bio form 5 chapter 2 (1)

8/16/2019 Bio Form 5 Chapter 2 (1)

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Biology Form 5: Chapter 2

Chapter 2: Locomotion and Support

2.1 Support and Locomotion in Humans and Animals

Support System and Locomotion

1. Provided by a skeleton.

2. Types of skeleton:

a) Exoskeleton s!ell " insects and crabs

" importance: i) supports important body or#ans

ii) protects t!e internal structures from dama#e

iii) allo$s movement iv) $axy cuticles found on t!e surface of insects prevents

$ater loss.

b) Endoskeleton bones and cartila#e

" vertebrates " importance: i) maintainin# body s!ape

ii) supportin# soft tissue iii) protectin# internal or#ans from in%ury

iv) stores mineral &calcium and p!osp!orus)

v) produce blood cellsc) 'ydrostatic skeleton internal $atery fluids !eld under pressure contained $it!in

confined spaces in t!e body surrounded by t!e muscles.

" caterpillar and eart!$orm

The human skeleton

1. Parts:a) axial skeleton

b) appendicular skeleton

T!e axial skeleton

1. (onsists of:

a) skull b) vertebral column

c) t!e ribs

d) sternum2. Skull consist of:

a) (ranial bones enclose and protect t!e brain

b) acial bones protect and provide support for t!e entrances to t!e di#estive systemand respiratory system

c) Suture immovable %oints $!ic! securely !old bones t!at make up t!e skull

d) *a$ movable %oint

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+. ,ertebral column &spine or backbone)

a) composed of vertebrae.

b) encloses and protects t!e spinal cord.c) supports t!e !ead

d) serves as a point of attac!ment for t!e ribs- pelvic #irdle and t!e muscles of t!e backand neck.e) cervical- t!oracic and lumbar are moveable.

f) sacrum and coccyx are immovable.

#) invertebral discs in t!e vertebrae permits movement of t!e vertebral column andabsorb vertical s!ock.

!) varies in sie and s!ape.

i) vertebral foramen encloses t!e spinal cords.

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/. (ervical vertebraea) 'ave transverse foramen t!rou#! $!ic! blood vessels and nerve pass.

0. T!oracic vertebraa) 'ave spinous processes t!at are lon# directed do$n$ards.

b) Spinous and transverse processes serve as points of attac!ment of muscles and

li#aments.

. Lumbar vertebra

a) Lar#est and stron#est.

b) 'ave lar#e centrums $!ic! bear t!e $ei#!t of t!e lo$er back.

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. T!orax:

a) t!oracic ca#e &consists of ribs and t!e sternum) b) encloses and protects t!e or#ans in t!e t!oracic cavity and upper abdominal cavity.

The appendicular skeleton

1. (onsists of:

a) Pectoral #irdle clavicle and scapula

b) 'umerus upper arm- lon#est bonec) 3lna

d) 4adius

e) (arpals " $rist

f) 5etacarpals palm of t!e !and#) P!alan#es fin#ers and toefin#ers

#) Pelvic #irdle consists of t$o !ip bones $!ic! provide stron# and stable support for

t!e vertebral column.!) emur t!i#! bone- lon#est- !eaviest and stron#est

i) Tibia

%) ibulak) Patella kneecap

l) Tarsals " ankle

m) 5etatarsals foot

The structure of a joint1. *oint a place $!ere t$o or more bones meet.

2. Li#aments 'old bones to#et!er and allo$ t!em to move+. Synovial %oint:

a) *oint t!at contains a cavity filled $it! fluid t!at allo$ free movement.

b) / features %oint capsule &%oint enclosure- reinforced and stren#t!ened $it! li#aments) " lined $it! t!in synovial membrane &inner surface of t!e capsule)

" secretes synovial fluid lubricant $!ic! reduces friction bet$een t!e ends of

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t!e bones)

" covered $it! cartila#e

/. (artila#e cus!ions t!e %oint- absorbs s!ock and reduces friction bet$een t!e ends of t!e bones.

0. *oints:"

a) 'in#e %oint knee- elbo$- fin#er and toe. " allo$s t!e le# to s$in# back and fort! &one plane).

" 167 de#ree

b) 8all and socket %oint rotational movement of bones in all directions.

" s!oulder and !ip %oint. " +7 de#ree




How movement is rou!ht aout in a lim

1. Skeletal muscle are responsible for voluntary movements of t!e body.2. 9 muscle is attac!ed to at least t$o bones across %oints t!rou#! tendons.

+. Tendons are tou#!- stron# and inelastic strands of dense connective tissues.

/. Skeletal muscle produce movements by pullin# on tendons attac!ed to bones.0. 9 muscle can only pull.

. t pulls $!en it contracts.

