biology of the mind
organisation of the nervous system
CNS
brain and spinal cord
efferent nerves
from CNS to PNS
afferent nerves PNS to CNS
neurone anatmy
dendrites
axon
node of ranvier
synaptic terminal
presynaptic axon terminal
neurone classification
structure
sensory
motor
actions
excitatory
inhibitory
glial cells
myelinating glial cells
schwann cells in PNS
oligodendrocytes in CNS
supporting glia
astrocytes
star shaped
provide nutrients
role in repairing brain
set environment
synaptic specialisation
sides are thicker
post synaptic structure is part of dendrite
synapse covered with processes of astrocyte to mop up excess transmitters
satellite
astrocytes of sensory ganglia
surround neurone and ganglia's stomatas
somatic nervous system
voluntary nervous system
has
somatic motoneurones
sensory afferent fibres
efferent motor neurone
target= skeletal muscle
terminal has vesicles containing acetylcholine
axon travels from CNS to target
myelinated axon
sensory afferent neurone
myelinated or unmyelinated axon
cell body within ganglion
sensory ganglia run adjacent to spinal cord--> dorsal root ganglion
releases glutmate
autonomic nervous system
involuntary
controls
heart rate
blood pressure
gut movements
two branches
sympathetic
parasympathetic
general principles
efferent neurones have cell bodies in CNS
axon project out of CNS and form synapse= ganglia in PNS
anatomy of sympathetic organisation
cell body in CNS
small axon on pregnaglionic neurone
has acetylcholine transmitter with nicotinic receptor
postganglionic neurone has long axon
uses noradrenaline
parasympathetic organisation
cell body in CNS
preganglionic axons mylinated and in target organ
uses acetylcholine neurotransmitter and nicotinic receptor
postganglionic receptor is muscarinic
axon comes from dorsal vagal nucleus to ganglion near target organ
cholinergic
sympathetic and parasympathetic nervous systems
heart has vagus nerve
sympthetic activity comes from thoracic and upper lumbar spinal cord
innervates organs
slows heartbeat
acts as tonic break
preganglionic cells send axons to ganglia= ganglionic neurones accelerate heartbeat
change in balance causes change in heartbeat
enteric nervous system
works autonomously to control activity of GIT
consists mainly of myenteric plexus
autonomic innervation from vagus and sympathetic chain
basic anatomy of CNS
classification of brain structures
Anatomical terminology
Anterior→ towards front of body
Posterior→ towards back of body
Rostral→ towards head of body
Caudal→ towards tail of body
Lateral→ farther from midline
Medial→ nearer to midline
Dorsal→ towards back of body
Ventral→ toward front of body
Superior→ towards head of body
Inferior→ toward tail of body
corpus callosum
made up of exons that connect one side of the brain to the other
parts of the brain
hindbrain
ie brainstem
reticulum formation in medulla and midbrain
raphe nuclei in midline areas of medulla and midbrain
invloved in mood memory sleep cognition
contains 5 HTP
postrema in pons and medulla
contains chemoreceptor trigger zone
triggers vomming
locus coeruleus in pons
cells loosely packed
for cardio control and alertness
midbrain
substantia nigra
contains dopamine
superior colliculus
recieves visual inputs
periaqueductal grey matterQ
pain pathway and fear
red nucleus
motor control centre
sagittal section
diencephalon
thalamus
relay nucleus from sensory modaltites to cortex
pituitary gland
release hormones
hypothalamus
involved in homeostasis and endocrine function
limbic system
mood and emotion
telencephalon
cerebral hemispheres, cerebral cortex, neocortex
higher functions occur here
basal ganglia, corpus striatum and caudate nucleus
part of extrapyramidal motor system
brain divisions
temporal lobe
occipital lobe
parietal lobe
frontal lobe
the spinal cord
ventral
where motor nerves come from
dorsal
efferent nerves, dorsal root ganglion and collection of sensory nerve cell bodies are
sympathetic nerves come out of ventral root and into ganglia
dorsal root ganglia on rhs
axon comes into dorsal horn
sympathetic neurones in intermediolateral cell column
motor neurones in ventral horn
rats and mice
used in labs
cerebral hemispheres are smooth and folded in rat
refractory bulb is smaller and tucked under in humans
both have cerebellums
have similar functions, cortex and midbrains
the meninges
CNS has 3 membranes
dura mater
marachnoid mater
pia mater
brain and spinal cord have the membranes
helps contain fluid they exist in
provide nutrients
fluid made by choroid plexus
fluid passes into ventricles before into extracellular space
cerebral aqueduct= channel between 4th ventricle and brain stem