AS structure & function of the NS and endocrine system

• Brain and neuropsychology 

  The human body is a collection of systems which integrate to help us live. They are useful in explaining the behaviour and psychology of the individual.

  Biopsychology is a branch of psychology that analyses how the brain and neurotransmitters influence our behaviours, thoughts and feelings.

   This field can be thought of as a combination of basic psychology and neuroscience.
• Brain and neuropsychology 

  Biopsychologists assume that behaviour and experiences are caused by activity in the nervous system 

  The nervous system is a specialised network of cells in the human body and is our primary internal communication system. It has two main functions:

  • To collect, process and respond to information in the environment
  • To coordinate the working of different organs and cells
• The central nervous system

  The CNS is made up of the brain and spinal cord. The brain is divided into a left and right hemisphere

  • The right hemisphere controls the left side of the body
  • The left hemisphere controls the right side

  The brain is the centre of all conscious awareness & decision making 

  The brainstem connects the brain to the spinal cord and controls a number of important basic functions.

  The spinal cord carries incoming and outgoing messages between the brain and body
• The peripheral nervous system

  = peripheral means around the outside

  The PNS supports the actions of the CNS. 

  It receives messages from the CNS and and also sends messages to it. The PNS contains millions of specialised neurons that operate in sequence with one another. 

  The PNS is subdivided into:

  • The autonomic NS
  • The Somatic NS
• The somatic nervous system

  = Somatic means body 

  The SNS controls voluntary movement of the muscles in and around the body. As much of our movement is voluntary (like walking) so is the system that controls it. The only exception to this is the reflex arc

  The SNS takes information 

  in from the sensory organs 

  and transmits them to the 

  CNS as a branch of the PNS
• The somatic nervous system

  = Somatic means body 

  This is the part of the PNS that is 

  responsible for carrying sensory and 

  motor information to and from the 

  spinal cord
• The autonomic nervous system

  The ANS is automatic, it acts involuntarily. 

  It coordinates important functions in the body, vital for human life i.e. breathing, heart rate, digestion etc. (If we had to consciously think about these things all the time we would die… hence them being involuntary)

  It is also involved in the body’s response to stress (the fight or flight response) which we will look at next week
• The autonomic nervous system

  The autonomic nervous system further subdivides into two branches:

  • The parasympathetic nervous system (slower acting, like a parachute - responsible for normal bodily functions)

  The sympathetic nervous system (faster acting - responsible for reacting to stress and the fight or flight response)
• The endocrine system

  The endocrine system is in charge of body processes that happen slowly, such as cell growth. 

  Faster processes like breathing and body movement are controlled by the nervous system. 

  However,  even though the nervous system and endocrine system are separate systems, they often work together to help the body function properly.
• The endocrine system

  Glands = organs in the body that produce hormones.

  The major endocrine gland is the, located in the brain. It controls the release of hormones from all the  other endocrine glands in the body.

  Hormone = secreted in the bloodstream and affect any cell that has a receptor for that particular hormone
• Hormones are secreted in the bloodstream and affect any cells in the body that has a receptor for that particular hormone

  Example: thyroxine produced by thyroid gland affects cells in the heart and cells throughout the body, which increase metabolic rates.
• Adrenal glands

  These release the hormone adrenaline directly into the bloodstream which prepares the body for fight or flight by constricting blood vessels in the stomach. 

  This inhibits digestion and gives you that sick feeling as well as increasing your heart rate