Locomotion lecture notes

Skin- the body’s protection

Epidermis-the outer layer

• Exterior layer-20-30 layers of dead flattened cells

• Interior layer- living cells continually dividing

• Melanin- protective skin pigment

• Keratin-protective protein (elasticity)

• Epidermal ridges on fingers and palms good for gripping because the provide more friction

  Dermis-the inner layer

• Blood vessels, nerves, nerve endings, hair follicles, sweat and oil glands

• Layer of fat underneath-insulation and protection

Functions of the skin

• Regulate body temperature

• Sense organ

• Vitamin D production

• Physical barrier against damage and microbial invasion

Aging

• Drier-glands decrease production

• Skin loses its elasticity > wrinkles

• Accelerated by prolonged exposure to UV rays

The skeletal system

Axial skeleton

• Includes the skull, vertebral column, ribs, and sternum

Appendicular skeleton

• Includes the bones of the arms and the legs and associated structures

Joints-places where bones are connected

Ball and socket joint

• Allows for rotational movement

• Hips and shoulders

Hinge joint

• Allows for back and forth movement

• Elbows, knees,fingers, and toes

  Pivot joint

• Allows bones to twist around each other

• Neck and elbows

  Gliding joint

• Allows bones to slide past each other

• Wrists and ankles

Fixed joint

• Also called a fused joint

• Allows for no motion

• Skull

Cartilage

• Bones are cushioned by a thin layer of cartilage

• Flexible, elastic tissue

• Nose, ears, trachea, between each vertebrae

Bursae

• Fluid-filled scan between bones

• Absorb shock

Arthritis

• Inflammation of the joints

• Wearing down of cartilage

• Bone spurs-splinters

• Causes-infections, aging, injury, and is genetic

Connective tissues

• Ligaments- connect bone to bone

• A sprain is a torn or stretched ligament

• Tendons-connect muscles to bones

• Tendinitis-inflammation of the tendon

Bone structure

Compact bone

• Very dense and strong

• Outside of ends and along shafts

• Osteocytes-bone cells

• Osteo systems (Haversian canals)-are openings allowing blood vessels and nerves through the bone

Spongy bone

• Less dense, porous

• Ends of bone

• Periosteum-outer covering of bone shafts

Osteoblasts-potential bone cells

• Secrete a protein called collagen

• Deposition of minerals turns them into osteocytes-ossification

• Osteoporosis-loss of bone mass

• Growth happens vertically in the cartilage plates at the end of a bone and horizontally at the outer surface

• After growth-repair and maintenance

Marrow-found at the center of bones

• Red marrow-is in long bones only and they produce blood cells

• Yellow marrow- is in MOST bones and it stores fat

Functions of the skeletal system

• Protects internal organs

• Framework for body tissues

• Attachment for muscles

• Production of blood cells

• Mineral storage

Muscles-3 types

Smooth muscle

• Sheets of cells

• Walls of internal organs and blood vessels

• Function-squeezing (pressure)

• Involuntary- not under conscious control

Cardiac muscle

• Found in your heart

• Interconnected bands of muscle fibers-striated

• Adapted to generate and conduct electrical impulses

• Involuntary

Skeletal muscle

• Attached to bones

• Controls movement

• Work in opposing pairs-1 bends a limb and the other extends the limb

• Striated in appearance

• Voluntary

Muscle Strength

• The number of muscle fibers you have is fixed before birth

• Muscle fibers get bigger and more fibers contract as you increase your strength

Muscle fatigue- when muscles hurt after use

• Due to decreased available oxygen

• Cells switch from aerobic to anaerobic

• Lactic acid buildup-toxic, causes pain

• Cure-rest

• Not resting can result in permanent muscle damage

Comparative anatomy

Amoeba

• Pseudopods-false feet

• Extensions of the cell membrane that can reach in any direction

• Locomotion

Paramecium

• Have cilia to propel them through the water

• Locomotion

Hydra

• Pull with tentacles

• Glide on base

• Somersaulting

• Movement

Earthworm

• Setae-bristles used as anchors

• Longitudinal muscles-shorten body

• Circular muscles-lengthen body

Grasshopper

• Jointed appendages

• Walking legs and jumping legs

• 2 sets of wings

• Exoskeleton made of chitin which is an attachment sites for muscles