biopsych

• Central Nervous System (CNS)

  • Brain
  • Spinal cord
• Peripheral Nervous System (PNS)

  • Nerve fibres outside of the CNS
  • Connects the CNS to the rest of the body
• Peripheral Nervous System (PNS)

  • Autonomic NS
  • Somatic NS
• Autonomic Nervous System (ANS)


  Sends & receives messages to regulate the autonomic behaviours of the body (e.g., heart rate, respiration, digestion)
• Somatic Nervous System

  • Controls voluntary muscles
  • Conveys sensory information to CNS
• Autonomic Nervous System

  • Parasympathetic NS
  • Sympathetic NS
• Parasympathetic Nervous System

  • Facilitates vegetative, nonemergency response
  • Conserves bodily resources
• Sympathetic Nervous System

  • Network of nerves that prepares the organs for rigorous activity
  • Mobilises bodily resources
• Anterior

  Toward the front end
• Posterior

  Toward the rear end
• Dorsal

  Toward the back, away from the ventral (stomach) side
• Ventral

  Toward the stomach, away from the dorsal (back) side
• Lateral

  Toward the side, away from the midline
• Medial

  Toward the midline, away from the side
• Spinal Cord

  • Part of the CNS within the spinal column
  • Base of your brain to just below your waist, with a segmented structure
  • Communicates with the sense organs and muscles, except those of the head
• Spinal Cord

  • Sensory nerves: bring sensory info from body to brain (entering dorsal roots)
  • Motor nerves: transmit motor info from brain to body (exiting ventral roots)
• Spinal Cord

  • Grey matter: located in the centre, densely packed with cell bodies and dendrites
  • White matter: composed mostly of myelinated axons, carries information from the grey matter to the brain or other areas of the spinal cord
• Spinal Reflex

  • Spinal reflexes occur independently of the brain
  • Interneurons in the spinal cord receive sensory input and excite motor neurons controlling muscles that withdraw the limb
• Brainstem

  • Hindbrain structures, the midbrain, and other central structures of the brain combine and make up the brain stem
  • Located at the posterior portion of the brain
• Hindbrain


  • Medulla
  • Pons
  • Cerebellum
• Medulla


  • Located just above the spinal cord
  • Comprised of ascending & descending tracts
  • Small nuclei at its core is the reticular formation
  • Responsible for vital reflexes such as breathing, heart rate, vomiting, salivation, coughing, and sneezing
  • Damage often fatal
• Cranial Nerves


  • Twelve pairs of nerves that enter and exit brain directly
  • Allow the medulla to control sensations from the head, muscle movements in the head, and many parasympathetic outputs
• Cranial Nerves


  • Olfactory
  • Optic
  • Oculomotor
  • Trochlear
  • Trigeminal
  • Abducens
  • Facial
  • Statoacoustic
  • Glossopharyngeal
  • Vagus
  • Accessory
  • Hypoglossal
• Pons


  • Fibre tract that lies on anterior and ventral to the medulla
  • The term pons is Latin for "bridge"
  • Axons from each half of the brain cross to the opposite side of the spinal cord (contralateral control)
• Cerebellum


  • Structure with many deep folds
  • Helps regulate motor movement, balance, and coordination
  • Important for shifting attention between auditory and visual stimuli
  • Greatly affected by alcohol
• Midbrain

  • Tectum: roof of the midbrain, composed of superior & inferior colliculi (involved in sensory function)
  • Tegmentum: contains nuclei for cranial nerves and part of the reticular formation; red nucleus and substantia nigra (both involved in sensorimotor function); and the periaqueductal gray
• Forebrain


  • The most anterior and prominent part of the mammalian brain, with two cerebral hemispheres
  • Consists of the outer cortex and subcortical regions
  • Outer portion is known as the "cerebral cortex"
  • Each side receives sensory information and controls motor movement from the opposite (contralateral) side of the body
• Forebrain


  • Hypothalamus
  • Thalamus
• Hypothalamus


  • Small area near the base, just below the thalamus (hypo = below)
  • Conveys messages to the pituitary gland to alter the release of hormones
  • Associated with motivated behaviors (e.g., eating, drinking, sexual behavior)
• Limbic System


  • Consists of a number of other interlinked structures that form a border around the brainstem
  • Includes the olfactory bulb, hypothalamus, hippocampus, amygdala, and cingulate gyrus of the cerebral cortex
  • Associated with motivated and emotional behaviour (e.g., eating, drinking, sexual activity, anxiety, & aggression)
• Thalamus


  • Large two-lobed structure at top of brain stem
  • Relay station from the sensory organs (except smell); main source of input to the cortex
  • Integrates information across senses
• Information routes from Thalamus to Cerebral Cortex

  • Lateral geniculate nuclei: vision
  • Medial geniculate nuclei: hearing
  • Ventral posterior nuclei: touch
• Ventricles

  • Four fluid-filled cavities within the brain's central canal containing cerebrospinal fluid
  • Provides "cushioning" for the brain
  • Reservoir of hormones and nutrition for the CNS
• Blockage of CSF flow


  • Brain expands
  • Leads to cognitive impairments if not addressed
• Hydrocephalus


  Condition caused by blockage of CSF flow
• Meninges


  • Dura mater
  • Arachnoid mater
  • Pia mater
• Meninges


  • Membranes that surround the brain and spinal cord
  • Contain pain receptors
  • Cerebrospinal fluid flows through the spaces between the brain & meninges
• Cerebral Cortex


  • Also known as the cerebrum
  • Consists of the cellular layers on the outer surface of the cerebral hemispheres
  • Highly convoluted outer layer
  • Grooves = sulci, Bumps = gyri
  • Most recently evolved, mediates most complex functions
• Cerebral Cortex


  • The longitudinal fissure separates the two cerebral hemispheres
  • The hemispheres joined by two bundles of axons called the corpus callosum and the anterior commissure
  • Divided into four lobes
• Occipital Lobe


  • Located at the posterior end of the cortex
  • Known as the striate cortex or the primary visual cortex
  • Highly responsible for visual input
  • Damage can result in cortical blindness