Nervous System and Endocrine System

• Nervous system


  The body's speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems.
• Central nervous system


  Brain and spinal cord

  
• Peripheral nervous system


  A division of the nervous system consisting of all nerves that are not part of the brain or spinal cord.

  
• Brain


  The mass of nerve tissue that is the main control center of the nervous system

  
• Cerebral cortex


  The intricate fabric of interconnected neural cells covering the cerebral hemispheres; the body's ultimate control and information-processing center.

  
• Hemispheres of the brain

  The human brain is divided into two halves called the left and right hemispheres

  
• Spinal cord


  Nerves that run up and down the length of the back and transmit most messages between the body and brain

  
• Autonomic nervous system


  - A subdivision of the peripheral nervous system.

  - Controls involuntary activity of visceral muscles and internal organs and glands.
• Somatic nervous system


  Division of the PNS that controls the body's skeletal muscles.
• Endocrine system


  Glands secrete hormones that regulate processes such as growth, reproduction, and nutrient use (metabolism) by body cells.

  
• Glands


  Organs or tissues in the body that create chemicals that control many of our bodily functions
• Thyroid gland


  Produces hormones that regulate metabolism, body heat, and bone growth

  
• Hormones


  Chemical messengers, mostly those manufactured by the endocrine glands, that are produced in one tissue and affect another
• Thryoxine


  Regulates metabolism
• Pituitary gland


  - The endocrine system's most influential gland.

  - Under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands.

  
• Hypothalamus


  A neural structure lying below the thalamus; it directs several maintenance activities (eating, drinking, body temperature), helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward.

  
• Fight or Flight Response


  - The body switches from resting parasympathetic state to the physiologically aroused sympathetic state.

  - The sympathetic state triggers the adrenal medulla to release adrenaline into the bloodstream.

  - The adrenaline increases heart and breathing rate, dilates pupils and inhibits digestion and saliva production.

  - One danger has passed, sympathetic changes back to the parasympathetic state and all processes go back to normal.
• Sympathetic state


  - Increases heart rate

  - Increases breathing rate

  - Dilates pupils

  - Inhibits digestion

  - Inhibits saliva production

  - Contracts rectum
• Parasympathetic state


  - Decreases heart rate

  - Decreases breathing rate

  - Constricts pupils

  - Stimulates digestion

  - Stimulates saliva production

  - Relaxes rectum
• Adrenaline


  A hormone released into the bloodstream in response to physical or mental stress