Brain II - BIO210 Human Anatomy

protection of brain

• cranial meninges

• cerebrospinal fluid

• cranium = skull bones

• blood-brain barrier - astrocytes!!

what do brain and spinal cord not have?

they don’t have serous membranes they have meninges

ventricles of the brain

• space that contain CSF

• 4 ventricles

  • 1) right lateral ventricle

  • 2) left lateral ventricle

  • 3) third ventricle

    • cerebral aqueduct connects 3rd to 4th ventricle

  • 4) fourth ventricle

cerebrospinal fluid

• cushions the CNS

• supports the brain - the brain is floating in the CSF

• CSF transports nutrient/wastes etc (transports waste away/out of brain)

• fills ventricles

choroid plexus

• produces CSF 500 ml/day

• composed of ependymal cells and capillaries (neuroglial cells responsible for producing CSF)

• found at the edge of each ventricle

  • choroid = vascular

  • plexus = braid

what creates the choroid plexus?

union of ependymal cells and capillaries

where is CSF produced?

choroid plexus within brain ventricles

where does CSF drain?

arachnoid granulations into superior sagittal sinus and other dural sinuses

• dural sinuses = blood vessels

• CSF empties back out into blood stream

arachnoid granulations are part of what?

the meninges

frontal lobe function

• controls skeletal muscles (primary motor cortex)

• somatic motor control

temporal lobe function

• auditory & olfactory cortex

• sense of smell

insula lobe

• gustatory cortex (taste)

• sweet, sour, bitter, umami, salty, water

parietal lobe

• receives general sensory info (somatic sensory cortex, detected in skin, muscles, and joints)

occipital lob

• visual cortex

cerebrum = telencephalon

• central white matter

  • corpus callosum - myelinated tract connecting left and right hemispheres

diencephalon

• location is in hollow space

• surrounds 3rd ventricle

  • tissue of thalamus surrounds 3rd ventricle

epithalamus

• pineal gland - biological clock

• produces melatonin, we produce more melatonin when it is dark outside

thalamus

• two egg-shaped bodies

  • interthalamic adhesion connects them (ball/sphere shape in center of thalamus)

  • comprised of nuclei (gray matter)

• “walls” of third ventricle

main function of the thalamus:

• process & relay sensory & motor info

• sensory in inferior parts of thalamus pass higher up to superior parts

• motor goes in to more inferior parts of thalamus

functions of hypothalamus (hey I am happy everybody)

• hypothalamus

• involuntary skeletal (visceral motor)

• autonomic function (visceral motor)

• hormones

• emotions

brain stem

• includes midbrain, pons and medulla oblongata

mesencephalon - midbrain

• location

  • in the center of the 5 areas of the brain

• comprised of

  • nuclei (grey matter)

  • tracts (white matter)

corpora quadrigemina (mesencephalon)

• four nuclei located posteriorly

  • superior colliculi (two, right and left)

    • visual reflexes

  • inferior colliculi (two)

    • auditory reflexes

cerebellum

• not part of brain stem function

• skeletal muscle coordination (subconscious)

• maintains equilibrium by subconscious adjustment of postural muscles

• fine, precise motor control

medulla oblongata - myelencephalon

• nuclei (cell bodies of neurons)

  • sensory & motor nuclei of some cranial nerves

  • cardio, digestive, and respiratory centers

• tracts

  • connect brain and spinal cord

reticular formation

• interconnected network of nuclei

  • extending through brain stem

• functions

  • role in sleep-wake cycle

  • consciousness

• coma (from injury of reticular formation)

• spans throughout the brainstem (mesencephalon, pons, medulla oblongata)