The brain, brainstem, cerebellum, and spinal cord make up the __________.
Central Nervous System (CNS)
Consists of the cranial nerves and spinal nerves & is sometimes called the lower motor neuron.
Peripheral Nervous System (PNS)
Consists of peripheral nerve fibers that send sensory information to the central nervous system AND motor nerve fibers that project to skeletal muscle.
Somatic Nervous System
Self-regulating functioning; part of the PNS. It controls many organs & muscles within the body & functions in an involuntary, reflexive manner. (Breathing, HR, BP, etc.)
Autonomic Nervous System
3 membranes that enclose the CNS.
Tough, slightly elastic, outermost membrane that encloses the brain & spinal cord and lines the inner surface of the cranial vault.
Dura mater (meninges)
Which layer of dura mater is vascular & attaches to skull forming the periosteal layer of the calvarium.
Inner surface of the dura is attached to the ________.
Complex system of cavities and channels where the layers of dura separate; collect used blood (venous) flowing down from brain & funnel it into jugular for return to heart & lungs.
Dural Venous Sinuses
Long, crescent-shaped band of dura that slips downward along the midline of skull dividing cranial vault into 2 compartments (hemispheres)
Dome-shaped sheet of dura mater creating 2 compartments: upper-holds the hemispheres & lower-holds the cerebellum.
Cobweblike sheet of tissue sandwiched bet/ the dura & pia mater. It has no blood vessels & doesn't conform closely to the contours of the underlying pia mater, thereby creating a space.
Space in the arachnoid that is filled with CSF.
Cerebrospinal Fluid (CSF)Clear, colorless fluid that serves what 3 functions?
Cushions & protects CNS against trauma
Transport pathway for metabolic/nutritional compounds to reach CNS & waste products away from CNS
Arachnoid protrusions into the venous sinuses that provide places at which excess CSF is resorbed into the venous blood & removed from the subarachnoid space.
Arachnoid Villi (granulations)
Fragile, innermost meninges layer adhering tightly to the brain's surface like shrinkwrap.
Outer surface of pia mater has many _________ that cross the space between the pia mater and the arachnoid.
Capillaries (blood vessels)
An average human brain weighs about ___ pounds which is _____% of body mass and is _____% water.
2% body mass
The brain requires _____% of blood & oxygen.
Permanent brain damage can begin to occur after ___ minutes of loss of oxygen to the brain.
These cells are the "bricks & mortar" supporting and separating nerve fiber tracts & are also "housekeepers" that regulate fluid levels, remove foreign substances & participate in brain metabolism.
Gial cells are _____ times more numerous than neurons & account for ____ of the brain's solid mass.
What part of a neuron generatesimpulses?
What part of a neuron collects impulses?
What part of a neuron is the conducting process of a nerve cell and carries impulses?
Fatty material that surrounds axons of neurons providing an electrical insulation and allows transmission of info to be faster.
Point at which the transfer of impulse from axon to dendrite from one neuron to the next. What's the tiny space where this happens called? What type of process is this?
What type of neurons respond to stimulation such as touch or temperature and serve as receptors?
What are the "first order neurons" of the CNS known as the pyramidal system & is responsible for initiating control skilled, specific voluntary movements and inhibit reflexive innervation motor& are made up of motor neurons in the mortor cortex together with projection fibers?
Upper Motor Neuron (UMN)
The top-to-bottom "unit" responsible for direct innervation of specific skeletal muscle
Loss or damage to UMNs result in what effect on the body?
What tract of UMNs go from the cortex to the cranial nerves in the brainstem?
What tract of the UMNs go between the cortex to the spinal nerves of the spinal cord?
Another name for PNS that consists of the cranial & spinal nerves that provide gross, crude, undifferentiated innervation of muscle. Where reflexive motor actions are mediated.
Lower Motor Neurons (LMN)
"Final common pathway" for motor commands going to muscle fibers
LMNs that exit the CNS
... below the cranium are called (_______ nerves
…inside the cranium are called (_______nerves)
Loss/Damage of LMN results in what effect on the body?
