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)