Chapter 15: Brain and Cranial Nerves Flashcards
What are the 6 regions of the adult brain?
Cerebrum Diencephalon mesencephalon Cerebellum Pons Medulla Oblongata
Describe the dura mater (3)
outer-most mater
forms internal periosteum of skull
no epidura
What are the three dura mater partitions? what does each separate?
Falx Cerebelli: separates right and left cerebellar hemispheres
Falx Cerebri: separates right and left cerebral hemispheres
Tentorium Cerebelli: separates lobes of cerebrum from cerebellum
describe the arachnoid mater (2)
- spidery
- spreads over brain but doesn’t extend into grooves and depressions
describe the pia mater (3)
- inner most mater
- aids in nourishing brain
- attached to surface of brain
what are ventricles? how many are there?
spaces filled with CSF; 4
Where are each of the 4 ventricles connected?
-2 lateral ventricles connected by interventricular foramen to the 3rd ventricle connected by cerebral aqueduct to the 4th ventricle connected to central canal of spinal cord
What are the functions are CSF? (3)
- Cushions
- Transport nutrients, wastes, and other chemicals
- Supports the brain
what is the location of CSF formation?
choroid plexus
what is the choroid plexus?
what does it consist of?
lobes located in the ventricles
consists of ependymal cells and permeable capillaries
CSF is taken from ________ by________ cells and pooled in the ___________
blood; ependymal; ventricles
True or False: CSF moves entirely though out the CNS and PNS
false; only through the entire CNS not PNS
Where does CSF movement originate?
ventricles
the CSF moves through ________ in the 4th ventricle to sub-arachnoid space
apertures
CSF moves though the _______ and around the _________
central canal; subarachnoid space
CSF is reabsorbed in the _________
sagittal sinus
describe the sagittal sinus (4)
- a large venous tube within the dura mater
- extends along the midline of the cerebral hemispheres
- arachnoid extends into sinus through arachnoid granulations
- CSF goes back to the blood
what are the five functions of the cerebrum?
- interpret sensory impulses
- voluntary muscular movements
- memory
- reasoning process
- intelligence and personality
the two cerebral hemispheres are connected by the _______ and separated by the ________
corpus callosum
longitudinal fissure
what is the name for the ridges in the cerebrum?
Grooves?
Gyri- ridges
Sulci-grooves
other than connecting the two cerebral hemispheres, what else does the corpus callosum do?
allows for communication between the hemispheres
describe the hemisphere specialization for the two hemispheres of the cerebrum
one hemisphere receives sensory and generates motor information to the opposite side of the body of that hemisphere
describe cerebral gray matter (3)
Cell Somas
-outer regions of cerebral lobes
-centralized in masses called basal nuclei
(slide14)
does the cerebral gray or white matter have myelinated axons?
white matter
what are the three fibers located in the cerebral white matter? describe them
Commissural fibers: connect corresponding gray areas on different hemispheres
Association fibers: connect different parts of same hemisphere
Projection fibers: connect cerebrum to lower brain areas
what are the 5 cerebral lobes
- Frontal
- Parietal
- Temporal
- Occipital
- Insula
What is the sulci that separates the frontal lobe from the parietal lobe ?
Central Sulcus
what is the sulci that separates the parietal lobe from the temporal?
Lateral sulcus
what is the sulci that separates the parietal lobe from the occipital?
Parieto-occipital sulcus
describe the primary motor cortex (4)
- Anterior to central sulcus in frontal lobe
- conscious control of skeletal muscles
- learned motor skills
- speech and eye movements
describe the primary sensory cortex (3)
- posterior to central sulcus on parietal lobe
- somatic sensory information from touch, pain, pressure
- monitor environment consciously
What are the 4 other sensory cortexes in the cerebrum?
State the name, location, and sense
VIsual Cortex -occipital lobe -sight Auditory Cortex -temporal lobe -sound Olfactory Cortex -temporal lobe -smell Gustatory Cortex -Insula and frontal lobe -taste
What are the three High Order Integrative Regions of the cerebrum?
Prefrontal Cortex
Broca’s speech center
General interpretive area
what is the prefrontal cortex responsible for? (4)
What is removal of the prefrontal cortex called?
- abstract intellectual function
- predictions, problem solving
- emotional context and motivation
- timing and temporal relationships
Removal= pre-frontal lobotomy
Broca’s speech center regulates ________ and _______
breathing and vocalization
What two things are the General Interpretive Area responsible for?
- interpretation of both written and verbal language
- sentence structure and word linkage
damage to either the Broca’s speech center or the General interpretive area results in some sort of _______
aphasia
slide 24
:)
what are basal nuclei?
masses of gray matter deep in cerebral hemisphere
Basal nuclei act as a relay station for….
motor impulses starting in cerebral cortex and passing to brain stem and spinal cord
what does the Claustrum do?
- focuses visual attention
- Processes unconscious visual info
what does the Lentiform Nucleus do?
controls & adjusts muscle tone
what does the Caudate nucleus look like and what does it do?
- Massive head, slender tail
- maintains pattern & rhythm of movement
The Amygdaloid nucleus is located at the_____________ and is part of the ________ system
tip of caudate tail; limbic
What makes up the diencephalon?
Epithalamus
Posterior Pituitary gland
Thalamus
Hypothalamus
The epithalamus contained what gland? what does this produce?
pineal
produces melatonin
True or False: the thalamus is central to the cerebrum
true
what divides the two major bodies of the thalamus?
what connects the bodies together?
third ventricles
interthalamic adhesion
What are the three functions of the thalamus?
