Central Nervous System Flashcards
How many regions of brain?
4
Cerebrum?
Outer most superficial folded layer - thoughts, emotions Ect
Diencephalon?
Contain thalamus - gateway for sensory info, hypothalamus - homeostasis, hunger, ANS,
Pituitary gland - release hormones
Brain stem
Connect brain to spinal cord and contain midbrain, pons and medulla
Cerebellum?
Back of the brain known as the mini brain - coordinate movement of muscle
Structural complexity of brain decreases?
Decreases from cerebrum to brain stem
Gyri?
Elevated ridges or hills
Sulci?
Valleys or grooves between gyri
Fissures?
Deeper grooves that separate major cerebrum regions
What do longitudinal fissures do?
Divide the brain into left and right hemispheres
What is the cerebral cortex covered with?
Grey matter covers the superficial region of the cerebrum
Where is the white matter in the brain?
Deep to the cortex
How many lobes does the cerebrum have?
5
Frontal lobe functions?
Front of the head -voluntary movement, attention, planning, decision and personality
Temporal lobe?
Near the ears - auditory processing + memory + olfaction
Parietal lobe?
Middle of head - body sensation, language comprehension + audio-visual integration
Occipital lobe?
Back of head - visual processing
Insula?
Deep to upper three lobes - memory, feelings + cognition
Falx cerebri?
separates left and right hemispheres of the brain
Pregyrus?
Front part of cerebrum - motor
Post-gyrus
Back part of cerebrum - sensory
Large portions of brain functions are dedicated to what?
Sensory touch & motor control
Motor control & sensory processing are what?
Contralateral - the left motor controls the right limb
Reduction of blood flow to right side of frontal lobe lead to paralysis in what side?
left side
Types of cerebral white matter?
Commissural, association and projection fibers.
Commissural fibers?
AKA corpus calusum connect grey areas of two hemispheres
Association fibers?
Connect areas within same hemisphere
Projection fibers?
Connect hemispheres with lower parts of spine or brain
Visible spinal enlargements?
Superior cervical, inferior lumbar
Conus Medullaris?
Conical structure that terminates spinal cord below the ribs
Filum terminale?
Extensions of pia mater from conus medullaris that anchor the spine to coccynx
What do spinal grey matter contain?
Cell bodies that form functional groups called nuclei which receive and output motor or sensory input
What do spinal white matter contain?
Ascending (sensory) and descending tracts (motor)
What is the central canal?
A small tube in the middle of the spine that extends of entire length and contains CSF
What four structures protect the CNS?
Bone, meninges, CSF, blood brain barrier
What are the 4 functions of meninges?
Cover & protect CNS, protect blood vessel & sinuses, contain CSF, form partisans in the skull
What is the dura mater?
Outer most meninges made of double layer of connective tissue - periosteal fused deep to meninges and wraps around sinuses
What is the Arachnoid mater?
Middle layer - thin avascular layer of collagen & elastic web-like extensions that provide primary blood network to brain and contain arachnoid villi that project into the sinuses
What is the subdural space?
Layer of interstitial fluid between dura and arachnoid mater
What is pia mater?
Inner most layer of delicate transparent connective tissue that adheres to the CNS and contains blood vessels to provide spine with nutrients
What is the subarachnoid space?
Space between the arachnoid and pia mater which contain shock-absorbing CSF and drain into sinuses
What is CSF formed from?
Blood plasma
How does CSF circulate?
Circulates in 4 ventricles - 2 lateral ventricles, 1 between thalamus, 1 between brain stem and cerebellum
Where is CSF produced?
In choroid plexuses – thin-walled capillaries in the ventricles enclosed by pia mater and tight junctions of ependymal cells
How does CSF flow?
From lateral ventricles to the 4th ventricle each time increasing CSF volume, to the central canal of the spinal cord, subarachnoid space, and reabsorbed into bloodstream by arachnoid villi that lead to the Dural sinuses.
Functions of CSF?
Mechanical protection, homeostatic function, and circulation of nutrition
What is the blood brain barrier?
Blood-brain-barrier is a semipermeable tight junction of endothelium cell in brain capillaries along with astrocytes that regulate the permeability of the junctions and protect the CSF from chemical in the blood.
At which sites is the BBB leaky?
In the hypothalamus, pineal gland, choroid plexuses and pituitary gland which may be sensitive to osmotic pressure or toxins
