Skeletal System Flashcards Preview

Biology > Skeletal System > Flashcards

Flashcards in Skeletal System Deck (67)
Loading flashcards...
0

5 Skeletal Functions

1) Supports the body
2) Protects soft body parts
3) Produces blood cells (in red bone marrow)
4) Stores minerals (calcium and phosphate) and fat (yellow bone marrow)
5) Permits flexible body movement (via attached muscles)

1

5 Types of Bones

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

2

Long Bones

Longer than they are wide - e.g., femur

3

Short Bones

Generally cube-shaped, e.g. carpals

4

Flat Bones

Thin bones consisting of spongy bone sandwiched between two parallel layers of compact bone (e.g. skull bones)

5

Sesamoid Bones

Embedded in tendons and increase muscle leverage (e.g., patella)

6

Irregular Bones

Bones that don't fit into any other category

7

A long bone is comprised of...

Compact bone and spongy bone

8

Epiphysis

End of a bone

9

Diaphysis

Shaft of a bone

10

Medullary Cavity

Space in compact bone, especially in the diaphysis (shaft)

11

Compact Bone

Living tissue composed of tubular units called osteons

12

Osteocyte

Bone cells, housed in the lacunae.

13

Lacunae

Spaces in which osteocyte reside

14

Lamella

Layer of matrix made with calcium phosphate and collagen fiberfs

15

Spongy Bone

Lighter than compact bones, but still strong. Composed of numerous thin plates called trabeculae, separated by uneven spaces, which often contain red bone marrow.

16

Cartilage

Not as strong as bone, but more flexible, composed of many collagenous and elastic fibers. Lack of nerves allows for suitable "padding", but a lack of blood vessels results in slow healing.

17

Chondrocytes

Cartilage forming cells that lie within lacunae

18

Hyaline Cartilage

Firm but somewhat flexible; found in ends of long bones, nose, larynx, trachea

19

Fibrocartilage

Stronger than hyaline; found in disks between vertebrae

20

Elastic Cartilage

More flexible than hyaline cartilage. Found in ear flaps.

21

Ossification

Formation of bone

22

Intramembraneous Ossification

Bone development between sheets of fibrous connective tissue (used in flat bones)

23

Endochondral Ossification

Cartilage provides a "template" that is replaced by bone (used by most bones)

24

Mesenchyme

Undifferentiated connective tissue

25

Osteoblasts

Bone-forming cells

26

Epiphyseal Plate

Growth plate via which bones grow and lengthen

27

Males stop growing around age...

20.

28

Females stop growing around age...

16-18.

29

Hormone

A chemical messenger (protein or steroid) that is produced in one part of the body and acts on another.

30

Growth Hormone

Stimulates general bone growth and growth of the epiphyseal plates.

31

Sex Hormones

Increases growth during adolescence by stimulating osteoblast activity (estrogen is essential for bone maintenance in adult females and males).

32

Vitamin D

Converted to a hormone to allow calcium absorption in intestines.

33

Osteoclast

Bone-absorbing cells

34

Role of bone in homeostasis

Calcium, important in cell signaling, nerve and muscle function, and blood clotting, stored in bones. Body regulates calcium levels in the blood via hormones - parathyroid hormone and calcitonin.

35

Parathyroid Hormone

Increases blood calcium by accelerating bone recycling, stimulates osteoclast.

36

Calcitonin

Decreases blood calcium by stimulating osteoblast.

37

Osteoperosis

Weakening of bones due to decreased bone mass.

38

Bone absorption exceeds formation by when?

Age 40, usually.

39

Risk factors for osteoperosis

Woman, white or Asian, thin, family history, smoking, diet low in calcium, excessive caffeine or alcohol consumption, sedentary lifestyle.

40

Four stages of bone repair

1) Hematoma
2) Fibrocatilaginous callus
3) Bony callus
4) Remodeling

41

Hematoma

Blood clot; forms between 6-8 hours after a bone break

42

Fibrocartilaginous Callus

Forms between broken bones, about 3 weeks after a break

43

Bony Callus

The fibrocartilaginous callus is converted into bone, about 3-4 months after a break.

44

Remodeling

Bony callus is replaced by new compact bone tissue. Osteoclasts absorb spongy bone to create the medullary cavity.

45

Articulations

Where bone meets bone (aka "joint")

46

Types of Articulations

Fibrous
Cartilaginous
Synovial

47

Fibrous Articulations

Usually immovable, such as the sutures between cranial bones

48

Cartilaginous Articulations

Tend to be slightly movable such as the intervertebral disks

49

Synovial Articulations

Freely movable joints - several classes - including the knee joint, ball and socket joint (shoulder, hip), and hinge joints (elbow).

50

Flexion

Joint angle decreases

51

Extension

Joint angle increases

52

Adduction

Body part moves toward midline

53

Abduction

Body part moves away from midline

54

Rotation

Body part moves around its own axis

55

Circumduction

Body part moves in a cone shape

56

Inversion

Sole of foot turns inward

57

Eversion

Sole of foot turns outward

58

Axial Skeleton

Lies in the mid-line of the body

59

Appendicular skeleton

Lies away from the mid-line axis

60

Hyoid Bone

Anchors the tongue; attachment point for muscles used in swallowing

61

Vertebral Column

Cervical
Thoracic
Lumbar
Sacral
Coccyx

62

Cervical Vertebrae

Vertebrae 1-7

63

Thoracic Vertebrae

8-19

64

Lumbar Vertebrae

20-24

65

Sacral Vertebrae

25-29, fused

66

Coccyx Vertebrae

30-33, fused