- )Part of the limbic system
- Emotion, memory, learning
- Conscious awareness of emotion - )Connect basal nuclei and cerebral cortex
- To each other
- To other parts of the CNS - ) Sends sensory information to proper location within cerebrum
describe the location of the hypothalamus
Below (hypo) the thalamus
Above and connected to the posterior pituitary gland
what are the 7 functions of the hypothalamus
Subconscious control of skeletal muscles
Coordinates autonomic nervous system
The connection between the endocrine and nervous system
Directly produces hormones
Produces behavioral drives (emotions, hunger, thirst)
Regulates body temperature
Controls sleep patterns such as circadian rhythms
describe the mesencephalon (4)
- A.k.a. Midbrain
- Connects brain stem & spinal cord with higher areas
- act as relay centers
- Contain cerebral aqueduct that connects 3rd & 4th ventricles
what are the 4 parts of the mesencephalon
Cerebral peduncles
Red nucleus
Substantia nigra
Corpora quadrigemina
describe cerebral peduncles
Only connecting fibers and no nuclei
- Motor fibers connecting the cortex to the spinal cord
- Sensory fibers that synapse with the thalamus
describe the red nucleus
Highly vascularized (Hence red color)
Connects cerebrum and cerebellum
Controls posture and reflexes
what does the substantia nigra do?
what does it produce?
- controls and integrates the motor output of the basal nuclei
- produces dopamine (making it black in color)
deterioration of the substantia nigra leads to what disease?
Parkinson’s Disease (loss of control of voluntary motor function)
the Corpora Quadrigemina consists of ________ and _______. describe what they do
Superior Calliculi
-receives visual input from thalamus
Inferior Calliculi
-receives auditory input from medulla
describe the Pons (5)
- Rounded bulge on underside of brain stem
- Separates midbrain from medulla
- Masses of gray matter & nerve fibers
- Relays impulses to & from medulla & cerebrum
- Regulates depth of breathing
the two hemispheres of the cerebellum are separated by the _______ and connected by the _______
falx cerebelli
vermis
is the cerebellum mainly white or gray matter?
white (arbor vitae)
what are four functions of the cerebellum?
- Integrates sensory information about the position of body parts
- Coordinates muscle activities
- Maintain posture
- Fine tunes voluntary and involuntary movements
describe the medulla oblongata (3)
- From foramen magnum to pons
- A point of connection for several cranial nerves
- Oval swelling = olivary nucleus
What are the two reflex centers in the medulla oblongata? describe them
Cardiovascular center
-Adjusts blood flow and heart rate
Respiratory rhythmicity center
-Basic pace of respiratory movements
describe the reticular formation (3)
-network of nerve fibers associated with islands of gray matter
-Interconnects areas with fibers in all major tracts
-Regulates motor activities
Inc activity –> wakefulness
Dec activity–> sleep
what is the limbic system?
Nuclei and tracts along the boarder of cerebrum and diencephalon
where in the cerebrum is the limbic system?
Limbic lobe (deep to all other lobes) Hippocampus (nucleus within the lobe) Amydaloid body (basal nucleus)
where in the diencephalon is the limbic system?
Thalamus (relay center)
Hypothalamus (behavioral drive center)
where in the medulla is the limbic system?
Reticular formation (sleep and wakefulness)
what are three functions of the limbic system?
- ) Establishes emotional states and related behavioral drives
- ) Links intellectual functions of cortex to unconscious functions of lower brain
- ) Facilitates memory storage
describe cranial nerves (5)
- 12 total
- All originate from brain stem except 1st pair
- Cell bodies for sensory found in ganglia outside brain
- Cell bodies for motor found in gray matter
- Pass through foramina in skull
slide 47
wooooo anatomy
Olfactory
Sensory
Smell
Pass through cribriform plate
Optic
Sensory
Vision
Pass through optic foramina
Oculomotor
Motor
Move the majority of eye muscles
Trochlear
Motor
smallest pair
Superior oblique muscle of eye only
Trigeminal
both
largest
3 branches
-eye, tear gland & skin of ant scalp, forehead & upper eyelid
-upper teeth, gum, lip & mucous lining of palate & skin of face
-scalp, skin of jaw, lower teeth, gum & lip; muscles of mastication
Abducens
motor
from pons
lateral rectus eye muscles only
Facial
- both
- from pons
- sensory: taste receptors on ant 2/3 of tongue
- motor: to muscles of facial expression; stimulate tear & salivary glands
Vestibulocochlear
-sensory
-auditory nerve from medulla
2 parts
-sensitive to changes in position of head
-interpreted as hearing
Glossopharyngeal
- both
- sensory: form lining of pharynx, tonsils & post 1/3 of tongue
- motor: to wall of pharynx to help swallowing
Vagus
- both
- from medulla to chest & abdomen
- sensory from lining of pharynx, larynx & esophagus & abdomen
- Somatic motor: to muscles of larynx –>speech & swallowing
- Autonomic motor: to heart, other smooth muscles & glands in visceral organs
Accessory
-motor
2 branches
-cranial: from medulla to muscles of soft palate, pharynx & larynx
-spinal: sends motor fibers to trapezius & sternocleidomastoid
Hypoglossal
- motor
- from medulla to tongue
- for speaking, chewing & swallowing
