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Automatic traslation
Search the siteThe Organisation of the Brain
2nd August 2016
The brain is organised in functionally distinct areas.
Neurons in different parts of the nervous system (NS) are similar - though regions differ in their numbers of neurons and their interconnective patterns.
Signalling of these neurons → behaviour
Perception
Signals to move muscles
Also autonomic functions: heart, resporation, etc
Breaking down a behaviour we can identify the brain region(s) responsible for each small act.
e.g. amygdala for heart rate
cerebral cortex for cognition
Spinal cord: grey center surrounded by white
Grey: contains nerves, divided into dorsal and ventral horns [dorsal horns: sensory neurons receive from PNS] [ventral horns: motor neurons and interneurons regulate motor functions] White: Ascending and descending tracts of myelinated axons [ascending: carry informaiton to the brain] [descending: carry motor signals to muscles]
31 spinal nerves on the spinal cord
In dorsal root, different axons carry pain, temperature, touch, visceral info In ventral root, different -
Spinal cord: mediates sensation and motor control of limbs
Brain: 6 regions:
Spinal cord, brain stem, diencephalon: mostly life-sustaining functions
Outer layer of cerebral hemispheres: actions of everyday life
Medulla: regulates BP, respiration
Pons: info about movement, resporation, taste, sleep
Midbrain: motor, audio, visual, eye movement
Brain stem: mediates sensation and motor of head, neck, face
Also cardial output, BP, gut peristalsis, constriction of pupils
Also carries info (sensory and motor) elsewhere in CNS
Also regulates alertness and arousal
Cerebellum: posture, coordinates head, eyes, arm movements, minute regulation of motor output and learning motor skills, language and other cognitive unctions. Contains far more neurons than all other regions.
Diencephalon: thalamus, hypothalamus
Thalamus: info from PNS to cerebral hemispheres (selective – i.e. controls which info to pass on). Also connects cerebral cortex regions
Also involved in attention and consciousness
Hypothalamus: controls pituitary gland hormones
→Controlssomatic growth, eating, drinking, maternal behaviour, motivational systems, circadian rythms
Cerebral hemispheres: inc. cerebral cortex, underlying white matter, basal ganglia, amygdala, hippocampal formation: perception, motor, memory, emotion, cognition
Corpus callosum: links the two hemispheres
Cerebral cortex: 4 lobes
Distinct functional compounds of NS are connected via tracts of bundled axons
In CNS discreet systems for each 5 senses, for different types of movement (eyes, hands, etc), for language, etc.
But all act together.
Usually info is either amplified or attentuated as it oves from synapse to synapse.
A neuron can receive info from 1000s of other neurons.
CNS: short axons
PNS: longer axons
Some axons can be as long as 1 meter:
Brain: ∼100 million neurons
Ganglion: nerve cell cluster
Usually in PNS with the exception of the basal ganglia in the brain
Somatic: sense and motor info brain < – > muscles
Autonomic: brain – > Heart, gut muscles, glands, etc.
Autonomic brain: divided in sympathetic NS and parasympathetic NS)
Neurons in different parts of the nervous system (NS) are similar - though regions differ in their numbers of neurons and their interconnective patterns.
Signalling of these neurons → behaviour
Perception
Signals to move muscles
Also autonomic functions: heart, resporation, etc
Breaking down a behaviour we can identify the brain region(s) responsible for each small act.
e.g. amygdala for heart rate
cerebral cortex for cognition
Spinal cord: grey center surrounded by white
Grey: contains nerves, divided into dorsal and ventral horns [dorsal horns: sensory neurons receive from PNS] [ventral horns: motor neurons and interneurons regulate motor functions] White: Ascending and descending tracts of myelinated axons [ascending: carry informaiton to the brain] [descending: carry motor signals to muscles]
31 spinal nerves on the spinal cord
In dorsal root, different axons carry pain, temperature, touch, visceral info In ventral root, different -
Spinal cord: mediates sensation and motor control of limbs
Brain: 6 regions:
- Medulla
- Pons
- Midbrain
- Cerebellum
- Diencephalon
- Cerebral hemispheres or telencephalon
Spinal cord, brain stem, diencephalon: mostly life-sustaining functions
Outer layer of cerebral hemispheres: actions of everyday life
Medulla: regulates BP, respiration
Pons: info about movement, resporation, taste, sleep
Midbrain: motor, audio, visual, eye movement
Brain stem: mediates sensation and motor of head, neck, face
Also cardial output, BP, gut peristalsis, constriction of pupils
Also carries info (sensory and motor) elsewhere in CNS
Also regulates alertness and arousal
Cerebellum: posture, coordinates head, eyes, arm movements, minute regulation of motor output and learning motor skills, language and other cognitive unctions. Contains far more neurons than all other regions.
Diencephalon: thalamus, hypothalamus
Thalamus: info from PNS to cerebral hemispheres (selective – i.e. controls which info to pass on). Also connects cerebral cortex regions
Also involved in attention and consciousness
Hypothalamus: controls pituitary gland hormones
→Controlssomatic growth, eating, drinking, maternal behaviour, motivational systems, circadian rythms
Cerebral hemispheres: inc. cerebral cortex, underlying white matter, basal ganglia, amygdala, hippocampal formation: perception, motor, memory, emotion, cognition
Corpus callosum: links the two hemispheres
Cerebral cortex: 4 lobes
- Frontal
- Parietal
- Temporal
- Occipital
- (and two additional regions: cingulate cortex, insular cortex)
Distinct functional compounds of NS are connected via tracts of bundled axons
In CNS discreet systems for each 5 senses, for different types of movement (eyes, hands, etc), for language, etc.
But all act together.
Usually info is either amplified or attentuated as it oves from synapse to synapse.
A neuron can receive info from 1000s of other neurons.
CNS: short axons
PNS: longer axons
Some axons can be as long as 1 meter:
Brain: ∼100 million neurons
Ganglion: nerve cell cluster
Usually in PNS with the exception of the basal ganglia in the brain
Somatic: sense and motor info brain < – > muscles
Autonomic: brain – > Heart, gut muscles, glands, etc.
Autonomic brain: divided in sympathetic NS and parasympathetic NS)
