Lesson 15-16 Part II Flashcards
cerebrum
develops from what?
develops from the telencephalon and is the largest, most conspicuous part of the human brain
gross anatomy: cerebrum
- two cerebral hemispheres
- longitudinal cerebral fissure
- gyri and sulci
- corpus callosum
- each hemisphere has five distinct lobes
three functional principles of the cerebrum
- each hemisphere receives sensory info from, and sends motor commands to, the OPPOSITE side of the body
- the two hemispheres have different functions, although structures are alike
- correspondence between a specific function and specific region of the cerebral cortex is not precise
frontal lobe
rostral to the central sulcus
- responsible for voluntary motor functions, motivation, foresight, planning, memory, mood, emotion, social judgment, and aggression
prefrontal cortex
integrates information from sensory association areas, allowing us to perform abstract intellectual activities, like predicting consequences
Damage to this area affects temporal relationships between events
prefrontal cortex
parietal lobe
between the central sulcus and parieto-occipital sulcus
- integrates general senses, tase, and some visual information
occipital lobe
caudal to the parieto-occipital sulcus
- primary visual center of the brain
temporal lobe
lateral and horizontal; below the lateral sulcus
- functions in hearing, smell, learning, memory, and some aspects of vision and emotion
insula
deep to the lateral sulcus
- helps in understanding spoken language, taste, integrating information from visceral receptors
three types of tracts
projection tracts, commissural tracts, and association tracts
projection tracts
extend vertically between cerebrum and lower brain and spinal cord centers
commissural tracts
cross from one cerebral hemisphere to the other allowing communication between two sides of the cerebrum
disconnection syndrom
each hemisphere is unaware of the other, generally caused by a cutting of the corpus callosum
association tracts
connect different regions within the same cerebral hemisphere
- long association fibers connect different lobes
- short association fibers connect gyri within a lobe
cerebral cortex
- layers of gray matter covering the surface of hemispheres
- 90% is neocortex
neocortex
six-layered tissue that has relatively recent evolutionary origin (the cerebral cortex)
limbic system
important center of emotion and learning
- contains regions of the cerebrum and diencephalon
- link conscious functions with autonomic ones
- establishes emotional states
- facilitates memory storage and retrieval
- has structures for reward and aversion
primary somatosensory cortex (postcentral gyrus)
site where sensory input is first received and becomes conscious of the stimulus
- association areas near primary sensory areas process and interpret that sensory info
somatotopy
point-to-point correspondence between an area of the body and an area of the CNS; reflected in the sensory homunculus is the postcentral gyrus
primary visual cortex
posterior region of the occipital lobe; receives visual signals from the eyes
primary auditory cortex
superior region of the temporal lobe; receives auditory signals
auditory association area
inferior to the primary auditory cortex; recognizes spoken words, music, and voices
primary gustatory cortex
inferior end of the postcentral gyrus
primary olfactory cortex
medial cortex of the temporal lobe
sensor homunculus
diagram of sensory inputs to the primary somatosensory cortex in the parietal lobe
primary motor cortex (postcentral gyrus)
voluntary motor commands are transmitted to these neurons; send signals to the brainstem and spinal cord leading ultimately to muscle contraction
Wernicke’s area
posterior speech area
- posterior to the lateral sulcus, usually in the left hemisphere; recognition of spoken and written language
Broca’s area
motor language area
- inferior to the prefrontal cortex, usually in the left hemisphere; generates motor program for the muscles of the larynx, tongue, cheeks, and lips for speaking and hands when singing
when we intend to speak, _____ area formulates phrases and transmits plans of speech to _____ area
Wernicke’s, Broca’s
_____ area transmits the program to the _____ _____ cortex for commands to the lower motor neurons that supply relevant muscles
Broca’s, primary motor
aphasia
any language deficit from lesions in Wernicke’s or Broca’s area
nonfluent aphasia
approximate words
fluent aphasia
make up words
cerebral lateralization
difference in structure, function, between the two cerebral hemispheres
left hemisphere (4)
usually the categorical hemisphere
- specialized for spoken and written language
- sequential and analytical reasoning (math/science)
- breaks information into fragments and analyzes it
right hemisphere (6)
usually the representational hemisphere
- perceives info in a more integrated way
- seat of imagination and insight
- musical and artistic skill
- perception of patterns and spatial relationships
- comparison of sights, sounds, smells, and taste
lateralization is correlated with… (3)
handedness, age, and sex
electroencephalogram (EEG)
recording of brain waves, rhythmic voltage changes in surface layers of the cortex
what are EEG’s useful for?
- studying normal brain functions as sleep and consciousness
- helps in diagnosis of degenerative brain disease, metabolic abnormalities, brain tumors, and trauma
alpha brain waves (3)
- 8 to 13 Hz
- awake and resting with eyes closed and mind wandering
- suppressed when eyes open or performing a mental task, absent during sleep
beta brain waves (3)
- 14 to 30 Hz
- accentuated during mental activity and sensory stimulation
- appear when awake and concentrating on something/performing a task
theta brain waves (3)
- 4 to 7 Hz
- found normally in children, or in intensely frustrates, drowsy, or sleeping adults
- may indicate a brain disorder or brain tumor in adults
delta brain waves (3)
- < 3.5 Hz
- high amplitude
- found in adults in deep sleep, in adults with brain damage
sensory cranial nerves
I, II, and VIII
- carry signals only from outlying sense organs to the brain
motor cranial nerves
III, IV, VI, XI, XII
- stimulate muscle but also contain fibers of proprioception
mixed cranial nerves
V, VII, IX, X
- sensory functions may be quite unrelated to their motor function
ex. facial nerve 7 has a sensory role in taste and a motor role in facial expression
cranial nerves: olfactory (I)
sensory function - smell
cranial nerves: optic (II)
sensory function - vision
cranial nerves: oculomotor (III)
motor function - eye movement, iris
cranial nerves: trochlear (IV)
motor function - eye movement
cranial nerves: trigeminal (V)
sensory of the face and mouth, and motor of the mouth
cranial nerves: abducens (VI)
motor function - eye movement
cranial nerves: facial (VII)
sensory function of taste and motor function of facial expression
cranial nerves: vestibulocochlear (VIII)
sensory function - hearing, balance, equilibrium
cranial nerves: glossopharyngeal (IX)
sensory function of taste and motor function of the head and neck
cranial nerves: vagus (X)
sensory of the viscera and motor of the digestive and respiratory tracts
cranial nerves: accessory (XI)
motor functions of the neck and upper back
cranial nerves: hypoglossal (XII)
motor function of the tongue