Stimulation of a sensory nerve is transmitted to a motor nerve via what type of nerve cell activating the reflex arc.
Permits rapid responses/movements to stimuli (pain) w/out participation of higher centers of the nervous system.
What matter consists of neurons and glial cells?
What matter consists of bundles of myelinated axons arranged into nerve fiber tracts.
What's the term for collections of interacting neurons whose function is closely related?
What are the major divisions of the brain?
Deep Brain Structures (Ventricles, Diencephalon, Internal Capsule)
What deep fissure divides the cerebrum into 2 hemispheres?
Longitudinal Cerebral Fissure
Rigid sheet of dura mater that serves as a partitition w/in the longitudinal cerebral fissure & crosses front to back on the midline of the cranial vault.
Rigid sheet of dura that horizontallyseparates the cerebellum from the base of the brain.
Convolutions/ridges of the brain's surface
Depressions/valleys in the brain's surface
Very deep sulci
Prominent sulcus/fissure that travels vertically down each hemisphere dividing it into roughly equal anterior and posterior regions. (3 names for the same area)
Fissure of Rolando (marble roll on down)
Central Cerebral Fissure
Deep groove that separates the temporal lobe in each hemisphere from the frontal and parietal lobes horizontally. (3 names)
Lateral Cerebral Fissure
Fissure of Sylvius
Less prominent deep groove in the occipital lobe of each hemisphere. It's important bec/ visual cortex is adjacent to it.
Calcarine fissure (calx-heel)
What are the 4 names of lobes of the brain?
Anterior 1/3 of the brain involved in planning. Inferior boundary--Lateral Cerebral (Sylvian) Fissure Posterior boundary--Central sulcus (Rolandic fissure)
Part of cortex where sensory strip is located so is important for somesthic sensation (skin, muscle, joint, & tendon).
Anterior boundary--Central sulcus (Rolandic fissure)
Posterior boundary--Occipital pole
Inferior boundary--Lateral (Sylvian) fissure
Bottom 1/3 of each hemisphere; important role in language & audition.
Superior boundary--Lateral (Sylvian) fissure
Inferior boundary--Midline underside of hemisphere
Posterior boundary--Imaginary Occipital anterior boundary line
Most posterior portion of the brain hemispheres where the visual cortex is located.
Superior boundary--Parietal lobe
Anteror boundary--Occipital lobe's longitudinal fissure
Patch of cortex folded into the Lateral (Sylvian) fissure; operculum surrounds it.
Which gyrus anterior to central sulcus is the motor strip located?
Structure where we initiate specific, voluntary movements***
Which gyrus posterior to central sulcus is the sensory strip located?
What are the superior, middle, and inferior temporal gyri responsible for?
What gyrus (curves around the end of the Lateral (Sylvian) fissure) is important for the process of writing?
What gyrus (posterior to supramarginal gyrus/end of superior temporal gyrus) is important for reading?
Strip of brain cortex in the posterior frontal lobes said to be important for planning volitional movements.
Area of brain cortex responsible for reasoning, thinking, & planning.
In what gyrus is Broca's area located?
3rd Inferior Frontal convolution/gyrus
What term of the brain derives from "bark"?
Largest & most important crescent-shaped commissure (structural bridge bet/2 hemispheres); responsible for interhemispheric communication.
Major fiber tract in the left hemisphere that's considered the major pathway by which info from lang. centers in temporal lobe reach frontal lobe for conversion into spoken or written output.
Integral gyrus of the limbic system which is involved with emotion formation and processing, learning, and memory.
The ventricles contain _____% of CSF; ____% in the subarachnoid space
What are the 4 CSF filled cavities called ventricles within the brain?
2 largest crescent-shaped ventricles
Irregularly-shaped disk-like cavity standing on the edge on the midline below the lateral ventricles
Narrow tubular cavity extending down through the brain stem, ending at an opening into the subarachnoid space
Clear, colorless fluid that fills the ventricles and surrounds the brain, brainstem cerebellum, and spinal cord
Cerebrospinal Fluid (CSF)
What are the 4 functions of CSF?
