SUPPORT & MOVEMENT IN ANIMALS

SUPPORT & MOVEMENT IN ANIMALSWhy is locomotion important to animals? To escape unfavourable conditions, e.g. predators, To find food; To seek mates;To disperse to new habitats; To seek favourable environments; e.g. shelter

Locomotion in Unicellular OrganismsInvolves using;Pseudopodia e.g. amoeba. flagellum e.g. Trypanosoma spp. cilia e.g. Paramecium spp.

Locomotion in Multicellular organisms

Requires;Muscles, a contractile tissue, which provide a source of powerSkeleton, on which muscles can act to bring movement

Types of Skeleton

Hydrostatic (hydraulic), Exoskeleton, Endoskeleton,

Hydrostatic (hydraulic)

Mechanical support is provided by an internal fluid-filled system. E.g. most invertebrates like earthworm, leeches, caterpillars and maggots.

Exoskeleton

E.g. arthropods made of chitin, Exoskeleton forms a hard casing enclosing the softer tissues of the arthropod body, Jointed limbs movements are due to antagonistic muscles,The Muscles are attached internally,

Endoskeleton E.g. chordates

made up of; bones, cartilage tissue,

General Functions of the Endoskeleton

The Endoskeleton has nine main functions:Provide shape and support,Provide Attachment,Provide a frame work for Movement,Provide Protection,Site of Blood cell production,Provide Storage,Involved in pH buffering,Involved in Detoxification,Involved in Sound transduction,

The Mammalian Skeleton

Major components include: the axial skeleton,the appendicular skeleton, Human front skeletal view

10axial skeletonThe axial skeleton has five areas;Skull, Ossicles bones, Hyoid bone in the throat, Vertebral column, Chest,

Appendicular Skeleton

The appendicular skeleton consists of; the limb bones, the pelvic girdle, pectoral girdle, SkullThe Skull:Consists of cranium, facial bones and two jaws, At the base of the cranium, are occipital condyles which articulate with the first vertebral bone, atlas,

Functions of the Skull;Mechanical protection of brain & sensory organs.Upper & lower jaws used for chewing food.Front view & Lateral view of Human skull

Cranium bones include;Nasal bones,Frontal bones,Parietal bones,Temporal bones,Zygomatic arches,Occipital bones,

THE VERTEBRAL COLUMN

Backbone consists of Vertebrae (Singular- vertebra) grouped into;Cervical vertebraeThoracic vertebrae,Lumbar vertebrae,Sacral vertebrae,Caudal vertebrae (coccyx),A TYPICAL VERTEBRA

A main parts of typical vertebra;neural canal- passage of spinal cord,Neural arch- surrounds neural canal,Neural spine- projects upwards/dorsally,Centrum (plural-centra)- ventrally located and fits into intervertebral discs on both sidesTransverse processes- on either side of neural arch,Zygapophyses (singular-zygapophysis)- articulation smooth facets with adjacent vertebra,

Cervical VertebraeComprising of ;1st Cervical vertebra (Atlas vertebra), 2nd Cervical vertebra (Axis vertebra), 3rd -7th cervical vertebrae,Distinguishing features of cervical vertebraeAll 7 cervical vertebrae have;vertebrarterial canals,transverse processes flattened out to form cervical ribs, large neural cavity, small centrum,

Atlas vertebra dorsal view

Features of the Atlas vertebra;Very large Neural canal,Prominent cervical ribs (transverse processes),Large hollow facets (articulate with occipital condyles)Reduced centrum,Reduced neural spine,Large Postzygapophyses to articulate with prezygapophyses of axis,

Atlas anterior view

Showing the articulation surface with the occipital condyles of the skullAtlas posterior view

Axis vertebra lateral view

Features of Axis vertebra;Large centrum forming Odontoid process, large neural spine,Flat cervical ribs,postzygapophysesAxis Vertebra Anterior view

Axis Vertebra posterior view

3rd 7th Cervical vertebra anterior view

All 7 cervical vertebrae have;vertebrarterial canals,transverse processes flattened out to form cervical ribs, large neural cavity, small centrum,

3rd-7th Cervical vertebrae Posterior view

Adaptations of cervical vertebrae broad neural arch for protection of the spinal cord. forked and short transverse processes for the attachment of neck muscles. Atlas has broad surfaces for articulation with the occipital condyles of the skull to permit nodding movement of the skull. vertebrarterial canals for passage of neck blood vessels and nerves.

continuedAxis has odontoid process; a projection of the centrum to permit rotator movement of the skull. The odontoid process acts as a pivot; for the atlas and skull. short neural spine for attachment of neck muscles. wide neural canal for passage of the enlarged spinal cord.

