Supporting systems & Movement (in animals) Flashcards
(116 cards)
1
Q
What are the 3 types of skeletons?
A
Hydrostatic, exoskeletons and endoskeletons
2
Q
Define a hydrostatic skeleton
A
Consists of fluid-filled, closed chambers within an organism that provide support against which muscles can contract to bring about movement
3
Q
Give examples of animals with a hydrostatic skeleton
A
Soft-bodied invertebrates like jellyfish, earthworms or roundworms
4
Q
How do animals with a hydrostatic skeleton move
A
Contracting the muscles surrounding the fluid-filled cavity creates pressure that causes a change in the shape of the animal. This causes movement such as burrowing, crawling or swimming.
5
Q
How do jellyfish move?
A
jellyfish move by contracting their bell-shaped form, forcing water out of the bell, which propels the jellyfish forward. This type of skeleton is well suited for aquatic animals.
6
Q
How do earthworms move?
A
earthworms use their hydrostatic skeletons to change their body shape as they move forward by peristalsis. Circular and longitudinal muscles produce movement through waves of contraction and relaxation. When lengthwise muscles contract, segments of the body shorten; when circular muscles contract, segments of the body elongate. Chaetae (bristles) press into the ground to ensure that the earthworm moves forward.
7
Q
What are the disadvantages of hydrostatic skeletons?
A
These mainly soft bodied animals:
* lack well developed skeletal defense mechanisms
* have a restricted range of movement
* are confined to areas near or in water as they lose water so readily
* cannot reach any great size, whether they live on land or in the water
8
Q
Define an exoskeleton
A
A skeleton that surrounds the body of an organism
9
Q
What organisms have exoskeletons?
A
Although exoskeletons are found in many groups of animals such as tortoises, corals, star fish, molluscs with shells and diatoms, arthropods form the main group of animals that have exoskeletons.
10
Q
What is an exoskeleton made of
A
In arthropods the exoskeleton is made from the polysaccharide, chitin - a substance similar to cellulose found in the cell walls of plants. It is a light and quite strong compound.
11
Q
What are the advantages of an arthropod exoskeleton?
A
is an external structure that supports the animal and protects its internal organs from injury.
* has muscles attached to knobs and plates so it allows for movement.
* has joints where the exoskeleton is thin and flexible, enabling the animals to move more easily.
* is often covered with a layer, of wax called a cuticle that reduces loss of water from the body, preventing the animal from drying out.
12
Q
What are the disadvantages of exoskeletons?
A
Because of their rigidity, exoskeletons limit mobility.
They also limit growth. A large animal would need a large exoskeleton that would be very heavy and restrict movement.
13
Q
How can growth limitation of exoskeletons be overcome
A
Growth limitations are overcome in the following ways:
Arthropods shed their exoskeletons to enable them to grow - a process called moulting or ecdysis. A new exoskeleton is regenerated by the underlying epidermis. After the exoskeleton is shed, the arthropod pumps up its body by the intake of air or water to expand, the new exoskeleton to a larger size. Dehydration of the cuticle then takes place which causes it to harden into an exoskeleton. Animals become easy prey to predators when they are moulting.
Many molluses have calcareous shells and, as they grow, the diameter of the shell is added to and enlarged without altering its shape.
14
Q
How can movement limitation of exoskeletons be overcome
A
by allowing flexibility in the following ways:
* The arthropod exoskeleton is divided into different functional units, e.g. the head, thorax and abdomen of insects.
Arthropods have jointed limbs where the exoskeleton is thin at the joints, enabling the leg to move.
15
Q
Define an endoskeleton
A
Endoskeletons are found within the body of an animal.
16
Q
What type of animals have endoskeletons and what is it made out of?
A
All vertebrates possess an endoskeleton. Some, such as turtles, terrapins and tortoises also have an exoskeleton.
Vertebrate skeletons are made of either bone and/or cartilage. Sharks and rays have skeletons made of cartilage which is softer and lighter than bone.
