Dr. Lea 2 INTRODUCTION TO​ CARTILAGE, BONES, JOINTS and MUSCLES

Question 1

What are the 2 functional parts of the skeletal system?

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Answer 1

Axial Skeleton

a. Bones of the head – cranium or skull
b. Bones of the neck – hyoid bone and cervical vertebrae
c. Bones of the trunk – ribs, sternum, vertebrae, sacrum, coccyx

Appendicular Skeleton

a. Bones of the limbs
b. Bones of the pectoral/shoulder and pelvic girdles
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Question 2

What are the types of vertebrae in the vertebral column

Answer 2

7 Cervical vertebrae

12 Thoracic vertebrae

5 Lumbar vertebrae

1 Sacrum (5 fused sacral vertebrae)

1 Coccyx (4 fused coccygeal vertebra)

Question 3

What are the 3 types of cartilage?

Answer 3

• Hyaline cartilage - most common type, found in the ribs, nose, larynx, trachea. A precursor of bone in some locations
• Fibrocartilage - is found in intervertebral discs, joint capsules
• Elastic cartilage - is found in the external ear, epiglottis, and larynx

Question 4

Why does cartilage never heal?

Answer 4

Because its avascular

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Question 5

What are the 5 functions of bones?

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Answer 5

1. Support for the body and its vital cavities; it is the chief supporting tissue of the body
2. Protection for vital structures (e.g. heart and lungs)
3. The mechanical basis for movement (leverage)
4. Storage for salts (e.g. calcium & phosphorus)
5. Hemopoiesis (blood cell production) - A continuous supply of new blood cells (produced from the marrow in the medullary cavity of many bones)
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Question 6

What are the two types of bones?

Answer 6

Compact Bone

• Hard outer layer of the bone, made up of Haversian systems (or osteons)
• Provides strength for weight bearing
• In long bones designed for rigidity and attachment of muscles and ligaments, the amount of compact bone is greatest near the middle of the shaft (where bones are liable to break)
  2. Spongy or Cancellous Bone
• Trabecular (meshwork) inner layer of the bone.
• Where the bone marrow is located
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Question 7

What are the 6 classifications of bones?

Answer 7

1. Long bones- ex. femur, humerus
2. Short bones: square-ish in shape ex. wrist(carpal), ankle (tarsal) bones
3. Flat bones – ex. skull
4. Pneumatic bones – air filled spaces within bone ex maxilla of face
5. Sesamoid bones – bones in tendons ex. patella (knee cap)
6. Irregular bones – various shapes

Question 8

What are the parts of long bones?

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Answer 8

• Epiphysis: knob at either end; composed of spongy bone covered by compact bone
• Diaphysis: shaft of the long bone, almost totally composed of compact bone; hollow center lined with thin region of cancellous bone, containing marrow
• Metaphysis: flared region between diaphysis & epiphysis
• Epiphyseal plate: hyaline cartilage separating epiphysis & metaphysis; region of endochondral bone formation, growth in length

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Question 9

True or False: Periosteum is innervated by nerves that carry pain sensations.

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Answer 9

True

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Question 10

Where are short bones found?

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Answer 10

•Found in the hand and foot (carpal and tarsal bones)

Wrist - scaphoid, lunate, trapezium, trapezoid etc.

Ankle – talus, calcaneus, navicular etc

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Question 11

Where are flat bones found and the layers that makeup them?

Answer 11

• Found in the vault of the skull (frontal and parietal bones)
• Composed of an outer table of compact bone and a thin inner table separated by a layer of cancellous bone, the diploë

Question 12

Where are pneumatic bones found?

Answer 12

• Have mucosa lined, air filled cavities (sinuses)
• E.g. Maxilla, ethmoid bones of the face,
• Not seen elsewhere in body

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Question 13

What is the function of sesamoid bones and what is the largest?

Answer 13

•Bones which develop within tendons that pass over a joint (in order to protect the tendon)

Patella

•The function of a sesamoid bone is to alter the direction of pull of a tendon and to reduce friction on the tendon

Question 14

What are two kinds of irregular bones?

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Answer 14

•vertebrae, and the pelvic bones

Question 15

Can you find the sesamoid bone in this x ray of a normal hand??

Answer 15

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Question 16

What are the 3 types of joints?

Answer 16

1.Synovial (most common) = freely movable (diarthrodial joints)

Hyaline cartilage and a synovial membrane ex. Hip, knee, shoulder, finger joints etc. what you commonly think of as a joint

2. Cartilaginous (less common) = slightly movable
   a. primary=synchondrosis, ex. hyaline cartilage growth plate of kids
   b. secondary=fibrocartilage ex. intervertebral discs, pubic symphysis
3. Fibrous (least common) = synarthrosis, syndesmosis (non-movable) ex. Sutures of the skull, gomphosis – tooth in its socket

Question 17

What are the 6 types of synovial joints?

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Answer 17

a. Ball and socket joints
b. Hinge joint
c. Pivot joint
d. Condyloid joints
e. Saddle joints
f. Plane/gliding joint
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Question 18

What type of movements do ball and socket joints make and what are examples of them?

Answer 18

•Multiaxial - allows movement in multiple axes and planes

Example: Shoulder and hip joints

•Permits free movement including flexion, extension, abduction, adduction, medial rotation, lateral rotation, and circumduction

Question 19

What type of movements do hinge joints make and what are examples of them?

Answer 19

•Resembles the hinge of a door, permits flexion and extension movements only

Examples: elbow, knee, ankle joints

Question 20

What type of movements do pivot joints make and what are examples of them?

Answer 20

•Permits rotation around a single axis

1) atlantoaxial joint (atlas rotates around the finger-like process, the dens of the axis)
2) head of radius in anular ligament
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Question 21

What type of movements do condyloid joints make and what are examples of them?

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Answer 21

• Condyloid joints have convex surfaces that articulate with concave surfaces
• Flexion, extension, abduction, and adduction are possible.
• Biaxial (movements along 2 planes and 2 axes)
• Circumduction is also possible

Example:

•Metacarpophalangeal joints or knuckle joints

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Question 22

What type of movements do saddle joints make and what are examples of them?

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Answer 22

• Articular surfaces are reciprocally concave-convex and resemble a saddle on a horse’s back
• Flexion, extension, abduction, adduction are possible
• Biaxial (movements in 2 planes and 2 axes)
• Circumduction is also possible

Examples: carpometacarpal joint of the thumb sternoclavicular joint

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Question 23

What type of movements do plane/gliding joints make and what are examples of them?

Answer 23

• the articular surfaces are flat or almost flat, and this permits the bones to slide/glide on one another
• Uniaxial (movement that occurs in one plane)

Examples: acromioclavicular joints, vertebral facet joints