Thoracic Vertebrae (lateral view)

Distinguishing features of a thoracic vertebra;Long neural spine projecting upwards & backwards,Short transverse processes,Tubercular facet (on ventral side of transverse processes),Capitular demi-facet,Other features;Large centrum,Large neural canal, Prezygapophyses,Postzygapophyses,Neural canal,

Thoracic vertebra Anterior view

Adaptations of thoracic vertebraeneural arch for protection of the spinal cord. centrum for attachment of the transverse processes.pre and post zygapophyses facets for articulation with those of the next vertebrae.

Continuedtubercular and capitular facets for articulation with the tuberculum and capitulum of the rib, reduced transverse processes for attachment of muscles, long neural spine for attachment of the back muscles,

Lumbar Vertebrae (Anterior view)

Distinguishing features of a lumbar vertebra;Broad neural spine pointing upwards & forward,Large, thick centrum, (supporting the weight of the animal),Large transverse processes, (abdominal muscle attachment),Metapophyses, (abdominal muscle attachment),Anapophyses, (abdominal muscle attachment),Hypapophyses, (abdominal muscle attachment),Lumbar vertebrae (anterior & lateral view)

Lumbar Vertebra Dorsal view

Lumbar vertebra posterior view

Rabbits Lumbar vertebra lateral view

37Lumbar vertebrae (anterior & lateral view)

Adaptation of lumbarbroad neural spine for attachment of powerful back and abdominal muscles. long and well developed transverse processes for attachment of muscles that maintain posture and flexes the spine. metapophyses projections provide additional surface for muscle attachment.continuedhypapophyes projections provide additional surface for muscle attachment. Thick and compact centrum for support. pre and post zygapophyses for articulation between the vertebraeSACRAL VERTEBRAE (Ventral view)

Distinguishing features of Sacral vertebrae;sacral vertebrae are fused to form, sacrum, 1st Sacral vertebrae transverse processes are large & fused with the pelvic girdle,Numerous foramen (canals),Reduced metapophyses,Large centrum,Narrow neural canal, neural spine reduce posteriorly,

Sacral vertebraeSacrum dorsal View

Sacrum lateral view

Adaptations of the Sacral VertebraeNumerous canals for passage of blood vessels and nerves,Sacral vertebrae are fused to provide strength and firmness,

continuedThe 1st sacral vertebra has well developed transverse processes, which are fused to the pelvic girdle to provide support and mechanical protection to lower abdomen organs.The 1st sacral vertebra has Large neural spine & transverse processes provide attachment to lower back & thigh muscles,

Coccyx (caudal) vertebraeConsists of four coccygeal vertebrae,Neural spine, transverse processes & neural canal reduced,

Ribs

Twelve ribs;Seven true ribs,Three False ribs,Two floating,The rib has two parts;Vertebral part; bearing tuberculum & capitulum,,Sternal part;

Rib cage

sternumConsists of three sections;Manubrium articulates with 1st two pairs of ribs,Body articulates to ribs 3rd-7th ,Xiphoid cartilage supports abdominal muscles,

Appendicular Skeleton

Pectoral girdle & ForelimbScapula

Adaptations of the scapula;Spine; large surface area for shoulder muscles attachment,Acromion; for clavicle articulation & muscle attachment,Glenoid cavity; form a ball socket joint with head of humerus,

ForelimbHumerus

Humerus; proximal end has a large, broad head, The head of humerus is covered with cartilage, Bears Tubercles/ tuberosities , the greater tubercle and below it is deltoid ridge/lesser tubercle, At the distal end the bone ends in two condyles / trochlea,

