Chapter 6: Skeletal System Flashcards

1
Q

What are the primary functions of the skeletal system?

A

Support: rigidity supports bodyweight, cartilage give firm yet flexible support

Storage: minerals in blood

Protection: protects organs

Production of blood cells

Movement:

  • skeletal muscles attach to bones by tendons, the contraction of the muscles move the bones.
  • joints allow movement.
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2
Q

Name two major types of fibers and molecules found in the extracellular matrix of the skeletal system. How did they contribute to the functions of tendons, ligaments, cartilage and bones?

A

Collagen fibre and proteoglycan,

  • In tendons: collagen gives it tough properties
  • In cartilage: it gives it strength and smooth and resilience
  • In bones: the collage: flexibility, minerals: compression strength
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3
Q

Define the terms diaphysis, epiphysis, epiphyseal plate, medullary cavity, articular cartilage, periosteum and endosteum.

A

Diaphysis: the shaft
Epiphysis: two ends of a bone
Epiphyseal plate: the area between each epiphysis and diaphysis where growth occurs
Medullary cavity: the hollow cavity of a compact bone where marrow is stored
Articular cartilage: the smooth ends of a bone to withstand friction and movement
Periosteum: the outer layer of a bone
Endosteum: the surface covering the medullary cavity

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4
Q

Describe the structure of compact bone.

A
  • Forms most of the diaphysis of long bones. - Most of the lamellae is organized into sets of concentric rings which surround the central haversian canals. These canals are called osteons or haversian systems. They are given the appearance of having tiny spaces or gaps by the canaliculi, which connects each osteocytes and functions as a passage for nutrients and waste excretion.
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5
Q

Describe the structure of a cancellous bone. What are trabeculae?

A

Cancellous bone forms most of the epiphysis of the bone. It is also called a spongy bone due to it’s structure of spaces and gaps. It consists of delicate interconnecting rods called trabeculae. It adds strength to the bone without any extra strength. The spaces between the trabeculae are filled with bone marrow.

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6
Q

Define and describe intramembranous ossification.

A

Intramembranous ossification: bone ossification within connective tissue

a. This occurs when osteoblasts produce bone in connective tissues
b. Osteoblasts line up on the surface of connective tissue bones and deposit bone matrix on to form trabeculae
c. This happens in ossification centers where the trabeculae radiates out from the center

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7
Q

Define and describe endochondral ossification.

A

Endochondral ossification: bone ossification within cartilage
a.This occurs when chondrocytes multiply, hypertrophy and die, forming calcified cartilage matrix
b. The osteoblasts produce a collar of bone around diaphysis and stimulate ossification to occur. The center where this happens is the primary ossification center
d. The osteoblasts invade the spaces in the calcified matrix. And the osteoclasts remove the calcified matrix
A medullary cavity forms as osteoclasts remove bone and calcified cartilage and replace it with bone marrow.
e. Later secondary ossification centers form in epiphyses

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8
Q

How do bones grow in diameter? How do long bones grow in length?

A

a. Chondrocytes increase in number on the epiphyseal side of the epiphyseal plate. When they line up in columns, they elongate, hypertrophy and dies to form calcified cartilage matrix
b. The calcified matrix is removed by osteoclasts and the dying osteoclasts and replaced by osteoblasts
c. The osteoblasts deposit bone lamellae on the surface of calcified cartilage. This produces bone on the diaphyseal side on the epiphyseal plate.

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9
Q

What is accomplished by bone remodeling? How does bone repair occur?

A
Changes accomplished by bone remodelling: 
Bone shape 
Adjustment of bone due to stress 
Bone repair 
Calcium regulation in blood
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10
Q

How does bone repair occur?

A

Steps of bone repair:
1. When a bone breaks, this damages the blood vessels and forms a clot, 2 or 3 days after injury

  1. Then a callus forms, to repair the tissue. The cells which invade the clot forms a fibrous network of connective tissues and holds the fragments together to fill the gap
  2. Osteoblasts enter the callus and form a cancellous bone, while uniting the broken ends of the fracture. This usually takes about 4-6 weeks after injury
  3. Then the cancellous bone is then replaced with compact bone overtime. This region will be remodelled to bring it back to normal.
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11
Q

Define the axial skeleton and the appendicular skeleton.

A

Axial skeleton consists of the skull, vertebrae, thoracic cage and sternum.
Appendicular skeleton consists of upper and lower limbs and their girdles.

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12
Q

Name the bones of the braincase and the face.

A

Braincase bones: frontal, parietal, temporal, sphenoid bones

Facial bones: Orbits and nasal cavity, zygomatic bone, maxilla, mandible

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13
Q

Give the locations of the paranasal sinuses.

