MaryBiraiCentralNervousSystem

Diencephalon

Cerebellum

CNS protection

Spinal cord

Brainstem

Cerebrum

Precentral gyrus: anterior to central sulcus. Primary motor complex. Control of voluntary movement

Postcentral gyrus: posterior to central sulcus. Primary somatosensory cortex: skin, muscles, joints (extremities), proprioception. Consciously aware of those sensations

Insula: gustation cortex. general visceral sensation ( stretch, discomfort, pain)

Broca area: on the left hemisphere. Controls motor movements of speech

Occipital lobe: location of visual cortex

Wernicke area: understanding of speech. Able to name objects and read words. In the left hemisphere

Temporal lobe: auditory, olfactory cortex. recognition of objects, words, & faces. Language comprehension. Emotional response and memory

Association tracts: connects parts of same hemisphere

Parietal lobe: Sensory part of brain, receives sensory info & processes it, Conscious awareness of a general somatic sensation - touch, pressure, temp

Commissural tracts: Corpus callosum - able to name objects and read words. Go from one part of the CNS to the other

Frontal lobe: Thinking & planning, making decisions, planning & initiating voluntary movement, memory

Projection tracts: communication between the cortex and the periphery. Either descend from cerebral cortex to more caudal parts or ascend to cortex from lower regions. Run vertically.

Thalamus: Is a paired structure

  • Has several nuclei
  • All sensory info on way to cortex goes through the thalamus except olfaction
  • Its a relay station. There can be amplification or "tone down" the signal

Hypothalamus:

  • Several nuclei
  • Main visceral control center
  • controls the autonomic nervous system with the help of grey matter in the brain stem
  • regulates body temperature, hunger/thirst, sleep/wake cycles
  • controls endocrine system
  • involved with emotion
  • controls motivational behavior: food & sex
  • formation of memory

Epithalamus:

  • forms part of roof of 3rd ventricle
  • Houses the pineal gland (a small unpaired knob) which is a hormone secreting organ
  • The pineal gland secretes melatonin & prepares us for sleep

Pons: 2nd region of brain stem

  • grey matter of the pons
  • reticular formation nuclei - involved with autonomic behaviors
  • contains middle cerebellar peduncles
  • contains Cranial nerve V, VI, and VII.

Medulla oblongata: continuous with spinal cord at level of foramen magnum

  • cardiac center: heart
  • vasomotor center - blood pressure
  • respiratory center- breathing rate
  • Pyramids: cortex of precentral gyrus. Motor output through pyramidal tracts.
  • Decussation of the pyramids: pyramidal fibers that cross from one side of the brain to the other. Result is each cerebral hemisphere controls voluntary movements of opposite side of body
  • cranial nerve nuclei: a place where cranial nerves connect with brain.
  • 10/12 nerves connect with portion of brain stem. olfactory and optic nerves do not

Midbrain: between diencephalon and pons

  • Motor movement - particularly movements of the eye & in auditory & visual processing.
  • Cerebral peduncles: on ventral surface of brain. Composed of pyramidal motor tracts to spinal cord
  • On dorsal aspect of midbrain, there is corpora quadrigemina
    • 2 superior colliculi are involved in visual reflexes
    • 2 inferior colliculi are involved in auditory reflexes

Filum Terminal: means "end filament"

  • a long filament of connective tissue that extends from the conus medullaris and attaches to the coccyx inferiorly
  • anchors the spinal cord in place so that it is not jostled by body movements

Anterior Roots: Ventral Roots

  • Grey matter of the spine
  • Motor 1/2 of the PNS
  • Contains visceral (autonomic) motor and somatic motor neurons
  • supplies muscles and glands

Cauda Equina: "horse's tail"

  • Collection of nerve roots at the inferior end of the vertebral canal that resembles a horse's tail

Posterior Roots: Dorsal Roots

  • Grey matter of the spine
  • Sensory 1/2 of the PNS
  • Contains Visceral sensory portion: interneurons receiving input from visceral sensory neurons
  • Contains Somatic Sensory portion: interneurons receiving input from somatic sensory neurons
  • axons reach the spinal cord

Conus medullaris: "cone of the spinal cord"

  • Tapers at the inferior end of spinal cord.

Pia Mater: Gentle Mother

  • 3/3 meninges
  • Fibrous connective tissue
  • Very vascular - capillary rich

Subarachnoid Space: Deep to the arachnoid membrane

  • Filled with cerebral spinal fluid
  • Holds arachnoid mater to pia mater
  • Contains large blood vessels that supply the brain
  • Arachnoid granulations allow cerebral spinal fluid to pass from subarachnoid space to dural venous sinuses.

Epidural Space

  • Filled with cushioning fat and a network of veins
  • Anesthetics are often injected here to block nerve impulses

Dura Mater: " tough mother"

  • 1/2 meninges
  • tough dense fibrous connective tissue
  • has 2 layer
    • perosteal layer - attaches to internal surface of skull bones ( this layer doesn't exist in spinal cord)
    • meningeal layer - forms true external covering of brain (also found in spinal cord)
  • subdural space has a little film of fluid

Arachnoid Mater

  • 2/3 meninges
  • Lies deep to the dura mater
  • Subdural space is between the arachnoid mater and dura mater
  • Subdural space is potential space that can be filled with blood or fluid as result of disease or trauma

Dural Sinuses:

  • this is formed from the separation of perosteal and meningeal portion of Dura Mater.
  • it is filled with deoxygenated blood
  • Collect blood from brain and conduct it to the large internal jugular veins of the neck.

Superior Cerebellar peduncles

  • efferent
  • connect midbrain to the cerebellum

Middle Cerebellar Peduncles

  • connects our cerebellum to the cerebral cortex
  • efferent
  • connects pons to cerebellum

Structure:

  • Outer grey cortex, internal white matter (arbor vitae), and deep grey matter called nuclei
  • Both grey portions are neuron cell bodies

Inferior Cerebellar peduncles

  • Connect medulla oblongata to the cerebellum
  • proprioception & equilibrium
  • afferent

Function

  • smooth & coordinate body movements with help of other brain parts.
  • It also maintains posture and equilibrium