Spongy masses of vascular tissue (capillaries), one in each ventricle, that are the body's primary producer of CSF; blood rich nutrients to CSF via these.
Choroid Plexi (plexus)
Short passageway bet/ each lateral ventricle & the thirdventricle for movement of CSF
Foramen of Munro (Interventricular foramen)
Long narrow passageway bet/ third & fourth ventricles. Occlusion in this area is common cause of hydrocephalus.
Aqueduct of Sylvius (Cerebral Aqueduct)
2 openings from the fourth ventricle into the subarachnoid space...also called Lateral aperatures.
Foramina of Luschka (lateral aperatures)--"roof" of the fourth ventricle
2 openings from the fourth ventricle into the subarachnoid space...sometimes called the Median aperature.
Foramen of Magendie "floor" of fourth ventricle
Which foramen (2) empties the subarachnoid space?
Foramina of Luschka "roof"
Foramen of Magendie "floor"
Deep central region w/in the brain hemispheres that contain the thalamus & basal ganglia. It plays an important part in the regulation & integration of motor activity & sensory experience.
Diencephalon "Deep Brain"
"Relay station" for all incoming sensory info; pair of egg-shaped nuclei in the diencephalon important for consciousness, alertness, attention, "appreciation" of pain. (may regulate overall activity of cortex)
Several nuclei in diencephalon near thalamus, responsible for regulation of major muscle groups that make postural adjustments& compensate for inertial forces during movement. Automatic background adjustments (Ex. walking on irregular sidewalk)
Degeneration and fading of the ____________ (basal ganglia) is frequently seen in Parkinson's Disease.
Structures for regulating automatic, background adjustments
Caudate nucleus, Putamen & Globus Pallidus (Lenticular Nucleus) make up what part of the deep brain?
Major neural pathway for motor commands traveling from the cortex to: spinal nerves (________) cranial nerves (________) pons and cerebellum (__________).
Region of highly compacted projection fibers deep in the cerebral hemispheres.
Section of corticobulbar & corticospinaltracts that lies w/in the basal ganglia.
"Little Man"--drawing of a human figure showing topographic representation of motor cortex. Shows how many neurons are dedicated to a particular body part.
Stalklike structure at base of brain atop spinal cord containing centers that regulate vital functions & contains most cranial nerve nuclei.
Mesencephalon--deep brain region that makes up the upper 1/3 of thebrain stem; contains several nuclei including cranial nerves that move the eyes.
Visual reflex processing (blinking)are mediated in this area of the midbrain.
Auditory reflex processing (loud sound--> ossicles tighten) is mediated in this area of the midbrain.
Prominent forward bulge of the middle 1/3 of brainstem containing 3 cranial nerve nuclei for eyes & face plus some nuclei concerned w/ balance & hearing
Hindbrain--bottom 1/3 of brainstem contains 5 cranial nerve nuclei plus centers (conerned with HR, vasoconstriction, breathing). Pyramidal decussation cross here.
Structures in the central core of brainstem that regulate individual's overall level of consciousness.
Mini-brain lies beneath posterior temporal lobes. Important in integration & coordination of volitional movements
Other than equilibrium and coordination, what other function is served by the cerebellum?
Gamma system – (background muscle tone.)
Structure for monitoring timing, range, and speed of movements.
Projection fibers include what type of fibers?
Sensory (______-______-_______) axons & cell bodies make up the spinal cord.
Portion of the spinal cord that contains nerve cell bodies that transmit sensory information to the postcentral gyrus.
Posterior Horn Cells
"Up & Down" nerve fiber tracts that connect brain, brainstem, & spinal cord. Motor (efferent) or Sensory (afferent).
"Across or Between" horizontal nerve fiber tracts that cary impulses from one hemisphere across to the other. Corpus callosum is the major tract.
Commissural fibers (Commisures)
"Within" hemispheric nerve fiber tracts connecting adjacent regions of the cortex. Arcuate fasciculus important for how brain deals with language.