17
Q
What are the
advantages of an
endoskeleton?
A
supports the body, giving it shape.
is made up of living tissue that can grow as the animal increases in size.
lungs and heart.
protects the internal organs such as the brain, provides anchors for muscles which work with bones to allow movement.
18
Q
What tissues make up an endoskeleton?
A
- Cartilage
- Bone
19
Q
What is cartilage and where is it found in the body
A
Cartilage occurs in isolated areas in the body such as in part of the ribs, the nose, pinna of the gear, between vertebrae and in the lining of joints.
Cartilage is much softer than bone because it contains less minerals. It has few blood vessels and no nerves.
20
Q
How is cartilage made up?
A
There are three types of cartilage - hyaline, elastic and fibrous cartilage.
21
Q
What are the basic components of cartilage
A
chondrocytes (mature cartilage cells) in lacunae (cavities) surrounded by
a matrix made up of a jelly-like substance in which both collagen fibres (for flexibility and strength) and elastic fibres (for elasticity) are deposited
a large amount of tissue fluid. In fact, cartilage is up to 80% water!
22
Q
give examples of places in body with 3 different cartilage types
A
ears - elastic
vertebrae - fibrious
pelvis - hyaline
23
Q
Why is cartilage important?
A
1. lines many joints, facilitating smooth movement acts as a shock absorber between vertebrae
2. forms flexible structures such as the epiglottis and pinna of the ear.
24
Q
What is bone?
A
Bone makes up the bulk of the skeleton. It is the hardest tissue in the body but it needs to be as light as possible to reduce the weight that an animal must move about. Bone tissue is supplied with blood vessels, nerves and lymph vessels.
25
How is bone tissue made up?
Bone tissue is made up of osteocytes in lacunae set in a matrix made up of the following:
1. collagen fibres (made up of complex proteins) that stick to each other in a criss-cross pattern, giving bone its flexibility, making it strong and durable. They have a glistening white appearance, and are also called white fibres.
Collagen fibres are stronger than steel fibres of the same size.
2. minerals, including calcium salts, that are incorporated into the matrix in a process called mineralization, account for the extreme hardness of bone.
26
How is bone tissue classified?
1. Compact bone
2. Spongy (cancellous) bone
27
Explain compact bone
Compact bone is:
* found on the surface of bones and the shafts of the limb bones
* very hard and dense and looks smooth and homogeneous
* made up of many Haversian systems or osteons
* provides strength and support to the body.
28
Explain spongy bone
Spongy bone (cancellous bone) is:
* lighter in weight and has a more open structure
made up of small thin plates of bone called trabeculae which form an irregular network able to resist stress as the plates of trabeculae are precisely arranged along lines of stress able to form red (erythrocytes) and white
(leucocytes) blood cells in the red marrow found in the spaces between the trabeculae.
29
What are osteocytes
Osteocytes are inactive mature bone cells. If more bone is needed they are stimulated and form osteoblasts which lay down new bone tissue. If bone tissue needs to be broken down osteoclasts
are formed in the lacunae to do this.
30
Why is bone important
Compact bone in the limbs and other parts of the skeleton gives strength and support to the body.
Spongy bone helps the skeleton to resist stress and to manufacture red and white blood cells.
31
What are the 4 groups of bones and give examples
1. Long bones (limbs and phalanges)
2. Short bones (carpals and tarsals)
3. Flat bones (cranial and sternum)
4. Irregular bones (vertebrae and hip)
32
Give the functions of the 4 types of bones
1. Long bones provide support for the limbs and for the attachment of muscles enabling limbs to bring about movement
2. The movement of short bones allows the wrists and ankles to rotate and move in many directions
3. Flat bones protect parts of the body and provide large areas of attachment for muscles
4. Irregular don't fit into other groups and have other specific functions for locations
33
What is a bone fracture
A bone fracture is a break or crack in a bone.
34
What is a stress fracture
A stress fracture is a small crack in a bone that occurs as a result of repeated pressure on the bone due to prolonged activities such as walking or running.
