week 2

• spinal cord - The main pathway information connecting the brain and peripheral nervous system.
• spinal cord - lt is elongated, cylindrical, suspended in the vertebral canal and protected by vertebrae
• spinal cord - Surrounded by the meninges and cerebrospinal fluid
• spinal cord - The primary function of spinal cord is the transmission of neural signals between the brain and the rest of the body.
• neural signals

  1. sensory
  2. motor
  3. local reflexes
• spinal cord - extended from foramen magnum to second lumbar vertebrae
• spinal cord - Continuous above with the medulla oblongata.
• spinal cord - The tapered inferior end forms conus medullaris.
• conus medullaris cauda equina

  A) conus medullaris

  B) caude equina

  
• spinal cord - lt is connected to the coccyx by a non-neuronal

  cord called Filum Terminale.
• spinal cord - Gives rise to 31 pairs of spinal nerves
• spinal cord - The bundle of spinal nerves extending inferiorly from lumbosacral enlargement and conus medullaris surround the filum terminale and form cauda equina
• segmented

  1. 8 cervical
  2. 12 thoracic
  3. 5 lumbar
  4. 5 sacral
  5. 1 coccygeal
• 2 enlargement

  1. cervical enlargement : supplies upper limbs
  2. lumbosacral enlargement : supplies lower limbs
• the basic unit of the nervous system is the nerve cell
• nerve cells are called neurons
• there are billions of neurons in the body. Some exist alone. Others are joined together to form organs like the brain and spinal cord
• There are 12 to 14 billions of neurons in one part of the body alone. A neuron has a cell body containing the nucleus. Projecting out from the cell body are a root like structure
• Dendrites - receive messages from other cells
• Soma- the cell body which maintains the health of the neuron
• Axon - passes message away from the cell body to other neurons, muscles, glands
• Neural impulse - electrical signal traveling down the axon
• Myelin sheath - covers the axon of some neurons and helps speed the neural impulses.
• Terminal branches of axon - form junctions with other cell.
• denrite

  A) dendrite

  B) cell body

  C) nucleus

  D) axon

  E) myelin sheath

  F) schwann cell

  G) node of ranvier

  H) axon terminal

  
• pseudounipolar - Neuron is a type of neuron which has one extension from its cells body. Type of neuron contains an axon that has split into two branches. a single process arises from the cell body and then divides into an axon and a dendrites
• control of body processes through the nervous system. -

  The nerve impulse.

  • Neurons our cells with the special ability to carry signals or impulses.
  • Thoughts emotions learnings and many body function are carried by nerve impulses in neurons
• A nerve impulse cannot jump from one neuron to another.
• when a nerve impulse comes to the end of an axon, it produces the chemical called neurotransmitter, to be the the release
• the chemical crosses the space between neurons called synapse and stimulates the nerve impulse to start in the next dendrite.
• Messages do not travel in both directions along the same neuron
• only the axon of the neuron releases neurotransmitters that crosses the space between neurons.
• reaction time is the length of time between application of a stimulus and detection of a response
• the chemical crosses the space between neurons called synapse
• axon

  A) axon

  B) synapse

  C) dendrites

  
• neuron

  A) several dendrites

  B) one axon

  C) motor

  D) neurons

  E) cns

  F) neurons

  G) one denrite

  H) one axon

  I) special

  J) sense organs

  K) eyes

  L) nose

  M) single axon

  N) sensory