Chapter 14 - Brain

cerebellum

"little brain" about absolute precision

cerebral cortex

2-4 mm thick surface layer of the cerebral hemispheres. composed of gray matter thus neuron cell bodies. 40% of brain mass.

cerebral cortex, cerebral white matter, and basal ganglia

3 distinct layers of nervous tissue in cerebral hemispheres

thalamus

80% of diencephalon. afferents from all senses and all parts of the body converge here and synapse with at least one of its nuclei. almost all sensory info comes here

language

Wernicke=____

pyramids in medulla

a ridge made by the corticospinal tract descending from the motor cortex. most fibers cross over here which is why right side of the brain controls the left and left controls the right

habituation of reticular formation

ability to ignore repetitive stimuli

motor, sensory, and association areas

activities of cerebral cortex grouped into

broca's speech area

anterior and inferior to the premotor area. thought to be in only one hemisphere usually the left and generates a motor plan to produce speech. sent to primary motor cortex to execute the plan

premotor cortex of cerebral cortex

anterior to the perecentral gyras in the frontal lobe. intention to contract skeletal muscle begins in this region. houses memories for learned motor skills. coordinates movements of several muscle groups

medulla oblongata

bottom of brain stem. transitions into the spinal cord at the foramen magnum. deals with equilibrium and balance

speech

broca=_____

tracts

bundles of axons (white matter)

white matter

bundles of axons. forms tracts that connect parts of the brain

arcurate fibers

connect adjacent gyri

longitudinal fasciculi

connect different cortical lobes

association tracts

connect one part of hemisphere to another

pons

connection from cerebellum to the rest of the nervous system

corpus callosum

connects cerebral hemispheres by bundle of nerve fibers

myelinated axons

connects cortex to the rest of the brain to body

anterior commissure

connects prefrontal cortexes

primary visual cortex

conscious awareness of sight

white matter

consists mainly of myelination axons or nerve tracts that are classified on the direction in which they run

pyramidal or corticospinal tract

contains large neurons called pyramidal cells that project all the way to the spinal cord and form a massive voluntary motor tract

inferior colliculi

controls auditory reflexes such as startle reflex and is a major relay from the hearing receptors to the sensory cortex

superior colliculi

controls visual reflexes that coordinate head and eye movement

functions of the hypothalamus

coordinates heart rate, blood pressure, respiration, and digestion, production of emotions and behavioral drives, and body temperature regulation, regulation of food intake, regulation of water balance & thirst, regulation of sleep & wake cycles, control of endocrine system function

nuclei

deeper masses of gray matter

cerebral hemispheres

deeper sulci and fissures divide each hemisphere into five lobes

primary somatosensory cortex

destination of sensory nerves coming from skin and skeletal muscle

function of the limbic system

emotional or affective region of the brain. your feelings. prefrontal lobe allows awareness of how you feel. allows emotions to over ride logic and allows use to control emotional responses (poker face). facilitation memory storage and retrieval.

gaze center of reticular formation

enables an eye to track and fixate on objects

functions of cerebellum

evaluation of sensory input, coordination and locomotor ability, spatial perception, timekeeping center, predicting movement of objects, distinguish pitch and similar sounding words, planning and scheduling task

trochlear nerve

eye movement (superior oblique muscle). damage causes double vision and inability to rotate eye inferolaterally

oculomotor nerve

eye movement, opening of eye, constriction of pupil, focusing. damage causes drooping eyelid, dilated pupil, double vision, difficulty focusing and inability to move eye in certain directions

frontal, parietal, occipital, temporal, and insula

five lobes of central hemispheres

gyri

folds

diencephalon

forms the central core of the forebrain and is surrounded by the cerebral hemispheres. plays a vital role in integrating conscious and unconscious sensory information with motor commands. consists of thalamus, hypothalamus, and epithalamus

prefrontal cortex

front of frontal lobe. well developed region, makes you unique with personality. involved with intellect and complex learning and personality abstract ideas, judgment, reasoning, etc

thalamus

gateway to the cerebral cortex. acts like a filter passing on only a small portion of the arriving sensory info. impulses of similar functions are grouped and relayed to the appropriate site within the cortex.

relay stations in medulla

grey matter where synapses form and info is relayed.

sulci

grooves

wernickes area

houses a lot of memory

reticular formation

if not particulary alert, its because ____ isn't sending info to cortex

reticular formation.

in midbrain. deals with alertness and concentration

red nucleus

in midbrain. red due to rich blood supply and iron pigments in the cell bodies of the neurons. relay nuclei in descending motor pathways that effect subconscious motor commands concerted with posture

substantia nigra

in the midbrain. dark due to the presence of melanin pigment which a precursor to the neurotransmitter dopamine. functional linked to the basal nuclei. function relates to movement

brain stem

inervation of face. controls swallowing and chewing

motor control areas of cerebral cortex

lie in the posterior part of the frontal lobe

primary visual cortex

located at the extreme posterior tip of the occipital lobe deep within the calcarine sulcus. receives visual info from the retinas to the eyes.

primary somatosensory cortex (postcentral gyrus)

located at the postcentral gyrus of the parietal lobe. functions to receives primary input from sensory receptors of the skin and proprioceptors in skeletal muscle

basal ganglia

located deep within the cerebral white matter of each hemisphere. receives extensive inputs from the entire cerebral cortex. relays through the thalamus to the premotor to influence muscle movement

cerebellum

located dorsal to the pons and medulla. processes input received from the cerebral motor cortex, various brain stem nuclei, and sensory receptors. LOTS OF SENSORY INFO.