35
What is a greenstick fracture
A greenstick fracture is an incomplete break of the bone. As the bone bends, it cracks on one side. This type of fracture is common in children as their bones are softer.
36
What causes a fracture?
Fractures occur when a bone cannot withstand the physical force exerted on it. This is usually caused by some sort of trauma such as:
injuries from falls, sport or vehicle accidents
physical abuses
diseases that weaken bone, e.g. osteoporosis.
37
Give 2 predispositions for fractures
Adults and children who play a lot of contact sport are more likely to break a bone. After middle age, women are more likely than men to break a bone because they suffer from osteoporosis (a disease that affects bone strength) more than men.
38
How are different fractures described?
* complete when the bone has broken into two pieces
incomplete - greenstick when bone cracks but does not break
simple fracture when the bone breaks cleanly but does not penetrate the skin compound or open fracture when the broken ends of the bone stick through the skin comminuted fracture when the bone fragments into many pieces.
* compression : e.g. in vertebra when jump
39
How can a fracture be treated?
A stress fracture usually only needs rest, ice packs, anti-inflammatories and to stop doing the activity that caused the injury.
40
How to treat a broken bone
An X-ray may be necessary to see what type of fracture it is.
The broken pieces may need to be put back in place (realigned). screws, pins, plates
The bone must be immobilized by a cast or by pins until they heal, as new bone forms around the break.
41
What are the functions of the skeleton? (SPMBMH)
Support - enabling the body to stay upright and keep its shape.
Protection - for the internal organs and tissues of the body such as the heart, lungs and brain.
Movement - by the muscles that are attached to the bones.
Blood cells - formed in the red marrow of bones.
Mineral salts - calcium and phosphates form part of bones and are stored in them.
Hearing - the ossicles in the middle ear transmit sound waves to the inner ear and enable us to hear.
42
How is the skeleton made up?
The 206 named bones making up the human skeleton can be grouped into two divisions:
Axial skeleton which forms the long axis of the body and is made up of the bones of the skull, the vertebral column and the rib cage and sternum.
Appendicular skeleton which is made up of the upper and lower limbs and the limb girdles which attach the limbs to the axial skeleton.
43
What makes up the axial skeleton
vertebral column - vertebrae
skull - cranium & facial bones
bony thorax - sternum & rib cage (true, false & floating ribs)
44
What makes up the appendicular skeleton
pectoral girdle - clavicle & scapula
upper limb - humerus, ulna, radius, carpals, metacarpals, phalanges
lower limb - femur, patella, tibia, fibula, tarsals, metatarsals, phalanges
pelvic girdle - ilium, ischium, pubis
45
Function of axial skeleton
The axial skeleton provides the central support for the body. It also protects the internal organs such as the brain, spinal cord and the organs in the thorax.
This part of the skeleton is made up of three regions:
skull
vertebral column (spine or spinal column)
bony thorax (rib cage and sternum)
46
Structure of the skull
Most skull bones are flat: bones which are immovably joined together. The mandible (lower jaw) is an exception in that it can move.
The skull is formed by two sets of bones:
Cranial bones form the cranium (brain box)
Facial bones form the face.
47
Structure of cranium
The cranium is made up of eight flat bones which form a helmet-shaped structure. The immovable fibrous joints between the bones are called sutures and are dove-tailed, together.
Like an eggshell, the curved upper part is self-bracing which allows the bones to be thin and very strong so they can protect the brain.
48
What adaptation of babies allows for better survival chance to do with the brain
At birth, membrane-filled spaces called fontanelles, exist between the bones of the cranium. The fontanelles allow the:
baby's head to be slightly compressed during birth
size of the brain to grow rapidly during infancy.
The bones grow gradually and all the fontanelles should be replaced by bone by the age of two years.
49
What is a concussion
A severe bump on the head may cause concussion; a condition causing loss of balance, dizziness and vomitting. After a bad knock on the head, a doctor should examine the patient.
