Brainstem Part 1 Flashcards
where is the brainstem located
Located between the forebrain and spinal cord
what makes up the brainstem
Comprised of the midbrain, pons and medulla
what is the oldest part of the brain
brainstem
what does the pons do
- it relays sensory information to the cerebellum and thalamus
- subconscious somatic and visceral motor centres
what does the midbrain do
- it processes visual and auditory data
- generation of reflexive somatic and motor responses
- maintenance of consciousness
what does the medulla do
- relays sensory information to the thalamus and other parts of the brainstem
- autonomic centres for regulation of visceral function such as cardiovascular, respiration and digestive system
what are the 3 functions of the brainstem
- conduits
- Cranial nerve functions
- integrative centres in the brainstem
what is the conduit function of the brainstem
long tracts to or from the spinal cord pass through the brainstem
what are the cranial nerve functions of the brainstem
- there is the sensory input and motor output for the head plus parasympathetic motor output;
- cranial nerves also carry special senses
- the brainstem coordinates reflexes involving them.
what are the integrative centres in the brainstem
sensoriomotor integration
brainstem core
- autonomic control
- somatic and autonomic modulation
what is sensorimotor integration
- this is connectivity with the cerebellum and where the reflex centres are
what is the brainstem core mediating
- autonomic control of important respiratory and cardiovascular reflexes & other behaviours e.g., swallowing, sneezing.
- Somatic/ autonomic modulation via descending pathways (reticulospinal tract, descending premotor sympathetic axons from hypothalamus)
different neuromodulatory systems are….
important in regulation of conscious states as well as affecting sensory, motor and cognitive functions.
where dot he sensory nucleic that were dorsal in the spaniel cord move when they enter the brainstem
they move laterally and ventrally(towards the front and down )
where do the motor nuclei that were ventral in the spinal cord move when they enter the brainstem
- the move more medially
how is the brainstem organised
It is divided into..
- Dorsal part
- middle part
- ventral part
what does the dorsal part(tectum) of the brainstem have in it
- cranial nerve nuclei and sensory reflex centres
what does the middle part (tegmentum) of the brainstem have in it
- it contains the ascending pathways and reticular formation (with integrating nuclei; descending sympathetic axons
what does the ventral part of the brain stem have in it
descending motor pathways e.g., corticospinal & corticobulbar tracts; rubrospinal, reticulospinal and vestibulospinal tracts arising in brainstem
what do conduit functions of the brainstem allow
- they allow integration of information at subconscious, reflexive level by connectivity with brainstem
how many Paris of cranial nerves are there
12 pairs
what do cranial nerves do
- Provide sensorimotor innervation of the skin, muscles and joints of the head & neck.
- Mediate vision, hearing, taste and olfaction (special senses)
- Carry autonomic fibres that control visceral functions e.g. gut, breathing, heart rate, and blood pressure regulation.
what are the origin of cranial nerves
Cranial nerve nuclei are one origin of preganglionic parasympathetic neurons
what surface of the brainstem can cranial nerves be seen from
Cranial nerves can be seen from the ventral surface
where do afferent cranial nerves arise form
- cranial nerves have afferents which arise from ganglia
where do 2nd order sensory nuclei arise from
they are located in cranial nuclei