Adaptations of the HumerusThe Humerus has a large head that fits in the glenoid cavity of the scapula, to form a ball & socket joint,The cartilage on the humerus head reduces friction in the ball & socket joint,The greater tubercle & deltoid ridge both provide surfaces for muscle attachment,Humerus condyles articulate with the sigmoid notch of radius and ulna to form the hinge joint,Radius & Ulna

Radius & Ulna form the elbow joint /hinge joint with the humerus,The ulna is longer than the radius,The ulna fits with humerus trochlea at the sigmoid notch,The ulna extends to form the olecranon process/elbow,

Adaptations of the radius & Ulnathe olecranon process; provides insertion for triceps muscle Olecranon process; prevents the overstretching of the joint,Radius; has an insertion for the biceps muscles;ulna & radius; articulates with humerus condyles in the sigmoid notch and forms the hinge joint at the elbow,Radius & ulna; form flexible joints allowing for forearm twisting,Pelvic girdle & hind limbPELVIC GIRDLE (Ventral view)

Half of the Pelvic girdle is made up of three fused bones ; ilium, ischium & pubis,Pubic bone has a socket the acetabulum, ischium and pubis surround a large opening the obturator foramen,

Pelvic girdle AdaptationsPubic symphysis ; has flexible cartilage which allows widening of females girdles at the time of child birth,Pubic bone has a socket the acetabulum in which the head of femur fits for articulation forming a ball and socket joint providing movement in all planes.

Continued/pelvic girdle adaptationsPubic also has an obturator foramen to allow passage of muscles for attachment, Ischium has a thick ridge for muscles attachment,Ilium has a broad facet for articulation with the sacrum,

Functions of the Pelvic GirdleSupports the weight of the body,Transmits the force / thrust from the legs to the rest of the body,Allows rotational movement giving more flexibility of movement of the leg,Offers sites for muscle attachment,

FemurFemur small head that fits into the acetabulum socket of the pelvic girdle forming a ball and socket joint, The head of femur is covered with cartilage, femur bears condyles which articulates with tibia to form the knee joint , Femur has projections trochanters,

Femur

Note the rounded head of the femurAdaptations of FemurFemur has a smaller head that fits into the acetabulum socket of the pelvic girdle forming a ball and socket joint that permits movement in all planes. The head of femur is covered with cartilage that reduces friction during locomotion.

Continued adaptations of femurAt the distal end femur bears two rounded condyles which articulates with tibia to form the knee joint which is an example of a hinge joint. Femur has a long shaft for muscle attachment and for support.Femur has projections, trochanters that provide surfaces for muscle attachment.

Tibia & FibulaTibia & fibula are fused on distal end, to form tibio-fibula,Tibia (larger) articulates with the femur,Enemial crest of the tibia, provide a firm attachment of muscles,Fibula (smaller) long to provide muscle attachment,

Tibia & Fibula

Note the tibio-fibulaJOINTSA joint is a point of articulation,Joints are classified on the basis of;Function,Structure,Types of joints (structural basis)Fibrous joint; fibrous tissues support articulating,Cartilaginous joint; cartilage join two bones,Synovial joint; synovial fluid & ligaments join two bones,Types of joints (functional basis)Immovable joint; e.g. sutures in the skull, (fibrous tissue join the bones)Slightly movable joint; e.g. pubis symphysis (cartilage bind the bones),intervertebral joints,Freely movable joint; e.g. elbow joint, knee jointMovable jointsThe main structures of a synovial jointA cartilage lines the end of the bones which reduce friction between the two bones. synovial fluid which absorbs physical shocks. Synovial fluid nourishes the cartilage. synovial membrane secretes & nourishes the synovial fluid,The two bones are held together by the capsular ligament, which is flexible but tough; Preventing dislocation of the two bones.