50
Function of cranium (3 Ps)
Protects the fragile brain.
Protects the sense organs of smell, sight and hearing.
Provides attachment for the muscles of the head.
51
How is a nodding movement possible
At the base of the skull there is a large opening, the foramen magnum, through which the medulla oblongata (lowest part of the brain) connects with the spinal cord.
On either side of this opening are two bumps', the occipital condyles. These articulate with the first vertebra, the atlas of the vertebral column in such a way that a nodding movement is possible.
52
Function of facial bones (F, 3 Ps + S)
There are 14 bones, mainly paired, making up this part of the skull.
The facial bones:
Form the structure of the face.
Protect the sense organs of smell, sight and taste.
Provide openings for the passage of food and air.
Provide attachment for the facial muscles which give rise to various expressions.
Secure the teeth.
53
What is the role of the teeth and jaws?
together with the action of the jaws, they masticate or chew food.
As the jaws are opened and closed and moved from side to side, the teeth tear and grind the food, breaking it down into smaller fragments.
During chewing, the upper and lower molars lock together; the cusps of the upper teeth fitting into the hollows in the lower teeth and vice versa. This action generates tremendous crushing force:
54
What are the functions of the vertebral column? (SESASS)
Supports the head.
Encloses and protects the spinal cord.
Serves as a point of attachment for the ribs.
Allows spinal nerves to pass through openings between the vertebrae.
Serves as a point of attachment for the muscles of the back.
S-shape absorbs jolts and aids in balancing.
55
Function of Intervertebral dises occur between vertebrae.
These have a jelly-like centre covered by fibrous cartilage. The discs act as shock absorbers during walking, jumping and running and they also allow the spine to flex and extend and even to bend sideways.
56
Can the vertebral column bend?
Each joint between consecutive vertebrae allows for a small amount of movement but, as a unit, a far greater degree of movement is allowed (the chainlink principle). This enables the vertebral column to bend forwards, backwards and sideways as well as rotating.
57
Function of S shape of vertebral column
Seen from the side, the backbone has four curves (two convex and two concave) forming an S-shape.
This is very important and helps to:
1. strengthens the backbone
2. balance the body
3. absorb jolts during movement.
58
Explain the cervical vertebrae referring to the 1st 2
These are small and light for flexibility - large vertebral canal- forked spinal process.
First two, the atlas and axis, are specially shaped to allow the skull to rotate and move up and down
The atlas lacks a centrum and a spinal process - has large articulating surfaces.
up+ down
The axis has a spinal process and a peglike odontoid process which acts as a pivotion which the atlas and head can rotate. side - side
It has large articulating surfaces to articulate with the atlas.
59
Thoracic vertebrae
They have long transverse processes for the attachment of the ribs.
60
Lumbar vertebrae
They are the largest and strongest vertebrae to support the weight of the body and provide attachment for the strong muscles in the lower back
61
Sacrum
They are fused to form a triangular bone at the base of the backbone to provide a strong anchorage for the pelvic girdle.
62
Coccyx
They are also fused and reduced, with no function.
63
What causes paralysis? Explain the different instances.
An injury can
crush or dislocate vertebrae,
damaging the spinal cord or even causing it to break. This in turn will damage nerves leading to muscles and other organs of the body resulting in paralysis. If muscles are not stimulated by nerves impulses, they cannot function.
If the spinal cord is damaged in the neck (cervical) region, the whole body below the neck may be paralysed: Such a person is a quadriplegic.
If the spinal cord in the lumbar region is damaged, the legs may be paralysed and the person is known as a paraplegic. As nerve tissue cannot regenerate, these patients may have to spend the rest of their lives being dependent on a wheelchair to get around.
64
How can back ache be prevented?
You all know that a good posture means holding your body in such a way that no strain is brought to bear on your back or muscles. Back ache is very common - 80% of adults suffer from it sometime in their lives and 20% of these will be permanently affected. Humans were designed to be hunter-gatherers, walking and running for 2 to 4 hours every day. Compare this to present-day lifestyles - sitting in front of a desk or a computer or a television screen for hours on end.
