Skeletal System Flashcards
Anterior
To the front or in front
Posterior
To the rear or behind
Medial
Towards the midline, an imaginary line down the centre of the body
Lateral
Away from the midline or axis
Proximal
Near to the origin
Distal
Away from the origin
Superior
Above
Inferior
Below
Long bones
Found in the limbs
Short bones
Small, light and strong
Flat bones
Thin, flattened and slightly curved
Irregular bones
Have complex shapes that fit none of the categories above
Sesamoid bones
Have a specialised function and are usually found within a tendon
Axial Skeleton
The main core or axis of your skeleton
Appendicular skeleton
Consists of the bones attatched to your axial skeleton
Cervical vertebrae
The seven vertebrae of the neck
Thoracic vertebrae
The 12 vertebrae of the mid-spine. They lie in the thorax
Lumbar Vertebrae
The five largest of the moveable vertebrae, situated in the lower back
Sacral vertebrae
The five sacral vertebrae are fused together to form the sacrum. A triangular bone located below the lumbar vertebrae
Coccygeal vertebrae
At the bottom of the vertebral column there are four coccygeal vertebrae, which are fused together to form the coccyx or tail bone
Kyphosis
The excessive outward curve of the thoracic region of the spine
Ossification
The process in which bones are formed
Osteoclasts
Where unnecessary calcium is removed
Osteoblasts
The cells that bring calcium to your bones
Epiphyseal plates
Plates which allow the bone to grow longer
Epiphyseal line
Once a long bone is fully formed the end of the bone fuses with the main shaft to create the epiphyseal line
Function of a long bone
Movement, support, blood cell production
Function of a short bone
Fine or small movements; shock absorption, stability, weight bearing
Function of a flat bone
Attachment for muscles; protection
Function of a sesamoid bone
Protection; reduction of friction across a joint
Function of an irregular bone
Protection (spinal cord); movement
Articulation
Where two or more bones meet to allow movement to occur
Fixed Joints, or fibrous or immovable joints
- bones overlap during childhood
- joints do not move
- example= between bone plates in cranium
Slightly moveable joints or cartilaginous joints
- allow slight movement
- ends of bone covered in shiny covering known as articular
- for example between most vertebrae
Synovial joints or freely movable joints
- High level of mobility
- consists of two or more bones
- all synovial joints consist of a joint capsule, a bursa, articular cartilage, a synovial membrane, synovial fluid, ligaments
Joint capsule or fibrous capsule
An outer sleeve to help to hold the bones in place and protect the joint. This capsule will also contain the main structure of the synovial joint
A bursa
A small fluid- filled sac which provides a cushion between the tendons and the bones, preventing friction. Bursae are filled with synovial fluid
Articular cartilage in the ends of bones
Provides a smooth and slippery covering to stop the bones rubbing or grinding together
A synovial membrane
The capsule lining that releases synovial fluid
Synovial fluid
A thick liquid that lubricates the joint and reduces friction between bones
Ligaments
Hold the bones together and keep them in place
Hinge joint
Allow movement in one direction only
Ball and socket
The round end of one bone fits into a cup- shaped socket in the other bone, allowing movement in all directions
Condyloid joint
- Also known as ellipsoidal joints. Similar to ball and socket joints.
- Example= while dribbling in basketball, with the wrist being used to create this action
Gliding joint
Allow movement over a flat surface in all directions, but this movement is restricted by ligaments or a bony prominence. This can be seen in a netball jump with the foot pointing downwards
Pivot Joint
A circular bone fits over a peg of another bone, allowing controlled rotational movement. When you turn your head in sport
Saddle Joint
These are similar to condyloid joints but the surfaces are concave and convex. You would use a saddle joint when gripping a racket in tennis or squash
Flexion
Reducing the angle between the bones of a limb at a joint
Extension
Straightening a limb to increase the angle at the joint
Dorsiflexion
An upward movement, pulling the toes towards the knee in walking
Plantar Flexion
A movement that points the toes downwards by straightening the ankle. This occurs when jumping to shoot in netball
Lateral Flexion
The movement of bending sideways, for example at the waist
Horizontal Flexion and horizontal extension
Bending the elbow (Flexion) while the arm is in front of your body; straightening the arm at the elbow is extension
Hyper-extension
Involves movement beyond the normal anatomical position in a direction opposite to Flexion. This occurs at the spine when a cricketer arches their back when approaching the crease to bowl
Abduction
Movement away from the body’s vertical midline, such as the hip in a side-step in gymnastics
Adduction
Movement towards the body’s vertical midline, such as pulling on the oars while rowing
Horizontal abduction and adduction
This is the movement of bringing your arm across your body (Flexion) and then back again (extension)
Circumduction
This is a circular movement that results in a conical action
Rotation
Circular movement of a limb. Rotation occurs at the shoulder joint during a tennis serve
Additional factors affecting the skeletal system
1) Arthritis
2) Osteoporosis
3) Age
