SUPPORT & MOVEMENT IN ANIMALS
Why 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 Organisms
Involves 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 power
• Skeleton, 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.
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
axial skeleton
The axial skeleton has five areas;
Skull,
Ossicles bones,
Hyoid bone in the throat,
Vertebral column,
Chest,
Appendicular Skeleton
The appendicular skeleton consists of;
Skull
The 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 vertebrae
 Thoracic 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 sides
 Transverse processes- on either
side of neural arch,
 Zygapophyses (singularzygapophysis)- articulation smooth
facets with adjacent vertebra,
Cervical Vertebrae
Comprising of ;
1st Cervical vertebra (Atlas vertebra),
2nd Cervical vertebra (Axis vertebra),
3rd -7th cervical vertebrae,
Distinguishing features of cervical vertebrae
All 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 skull
Atlas posterior view
Axis vertebra lateral view
Features of Axis vertebra;
Large centrum
forming
Odontoid
process,
 large neural
spine,
Flat cervical ribs,
postzygapophyse
s
Axis 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.
continued
• Axis 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 vertebrae
• neural 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.
Continued
• tubercular 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
Rabbit’s Lumbar vertebra lateral view
Lumbar vertebrae
(anterior & lateral view)
Adaptation of lumbar
• broad 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.
continued
• hypapophyes projections provide additional
surface for muscle attachment.
• Thick and compact centrum for support.
• pre and post zygapophyses for articulation
between the vertebrae
SACRAL 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 vertebrae
Sacrum dorsal View
Sacrum lateral view
Adaptations of the Sacral Vertebrae
• Numerous canals for passage of
blood vessels and nerves,
• Sacral vertebrae are fused to
provide strength and firmness,
continued
• The 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) vertebrae
Consists 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
sternum
Consists of three sections;
• Manubrium articulates with 1st two pairs of
ribs,
• Body articulates to ribs 3rd-7th ,
• Xiphoid cartilage supports abdominal muscles,
Appendicular Skeleton
Forelimb &
Pectoral
Girdle
Hind limb &
Pelvic girdle
Appendicular
Skeleton
Pectoral girdle & Forelimb
Scapula
(Shoulder
blade)
Pectoral
Girdle
Clavicle
(collar
bone)
Scapula
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,
Forelimb
Radius
humerus
&
ulna
forelimb
Humerus
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 Humerus
• The 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 & Ulna
• the 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 limb
ilium
Pubis
ischium
Pelvic
Girdle
PELVIC GIRDLE
(Ventral view)
Half of the Pelvic girdle is made
up of three fused bones ;

ilium, ischium &
pubis,
 Pubic bone has a socket the
 ischium and pubis surround
a large opening the
Pelvic girdle Adaptations
; has
which
allows widening of females girdles at the time
of child birth,
• Pubic bone has a socket the
in
which the head of femur fits for articulation
forming a ball and socket joint providing
movement in all planes.
Continued/pelvic girdle adaptations
• Pubic also has an
to allow
passage of muscles for attachment,
• Ischium has a
for muscles
attachment,
• Ilium has a
for articulation with
the sacrum,
Functions of the Pelvic Girdle
Femur
• Femur 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 femur
Adaptations of Femur
• Femur 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 femur
• At 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 & Fibula
 Tibia & fibula are fused on
distal end, to form tibiofibula,
 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-fibula
JOINTS
• A 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
joint
Movable joints
The main structures of a synovial joint
• A 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 JOINT
The main structures of a synovial joint
cartilage
synovial fluid
synovial membrane
capsular ligament,
Types of Movable Joints
• Hinge 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 joints
• Pivot joint: occurs between the skull and the atlas
vertebra, permits the nodding up and down
movement, of the head rotational movement (side-toside 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 joint
Hip joint
Freely movable
Rotational motion
Ball-like head fits
into a cup-like
depression
Knee joint
Freely movable
Angular motion
Convex surface fits
into a concave
surface
MUSCLE 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 Muscles
• Muscles are all contractile,
• Muscles contain numerous
mitochondria,
• Muscle cell membrane is electrically
charged,
Comparison between skeletal, visceral &
cardiac muscle
skeletal
Visceral/smooth
Alternative
names
Striated, striped,
voluntary
Non-striated,
unstriped,
involuntary, smooth
structure
Fibres formed from
many cells fused
Many nuclei in
surface layer of
sarcoplasm
Fibres consisted
of individual cells,
with a central
nucleus,
cardiac
Individual cells with a
central nucleus, cell
branched & linked by
intercalated discs
continued
skeletal
Visceral/smooth
cardiac
size
longest
smallest
medium
myofibrils
conspicuous
inconspicuous conspicuous
Physiology/
function
Contractions
rapid & powerful
but short-lived,
Contractions
slow &
sustained
Rapid
contractions
spread through
linked network,
continued
skeletal
Visceral/smooth
cardiac
control
Neurogenic; contraction
triggered by motor
neurons of CNS
Neurogenic; but
involves autonomic
nervous system
spread from cell to
cell,
Myogenic; contraction
triggered by muscle
itself; but rated
controlled by
autonomic nervous
system,
location
Muscles attached to
bones, skin,
diaphragm,
Visceral organs ,
blood vessels,
Ciliary muscles of
the eye
Heart only
Role 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;
continued
• the 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;
continued
• pectoral 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;
continued
• Presence 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;