65
Explain the muscles that work to help you breathe
Intercostal muscles (external and internal) occur between the ribs. On contraction of the external intercostals muscles, the ribcage moves upwards and outwards which results in inhalation (breathing in).
Exhalation
(breathing out) takes place when these muscles relax.
The internal intercostal muscles contract to force air out of the lungs, e.g. when coughing or sneezing.
66
What are the functions of the bony thorax?
1. Protects the vital organs of the thoracic cavity
- the lungs, heart and major blood vessels.
Supports the shoulder girdles and upper limbs (arms).
Provides attachment points for muscles of the back, chest and shoulders.
Aids in breathing.
67
Explain the components of the appendicular skeleton
The appendicular skeleton is made up of all the bones of the limbs, together with the bony girdles that anchor them to the axial skeleton.
The pectoral girdles are quite mobile and attach the upper limbs (arms) to the axial skeleton.
Upper limbs
The sturdy pelvic girdles are more rigid and secure the lower limbs (legs) to the axial skeleton.
Lower limbs
68
Function of appendicular skeleton
This part of the skeleton enables us to carry out all the movements we make during our very busy lifestyles - walking, playing sport, popping sweets into our mouths, brushing our hair, etc.
69
What are the functions of the pectoral girdle?
Attach the upper limbs to the axial‹skeleton.
Provide attachment points for many of the muscles that move the upper limbs.
They are very light and allow the upper limbs to move more freely than any other part of the body.
70
Why do the upper limbs move so freely?
Only the clavicle is attached to the axial skeleton.
The scapula can move quite freely across the thorax, allowing the arm to move with it.
The socket of the shoulder joint, the glenoid cavity, is shallow, so it does not restrict the movement of the upper limb. This arrangement is very good for flexibility but is bad for stability. This is why it is so easy to dislocate a shoulder.
71
How is the hand made up?
This part of the arm is used for gripping and manipulating. The hand is made up of 27 bones which are divided into three groups - the carpals in the wrist, the metacarpals in the palm and the phalanges in the fingers and thumb.
72
Change in pelvic girdle from kids to adults
During childhood, the girdle is made up of three bones, the:
ilium (the hip bone)
ischium (the sitting bones)
pubis (the two bones which join in the front by means of the pubic symphysis. (This is a semi movable cartilaginous joint).
In adults these bones become fused for strength and are called the coxal bones although they may still be referred to by their individual names.
73
What are the functions of the pelvic girdle?
Attaches the lower limbs to the axial skeleton.
Transmits the weight of the upper body to the lower limbs.
Supports and protects the organs pelvic area.
within the
Provides attachment points for the muscles that move the lower limbs.
74
Why are the lower limb bones big
The lower limb carries the weight of the whole erect body, which is why the bones are so thick and
strong.
The femur that makes up the thigh, is the largest, longest, strongest bone in the body.
75
How is the foot made up?
This part of the leg is used for support, balance and movement. It is made up of 26 bones which are divided into three groups - the tarsals make up the ankle, the metatarsals, the body of the foot and the phalanges the toes.
76
How does the depth of a ball and socket joint affect movement
Can you see that the acetabulum is a much deeper socket than the glenoid cavity? This is one of the reasons why the movement of the leg is more restricted than that of the arm.
77
Differentiate between 2 bone disorders that sound similar
Osteomalacia and osteoporosis are both bone disorders. Osteomalacia results from a defeet in the bone-building process whereas osteoporosis develops because of a weakening of previously constructed bone.
78
Describe cartilage
Cartlage also forms part of the human endoskeleton. Unlike bone, which is very hard and strong, cartilage is a semi-transparent, tough, elastic connectiv tissue.
79
What is a tendon
Tendons consist of inelastic, white, fibrous connective tissue that attaches muscle to bone.
