the 5 major subdivisions of the brain

the 5 subdivisions derive from…

embryonic devleopment of the brain

Medulla oblongata location:

just above the spinal cord

Medulla oblongata structures:

mainly myelinated tracts

reticular formation

recticular foramtion

collection of nuclei that passes info from the CNS to the PNS

main functions of the Medulla oblongata

1. sleep/arousal

2. attention

3. movement

4. muscle tone

5. cardiac, criculaotry and respiratory reflexes

metencephalon main structures

cerebellum

pons tract

reticular formation

main functions of the pons..

passage of fibres and the origin of 3 cranial nerves

main functions of the cerebellum

fine motor control/ coordination

balance

some cognitive functions (involved in the learning relationship between motor and sensory systems)

main structures of the mesencephalon

tectum

tegmentum

tectum functions…

basses of refelxive functions

visual and auditory orienting 

the 2 subsections of the tectum

1. super colliculi

2. inferior colliculi

superior colliculi

responsible for visual orienting

inferior colliculi

responsible for auditory orientating

tegmentum structures

1. reticular formation 

2. cerebral aqueduct 

3. periaquductal grey

4. substantia nigra 

5. red nucleus 

cerebral aqueduct

the duct connecting the 3rd and 4th ventricles

substance nigra and red nucleus are…

both important components in sensorimotor system

Diencephalon structures:

1. thalamus

2. hypothalamus

Thalamus

sensory relay centre at the centre of the brain

The thalamus contains specific….

nuclei which sends PNS info to specific areas

the 4 thalamus nuclei

1. sensory relay nuclei

2. lateral geniculate nuclei

3. medial geniculate nuclei

4. ventral posterior nuclei

sensory relay nuclei

most well understood thalamic nuclei that receive signals from sensory receptors, process them, and transit them

lateral geniculate nuclei

sensory relay nuclei which controls visual info

medial geniculate nuclei

sensory relay nuclei which controls auditory info.

ventral posterior nuclei

sensory relay nuclei controlling the somatosensory info

Hypothalamus is located…

below the anterior thalamus 

hypothalamus controls:

1. motivated behaviours

2. release of hormones from the pituitary gland

optic chiasm

point at which the optic nerve from the eye come together and then cross over to the other side of the brain

contralateral fibres 

decussating fibres that project from one side of the body to the other

ipsilateral fibers 

nondecessating fibres that stay on the same side of the body

mamillary bodies 

a pair of spherical nuclei located on the infieror surface of the hypothalamus just behind the pituitary gland

Telencephalon

largest division of the brain

main structures of telencephalon

cerebral cortex

limbic system

basal ganglia

main functions of the telecephalon

voluntary movements

perceptions

complex cognitive processes (learning, speaking, descion making, and personality)

corpus callosum 

responsible for interhemispheric transfer of information

The 4 lobes

1. frontal lobe

2. parietal lobe

3. occipital lobe

4. temporal lobe

all of the lobes are divided along…

fissures within the brain

most of the cerebral cortex is made….

neocortex

2 main types of cortical neurons

1. pyramidal cells

2. stellate cell

pyramidal cells (3)

1. multipolar neuron

2. long axon

3. communicates long distances

4. apical dendrite (large dendrite)

stellate cell (3)

1. interneuron

2. short axon

3. comicates locally

fissures

large furrows in a convoluted cortex

sucli

small furrows in convoluted cortex

gyri

ridges between fissures and scull

occipital lobe

part of the cerebral cortex that analyzes visual input to guide behaviour

parietal lobe

1. postcentral gyrus

2. posterior parts

postcentral gyrus

part of the parietal lobe that analyzes sensations from the body

posterior parts 

part of parietal lobe perceives location of objects and our body and directing attention

3 parts of the temporal lobe

1. superior temporal cortex

2. inferior temporal cortex

3. medial temporal cortex

superior temporal cortex

part of the temporal lobe responsible for hearing and language

inferior temporal cortex

part of the temporal lobe that identifies complex visual patterns

medial temporal cortex

part of the temporal lobe that is important for certain types of memory 

columnar organization

neruons in a given vertical column of the neocortex often form a mint circuit that performs single functions

main structures of the limbic system (6)

1. amygdala 

2. hippocampus

3. septum

4. fornix

5. mammillary bodies

6. cingulate cortex

main functions of the limbic system (3)

regulation of motivated behaviours (fighting, fleeing, feeding, sex)

learning and memory

emotions

main structures of the basal ganglia (5)

1. amygdala

2. caudate

3. putamen

4. globus pallidus

   1. nucleus accumbent

main functions of the basal ganglia 

voluntary motor responses

rewards