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
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)
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
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
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
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