2. Skeletal System Flashcards
1
Q
Supine
A
Lying face up
2
Q
Prone
A
Lying face down
3
Q
Medial
A
Nearer to the midline
4
Q
Lateral
A
Away from the midline
5
Q
Bilateral
A
Both sides
6
Q
Unilateral
A
One side
7
Q
Ipsilateral
A
On the same side
8
Q
Contralateral
A
On the opposite side
9
Q
Proximal
A
Nearer to the trunk
10
Q
Distal
A
Further from the trunk
11
Q
Anterior ( ventral)
A
Nearer the front
12
Q
Posterior (dorsal)
A
Nearer the back
13
Q
Superior
A
Towards the top
14
Q
Inferior
A
Towards the bottom
15
Q
Coronal / frontal plane
A
Separating the front and back
16
Q
Sagittal plane
A
Separating the left and right
17
Q
Horizontal / transverse plane
A
Separating the top and bottom
18
Q
How many bones in the human body?
A
206
19
Q
What percentage of body weight is the skeleton?
A
18%
20
Q
Functions of the skeleton
A
• Support framework for the body. • Forms boundaries(skull). • Attachment for muscles and tendons. • Permits movement(joints). • Haematopoiesis-formation and development of blood cells from the red bone marrow. • Mineral homeostasis (mostly calcium & phosphate). •Triglyceride storage(yellow bone marrow).
21
Q
Bones Cells
A
- Osteogenic cells: 2. Osteoblasts: 3. Osteocytes: 4. Osteoclasts:
22
Q
Osteogenic Cells
A
Bone stem cells. They are the only bone cell to undergo division (producing osteoblasts).
23
Q
Osteoblasts
A
•These are bone building cells. •They synthesise and secrete collagen and other components of bony matrix. •They are trapped and become osteocytes.
24
Q
Osteocytes
A
•Osteocytes are mature bone cells.They maintain the daily metabolism of bone, such as nutrient exchange.
25
Osteoblasts
•Osteoclasts are huge cellsderived from the fusion of as many as 50 monocytes (WBCs). •On the side facing the bone surface, the cell membrane is folded into a ‘ruffled border’,where the cell releases powerful lysosomal enzymes and acidsthat digest bone matrix. •‘Resorption’ is the breakdown of bone matrix. •Osteoblast and osteoclasts work together to ‘remodel’ bone throughout life. Excess osteoclast activity leads to a loss of bone density.
26
Types of Bone
Compact Spongy
27
Compact Bone
80% of the skeleton Contains few spaces and is strong Found beneath the periosteum and makes up most of the diaphysis (shaft) of the long bones Structural unit of compact bone is an 'osteon' (aligned along stress lines)
28
Four parts of an Osteon
1. Haversian Canal 2. Lamallae 3. Canaliculi 4. Lacunae
29
Haversian Canal
Contains blood vessels ad nerves
30
Lamallae
Concentric rings of extracellular matrix containing minerals and collagen
31
Canaliculi
A mini system of interconnected canals that provide a route for nutrients/waste
32
Lacunae
Small spaces containing osteocytes
33
Spongy Bone
Spongy bone does not contain osteons. Instead it consists of an irregular lattice of thin columns called trabeculae that are aligned along stress lines. Microscopic spaces between trabeculae make bones lighter and contain bone marrow. Spongy bone makes up the interior of short, flat and irregularly shaped bones and the end of long bones. Spongy bone is always covered with compact bone.
34
Bone Matrix
An extracelluar matrix which surrounds separated cells made up of collagen and minerals (calcium phosphate as well as magnesium, sulphate and potassium).
35
Long Bones
Bones that have greater length than width. Contain diaphysis and 2 epiphyses Femur, tibia, humerus etc
36
Diaphysis
Shaft of long bones Contains mostly compact bone Covered by periosteum Contains a central 'medullary cavity' containing red and yellow bone marrow
37
Epiphyses
Ends of long bones (proximal and distal) Contains spongy bones with red bone marrow surrounded by compact bone and hyaline cartilage
38
Epiphyseal plate
Growth plate A layer of hyaline cartilage that allows the diaphysis to grow
39
Periosteum
Covers the bone when it is not covered by cartilage Pain sensitive, highly vascular membrane Protects bone Serves as an attachment for ligaments and tendons Contains two layers: outer fibrous layer (protects) and inner osteogenic layer (assist in growth and repair)
40
Medullary cavity
Cavity of long bones containing red/yellow bone marrow
41
Short Bones
Cube shaped Carpals, Tarsals
42
Irregular Bones
Complex shapes Vertebrae
43
Flat Bones
2 plates of compact bone Skull, scapula
44
Sesamoid Bones
Patella
45
Bone formation
1. Intermembranous ossification 2. Endochondral ossification
46
Intermembranous Ossificiation
Bone develops from connective tissue
47
Endochondral Ossification
Bone develops by replacing hyaline cartilage
48
Epiphyseal Line
The remnant of what was once the growth plate
49
Bone Hormones - Osteoblast
Growth Hormone & Thyroid Hormone Oestrogen & Testosterone Calcitonin (moves calcium from blood to bones)
50
Bone Hormones - Osteoclast
Parathyroid Hormone Cortisol (& steroid medications)
51
Bone Homeostasis
Hypocalcaemia - blood calcium is low Hypercalcaemia - blood calcium is high
52
Parathyroid and bones
Parathyroid Hormone increases blood calcium. 1. Increases the activity of osteoclasts (“resorption”). 2. Stimulates the kidneys to reabsorb & retain calcium in the blood. 3. Increases formation of calcitriol (active form of Vit D) which promotes calcium uptake from food in the intestines.