. 9 pair of muscle &anta#onistic muscle) $ork to#et!er to allo$ coordinated movement

of t!e skeletal %oints.6. T!is means $!en one muscle contracts- t!e ot!er muscle relaxes.

;. 8endin# of t!e arma) <!en t!e biceps contract.

b) T!e tendons transmit t!e pullin# force produced by t!e contraction to t!e forearm.

c) 9t t!e same time- t!e triceps relaxes.

d) T!e bicep pulls t!e radius.e) 9s a result- t!e elbo$ %oint flexes or bends and t!e forearm moves up$ards.

f) T!is causes t!e bendin# of t!e arm.




The structure of a muscle

1. 9 skeletal muscle suc! as t!e biceps consists of bundles of muscle fibres and lar#esupply of nerves and blood vessels.

2. 9 muscle fibre is a sin#le- lon# cylindrical cell t!at contains many nuclei.

+. 9 muscle fibre is made up of bundles of smaller units called myofibrils./. Eac! myofibril is made up of actin and myosin &protein filaments).

0. T!e interaction of bot! t!ese proteins causes muscle contractions.

. 5uscle contraction involves t!e nervous system and re=uires ener#y.

Conse"uences of impaired musculoskeletal s#stem on support and locomotion

1. 5uscle cramp

>efinition: sudden contraction of one or more muscles $!ic! results in a sudden- intense pain and inability to use t!e affected muscle.

(auses: " common amon# endurance at!letes.

" inade=uate stretc!in# and muscle fati#ue.2. 5uscular dystrop!y

>efinition: (aused by t!e pro#ressive de#eneration and $eakness of t!e skeletal muscles

T!at control movement.(auses: " mutated #ene $!ic! is found on t!e ? c!romosome and mainly affects t!e

boys.

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+. @steoporosis

>efinition: (ommon bone disorder- especially amon# elderly $omen. T!e bones becomet!inner- more brittle and more porous.

(auses: " Loss of bone mass be#ins after t!e a#e of +7 and accelerates #reatly around t!ea#e /0.

" f dietary intake of p!osp!ate and calcium are insufficient.

" 8one production and bone tissue $ill suffer resultin# in brittle and fra#ile

bones.Symptoms: " fractures of t!e vertebrae- $rist or !ips

" loss of !ei#!t and stooped posture

Prevention: " 9de=uate intake of calcium- p!osp!orus and vitamin >. " 4e#ular exercise

/. 9rt!ritis

>efinition: " >ecreased production of synovial fluid in %oints and cartila#e bet$een bones

become t!inner &osteoart!ritis)- and li#aments s!orten and lose some of t!eir elasticity.

" Suffer from a painful and stiff knee $!ic! restricts daily activities like

$alkin#.

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The mechanism of locomotion in animals

Locomotion in an animal $it! a !ydrostatic skeleton &eart!$orm)

1. Eart!$orms !ave a !ydrostatic skeleton &t!e force of contraction is applied to a coelum

&fluid filled c!amber).

2. (oelom is surrounded by t$o anta#onistic muscle:a) circular muscles surround t!e c!amber

b) lon#itudinal muscles extend from one end to t!e ot!er.

+. T!inner and lon#er: <!en circular muscle contract and t!e lon#itudinal muscle relax./. S!orter and t!icker: <!en circular muscle relax and t!e lon#itudinal muscle contract.

0. T!e muscles contract r!yt!mically to produce peristaltic $aves $!ic! be#ins at t!e

front and move to$ards t!e end of t!e body.. Eart!$orm !as c!aetae &bristles) $!ic! anc!or parts of t!e body to t!e #round so t!at

ot!er parts can be pulled to$ards it.

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Locomotion in an animal $it! exoskeleton &#rass!opper)

1. 9 #rass!opper uses t!ree le#s to support t!e body off t!e #round- $!ile t!e ot!er t!reele#s move to#et!er to make successive steps $!ile $alkin#.

2. T!e flexor and extensor &anta#onistic) muscles are attac!ed to t!e internal surface of

t!e exoskeleton.+. lexor muscles bend a %oint.

/. Extensor muscles strai#!ten it.

0. T!e rear le#s of a #rass!opper are lon# and muscular and is adapted for !oppin#.

. Sittin# position: <!en t!e flexor muscle contracts- t!e lo$er le# is pulled to$ards t!e body. T!e !ind le# is folded in a A s!ape and ready for a %ump.

. *ump: <!en t!e extensor muscle contracts- t!e le# %erks back$ards- propellin# t!e#rass!opper for$ard and up$ard into t!e air.

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Locomotion in an animal $it! an endoskeleton &fis!)

