Skeletal System 2 Flashcards
Explain Anatomical Position
Person stands erect
Palms forward
Feet parallel, flat on the floor
Arms to the side of the body
Supine
Body lying face up
Prone
Body lying face down
Distal
Further from trunk
Unilateral
one side
Medial
Neaer the midline
Bilateral
Both sides
Proximal
Nearer trunk
Contralateral
On the opposite side
Ipsilateral
On the same side
Lateral
Away from the midline
Anterior / ventral
Nearer to the front
Inferior
Towards the bottom
Posterior
Nearer the back
Coronal plane
Separating front and back
Sagittal
Separating right and left
Horizontal
Separating top and bottom
4 functions of human skeleton
Movement
Supportive framework
Attachment for muscles
Boundries (skull)
Osteogenic
Only bone cell to undergo division
Osteoclasts
Huge cells derived from a fusion of as many as 50 monocytes
Osteoblasts
Bone building cells.
Synthesise and secrete collagen and other components of bony matrix
Osteocytes
Mature bone cells
Maintain daily metabolism of bone such as nutrient and waste exhcange
Which bone cell can transform to an osteocyte
Osteoblasts
3 features of compact bone
Few spaces
Structural unit is an osteon
Found beneath the peristeum of all bones
How much of the skeleton is compact bone
80%
Where is compact bone located
Beneath peristeum
Bulk of diaphysis in long bones
Structural unit of a compact bone
Osteon
Haversian canal
Contains blood vessels and nerves
Lamellae
Concentric rings of calcified extracellular matrix containing minerals and collagen
Lacunae
Small spaces between lamellae
Contain osteocytes
Canaliculi
Mini system of inter connected canals that provide a route for nutrients and waste
2 features of spongy bone
Does not contain osteons
Consists of irregular lattice of thing columns called trabeculae
What are the columns in spongy bone called
Trabeculae
Why is Spongy bone always covered in a layer of compact bone
For strength and stability
Epiphysis
heads of a long bone - proximal and distal
Diaphysis
Shaft of a long bone
2 examples of long bones
Femur, tibia, humerus
Epiphyseal plate
Layer of hyaline cartilage that allows the diaphysis of a bone to grow in length
Long bones inner spongy bones contain
red bone marrow
What is the diaphysis of of a long bone covered by
Periosteum
What colour bone marrow is in the diaphysis of a long bone
yellow bone marrow
3 functions of periosteum
Pain sensitive
Highly vascular
Attachment for ligaments and tendons
Difference between inner and outer layers of periosteum
Tough outer fibrous layer
Osteogenic (bone forming) inner
Compact bone examples
Carpels
4 Function of skeleton
Supports framework for the body.
* Forms boundaries (skull).
* Attachment for muscles and tendons.
* Permits movement (joints).
* Haematopoiesis
* Mineral homeostasis (mostly calcium and phosphate).
* Triglyceride storage (yellow bone marrow).
Most abundant mineral in bone
calcium phosphate.
4 minerals found in bones
calcium phosphate
magnesium,
sulphate,
potassium.
Short bone examples
Carpals, tarsals
Irregular bone example 1
Vertebrae
Flat bone examples
Skull, scapula
Sesamoid bone example 1
Patella (kneecap)
Difference between Intromembranous & Endochondral ossification
Intramembranous - bone develops from connective sheets
Endochondral - replacing hyaline cartilage
Which bone grows lengthwise
Long bone
2 factors that influence bones as they grow in thickness
Physical stress
Muscle activity
Weight
Role of epiphyseal plate
Layer of hyaline cartilage where osteoblasts are produced
2 hormones that promote osteoblast activity
Growth hormone
Thyroid hormone
Oestrogen
Testosterone
Calcitonin