Nervous system

• what is the nervous system?

  the major controlling, regulating, and communicating system of the body
• first interelated function

  monitors changes inside and outside of the body using millions of sensory receptors - changes called stimuli - information gathered from stimuli - sensory input
• second interrelated function


  processes and interpets sensory input and decides what actions need to be taken - integration
• third interrelated function 


  then initiates a response by activating muscles or glands (effectors) via motor output
• central nervous system


  consist of brain and spinal cord, acts as command center for nervous system
• peripheral nervous system (PNS)


  consist if nerves that extend from the brain and spinal column
• sub-divisions of the peripheral nervous system

  afferent (sensory) division, efferent (motor) division
• efferent motor - subdivisions

  the somatic or voluntary nervous system, the autonomic nervous system (ANS)
• the autonomic nervous system (ANS)


  two parts, sympathetic; flight or flight, and parasympathetic systems; the body under normal body conditions
• what are nerves?


  a single nerve - a bundle of neurons found outside CNS, made up of two types of cells; supporting cells and neurons.
• what are neurons?


  referred to as 'nerve cells', highly specialised cells, transmit messages from one part of the body to another
• neuron major functions


  ability to respond to a stimulus and convert it into nerve impulse, ability to transmit the impulse to other neurons, muscles, or glands.
• central nervous system (CNS) - the brain

  the brain is a wrinkled pink clump of tissue that weighs over 1.3kg, is located in cranial activity. Largest and most complex organ of nervous system.
• The four regions of the brain

  cerebrum, diencephalon, brainstem, cerebellum
• the lobes of the brain include

  parietal, occipital, temporal, frontal lobes
• parietal lobe


  responsible for - interpreting impulses traveling from body sensory receptors. recognize pain, cold, taste, smell, touch.
• occipital lobe


  responsible for - visual interpretation and recognition, damage - cause blindness
• temporal lobe


  responsible for - hearing, language, processing, and memory. damage - memory loss
• frontal lobe


  responsible for - conscious movement of skeletal muscles, contains special area, Broca's area - speech
• major structures of the diencephalon

  thalamus, hypothalamus, epithalamus
• thalamus


  relay station sensory impulses upward to the sensory cortex
• hypothalamus


  part of ANS, role - regulation of temperature/water balance. center for emotions/urges. E.g thirst, appetite, pain, sex, and pleasure centers. helps regulate hormones of the endocrine system
• epithalamus


  contains body of the pineal gland of the endocrine system - responsible for secreting melatonin.
• brainstem - midbrain


  function - transmit ascending and descending impulses. reflex center involved with vision and hearing
• brainstem - pons


  made up of fibres, involved in control of breathing
• What are the primary functions of the nervous system?

  1. Sensory Input: Collects information from internal and external environments. 2. Integration: Processes and interprets sensory information. 3. Motor Output: Generates responses by activating muscles and glands. 4. Homeostasis: Maintains internal balance of the body. 5. Higher Functions: Enables complex cognitive processes like thinking and memory.
• Disorders of the nervous system

  Epilepsy Meningitis Multiple Sclerosis (MS)
• subdivisions breakdown - nervous system

  
• neurons

  
• lobes of the brain - nervous system