of having this characteristic?

Answer 48

They have poor vascularity (blood supply) so they don’t heal or repair well and may be slower to adapt to stresses placed on the body

Question 49

What are the best kinds of exercises to help strengthen bones?

Answer 49

Weight bearing ones because they force the bones to work against gravity and thus helps them become stronger.