wernickes area

located in parts of temporal, parietal, and occipital lobes. receives input from all sensory association areas. integrates all incoming signals into a single thought or understanding

olfactory cortex

located in the medial aspect of the temporal lobes at the uncus. fibers form the smell receptors transmit impulses along the olfactory tract to the cortex where conscious awareness of different odors occurs

gustatory cortex

located in the parietal lobe deep to the temporal lobe and represents the tongue of the somatosensory homunculus. responsible for the perception of taste.

primary motor cortex of cerebral cortex

located in the precentral gyrus of frontal lobe of each hemisphere. allows conscious control of the movements of our skeletal muscles. contains pyramidal tract.

primary auditory cortex

located in the superior margin of the temporal love next to the lateral sulcus. receives inputs from the cochlear where pitch rhythm and loudness is interpreted.

midbrain

located inferior to the diencephalon and superior to the pons. contains corpora quadrigemina

auditory association area

located more posterior and permits the perception of sound as speech, music, noise, etc

limbic system

located on the medial aspect of each cerebral hemisphere and in the diencephalon

somatosensory association area

located posterior to the primary somatosensory cortex and makes connections with it. functions to integrate and analyze different somatic sensory inputs into a comprehensive "picture." makes us aware of the positions of our limbs. deals with memory and somatosensation

visceral association area

lovated in the insula and primary sensory cortex. involved in the perception of visceral sensation like full bladder. where internal organs are represented.

hypothalamus

main visceral control center of the body and is vitally important to overall body homeostasis

pons

mainly white matter. myelinated tracts connecting higher brain to lower. bulging region at the brain stem between the midbrain and medulla. dominated by cerebellar peduncles (fiber tracts) that connect medulla to cerebellum

wernickes area

major language area. present in only left hemisphere. responsible for the recognition of spoken and written language. area where you pick the appropriate words for the situation.

wernickes area

man was unable to speak. hard time understanding where he was and what was going on. he could talk but his words made no sense. his ______ was affected

gray

matter in cortex

white

matter under cortex

epithalamus

most dorsal part of the diencephalon. includes the pineal gland which releases the hormone melatonin at night and serotonin during the day which along with the hypothalamus regulate sleep patterns.

cerebral hemispheres

most superior part of the brain. 83% of brain mass. covered in gyri and sulci.

functional brain systems

networks of neurons that work together but span relatively large distances within the brain so they cannot be localized to specific brain regions.

gray matter

neuron cell bodies, dendrites, and synapses. forms cortex over cerebrum and cerebellum. forms nuclei deep within the brain

primary motor cortex

once a motor program is established it is sent to the ______ for execution

frontal eye field

part of the primary motor cortex. controls voluntary movements of the eyes and eye lids

somatic motor control of reticular formation

part of the reticulospinal tract that helps control skeletal muscles during coarse movements of the limbs. adjusts muscle tone. maintains balance and posture particularly during movement.

reticular formation

project to the hypothalamus, thalamus, cerebellum, and spinal cord. contains nuclei that regulates vital autonomic functions. most deals with controlling viscera

Abducens nerve

provides eye movement (lateral rectus m.) damage results in inability to rotate eye laterally and at rest eye rotates medially

vestibulocochlear nerve

provides hearing and sense of balance. damage produces deafness, dizziness, nausea, loss of balance

basal ganglia

provides subconscious control of skeletal muscle tone and coordinates learned movement patterns.

cerebral white matter

provides the communication link between different areas of the cerebrum

optic nerve

provides vision. damage causes blindness in visual field

midbrain, pons, medulla oblongata

regions of the brain stem

prefrontal cortex

requires feedback and input from the environment and individual experiences. developed around 25,

cochlear nuclei of medulla

sense info

olfactory nerve

sense of smell. damage causes impaired sense of smell

trigeminal nerve

sensory to face (touch, pain, and temperature) and muscles of mastication. deals with sense of touch to face and muscles we need to chew. damage produces loss of sensation and impaired chewing

functions of reticular formation

somatic motor control, gaze center, cardiovascular control, respiratory control, pain modulation, sleep and consciousness, and habituation

corpora quadrigemina

split into 2 halves - superior and inferior colliculi

cortex

surface layer of gray matter

visual association area

surrounds the primary visual area interprets and evaluates visual stimuli and compares it with past visual experiences (how we recognize a person's face)

accessory nerve

swallowing, head, neck and shoulder movement. damage causes impaired head, neck, shoulder movement

glossopharyngeal nerve

swallowing, salivation, gagging, control of blood pressure, and respiration. sensations from posterior 1/3 of tongue. damage results in loss of bitter and sour taste and impaired swallowing

vagus nerve

swallowing, speech, regulation of viscera. damage causes hoarseness or loss of voice, impaired swallowing, and fatal if both are cut. 80% of parasympathetic is in this nerve

hypoglossal nerve

tongue movements for speech, food manipulation and swallowing. if both are damaged, cant protrude tongue. if one side is damaged, tongue deviates toward injured side

osmoreceptors

triggers releases antidiuretic hormone from the posterior pituitary

facial nerve

very large nerve. biggest part of sense of taste. motor areas control facial expressions, salivary glands, and tear, nasal and palatine glands. damage produces sagging facial muscles and disturbed sense of taste (no sweet and salty)