Brain and Cranial Nerves

Areas of the brain

forebrain, midbrain, hindbrain

Lobes of the brain

frontal, parietal, occipital, temporal

frontal lobe function

involved in motor function: problem solving, memory, judgment, impulse control

occipital lobe function

vision

parietal lobe function

sensation

temporal lobe function

hearing and smell

Diencephalon structure

thalamus, hypothalamus, epithalamus

diencephalon function

memory processing and emotional response

Thalamus function

processes sensory information

hypothalamus function

hormone production, emotion, autonomic function

pituitary gland is connected to

hypothalamus by the infundibulum

infundibulum

A stalk that attaches the pituitary gland to the hypothalamus.

pituitary gland interfaces

nervous and endocrine systems

brain stem function

processes information between spinal cord and cerebrum or cerebellum

Midbrain (mesencephalon)

Processes sight, sound, and associated reflexes, Maintains consciousness

pons

connects the cerebellum to the brain stem

medulla oblongata

Connects brain to spinal cord, Relays information, Regulates autonomic functions (Heart rate, blood pressure, and digestion)

embryonic development

determines organization of brain structures

neural tube

an embryonic structure that gives rise to the central nervous system

origin of the brain

neural tube

the neural tube enlarges into

3 primary brain vesicles

three primary brain vesicles

prosencephalon, mesencephalon, rhombencephalon

Five secondary brain vesicles

telencephalon, diencephalon, mesencephalon, metencephalon, myelencephalon

diencephalon and mesencephalon

to persist

Telencephalon

becomes cerebrum

metencephalon

forms cerebellum and pons

Myelencephalon

becomes medulla oblongata

Origin of ventricles

The neural tube encases neurocoel, a fluid-filled internal cavity, which then expands to form the ventricles lined with ependyma cells

Each cerebral hemisphere contains

one large lateral ventricle, Separated by medial partition (septum pellucidum)

ventricles of the brain

canals in the brain that contain cerebrospinal fluid

What are the ventricles of the brain?

lateral ventricles, third ventricle, fourth ventricle

third ventricle

Ventricle of the diencephalon, Lateral ventricles communicate with third ventricle, Via interventricular foramen (foramen of Monro)

fourth ventricle

Extends into medulla oblongata, Becomes continuous with central canal of the spinal cord, Connects with third ventricle, Via narrow canal in midbrain called the cerebral aqueduct

lateral ventricles communicate with

third ventricle

interventricular foramen

connects lateral ventricles to third ventricle

cerebrospinal fluid production

produced by choroid plexuses

choroid plexus produces

500 mL of CSF/day

cerebrospinal fluid drainage

drainage via arachnoid granulations into superior sagittal sinus

functions of cerebellum

Adjusts postural muscles, Fine-tunes conscious and subconscious movements

functions of cerebrum

Controls all conscious thoughts and intellectual functions, Processes somatic sensory and motor information

white matter of the cerebrum

deep to cortex and around basal nuclei

white matter of the cerebrum

association fibers, commissural fibers, projection fibers

association fibers

connections within one hemisphere

commissural fibers

bands of fibers connecting two hemispheres

projection fibers

connect cerebrum with lower areas

all lobes

association areas, integration and processing of sensory data; processing and initiation of motor activities

cranial nerves

12 pairs of nerves that carry messages to and from the brain

12 cranial nerves

olfactory, optic, oculomotor, trochlear, trigeminal, abducens, facial, vestibulocochlear, glossopharyngeal, vagus, accessory, hypoglossal

Olfactory (N1)

sense of smell

optic (nii)

sensory; visual

oculomotor (niii)

eye movement

Trochlear (niv)

eye movement

trigeminal (nv)

general sensory, chewing

Abducens (NVI)

eye movement

Facial (NVII)

facial expression, taste

vestibulocochlear (nviii)

hearing and balance

glossopharyngeal (nix)

taste and swallowing

Vagus (nx)

Taste, hunger, and GI Tract

accessory (nxi)

moving head and shrugging shoulders

hypoglossal (nxii)

tongue movement

primary somatosensory area function

receives sensory impulses from sensory receptors responding to touch, temperature and proprioception

primary somatomotor area

precentral gyrus

primary somatosensory area

postcentral gyrus

function of primary somato motor area

voluntary activation of skeletal muscles