REVISION FORM 5 CHAPTER 2 : LOCOMOTION AND SUPPORT

STUDY TIPS :Paper 2

1. Able to identify and state ONE special feature of cervical vertebrae, thoracic vertebrae, lumbar vertebrae2. The role of bones [ 2marks], tendon [ 2 marks], ligament [2 marks], skeletal muscles[3 marks], joints [ 1 mark] IN movement.3. Healthy musculoskeletal system : balanced diet and good posture.

Locomotion in Earthworm LOCOMOTION IN AN EARTHWORM-SPM 2005 ( 5 marks)-An invertebrate which has a hydrostatic skeleton.-Body wall has longitudinal and circular muscles-These muscles act antagonistically to cause movement-Contractions of circular muscles cause the segments to extend while longitudinal muscles relax //Conversely the contractions of the longitudinal muscles cause segments to shorten.-Locomotion takes place when the chaetae secure shortened segments in the posterior to the ground while //The anterior segments extend owing to contractions of the circular muscles.-Fluid in the body cavity helps the earthworm to move.

Locomotion in Grasshopper Some of the explanation for grasshopper is also applicable for frogs Grasshopper have an exoskeleton Muscles are attached to the inside of the exoskeleton, across the joints They exist in antagonistic pairs known as flexor and extensor muscles (Grasshoppers have three pairs of legs) During walking movements: body is supported on a tripod of three legs //the other three legs pull or push the body forward The rear legs are bigger and longer, (adapted for jumping) The extensor muscles attached to tendons During a jump, the flexor muscles relaxed, extensor muscles contracts suddenly Causing the rear legs to straighten Energy stored in tendon propels the grasshopper into the air. During flight, the wings moved forwards and backwards // upwards and downwards through the air Owing to the contractions of the flight muscles Which produces a lift ( by driving the air downwards which in turn )enables the grasshopper to( lift off and) fly.

Locomotion in fish Fish ~ Endoskeleton

* Water provides buoyancy and support for the fish* The fish faces the problem of water resistance as water is denser than air* To overcome this, i. it has streamlined and slimy body ii. and scales which face backwards The fish has strong myotome muscles and fins adapted for swimming.~Contraction and relaxation of the myotome muscles causes the body and the caudal fin to move from side to side, producing a forward thrust to push the fish forward.

ESSAY ~LOCOMOTION IN A FISH ( 10 marks max) Fish are aquatic organisms They face resistance when moving in water The streamlined shapes --to overcome water resistance and enable to move quickly in the water. The skin is covered with scales that have slimy coat---help reduce water resistance The muscles consist of muscle blocks i.e., MYOTOMES arranged in segments on both sides of the vertebral column. The muscles act antagonistically. Contraction of myotomes on one side of the vertebral column and relaxation on the other side Causes the body to bend in a direction of the contraction Alternate contractions of the right and left myotome blocks causes body to bend side to side and the tail to bend accordingly. This produce a forward thrust which propels the fish forward Presence of fins i.e. dorsal and ventral fins, paired pectoral and pelvic fins.--- for stability

SPM Essay 2005 (3 marks)-Fish has endoskeleton. It is a place of muscle attachement. --- Left myotome muscles contract and right myotome muscle relax antagonistically-- - and tail moves to the left and right producing forward force.

Cartilage and Joints FUNCTIONS OF CARTILAGE AND SYNOVIAL FLUID AT JOINTS

1. The places where two bones meet in the body are called joints.

2. In movable joint, the bones forming the joint are surrounded by a fibrous capsule.

3. Within the capsule is a membrane : synovial membrane which secretes synovial fluid

4. The fluid fills the space that separates the articulating surfaces of two bones,

5. Function of Synovial Fluid?is to lubricate the joint, REDUCING friction when bones move And to nourish the cartilage found on the end surfaces of the bones which forms the joint.

6. Function of the cartilage? AS A SHOCK ABSORBER PREVENTING THE BONES FROM DAMAGE WHEN A PERSON MOVES.

(Skeletal) Muscles,Ligaments,Tendons, Bones~IN MOVEMENT ROLE OF THE MUSCLES, LIGAMENTS AND TENDONS IN MOVEMENT SKELETAL MUSCLES:

1. The skeletal muscles are made up of bundles of muscle fibres.

2. These muscles are attached to the bones of the skeleton to effect movement.

3. The skeletal muscles are not attached directly to the bones. They are attached to at least two bones across joints through the tendons.

4. The bones of the skeleton to which the muscles are attached operate as levers.

5. Skeletal muscles produce movements by exerting the force to pull on the tendons which are attached to bones. 6. All skeletal muscles exist in pairs

7. They act as antagonistic pairs, meaning: when one member of a pair of muscles contract, the other must relax.8. Example: The movement of forelimb is brought about by the contraction and relaxation of a pair of antagonistic muscles, which is called the biceps and triceps.

TENDONS:9. Tendons are tough, strong and inelastic strands of dense connective tissues made up of fibres.

10. Tendons join skeletal muscles to the bone

LIGAMENTS:11. Ligaments held the bones together at the joints.

12. Ligaments are connective tissues which are flexible, strong and elastic.

13. This allows two bones to be held together and,

14. Permits limited movement but at the same time, ensures that bones do not become dislocated.15. Since muscles can only contract, at least two muscles must be used to move a bone in a position and back again.

16. Movements of the body are brought about by the contraction of a pair of antagonistic muscles.

17. All muscles have two primary proteins : i. Actin ii. Myosin Together they form ACTOMYOSIN complex that, in presence of ATP, will contract.

