Lec 10-11 Flashcards
CNS
Brain/spinal cord
Brain protect by
Bones of cranium
Spinal cord protect by
Bones of vertebral column
Meninges
Tissue membrane
Stabilize and protect neural tissue
Lie between bones and brain/spinal cord
Meninges parts from out to in
1- Dura meter
2- Arachnoid membrane
3- Pia meter
Ventricles of brain
4 ventricles
-within ventricles CSF produce
Functions of CSF
1- Physical Protection
——keeps brain tissue buoyant(reduce pressure)
——absorbs shock
2- Chemical Protection
——delivering nutrients to the brain
——removing waste
——allow tightly regulated extracellular environment
CSF is produced in
Choroid Plexus of ventricles
Choroid plexus
-Meeting of capillaries and ependymal cells
-Plasma filtered into ventricles
-Ependymal cells selectively transport solutes, water flow by osmosis
-transport ions and nutrients from blood to cerebrospinal fluid
CSF composition
Similar chemical composition to plasma but
——very low protein content in CSF
CSF is absorbed from subarachnoid space into venous circulation by——
Arachnoid villi
Total volume of CSF in adult
150 ml
-rate of secretion and absorption is equal
Subarachnoid space
Filled with CSF
Tight junction
Prevent moving larger solutes between endothelial cells
Astrocyte foot processes
Secrete paracrine onto endothelial cells that promote tight junction formation
Blood-Brain-Barrier
Blood-brain is leaky without astrocytes
Tight junction are caused by paracrine which is produced by astrocyte
Metabolic needs of neural tissue
1- Oxygen:
——pass freely across BBB
2- Glucose:
——need transporters - trancellularly
——only replacement is ketone——emergency situations
——brain consumption is about 20% of body total amount
——hypoglycemia leads to confusion
Gray matter
Nucleus
Dendrite/synapses
Deep inside or peripheral in BRAIN
White matter
Tracts of myelinated axon fibers
Lots of myelin
Dorsal root
Posterior sensory
Bringing information to brain
Dorsal=Sensory=Afferent
Ventral root
Outgoing information from brain to body
Ventral=Motor=Efferent
Spinal cord
White is peripheral
Gray central
Ascending tract
Axons from Spinal cord to brain
Descending tract
Axons from brain to spinal cord
Brain compartments
Forebrain
Brainstem
Cerebellum
Medulla
Network automatic function
Ascending and descending tracts
Pons
-some neuron for respiration
-Relay station for pathway
Midbrain
Network eye movement and hearing
12 cranial nerves
Main nerves that project directly to/from brain rather than spinal cord
Basal ganglia
Control of limb movement,
eye movement,
Smoothing the movements when you want
Preventing movement when you don’t want
Loss of neurons in basal ganglia
Huntington disease
Parkinson disease
Cerebral cortex
1- Frontal Lobe——think
2- Parietal Lobe——touch, smell, hear
3- Occipital Lobe ——vision
4- Temporal Lobe ——hearing
Only lobe that is two
Temporal lobe
Thalamus
Relay station: receive sensory and motor info
Hypothalamus
Homeostasis and behavior
Pituitary gland
1- anterior: secrete hormones
2- posterior: secrete neurohormone that are mad in hypothalamus
Pineal gland
Secrete melatonin and regulate sleep-wake cycle
Major homeostatic control center
Hypothalamus
Hypothalamus functions
1- maintain body temperature
2- control body osmolarity
3- influence cardiovascular control
4- secrete trophic hormones
Limbic system
1- cingulate gyrus
2- hippocampus —— memory
3- amygdala —— emotion
Cerebullum
Rate,range,force of movement
Input: all senses
Output: cortex via thalamus and spinal cord via brain stem
Broca’s area
Verbally responding
Wernicke’s area
Language understanding center
Damage to wernicke
Receptive aphasia
Loss of understanding but expression without meaning
Damage to broca
Expressive Aphasia
Understanding maintain but lose ability of expression
