musculoskeletal and nervous system

The Musculoskeletal System

• Supports the body, protects delicate organs, and makes movement possible

• Made up of all the bones in the body and the muscles that move them (i.e. connective and muscle tissues)

• 206 bones in adult humans

Tendons and ligaments

• Connective tissues that supports and helps with movement

• Tendons - connects muscles to bones

• Ligaments - connects bones to bones

muscles

• 3 types:

  • Cardiac

  • Skeletal

  • Smooth

• Skeletal muscles are made up of bundles of myocytes (muscle cells) lined with proteins

Voluntary vs Involuntary Muscles

• Voluntary muscles - you can control them (i.e. skeletal muscles)

• Involuntary muscles - you cannot control them (i.e. cardiac and smooth muscles)

How muscles help you move

• Muscles move parts of your body by contracting (i.e. pulling); they cannot push!!!

• Everytime you move, some muscles will contract and others will relax

• With you curl your arm, your biceps contract and your triceps relax

• When you stretch your arm, the biceps relax and your triceps contract

Problems with the musculoskeletal system

• muscular dystrophy

  • genetic disease that causes the degeneration of muscles

• osteoporosis

  • bone disease

Nervous system

• Senses the environment and coordinates appropriate responses

• Two parts:

  • Central nervous system (CNS) - brain and spinal cord

  • Peripheral nervous system (PNS) - nerves that branch from the CNS

Peripheral nervous system, three groups

• Three groups:

  • Nerves that control the voluntary muscles

  • Nerves that carry information from the sensory organs

  • Nerves that regulate involuntary functions

nerve bundle

• Because axons are so long, they are often found in bundles surrounded by connective tissue

• Each axon may also be covered by myelin sheath produced by Schwann cells as insulation

neurons

• Contains a soma (body) and an axon with highly branched extrusions

• No centrosomes (cannot undergo cell division)

how signals transmit across the body

• Travels in one direction

• Stimuli will result in an electrical signal being sent down the affected neuron

• Electrical signal converted to chemical signal as it crosses the synapse between neurons in the form of neurotransmitters

• Converts back into electrical signal as it travels down the next neuron

problems with the nervous system

• multiple sclerosis

  • body attacks its own nervous system

• parkinsons disease

  • chronic disorder where neurons in the brain slowly die

• alzheimers disease

  • proteins build up in the brain leading to the death of brain cells and memory loss

joints

• Where two bones meet

• 6 types of joints allow for different types of movement