18. Energy for this contraction comes from ATP produced by the mitochondria in the muscles.19. Muscles which contract when receiving impulses from the brain are voluntary muscles.

Task 2 Explain how the bones, skeletal muscles, tendons and joints bring out movement in the arm or leg. (10 marks)

Muscle Cramp What do you require to know about Muscle Cramp?

WHAT?It is not a disease...A muscle cramp is an involuntarily and forcibly contracted muscle that does not relax.

( When we use the muscles that can be controlled voluntarily, such as those of our arms and legs, they alternately contract and relax as we move our limbs. Muscles that support our head, neck, and trunk contract similarly in a synchronized fashion to maintain our posture.)

A muscle (or even a few fibers of a muscle) that involuntarily (without consciously willing it) contracts is in a "spasm." If the spasm is forceful and sustained, it becomes a cramp. Muscle cramps cause a visible or palpable hardening of the involved muscle.

Muscle cramps can last anywhere from a few seconds to a quarter of an hour or occasionally longer.

It is not uncommon for a cramp to recur multiple times until it finally goes away.

The cramp may involve a part of a muscle, the entire muscle, or several muscles that usually act together, such as those that flex adjacent fingers.

WHO ?

Cramps are extremely common.

Almost everyone (one estimate is about 95%) experiences a cramp at some time in their life. Cramps are common in adults and become increasingly frequent with aging. However, children also experience cramps.Any of the muscles that are under our voluntary control (skeletal muscles) can cramp.

Cramps of the extremities, especially the legs and feet, and most particularly the calf (the classic "charley horse"), are very common.

Involuntary muscles of the various organs (uterus, blood vessel wall, intestinal tract, bile and urine passages, bronchial tree, etc.) are also subject to cramps.

WHY?....and.... WHEN ?

Vigorous activity: True cramps are commonly associated with the vigorous use of muscles and muscle fatigue (in sports or with unaccustomed activities).

Such cramps may come during the activity or later, sometimes many hours later. Likewise, muscle fatigue from sitting or lying for an extended period in an awkward position or any repetitive use can cause cramps.

Older adults are at risk for cramps when performing vigorous or strenuous physical activities.Rest cramps: Cramps at rest are very common, especially in older adults, but may be experienced at any age, including childhood. Rest cramps often occur during the night. While not life-threatening, night cramps (commonly known as nocturnal cramps) can be painful, disruptive of sleep, and they can recur frequently (that is, many times a night, and/or many nights each week).

The actual cause of night cramps is unknown. Sometimes, such cramps are initiated by making a movement that shortens the muscle. An example is pointing the toe down while lying in bed, which shortens the calf muscle, a common site of cramps.

Dehydration: Sports and other vigorous activities can cause excessive fluid loss from perspiration. This kind of dehydration increases the likelihood of true cramps. These cramps are more likely to occur in warm weather and can be an early sign of heat stroke.

Chronic volume depletion of body fluids from diuretics (medicine that promote urination) and poor fluid intake may act similarly to predispose to cramps in seniors.

HOW?

How can muscle cramps be prevented?Activity: Authorities recommend stretching before and after exercise or sports, along with an adequate warm-up and cooldown, to prevent cramps that are caused by vigorous physical activity.

Good hydration before, during, and after the activity is important, especially if the duration exceeds one hour, and replacement of lost electrolytes (especially sodium and potassium, which are major components of perspiration) can also be helpful.

Excessive fatigue, especially in warm weather, should be avoided.

Rest cramps: Night cramps and other rest cramps can often be prevented by regular stretching exercises, particularly if done before going to bed.

Even the simple calf-stretching maneuver (described in the first paragraph of the section on treatment), if held for 10 to 15 seconds and repeated two or three times just before going to bed, can be a great help in preventing cramps.

Another important aspect of prevention of night cramps is adequate calcium and magnesium. . Calcium intake of at least 1 gram daily is reasonable, and 1.5 grams may be appropriate, particularly for women with osteoporosis. An extra dose of calcium at bedtime may help prevent cramps.

Muscle cramps and Nutrition Muscle cramps usually occur in the legs but sometimes in other parts of the body. They hurt a lot and are inconvenient when you're out socializing or even just sleeping. However, you may be able to treat your cramps through nutrition alone.

1. Drink plenty of fluids to prevent dehydration, which often leads to muscle cramps. Water is the most nutritional substance humans can take and its always available--and we'll never run out of it. If you exercise, you may also want to consume some fitness beverages to replace valuable electrolytes during or after your workout.

2. Stock up on minerals because when minerals become unbalanced in your body, you can experience muscle cramps. Focus on the big ones--calcium, magnesium, vitamin E, vitamin C and potassium. You can take supplements or plan your diet so you're getting all the minerals you need from food.

3. Take it easy on the salt intake. Diets high in salt and low in fruits and vegetables can cause muscle cramps.

Support in Aquatic Plants

Submerged plants Eg. Hydrilla or Elodea sp

Fact : Thin, narrow, flexible leaves . Explanation : provides little resistance to water flow.

Fact: Air sacs/ air spaces inside leaves and stems . Explanation : which keep the plants afloat close to the surface to obtain maximum sunlight

Fact : their stems have no woody tissue. Explanation: Water buoyancy provides support for these plants .//If the plants are removed from water, they become limp and floppy.

Floating plants Eg. Eichornia crassipes (water hyacinth)

Fact: Broad leaves that are firm but flexibleExplanation: to resist tearing by wave action

Fact:Aerenchyma tissues in the stems and leaves //Aerenchyma are spongy tissues with large air spaces between the cells. Explanation:They provide buoyancy so that plants can float on the water surface