A

Locations: in the nasal cavity, the perpendicular is superior to vomer bone, the middle nasal concha is a projection from ethmoid bone, the inferior nasal concha is a separate bone

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14
Q

What are the functions of paranasal sinuses?

A

Functions: decrease weight of skull, acts as a resonating chamber during voice production and increase SA

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15
Q

What is the function of the hard palate?

A

Has uvula, forms floor of nasal cavity and roof of mouth

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16
Q

Through what foramen does the brain connect to the spinal cord?

A

Foramen magnum

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17
Q

How do the vertebrae protect the spinal cord?

A

The spinal cord is protected by bones, discs, ligaments, and muscles. The spine is made of 33 bones called vertebrae. The spinal cord passes through a hole in the center (called the spinal canal) of each vertebra. Between the vertebrae there are discs that act as cushions, or shock absorbers for the spine.

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18
Q

Name and give the number of each type of vertebra.

A
Cervical: 7 
Thoracic: 12 
Lumbar: 5
Sacral : 1
Coccyx 1
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19
Q

What is the function of the thoracic cage?

A

Function of thoracic cage: Protects organs, prevent collapse of thorax during respiration

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20
Q

Name the parts of the sternum.

A

Parts of sternum: manubrium, body and xiphoid process

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21
Q

Distinguish true, false, and floating ribs.

A

True ribs: 17 directly connected to sternum by costal cartilages
False ribs: 8-12not attached directly to sternum
Floating ribs: 11, 12 no attachment to sternum

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22
Q

Name the bones that make up the pectoral girdle, arm, forearm, wrist and hand. How many phalanges are in each finger and in the thumb?

A
Pectoral girdle: Clavicle and scapula
Arm: humerus 
Forearm: radius, ulna 
Wrist: carpals 
Hand: metacarpals, phalanges 
3 phalanges in each finger, 2 in thumb (distal, proximal)
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23
Q

Define the pelvic girdle. What bones fuse to form each coxa? Where do the bones of the coxae articulate?

A

The pelvic girdle is made up of two coxae. Each coccyx consists of ilium, ischium, and pubis. The coxae, sacrum and coccyx form the pelvis.

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24
Q

Name the bones of the thigh, leg, ankle and foot.

A

Thigh: femur
Ankle: tarsals
Foot: metatarsals, phalanges

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25
Q

Define the term articulation, or joint. Name and describe the differences between the three major classes of joints.

A
Articulation: the point where two points unite 
Fibrous joints (no movement) , synovial joints (freely) , cartilaginous joints (slight)
26
Q

Describe the structure of a synovial joint.

A

A synovial joint, also known as a diarthrosis, is the most common and most movable type of joint in a mammal’s body. Diarthroses are freely movable articulations. In these joints, the contiguous bony surfaces are covered with articular cartilage and connected by ligaments lined by synovial membrane

27
Q

Describe the different types of synovial joints, and give examples of each.

A
6 different types 
Plane: intercarpal 
Ball and socket : hip, shoulder 
Hinge : elbow, knee, ankle 
Saddle: sternoclavicular 
Pivot : distal radioulnar 
Ellipsoid :  radiocarpal (wrist)
28
Q

Describe and give examples of flexion / extension, abduction / adduction, and supination / pronation.

A

Flexion: movement in the anterior or ventral to the coronal plane (knee)

Extension: movement in the posterior or dorsal to the coronal plane

Abduction: movement away from median or sagittal plane (leg)

Adduction: movement away from median plane

Supination: rotation of forearm, palm is down (palm)

Pronation: rotation of forearm, palm is up

29
Q

How do the different parts of the joint function to permit joint movement?

A

Synovial joints achieve movement at the point of contact of the articulating bones. Synovial joints allow bones to slide past each other or to rotate around each other. This produces movements called abduction (away), adduction (towards), extension (open), flexion (close), and rotation.

30
Q

How does marrow form in adults and in children?

A

Children: more red than yellow

Adults: yellow turns red, red is located in central axis of body

31
Q

What are the 4 types of bone?

A

Long: limbs
Short: wrist, ankle
Flat: cranium, ribs, scapulae
Irregular: vertebral, facial bones

32
Q

What is the epiphyseal plate?

A

Where bone grows in length, between epiphyses and diaphysis

33
Q

Where is bone formed?

A
  • formed in lamellae
  • with bone cells : osteocytes
  • cell processes extend from matrix within canaliculi
34
Q

How do nutrients reach osteocytes in trabeculae?

A

Usually no blood vessels penetrate the trabeculae have no central canals but nutrients exit vessels in marrow and pass by diffusion through canaliculi to osteocytes.

35
Q

How do nutrients reach the osteocytes in a compact bone?