The inelasticity of the tendons is essential because it makes it possible for the contraction and relaxation of the muscles to be transferred to the bone to which the tendon is attached. This facilitates movement.
80
What is a ligament
contents consist of tough, yellow, elastic connective tissue that attaches bone
* Ligaments stretch only enough to control the movement in a joint.
* They keep the bones in position and in such a way stabilise the joint
81
How is a joint classified
A joint is classified according to the degree of movement it permits.
82
Immovable joints
This type of joint does not allow any movement.
* Example: The serrated sutures between the bones of the cranium.
83
Semi-movable joints
This type of joint allows a slight degree of movement.
Examples: The joints between the vertebrae and the pubic symphysis (between the two pubic bones in the pelvic girdle).
84
Freely movable (synovial) joints
This type of joint allows free movement.
85
Joint definition
A joint is a junction in the skeleton where two or more bones meet and are joined by ligaments or cartilage.
86
Describe the structure of a synovial joint
In a synovial joint the ends of the two bones forming the joint are covered with a layer of hyaline cartilage.
The whole joint is enclosed by a sac made up of a ligament known as the joint capsule.
The joint capsule is lined with a membrane, the synovial membrane.
This membrane secretes a fluid, known as synovial fluid, which prevents friction in the joint.
In some synovial joints there are also ligaments that attach the two bones of the joint to each other
87
How are synovial joints classified
Types of synovial joints
Synovial joints are classified according to the type of movement that takes place at the joint:
88
Ball-and-socket joint
In this joint the head of one bone fits into the socket of another. This joint allows movement in any direction.
Examples: shoulder and hip joint
89
Hinge joint
This joint permits movement in only one plane.
Examples: elbow and knee joint
90
Pivot joint
In this joint one bone rotates around another.
Example: The first cervical vertebra (atlas) rotates around a bony projection of the second cervical vertebra (axis). This rotation makes the turning movement of the head possible.
91
Gliding joint
In this joint the flat articular surface of one bone slides over another.
Examples: bones of the wrist and ankle joint.
92
X-rays for bones
X-ray photos of bones are usually used by doctors to diagnose bone fractures and dislocation of joints. On the following X-ray photos various bones and joints are visible.
93
What are skeletal muscles
Skeletal muscles are muscles that are attached to the skeleton and bring about movement of parts of the body by contraction and relaxation.
94
CHARACTERISTICS OF SKELETAL MUSCLES
Skeletal muscles are attached to the skeleton by inelastic tendons.
They have dark and light bands (striated muscles).
They are under voluntary control.
95
HOW ANTAGONISTIC MUSCLES WORK
Skeletal muscles are often arranged in pairs, so that the one contracts as the other relaxes.
These muscles are known as antagonistic muscles and they make coordinated movements possible.
When one of the antagonistic muscles in thepair contracts and the other one relaxes, a controled movement is brought about, e-g. the forearm is raised.
To reverse this movement (lowering ontact.arm), the contracted muscle must
relax and the relaxed muscle must contract.
96
Example of antagonistic pair
A good example of antagonistic muscle action in the human body are the biceps and triceps.
97
Describe the biceps and triceps
The biceps is situated to the front of the upper arm.
Its one end, with two tendons, is attached to the pectoral girdle, while the other end is attached to the radius.
The antagonist of the biceps, the triceps, occurs at the back of the upper arm.
The one end of the triceps is attached to the pectoral girdle with three tendons, while the other end is attached to the ulna.
98
What do the prefixes of the muscles mean
biceps (bi = two), triceps (tri = three) - refers to the number of
tendons with which the muscles are attached to the pectoral girdle.
99
Explain how the biceps and triceps work together
When the biceps contracts and the triceps relaxes, the elbow joint bends and the forearm is lifted.
When the triceps contracts and the biceps relaxes, the elbow joint extends and the forearm is lowered.
The biceps is also known as a flexor muscle and the triceps is also known as an extensor muscle.
100
What is rickets
Rickets is a deficiency disease where the bones become soft, bend and weaken the skeleton.
