chapt 2

• the brain have an additional level of protection called "blood brain barrier". It prevents odd or weird things from going into the brain
• peripheral nervous system (PNS)

  1. somatic nervous system
  2. autonomic nervous system
  3. enteric nervous system
• Somatic nervous system: conscious nervous system, the things you are consciously aware of. Sensation and motor movements.
• Autonomic nervous system: conscious and unconscious (actions you dont pay attention to like heart rate or movement sensation of internal organs)
• enteric nervous system: digestive nervous system, helps to detect any dangers in the digestive system.
• functions of nervous system:

  • CNS: mediates behaviour (receiving signals, information and conducting movement). It goes to the brain and spinal cord.
  • Somatic NS: transmits sensation, produces movement. It goes in and out of the cranial nerves and spinal nerves.
  • Autonomic NS: balances internal functions (like hormones production). There is sympathetic division and parasympathetic division.
• Parasympathic system refers to calming, rest and restore or repair system
• Sympathetic system is the fight or flight and arousing response (increasing heart rate)
• Afferent information is sensory information going into the CNS, coming from senses

  Efferent information is information leaving the CNS to control motor movement

  
  

  in the brainstem (where spinal cord enters the skull)
• terminology:

  • dorsal: the top of the brain
  • posterior: back of the brain
  • anterior: front of the brain
  • medial: going towards the brain (at the side)
  • lateral: located towards the side of the brain (side of the brain)
• meninges: protective tissues that surrounds the brain

  • dura mater: tough outer layer of fibrous tissue
  • arachnoid layer: sheet of delicate connective tissue
  • pia mater: tough inner layer that clings to the brain's surface
• cerebral cortex (the forebrain) has 4 lobes:

  • occipital: visual
  • temporal: auditory, taste, smell, memory
  • parietal: sensory and intergration
  • frontal: motor and executive functioning
• Cerebrum: is the right and left hemisphere of the brain

  cerebellum (little brain): coordinates the motor movement and other mental processes

  gyrus: a protrusion or bump of the brain

  sulcus: a groove (groove downwards of the brain)

  fissure: a very deep sulcus
• brainstem: hindbrain, midbrain, thalamus, and hypothalamus is responsible for most unconscious behaviour
• grey matter: composes of cell bodies and blood vessels (brain cells located outside of the brain)

  white matter: rich in fat-sheathed neural axons (coated with myline sheet)

  corpus callosum: fibre system connecting the two cerebral hemisphere. It is a band of white matter.
• subcortical regions are forebrain structures that relates to the cortical areas that process motor, sensory, perceptual, and cognitive functions.


  basically redundant functions can still exist as many parts of the brain can have similar functions. so if you have a redundant in motor movement for cerebellum for example, there are still other subcortical regions that can help out with motor movement
• CNS 3 major components:

  1. spinal cord
  2. brainstem
  3. forebrain
• hindbrain contains cerebellum, reticular formation, pons and medulla

  • it controls various motor functions ranging from breathing to balance to fine movements
  • integrates both voluntary and involuntary body movement
• cerebellum:

  • controls complex movement and cognitive functions
  • size also increases with physical speed (lepard and sloth)

  Large cerebellum:

  • enables finely coordinated movements
• reticular formation (reticular activating system) involves in the stimulation of forebrain: regulation of sleep-wake behaviour and behavioural arousal
• pons: connects cerebellum to the rest of the brain, controls important movements of the body

  medulla: control of breathing and heart rate
• hypothalamus:

  • takes information to help regulate behaviours like: feeding, sexual behaviour, sleeping, emotional behaviour, etc.
  • hormone function -> through connections with pituitary glands
• thalamus:

  • a way to relay / channeling sensory information to the respective cortex (cortical regions)
  • primary role: sensory processing, motor processing, integrative functions
• forebrain:

  • neocortex (cerebral cortex): regulates various mental activities (conscious activities)
  • basal ganglisa: controls voluntary and involuntary movements
  • limbic system: regulates emotions and behaviours that store and require memory
• basal ganglisa: controls voluntary and involuntary movements

  • 3 principle structures: caudate nucleus, putamen, and globus pallidus
  • related disorders: parkinson disease and tourette syndrome
• limbic system: regulates emotion and behaviour and memory

  • structures: amygdala, hippocampus, and cingulate cortex
  • regulates emotional and sexual behaviours, memory, and spatial navigation
• hippocampus converting STM to LTM. Storing LTM.
• olfactory system is responsible for the sense of smell and is located at the front of the brain

  • structures: amygdala, pyriform cortex, and dorsomedial thalamus
• spinal nerves: dermatome


  area of the skin supplied with afferent nerve fibers by a single spinal cord dorsal root
• Somantic Nervous system:

  • dorsal fibers (afferent; sensory info): carry information from the body's sensory receptors
  • ventral fibers (efferent; motor info): carry information from the spinal cord to the muscle

  known as law of bell and magendie
• ENS: controls the gut

  • neurons in the gastrointestinal tract
  • microbiome - gut bacteria that regulates gut health
  • ENS connects through the ANS via vagus nerve
  • Stress/ anxiety can modify gut function
  • psychobiotic: increase seretonin
• Broca's area is located in the frontal lobes. It is linked to speech production.
• prefrontal cortex located in the frontal lobes regulates our thoughts, actions and emotions through extensive connections with other brain regions.

  Making us uniquely human
• The premotor cortex is involved in planning and organizing movements and actions.
• amygdala is located in the temporal lobes and is part of the limbic system.

  It plays a significant role in emotional memory, fear, and aggression (emotion and behaviour).