SYNOVIAL JOINTThe main structures of a synovial jointcartilagesynovial fluid synovial membrane capsular ligament,

Types of Movable JointsHinge joint; allows one bone to move like a door swings open or shut at its hinges. e.g. elbow, the knee, digits of the fingers and toes , the atlas and axis vertebrae,Ball and socket joint; the rounded end, (head) of a bone fits into a rounded cavity of another bone. Ball and socket joint permits rotational and swinging movements of the arm e.g. hip and shoulder.

Continued Types of movable jointsPivot joint: occurs between the skull and the atlas vertebra, permits the nodding up and down movement, of the head rotational movement (side-to-side movement) of the head. Gilding Joints: e.g. between cervical, thoracic and lumbar vertebrae, metacarpals, and metatarsals. One bone is separated from the other by cartilage, and allow one bone to slide smoothly against the other. Gliding joints make the vertebral column flexible, allowing the bending or curving of the back,

Hinge joint e.g. elbow joint

Showing the three joint bones; humerus, radius & ulna,Hinge joint /close up

Note the olecranon process, the sigmoid joint, and the three bones involved in the joint,Types of joints

Comparing the Hip joint & Knee jointHip jointKnee jointFreely movableFreely movableRotational motionAngular motionBall-like head fits into a cup-like depressionConvex surface fits into a concave surfaceMUSCLE TISSUE Types of muscles ;skeletal (or striated) muscle, attached to endoskeleton, visceral (or smooth) muscle, occurs in visceral organs, cardiac (or heart) muscle, occurs in the heart,

Common Features of MusclesMuscles are all contractile,Muscles contain numerous mitochondria,Muscle cell membrane is electrically charged,

Comparison between skeletal, visceral & cardiac muscleskeletalVisceral/smoothcardiacAlternative namesStriated, striped,voluntaryNon-striated, unstriped, involuntary, smoothstructureFibres formed from many cells fusedMany nuclei in surface layer of sarcoplasmFibres consisted of individual cells, with a central nucleus,Individual cells with a central nucleus, cell branched & linked by intercalated discscontinuedskeletalVisceral/smoothcardiacsizelongestsmallestmediummyofibrilsconspicuousinconspicuousconspicuousPhysiology/functionContractions rapid & powerful but short-lived,Contractions slow & sustainedRapid contractions spread through linked network,continuedskeletalVisceral/smoothcardiaccontrolNeurogenic; contraction triggered by motor neurons of CNSNeurogenic; but involves autonomic nervous system spread from cell to cell,

Myogenic; contraction triggered by muscle itself; but rated controlled by autonomic nervous system,locationMuscles attached to bones, skin, diaphragm,Visceral organs , blood vessels, Ciliary muscles of the eyeHeart onlyRole of muscles in movement of the arm in humans

FISH: LOCOMOTION

Explain how finned fish like tilapia are adapted to swimming?streamlined body to reduce resistance of water;fins and scales face backward to reduce the resistance;fish secrets mucus; to lubricate its body ;reducing friction as it moves;

continuedthe myotomes; which are found on either side of the vertebral columns; the backbone has little flexibility therefore when the myotomes contracts the large caudal fin creates a propulsive effect.Myotomes relax and contract antagonistically; to brings about lateral movements in the caudal fin;The paired fins (the pectoral and pelvic fins) help to maintain balance & steer fish;continuedpectoral and pelvic fins also control pitching; (the tendency of the interior body parts to plunge fish vertically downwards)The caudal fin has a large surface area; and when it is slashed from side to side it displaces a lot of water and creates forward movement;The caudal fin acts as a rudder; and kneel to control direction; of movements and keep fish in an upright position;

continuedPresence of the swim bladders; between the gut and vertebral column in some fishes enable them to change their position in water; when the swim bladder is filled with air and fish becomes lighter to float at higher water levels however the fish moves deeper by emptying the air in the swim bladders and allowing water to flow in making it to be heavier;The unpaired fins, (the dorsal, anal and caudal fins) and yawing (the lateral deflection of the interior part of the body as a result of propulsive action);The large surface area; of the body sides also reduces yawing;The large surface area highly sensitive; enables the fish to respond to changes in vibration and pressure of water;

Come Thou Fount of Every BlessingDavid DavidsonHymns of Hope, track 12008Country190835.3