4: STRUCTURE AND FUNCTION OF SKELETAL SYSTEM Flashcards
What are the 5 main functions of the skeleton
- Movement
- Shape + structure
- Protection
- Blood production
- Mineral storage
What are the 6 main fuctions affecting skeleton shape
- Weight
- Age
- Injury
- Physical activity
- Pregnancy
- Posture
How does age affect skeleton shape
bones gradually deteriorate
Bone density decreases = bones thinner and more fragile
Postural abnormalities become worse as spinal vertebrae and discs become thinner and compressed due to loss of minerals and moisture. Joints can become inflamed and less flexible as fluid in the joints decrease and cartilage erodes. Joints can also become stiff due to mineral deposits
How does physical activity affect skeleton shape
weight bearing activity can increase bone density
Can prevent the early onset of osteoporosis and slow down the deterioration for those who already have it
Increased amount of synovial fluid produced with activity
How does pregnancy affect skeleton shape
If pregnant woman’s calcium levels are low, growing baby will take from the mothers own supply
Produces more oestrogen to protect bones
Bone mass lost during pregnancy is restored several months after birth
Hormones relaxin and progesterone relax muscles and loosen ligaments and joints (especially in pelvic region) to get ready for birth. But this combined with extra weight gained can lead to discomfort and injury
How does posture affect skeleton
Can lead to muscles, ligaments and tendons adapting to new position and become unbalanced
Muscle imbalance pulls one of your joints out of position, putting strain on the joint
Strain stresses the nerves around the joints resulting in pain
If the body then tries to re-adjust, other sets of muscles can become imbalanced (compensation) and the cycle continues.
3 scientific body types
- Endomorph
- Mesomorph
- Ectomorph
Describe endomorph body type
Soft round shape with short limbs
Little muscle definition because of fat stored beneath the skin
Good at wrestling and lifting weights
Describe mesomorph body type
Sturdy skeleton and predominance of muscles
Muscular limbs
Good at sports involving power and strength
Describe ectomorphy body type
Lean, slim build without much muscle mass but good definition due to lower body fat
Good at endurance sports where height to weight ratio is important
What are the 2 sections of the skeletal system
- Axial
- Appendicular
What is the axial skeleton
The main frame
What is the appendicular skeleton
The extremities
What is included in the axial skeleton
Skull
Ribs
Sternum (chest)
Spine
What is the scapula
The shoulder blade. The bone that connects the clavicle to the humerus
What is the clavicle
The collarbone - connects the sternum to the shoulder
What is the humerus
Upper arm bone
What is the ulna
One of the bones that makes up the forearm
What is the radius
One of the bones that makes up the forearm
What are carpal bones
Bones of the wrist that connect the the radial and ulnar bones of the forearm to the bases of the five metacarpal bones of the hand
What are metacarpals
Bones between the wrist and the fingers
What are phalanges
finger bones
What is the Ilium
The largest and uppermost bone of the hip, the ilium, also known as the iliac bone, is an essential part of the pelvic girdle
What is the ischium
forms the lower and back part of the hip bone
What is the pubis
Together with the ilium and ischium, make up the hip bone - left and right of pelvic bone
What is the femur
Thigh bone
What is the patella
Knee
What is the tibia
shin bone
What is the fibula
a long bone in the lower extremity that is positioned on the lateral side of the tibia
What are the tarsal bones
7 bones that help the foot move. connecting the leg to the feet
What are metatarsals
a group of five long bones in the foot, located between the tarsal bones of the hind- and mid-foot and the phalanges of the toes
What bones make up the shoulder girdle
- Scapula
- Clavicle
What bones make up the pelvic girdle
- Ilium - largest of the 3
- Ischium (sitting bone)
- Pubis (at the front)
What are the 4 sections of the vertebral column
- Cervical spine
- Thoracic spine
- Lumbar spine
- Sacrum + coccyx
What is the cervical spine
Vertebrae C1 - C7 - the C1 = atlas, C2 = axis (form pivot joint for neck/head)
Lumbar curvature
What is the thoracic spine
made up of 12 vertebrae (T1 - T12)
Articulate with the ribs
Increase in size as go down
Kyphotic curvature
What is the lumbar spinee
Made up of 5 vertebra (L1 - L5)
Makes up lower back
Biggest in the spine
Carry the heaviest weight
Lumbar curvature
Which section of the spine is the most mobile
Cervical
