a powerpoint presentation on Yr 10 24 Skeletal system

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The functions of the skeleton (as
part of a healthy, active body)
• Shape and support
(allowing good
posture)
• Movement
Muscles attach to
bones and create
movement (levers)
around joints
• Protect internal
organs
• Produce red and
white blood cells
• Store minerals
Task
• Label the bones on the skeleton
3 categories of joint
• Fibrous or fixed
-
no movement
• Cartilaginous
-
slight movement
• Synovial
-
freely moveable
Hinge joint
• Movement in one
plane only
• Eg knee, elbow
Pivot joint
• Only allows rotation
Eg neck vertebrae
when turning head
ellipsoid
• Biaxial movement i.e.
in 2 planes
Eg playing a
badminton shot
gliding
• When two flat
surfaces glide over
one another
Eg carpal bones in
wrist when playing
hockey
Saddle joint
• When concave
surface meets convex
as in thumb gripping
tennis racket
Ball and socket
• When a round head
of bone sits in a
socket – allows wide
range of movement
Eg hip, shoulder
Cartilage
• Soft connective tissue
• Babies skeleton is
mainly cartilage –
through process of
‘ossification’ mostly
becomes bone
• Has no blood supply
Ligaments
• Connective tissue
between bones
• Tough, resilient, keep
joints together &
stable
• Prevent extreme
movement
• Resist dislocation
3 main types of cartilage
• Yellow elastic
- flexible (ear lobe)
• Hyaline (blue) articular
- on articulating
surfaces of bones.
Protective - allows
movement by limiting
friction. Thickens
through exercise
• White fibro
- tough shock
absorber, eg semi-lunar
cartilage in knee joint
Cartilage & ligament injuries
• Repeated small injuries can lead to
cartilage tears
• Degeneration (wear and tear of meniscus
cartilage)
• Cartilage is slow to heal as it doesn’t have
a blood supply
• Ligaments can sprain or tear
• Medial/cruciate – common knee ligament
injuries
Movement at joints
• Flexion
• Extension
• Abduction
• Adduction
• Rotation
levers
Q’s
• 1. explain how the skeletal system
responds to exercise (5)
• 2. name the two most common forms of
arthritis and describe their causes (6)
• 3. which category of person is most likely
to suffer from osteoporosis and what
factors could contribute to this (3)
Answer 1
• short term – in joints stimulates secretion of
synovial fluid, which becomes less viscous =
greater range of movement
• longer term – connective tissue becomes more
flexible. With time improved range of movement
becomes more sustained. Bone increases in
density = stronger = less risk of osteoporosis.
Hyaline cartilage, tendons and ligaments thicken
= reduced risk of injury. Bone mineral content
higher
Answer 2
• Osteoarthritis – caused by ageing and
general wear and tear, injury, overweight
• Rheumatoid – immune system attacks
cells within joint capsule. Women more at
risk, also genetic predisposition, smoking
and obesity
Answer 3
• Women over 60
• Inadequate calcium and vitamin D intake
• Lack of weight bearing exercise
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