Lab 1 - The Human Brain and Cranial Nerves

Brain protection structures

Cranial bones, meninges cerebrospinal fluid, and blood brain barrier

Cranial meninges layers

Dura mater, arachnoid mater, pia mater

Dura mater

Tough outer meningeal layer attached to skull with endosteal and meningeal layers

Arachnoid mater

Middle web like layer with subarachnoid space containing CSF and arachnoid villi for CSF reabsorption

Pia mater

Thin inner layer directly on brain surface containing blood vessels

Subarachnoid space

Space between arachnoid and pia filled with CSF

Cerebrospinal fluid CSF

Fluid that cushions brain maintains chemical environment and circulates through ventricles and meninges

Choroid plexus

Structure in ventricles that produces CSF

Ventricles

Four brain chambers that produce and circulate CSF

Four brain regions

Cerebrum, diencephalon, brainstem, and cerebellum

Cerebrum

Largest brain region responsible for higher thinking sensory perception and voluntary movement

Cerebral cortex

Outer gray matter layer responsible for higher intellect and functional areas

Gyrus

Ridge or fold on brain surface

Sulcus

Shallow groove on brain surface

Fissure

Deep groove separating brain regions

Longitudinal fissure

Separates left and right hemispheres

Corpus callosum

White matter tract connecting cerebral hemispheres

Frontal lobe

Involved in reasoning judgment motor function and personality

Parietal lobe

Processes sensory information like touch temperature and pain

Temporal lobe

Responsible for hearing memory and language

Occipital lobe

Primary visual processing center

Insula

Deep lobe involved in taste and internal awareness

Central sulcus

Separates frontal and parietal lobes

Lateral sulcus

Separates temporal lobe from frontal and parietal lobes

Parieto occipital sulcus

Separates parietal and occipital lobes

Primary motor cortex

Controls voluntary movements located in precentral gyrus

Primary sensory cortex

Receives sensory input located in postcentral gyrus

Broca area

Motor speech production area in frontal lobe

Wernicke area

Language comprehension area in temporal lobe

Visual cortex

Processes vision in occipital lobe

Auditory cortex

Processes sound in temporal lobe

Olfactory cortex

Responsible for smell in temporal lobe

Gustatory cortex

Responsible for taste in parietal lobe

Diencephalon

Region containing thalamus and hypothalamus

Thalamus

Relay station that sends sensory information to cerebral cortex

Hypothalamus

Maintains homeostasis regulates temperature hunger thirst hormones and autonomic functions

Pituitary gland

Master endocrine gland controlled by hypothalamus

Pineal gland

Produces melatonin and regulates sleep cycles

Brainstem components

Midbrain pons medulla oblongata

Midbrain

Relays motor and sensory signals and contains cranial nerve origins

Pons

Relay station sending sensory information to thalamus and cerebellum

Medulla oblongata

Controls vital functions like breathing heart rate and digestion

Decussation

Crossing of motor fibers in medulla causing opposite side control

Cerebellum

Coordinates movement balance posture and motor learning

Arbor vitae

Tree like white matter in cerebellum

Cranial nerves

Twelve pairs of nerves serving head and neck sensory and motor functions

Olfactory nerve I

Smell sensory

Optic nerve II

Vision sensory

Oculomotor nerve III

Eye movement and pupil constriction motor

Trochlear nerve IV

Eye movement downward and inward motor

Trigeminal nerve V

Facial sensation and chewing mixed

Abducens nerve VI

Lateral eye movement motor

Facial nerve VII

Facial expression and taste anterior tongue mixed

Vestibulocochlear nerve VIII

Hearing and balance sensory

Glossopharyngeal nerve IX

Taste posterior tongue swallowing mixed

Vagus nerve X

Parasympathetic control of organs in thorax and abdomen mixed

Accessory nerve XI

Neck and shoulder movement motor

Hypoglossal nerve XII

Tongue movement motor