A
  • Nutrients from the blood vessels pass through the canaliculi and diffuse to the osteocytes.
  • Waste products go the opposite direction. These blood vessels are connected to the blood vessels in the periosteum and endosteum.
36
Q

What is the role of calcium in bone?

A
  • major storage site
  • maintained within narrow limits
  • removed from blood when blood calcium levels decrease so need adequate supply of calcium
37
Q

What happens when there is too much bone deposition? Too little?

A

Thick, abnormal lumps

Weaken bones, susceptible to fracture

38
Q

What is gigantism?

A

Abnormally increased size in bones,

excessive endochondral growth of epiphyseal plate

39
Q

What is dwarfism?

A

abnormally small,

improper growth at epiphyseal plate

40
Q

What is osteogenesis imperfecta?

A

group of genetic disorders producing brittle bones, insufficient collagen

41
Q

What is rickets?

A

growth retardation from nutritional deficiencies,
minerals (ca, p),
which are necessary for Vit. D in bones
= soft, weak, easily broken bones

  • often in children with insufficient sunlight exposure or deficiency in Vit. D
42
Q

What is osteomyelitis?

A

bone inflammation, lead to complete destruction of bone

43
Q

What is staphylococcus?

A

wound infections

- can result from tuberculosis, a lung disease that affect bones, can be complication of AIDS

44
Q

What is osteomalacia?

A

softening of bones from calcium depletion
(also called adult rickets from vit. D)

  • unusual need of calcium
    eg. pregnancy : mothers calcium will be removed and mother’s bones will soften and weaken
45
Q

What is osteoporosis?

A

porous conditions from reduction of bone tissues

46
Q

List the types of bone fractures.

A
  1. Open (compound)
  2. Closed (simple)
  3. Complete
  4. Incomplete
  5. Greenstick fracture
  6. Comminuted
  7. Impacted
  8. Linear
  9. Transverse
  10. Spiral
47
Q

How are joints classified?

A

By degree of motion at joint

  1. Synarthrosis: nonmovable joint
  2. Amphiarthrosis: slightly movable
  3. Diarthrosis: freely movable

By structure of joint:
according to major CT,
according to whether there is fluid filled joint capsule

48
Q

What are fibrous joints?

A

NO MOVEMENT

consists of two bones united by fibrous tissue

49
Q

What are sutures?

A

fibrous joints in between the bones of skull

in newborns:

  • allow flexibility during birth process
  • growth of head post natal
50
Q

What are syndesmoses?

A

fibrous joints in between where the bones are separated to some distance and held together by ligaments
eg. distal parts of radius and ulna

51
Q

What are gomphoses?

A

fibrous joints of pegs fitted into sockets and held by ligaments
eg. tooth and socket

52
Q

What are cartilaginous joints?

A

SLIGHT MOVEMENT

two bones joined together by cartilage

Eg. cartilage in epiphyseal plate of long bones, cartilage between ribs and sternum

53
Q

What are synovial joints?

A

FREELY MOVABLE
contains synovial-fluid in a cavity surrounding the ends of bones
- mostly between large bones (greater mobility)

54
Q

What are the effects of aging on skeletal system?

A
  1. more brittle bone matrix (decreased collagen)
  2. decrease in amount of matrix (slower rate of matrix formation)
  3. loss of bone : 0.3-0.5% / year
  4. rate of replacement declines, more rigid matrix = more chance of wear
  5. decreased production rate of synovial fluid
  6. arthritis
  7. shortened ligaments/ tendons = less flexibility = less motion of joint
55
Q

What is arthritis?

A

inflammation of joints

- caused by infectious agents, metabolic disorders, trauma and immune disorders

56
Q

What is rheumatoid arthritis?

A

tissue disorder, an autoimmune disease
- synovial membrane and associated CT cells proliferate and forms pannus in joint capsule into articulating surface of bones, destroying the articular cartilage and bones forming the joint may be fused

57
Q

What is osteoarthritis?

A

gradual wear and tear of tissues with age

58
Q

What is gout?

A

caused by increase in uric acid
- 1, 2 joints affected

effects:
1. base of great toe, leg joints
2. damage to kidney from crystals

59
Q

What is bursitis?

A

inflammation of bursea (shoulder and elbow)

60
Q

What is bunion?

A

joint of base of great toe by tight shoes

61
Q

What is joint replacement (arthroplasty)?

A
  • to eliminate unbearable pain
  • to increase joint mobility

artificial joints: made of metal and plastics

62
Q

What is the process of joint replacement (arthroplasty)?

A

bone of articular area is removed on one side or both then artificial structures are attached
- smooth surface rubbing the smooth plastic surface = low friction