Types of movement in joints
Adduction - Movement towards the body
Abduction - Movement away from the body
Rotation - Circular movement around a fixed point
Flexion - To bend or flex a limb inwards/closing a joint. A movement decreasing the angle between bones.
Extention - To straighten or extend a limb outwards/opening a joint. A movement increasing the angle between bones
Circumduction - Circular movement – the limb can draw a circle in space. True circumduction involves 360° movement. Only the ball & socket joints at the shoulder and hip allow true circumduction. Some joints (e.g. the wrist joint) appear as if they enable circumduction but they don’t – they appear to be able to do this through a combination of flexion, extension, abduction and adduction movements.
Synovial membrane - The synovial membrane is a layer of loose connective tissue that includes both elastin fibres and adipose tissue. The synovial membrane produces synovial fluid
Synovial fluid - The synovial fluid has 3 main functions :-
1 – it lubricates and reduces friction in the joint.
2 – it acts a s a shock absorber for the joint
3 - it supplies the joints with nutrients, removes metabolic waste products and enables phagocytic cells to remove microbes and debris resulting from mechanical damage from use of the joint
Cartilage - Cartilage is found on the end of the bones in the joint. It acts to reduce friction between the bones and as a shock absorber
Muscle - Muscle is specialised elastic tissue made up of fibres bound together in bundles and contained in a sheath or fascia. The end of muscles extend to form tendons which attach muscles to other parts of the body. A muscles main function is to contract in reaction to a nerve impulse sent from the brain via a motor nerve.
Tendon - Tendons join muscles to bones enabling them to move
Ligament - Ligaments join bones and stabilise the joint
Types of joints
Ball & Socket - A joint in which the rounded head of one bone fits into a cuplike cavity of the other and enables movement in any direction. Example – the hip joint and the shoulder joint. In the hip joint, the rounded, almost spherical head of the femur (thigh bone) fits tightly into the acetabulum, a deep socket in the os coxa (hip bone). This is the joint that is replaced when people have a hip replacement
Hinge - A hinge joint is the simplest type of joint. Hinge joints allow movement in only one direction. The hinge joint of the knee, the body's largest joint, is unusual because it can swivel on its axis, allowing the foot to turn from side to side. Thus, the knee is constantly rolling and gliding during walking. Example – elbow, knee and the joints of the fingers & toes
Pivot - Also called a rotary joint as it only allows rotary movement. Example – a pivot joint at the top of the spine allows the head to swivel & bend
Sliding/gliding - Gliding joints occur between the surfaces of two flat bones that are held together by ligaments. It is called a sliding or gliding joint because the movement involves layers of cartilage sliding or gliding over one another. Example – Some of the bones in your wrists and ankles move by gliding against each other.
Fixed - This type of joint doesn’t allow any movement at all. Example – the joint between the bones of the skull and the bones of the front of the pelvis
The brain is an organ of soft nervous tissue contained in the skull of vertebrates, functioning as the coordinating centre of sensation and intellectual and nervous activity.
The brain is divided into 2 hemispheres and 4 lobes. It has both grey and white matter. Grey matter has a pinkish-grey colour in the living brain and contains the cell bodies, dendrites and axon terminals of neurons, so it is where all synapses are. White matter is made of axons connecting different parts of grey matter to each other.
The spinal cord is the cylindrical bundle of nerve fibres which is enclosed in the spine. It extends from the brain and gives off pairs of spinal nerves, carries impulses to and from the brain, and serves as a centre for initiating and coordinating many reflex acts.
A neuron or nerve cell transmits electrical impulses around the body. There are different types of neurons that have different functions. You need to know about 2 of them - sensory and motor nerves. The key parts of a neuron are :-
1 - Dendrites which collect electrical impulses
2 - The cell body which integrates the incoming electrical impulses
3 - The axon which carries the electrical impulses to another neuron, a muscle etc
Carry signals from receptors to the spinal cord and brain. The nervous system has many types of sensory neurons. Nerve endings on one end of each neuron are encased in a special structure to sense a specific stimulus e.g. pain, heat, sound etc
Sensory neurons convert external stimuli from the environment into internal electrical impulses which they then transmit to the brain and spinal cord.