This weakening leads to deformities and a high incidence of bone fractures.
Rickets occurs in children, where bone development is still occurring. It is cause: by a shortage of vitamin D
101
Why is Vit D important
Vitamin D is essential for the absorption of calcium, which is needed for the development of strong bones and teeth.
Therefore a shortage of vitamin D decreases calcium absorption and bone development is impaired.
102
Explain osteoporosis
Osteoporosis is a disease of the bones that is characterised by a decrease in bone density.
Bones become porous and less dense due to a shortage of calcium.
It leads to weakened bones, which greatly increase the risk of a fracture of the hips, spine and wrists.
Osteoporosis is more common in older women.
A curved back and a decrease in height are visible signs of this disease.
103
What is arthritis
Arthritis is a disease that causes severe pain and a loss of movement in the joints.
The word arthritis literally means 'inflammation in the joints' (arthro = joint;
itis = inflammation).
104
What is inflammation
Inflammation is a reaction of the body's immune system to an injury or to the presence of pathogens (disease-causing agents), such as viruses and bacteria.
Inflammation causes swelling, pain and loss of movement in the affected area.
105
What is osteoarthritis
Osteoarthritis is a disease where the cartilage that forms part of a joint ages and disintegrates with time.
The bones in the joint grind against each other and cause inflammation.
Osteoarthritis commonly occurs in the hips, knees, feet, fingers and spine.
106
Explain rheumatoid arthritis
In rheumatoid arthritis the synovial membranes in the joints thicken and produce too much synovial fluid, which causes inflammation.
This is an autoimmune disease, where the body's immune system attacks its own tissues (in this case the cartilage, ligaments, bones and tendons).
Rheumatoid arthritis usually causes deformation of the joints and commonly affects the small finger joints, wrists, knees and toes.
107
What is a sprain
Spraining is the stretching or tearing of one or more ligaments due to sudden twisting or stretching in a joint. This injury causes bruising, swelling and pain and limits the movement of the joint.
108
What is a strain
Straining is when a muscle or tendon is over-stretched or torn. Straining can cause pain, weakness and muscular spasms.
A strain is often referred to as 'pulling a muscle'.
109
How to treat sprains and strains
Sprains and strains are usually treated with RICE (Rest, Ice, Compression and Elevation). Surgery and further therapy may be necessary for more severe injuries. Effective warming up exercises and the use of the correct equipment helps to reduce the risk of injuries.
110
What are cramps
Cramps develop when a muscle contracts suddenly and painfully. It may not relax for a prolonged period of time. These involuntary muscular spasms may be caused by an imbalance of minerals (e.g. sodium or potassium), cold, poor blood circulation, dehydration, medication or awkward positioning of body during sleep.
111
What is a dislocation
A dislocation occurs when a ligament is exposed to a sudden impact and the bones forming the joint are separated from each other. The bones are displaced and require medical intervention to return them into position.
112
Explain a fracture
A fracture refers to a break in a bone. Fractures are usually caused by a high impact forces placing pressure on a bone. They may also be caused by other medical conditions e.g. osteoporosis. Plaster casts immobilise the fractured bone to allow healing to occur.
113
What are back injuries
Back injury is the most common cause of disability worldwide and it affects workers from all occupations. More people are affected by musculoskeletal disorders than any other group of diseases.
114
Back injury causes
extreme exercise
repetitive actions lifting heavy objects
incorrect posture
sedentary lifestyle
slipped disc / pinched nerve
fractures
arthritis
infection / inflammation
115
Back injury treatment
physical therapy and exercise
painkillers / anti-inflammatories
hot-cold treatment
support / improved posture
acupuncture
surgery
116
Importance of exercise
Exercise is important for the development of a healthy skeleton and muscles.
Healthy tissues decrease the incidence of injuries.
Advantages of exercise
increases bone density
strengthens ligaments
thickens hyaline cartilage in the heads of bones
increases muscle strength
