the skeletal system Flashcards
long bones
- found in the limbs
- have a shaft known as a diaphysis
- two expanding ends known as epiphysis
eg femur, humerus, radius
(support, movement and red blood cell production)
short bones
small, light, strong, cube-shaped bones used for weight bearing
eg carpals and tarsals
(weight bearing, fine or small movements, sock absorption)
flat bones
flat, normally thin, slightly curved, large surface area, protect vital organs
eg scapula, sternum, cranium
(protection and attachment for muscles)
irregular bones
complex shapes and do not fit into long, short, or flat
eg vertebrae
(protection (of spinal chord) movement)
sesamoid bones
- usually found within a tendon
- smooth surface for tendon to slide over
eg patella
(reduce friction, protection)
axial skeleton
main core of your body
eg skull, sternum, ribs, spine
appendicular skeleton
your limbs
eg includes any bones attached to the axial skeleton
order of vertebral column (top to bottom)
cervical
thoracic
lumbar
sacral
coccyx
cervical
- top 7 vertebrae of the neck
- first two bones are known as the atlas and axis
- forms the pivot joint in the neck to allow to head to move freely
thoracic
- 12 vertebrae of the mid-spine
- bigger than the cervical
- attach ribs which protect heart and lungs
- attach muscles of the back
lumbar
- 5 largest vertebrae of the lower spine
- biggest of moveable vertebrae
- support weight of other vertebrae and attach the muscles of the lower back
- discs produce a concave appearance
sacral
- 5 fused vertebrae which forms the sacrum
- helps form the wall of the pelvis
- supports the weight of vertebrae
coccyx
- 4 fused vertebrae forms the coccyx
- has no function
main functions of the vertebral column
- protects spinal chord
- supports rib cage (thoracic)
- supports body weight (lumbar)
- offers attachment for muscles in the back
- intervertebral discs receive and distribute impact (reduce shock)
postural defects
neutral spine
kyphosis
scoliosis
neutral spine
refers to good posture
3 natural curves
when viewed from anterior it should be completely vertical
kyphosis
excessive outward curve of the spine (bends from front to back) of the thoracic region
gives a hunchback appearance
often caused by poor posture but can be by deformities of the vertebrae
scoliosis
abnormal curvature of the spine either to the left or right
most common in thoracic region
causes are unknown
process of bone growth (term)
ossification
osteoblasts
cells that bring calcium to the bone
osteoclasts
cells that remove excess calcium
what are the functions of the skeletal system
- support
- protection
- attachment for skeletal muscle
- source of blood cell production
- store of minerals
- leverage
- weight bearing
- reduction of friction across a joint
support (function)
your bones give you shape and provide the supporting framework for the soft tissue of your body
protection (function)
bones surround and protect vital organs. pelvis = reproductive organs. cranium = brain
attachment for skeletal muscle (function)
your skeleton provides a surface for muscle attachment, allowing you to move. tendons attach muscle to bone. muscles contact and pull on the bones
source of blood cell production (function)
blood vessels feed the centre of your bone and stored within is bone marrow. this continually produces red and white blood cells
store of minerals (function)
bones hold minerals such as calcium and phosphorus, essential for bone growth and health. these minerals are stored and released into blood stream as regulated
leverage (function)
the bones provide a lever system against which muscles can pull to create movement
weight bearing (function)
bones are strong to support your weight. large forces are applied to your body and your skeleton is strong to prevent injury
reduction of friction across a joint (function)
the skeleton has many different types of joint; synovial joints secrete fluid that prevents the bones rubbing together, reducing friction
joints definition
place where two or more bones meet. joints are necessary for muscles to lever bones and create movement
what are the classification of joints
fixed (fibrous)
slightly moveable (cartilaginous)
synovial joints
fixed (fibrous) joints
immoveable
form when bones interlock during early childhood
eg bone plates in your cranium fixed together to protect your brain
slightly moveable (cartilaginous)
the ends of the bone are covered in a smooth covering called articular cartilage, reducing friction
eg found between sections of the vertebrae
synovial joints
freely moveable
have high mobility
vital for sporting movements and all various actions when 2 or more bones meet to form the joint
distinctive structure
eg elbow, knee, shoulder, thumb