Carry signals from the CNS to effectors. A motor neuron is a type of cell in the nervous system that directly or indirectly controls the contraction or relaxation of muscles, which in most cases leads to movement.
Covers the outside of the axon and insulates it. This means that the electrical impulse remains as strong as possible all the way to its destination
The brain is divided into 2 halves or hemispheres – the left and right hemisphere. The two hemispheres are joined by a band of connective and neural tissue that enables the 2 hemispheres to communicate. There is a lot of evidence that each hemisphere has it’s own set of functions.
The left hemisphere is heavily involved in language whilst the right hemisphere is mostly involved with non-verbal processes.
The cerebral hemispheres are divided into 4 lobes:-
The cerebellum, or "little brain“ has two hemispheres and has a highly folded surface or cortex. Like the cerebral cortex, the cerebellum is comprised of white matter and a thin, outer layer of densely folded grey matter.
The cerebellum is associated with regulation and co-ordination of movement, posture, and balance.
The hypothalamus is involved in functions including homeostasis, emotion, thirst, hunger, circadian rhythms, and control of the autonomic nervous system.
It also controls the pituitary gland.
The pituitary gland is a pea-sized structure located at the base of the brain, just below the hypothalamus and attached to it by nerve fibres. It is part of the endocrine system and produces hormones which control other glands as well as various bodily functions including growth and physical maturation .
The pituitary gland is divided into three sections known as the anterior, intermediate and posterior lobes, each of which produces specific hormones. Hormones produced by the pituitary gland include thyroid stimulating hormone (TSH), luteinising hormone (LH), growth hormone and antidiuretic hormone (ADH).
The medulla oblongata is involved in several functions of the body including:-
•Control of Autonomic Functions •Relay of Nerve Signals Between the Brain and Spinal Cord •Co-ordination of Body Movements
The medulla or medulla oblongata is part of the hindbrain and controls autonomic functions such as breathing, digestion, heart and blood vessel function and swallowing .
Motor and sensory neurons from the midbrain and forebrain travel through the medulla. As a part of the brainstem, the medulla oblongata helps in the transferring of messages between various parts of the brain and the spinal cord.
The band of connective and neural tissue that connects the left and right cerebral hemispheres and enables them to communicate
•regulation and coordination of movement/posture/balance •fine tuning muscle movements •regulation of learnt patterns eg playing the violin •motor responses
Controls autonomic functions, and relays nerve signals
between the brain and spinal cord; functions include:
respiration, blood pressure, swallowing, vomiting,
defecation, urination, reflexes, heart rate, breathing rate.
Corpus callosum function
Route communication between the two hemispheres.
Cerebral hemisphere function
•language is mostly represented on the left hemisphere •non-verbal skills tend to be represented on the right •hemisphere •frontal lobe – associated with reasoning, planning, parts of speech, movement, emotions, and problem solving •parietal lobe – associated with movement, orientation, recognition, perception of stimuli •occipital lobe – associated with visual processing •temporal lobe – associated with perception and recognition of auditory stimuli, memory, and speech
Pituitary gland function
•Co-ordination of hormones •Produces hormones to control other bodily functions.
The pituitary gland manufactures eight different types of hormones :-
1.thyroid stimulating hormone (TSH) 2.luteinising hormone (LH) 3.follicle stimulating hormone (FSH) 4.prolactin 5.growth hormone 6.adrenocorticotropic hormone (ACTH) 7.antidiuretic hormone (ADH) 8.oxytocin •Controls growth and physical maturation
Sensory nerve function
Involved in co-ordination & balance
Detects pain/ touch / sound / light / heat / taste /smell
Motor nerve function
Involved in movement, balance & co-ordination
Allows the brain to stimulate muscle contraction
Carries signals from the brain to the muscles
Myelin Sheath function
The outer covering of the axon of a nerve
It acts as a layer of insulation and increases the speed of impulse transmission
It reduces the corruption of neural signals