Locomotion

Locomotion

Locomotion: the ability to move from one place to another

Motile: capable of locomotion

Sessile: incapable of locomotion; stationary

Advantages of Locomotion

Increases survival (avoid predators and dangers)

Increase food opportunities

Increase ability to find mates, shelter, water etc.

Adaptations

Algae: some have flagellaProtozoans– Paramecium use cilia (hair-like projections)– Amoeba use pseudopods (“false feet”)– Euglena use flagella (tail-like projections)

Hydra– Mostly sessile– Contractile fibers used for somersaults

Adaptations

Some sessile animals use protection in large numbers– Coral reefs

Others use chemical defense– Poisons/toxins found in the stingers of jelly-

fish and sea anemones

Human Locomotion

Involves the interaction of bones & muscles– Bones provide the structure and muscles

provide the movement

Skeletal System

Humans have an endoskeletonFunctions of bones– Protection of internal organs – Support/shape– Anchorage for muscles– Leverage for movement – Production of blood cells (bone marrow)– Store minerals (ex. Ca2+)

Organization of Bones

Number of bones– Baby: approx. 350– Adult: 206

Skeleton has two major subdivisions:– Axial: “central core” (skull, vertebrae, ribs &

breastbone) – Appendicular: “appendages”; that which

attaches

Axial Skeleton (80 Bones)

Skeleton of the trunk & head1) Skull

a) Cranium (8)1) Frontal (1): forehead2) Parietal (2): above temporal3) Temporal (2): sides/temples4) Occipital (1): back of the head5) Sphenoid (1): temple/eye area6) Ethmoid (1): part of eye socket

Skull cont.

b) Facial (14)1) Nasal (2): nose bridge2) Maxillary (2): upper jaw3) Zygomatic (malar) (2): cheek bones 4) Mandible (1): lower jaw5) Lacrimal (2): eye socket (inner corner)6) Palatine (2): form hard palate7) Inferior conchae (2): nasal cavity8) Volmer (1): nasal cavity

Skull cont.

c) Ear bones (6)1) Malleus (hammer)(2)

2) Incus (anvil) (2)

3) Stapes (stirrup) (2)

1 in each ear

Axial Skeleton

2) Hyoid (1): neck (non-cervical)

doesn’t form a joint

3) Vertebral column (26) a) Cervical (7): neck

b) Thoracic (12): back of chest

c) Lumbar (5): lower back

d) Sacrum (1): fused lower

e) Coccyx (1): fused tailbone

Axial Skeleton cont.

4) Sternum & ribsa) Sternum (1): breastbone

b) True ribs (7 pairs): join w/ sternum

c) “false” ribs (3 pairs): join w/ last true rib (not sternum)

d) “floating” Ribs (2 pairs): don’t join sternum

Appendicular Skeleton (126 bones)

1) Upper extremities (64)a) Clavicle (2): collarbone

b) Scapula (2): shoulder blade

c) Humerus (2): upper arm

d) Radius (2)

e) Ulna (2)

f) Carpals (16): wrist

g) Metacarpals (10): hand

h) Phalanges (28): fingers

Lower arm

Mrs. Cole’s sister w/broken clavicle

Appendicular Skeleton cont.

2) Lower extremitiesa) Pelvic bone (3):

• ilium, ischium & pubis

b) Femur (2): thighc) Patella (2): knee capd) Tibia (2): shine) Fibula (2): lower legf) Tarsals (14): anklesg) Metatarsals (10): footh) Phalanges (28): toes

Connective Tissues(other than bone)

Cartilage: – Flexible– Elastic– Fibrous– Cushions joints

An embryo’s skeleton is mostly cartilageAs development occurs, cartilage becomes bone (ossification)

Connective Tissues cont.

Cartilage is found in adults:– End of ribs– Between vertebrae– End of bones (joints) – Ears, nose & trachea

Connective Tissue cont.

Ligaments: tough & elastic– Connect bone to bone @ joints (knee,

elbow etc.)

Tendons: tough & inelastic– Attach muscle to bone

Joints

Place where two bones meet5 types:

1. Immovable/fixed: no movement (ex. skull and pelvis)

2. Hinge: back & forth motion (ex. knee & elbow)

3. Ball & socket: one bone fits into another; movement in all directions (ex. shoulder & hip)

Joints cont.

4. Pivot: side to side and up & down movement (ex. neck)

5. Gliding: allows bending and twisting (ex. wrist and vertebrae)

Gliding joint

Pivot joint

Muscles

Tissue made of cells “capable of contracting and exerting a force”

Voluntary: under conscious control (somatic NS)

Involuntary: not under conscious control (autonomic NS)

3 Types of Muscle

1. Cardiac: • only in heart• Involuntary and

cannot fatigue!• Striated/striped

Fibrous cells (green)

Cardiac muscle fiber (red)

Intercalated disc

nucleus

Cross-striations

muscle

2. Smooth (visceral):

• Found in walls of digestive tract and blood vessels

• Involuntary • Appear

smooth/not striated

muscle

3. Skeletal• Found fastened to bones of skeleton• Voluntary• Striated• Function is to move bones in a

coordinated manner

nucleus

Muscle cell

Cross-striations

Skeletal Muscles

Work in antagonistic pairs (opposite directions)

Ex. Bicep & triceps– Bicep muscle bends/flexes: called flexor– When bicep flexes, triceps relaxes (called

an extensor) making it possible for arm to bend

Antagonistic Pair

Skeletal Muscle Fatigue

Under “normal” conditions, muscle cells use O2 for energy (aerobic respiration)

During vigorous activity, muscle cells can function for a short time w/ available O2 until supply cannot keep up w/ demand for O2 and cells revert to anaerobic respiration

Lactic acid builds up and causes muscle fatigue