synovial fluid
reduces friction at the joint, provides lubrication, shock absorber
synovial membrane
contains and releases synovial fluid
articular cartilage
prevents friction or bones rubbing together, shock absorber
joint capsule
tough fibrous tissue, surrounds the synovial joint, protects and stabilises the joint
ligaments
attach bone to bone
bursa
sack of fluid, reduces friciton
types of synovial joints
hinge
ball and socket
condyloid
gliding
pivot
saddle
hinge joint
allows movement in one direction
(forwards and backwards)
- elbow knee and ankle
ball and socket joint
allows movement in all direction
round end of bone fits into a cup-shaped socket
- hip and shoulder
condyloid joint
movements are forward, backwards and side to side
bump on one bone sits in hollow formed by another
- wrist
gliding joint
bones glide in any direction
formed by bones that meet at flat surfaces
- carpals and tarsals
pivot joint
enables rotational movement
circular bones fitting in the peg of another
- atlas and axis of the neck
saddle joint
movements backwards, forwards, side to side
surfaces of bone are convex and concave
- base of thumb
types of movement at synovial joint
flexion
extension
dorsiflexion
plantar flexion
lateral flexion
horizontal flexion
horizontal extension
hyperextension
abduction
adduction
horizontal abduction
horizontal adduction
circumduction
rotation
flexion
reducing the angle at a joint (often at hinges and ball and socket)
extension
increasing angle at a joint (often at hinges and ball and socket)
dorsiflexion
bringing toes towards the shin
movement at ankle
plantar flexion
pointing toes away
movement at ankle
lateral flexion
movement of bending sideways from waist
horizontal flexion
with a straight arm or leg, moving a limb in front of your body
horizontal extension
moving the limb away from the front of the body
hyperextension
movement beyond the normal anatomical position, in the opposite direction to flexion
abduction
movement of limb away from the midline
adduction
movement of limb towards the midline
horizontal abduction
bringing a limb across your body
horizontal adduction
movement away from your body
circumduction
circular movement that results in a conical action
rotation
circular movement of a limb
responses of skeletal system to a single sport or exercise session
- production of synovial fluid
- increase in mineral uptake
- increased pliability of ligament
production of synovial fluid (responses)
helps joint become more lubricated, protects bones during increase demands that exercise puts on ligaments and joints.
the fluid becomes less vicious and range of movement at joint will increase
will also provide increased nutrients to articular cartilage
increased mineral uptake (responses)
as muscle becomes stronger the more you use it, a bone becomes stronger and denser. when we perform weight bearing activities, the body absorbs minerals such as calcium, which increases bone mineral density
increased pliability of ligament (responses)
tendons become more pliable which would increase the range of movement at the joint
adaptations of skeletal system to exercise
- increase in bone strength and density
- increase in ligament strength
increase in bone strength and density (adaptations)
regular weight bearing exercise results in bones becoming bigger and stronger, meaning less likely to get injured as stringer bones will be more resistant to the forces found in sport.
increase in ligament strength (adaptations)
ligaments attach bone to bone within a synovial joint. overtime, ligaments become more pliable, increasing flexibility and range of movement at a joint. it also means that they are less likely to become sprained (when a ligament tears due to stretching)
additional factors affecting the skeletal system
arthritis
osteoporosis
age
arthritis
inflammation in a synovial joint, caused by general wearing away by bones rubbing together overtime, reducing the normal amount of cartilage.
causes pain, swelling in the joints
- regular physical activity can keep the muscles around affected joints strong, decrease vines loss and may help control joint swelling and pain
osteoporosis
bone disease that develops when bone mineral density and bone mass decreases.
caused by lack of calcium and vitamin D.
bones become brittle and fragile and more resistant to weight training, likely to break under stress
- exercise can prevent osteoporosis as it can regulate bone maintenance and stimulate bone formation. it strengthens muscle, improves balance and reduces falls and fractures.
age
weight training is likely to harm a child’s growth as bones and still growing. the forces applied through the bone may damage the epiphyseal plates, stunting growth.
