Nervous System

• • complete network of nerves and cells

  Nervous System
• main processing center

  Central Nervous System
• organizer and distributor of information for the body

  Brain
• • large upper part of the brain
  • controls activity and thought

  Cerebrum
• • below the cerebrum
  • controls posture, balance, and coordination

  Cerebellum
• • connects the brain to the spinal cord
  • controls automatic functions such as breathing, digestions, heart rate, and blood pressure.

  Brain Stem
• channel for signal between brain and the majority of the body parts

  Spinal Cord
• Controls some musculoskeletal reflexes even without the processing of the brain.

  Spinal Cord
• connects the central nervous system to the organs and limb

  Peripheral Nervous System
• voluntary control of body movements

  Somatic
• carry motor and sensory signal between the spinal cord and the body

  Spinal Nerves
• nerve fibres that carry information in and out of the brain stem

  Cranial Nerves
• involuntary control of body movements

  Autonomic Nervous System
• activated when body is in dynamic role or stress

  Sympathetic
• • maintains body functions
  • restores the body to normal or relaxed mode

  Parasympathetic
• • basic unit of the nervous system
  • also called the neuron
  • composed of cell body, dendrites, and axons

  Nerve Cell
• Where the nucleus is

  Cell Body
• root-like structures carrying impulse toward the cell body

  Dendrites
• root-like structures carrying impulse away from the cell body

  Axons
• gap between neurons

  Synapse
• provides quick responses in maintaining homeostasis

  Nervous System
• maintained in the body by regulating the body temperature, blood pressure, pH, and glucose concentration

  Homeostasis
• this state is reached when each part of the body functions in equilibrium with other parts.

  Homeostasis
• attained through the regulation of the bodily functions by the endocrine and nervous systems.

  Homeostasis
• used by most of body systems to maintain homeostasis.

  Feedback mechanism
• • carry messages to and from the brain and spinal cord to various parts of the body.

  Nervous System
• body’s storage center of information

  Nervous System
• • body’s control system

  Nervous System
• controlling and coordinating all the organ systems by sending messages from the brain through nerve signals

  Nervous System
• • makes sure all the parts of the body are working together efficiently.


  Nervous System
• How long is the spinal chord

  40-50 cm
• •Contains all the nerves outside the brain and the spinal cord

  peripheral nervous system
• •Controlling the muscles in the heart and the smooth muscles in the internal organs such as the intestines, bladder, and the uterus

  autonomic
• •“fight or flight response”

  Sympathetic
• •responsible for the acceleration of heart rate, the constriction of the blood vessels, and the rise of blood pressure

  sympathetic
• •“rest and digest response”

  parasympathetic
• •it slows down the heart rate and increases the intestinal and gland activities

  parasympathetic
• •includes all the nerves controlling the muscular system and external sensory receptors which refer to the external sense organs

  somatic
• is what produces the myelin sheath.

  Schwann cell
• •A control system to reduce or minimize any internal or external change of the body

  Negative feedback mechanism