1. <!y can a fis! s$im in a viscous and dense environment:a) body $ei#!t is supported by $ater to overcome #ravity.

b) sleek and streamlined body to overcome resistance.

c) overlappin# scales on t!e body of a fis! face back$ards to overcome resistance.d) covered by slimy coatin# to minimie frictional dra# and maintains a smoot! flo$ of

$ater.

2. ,ertebral column of t!e fis! is moved from side to side by t!e contraction andrelaxation of myotomes.

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+. 5yotomes < s!aped muscle blocks t!at make up eac! side of t!e body of a fis! and

carry out opposite action.

/. 9lternatin# $aves of contraction and relaxation pass do$n t!e myotomes on eit!er sideof t!e body from t!e !ead to t!e tail.

0. T!ese cause different parts of t!e body to be s$ept from side to side pus!in# $ater

back$ards and side$ays and t!e body for$ards.. Tendency for a fis! to become unstable in $ater durin# movement- leadin# to:"

a) ya$in# side$ays movement

b) pitc!in# vertical plane movementc) rollin# transverse plane movement

. 5ovements are countered by fins.

6.(audal fin provides t!rust and controls t!e fis!Bs direction.

6. T!ese movements are countered by:"

a) ya$in# resisted by t!e median &dorsal and ventral) fin b) rollin# resisted by median fin

c) Pitc!in# resisted by paired pelvic fin and pectoral fin $!ic! acts as brakes and

rudders.;. 8ony fis! !ave s$im bladders to !elp t!em maintain buoyancy in t!e $ater.

17. T!e s$im bladder is a sac inside t!e abdomen t!at contains #as.11. (ontrollin# t!e amount of #as in t!e s$im bladder- a fis! can c!an#e its buoyancy sot!at it !as t!e same relative density as t!e surroundin# $ater.

1+

Ca$in#

4ollin#

Pitc!in#




2.2 Appreciatin! a Health# $uscoskeletal S#stem

1. 9de=ute calcium- p!osp!orus and vitamin > intake

2. 4e#ular p!ysical activities and exercisea) stren#t!en %oint structures- increase muscular performance and delay t!e pro#ress of

art!ritis.

2.% Support in &lants

1. <!yD

a) Plant #ro$s and it produces more leaves. b) ro$ tall t!erefore needs to $it!stand t!e forces of #ravity.

c) Spreadin# of leaves and branc!es !oriontally.

2. 9=uatic plants are supported by buoyancy and support.

Support in a"uatic and terrestrial plants

Submer#ed plants

1. Hydrilla sp. !ave t!in- narro$ and flexi ble leaves.

2. T!is type of leaves provide little resistance to $ater flo$s- plants can be tu##ed at and pulled by $ater currents $it!out bein# dama#ed.

+. 9ir sacs inside t!e leaves and stems keep t!e plant floatin# close to t!e surface to

obtain maximum sunli#!t.

/. T!eir stems !ave no $oody tissues.

loatin# plants

1. <ater !yacint! & Eichornia crassipes) !ave broad leaves t!at are firm but flexibleenou#! to resist tearin# by $ave action.

2. 9erenc!yma tissues &spon#y tissues $it! lar#e air spaces bet$een t!e cells) in t!e

stems and leaves provide buoyancy so t!at t!e plants can float on t!e surface of t!e $ater.

'erbaceous plants &Terresterial plants)

1. Support provided by t!e tur#idity of t!e parenc!yma and collenc!yma cells.

2. Tur#or pressure of t!e fluid content in t!e central vacuole pus!es t!e cell membraneand t!e cell contents a#ainst t!e cell $all- creatin# support for t!e stem- root and leaves.

+. T!e t!ickenin# of t!e cell $alls $it! cellulose and pectin in collenc!yma cells provide

additional mec!anical stren#t!.

<oody plants

1. Support provided by sclerenc!yma and xylem tissues.2. Sclerenc!yma tissue is composed of cells $it! secondary cell $alls t!at are usually

li#nified $!ic! support non"#ro$in# parts of plants.

+. T$o types of sclerenc!yma tissue:

a) fibres lon#- strai#!t and t!in

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" found around vascular tissues

b) sclereids s!ort- circular and irre#ular s!aped

" found in fruit and seeds/. >urin# primary #ro$t! development- t!e cell $alls of xylem vessels and trac!eids are

t!ickened $it! li#nin and forms vessels .

0. Type of vessels:a) annular &rin# s!aped) vessel

b) spiral vessel

c) scalariform &ladder like) vesseld) pitted vessel

. Secondary #ro$t! of xylem results in t!e formation of $ood $!ic! makes t!e plant

stron#er and and provides support.. @t!er supportin# structures:

a) 8uttress root roots t!at come out from t!e lo$er part of t!e trunk and #ro$ into t!e

#round- providin# support for t!e tree. b) (reepers- vines and lianas use ot!er trees for support.

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bio form 5 chapter 2 (1)

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