53
Thyroid and bones
Calcitonin is a hormone that lowers blood calcium levels. • Secreted by para-follicular cells of the thyroid gland. • It inhibits osteoclasts andpromotes osteoblast deposition of calcium in the bones. • The overall result is increased bone formation & decreased blood calcium.
54
Vitamin D
Facilitates calcium absorption in the intestines Works closely with Vit K2 D3 assists absorption whilst K2 activates a protein called ostocalcin which controls the utilisation of calcium in bones
55
Axial Skeleton
Central skeleton containing 80 bones Skull, inner ear, hyoid, thoracic cage and vertebral column
56
Skull
Forms the cranium (“upper head”) and face and encapsulates the Brain.The skull bones are joined with fibrous joints (‘sutures’). Sinuses are air filled cavities in the skull that: • Give resonance to the voice. •Lighten bones of face and cranium. Fontanelles: •Fibrous sutures (soft spots) on a baby’s head joining the skull Bones together.Ossify 12-18 months. •Allow the baby’s head through the birth canal.
57
Vertebral Column
24 moveable vertebrae Cervical (7) C1 - C7 Thoracic (12) T1 - T12 Lumbar (5) L1 - L5 Sacrum & Coccyx (fused bones)
58
Intervertebral Discs
23 shock absorbing discs which get progressively thicker Most hydrated in the morning and in those aged 30-40 Make up 1/3 of the length of the spine Annulus fibrosus, nucleus pulposus (gel like pad)
59
Thoracic Cage and Ribs
Sternum 12 ribs (11 and 12 are floating)
60
Appendicular skeleton
126 bones
Bones supporting the extremities
Shoulder girdle, arm and hand
Pelvic girdle, leg and foot
61
Arms and Shoulder
A - Clavicle
B - Scapula
C- Humerus
D - Ulna
E - Radius
F - Carpals
G - Metacarpals
H - Phalanges
62
Pelvic Girdle
A - Hip bone
B - Sacrun
C - Coccyx
D- Sarcro-iliac joint
63
Leg
A - Femur
B - Patella
C- Tibia
D - Fibula
64
Foot
A - Tarsals
B - Metatarsals
C - Phalanges (Toes)
65
Joints
187 joints in the human body
1. Fibrous Joints
2. Cartilaginous Joints
3. Synovial Joints
66
Fibrous Joints
Bones are held tightly together, permitting limited movement
eg. sutures in the skull
67
Cartilaginous Joints
Articulating bones tightly connected by cartilage and permit little to no movement
eg Epiphyseal growth plate, intervertebral disks
68
Synovial Joints
Permit the most movement
Bones are covered in hyaline cartilage called articular cartilage
Synovial fluid contains hylauronic acid and interstitial fluid
No blood supply, they obtain nutrients by diffusion
eg. 'ball and socket' hip/shoulder, and hinge elbow, knee
69
Bursa(e)
Bursa are sac-like structures that are strategically located to reduce friction
Contains connective tissue fluid
Located between skin & bone, tendon & bone, muscle & bone or ligament & bone
70
Flexion
Decrease in joint angle
71
Extension
Increase in joint angle
72
Rotation
Movement around its longitudinal axis. In the limbs it can be medial or lateral
73
Lateral Flexion
Movement of the trunk away from the midline
eg side bend
74
Abduction
Movement away from midline
75
Adduction
Movement towards midline
76
Circumduction
Circular
77
Elevation
Superior movement (up)
78
Depression
Inferior movement (down)
79
Protraction
Anterior movement (forward)
80
Retraction
Posterior movement (backwards)
81
Inversion
Medial movemet of sole (turn in, big toe up)
82
Eversion
Lateral movement of sole (turn out, big toe down)
83
Dorsiflexion
Bending foot up
84
Plantar flexion
Bending foot down
85
Supination
Movement of forearm to turn palm up
86
Pronation
Movement of the forearm to turn the palm posteriorly
87
Opposition
Movement of the thumb across palm to tough fingertips
