with Guaranteed Pass Solutions 2025-
2026 Updated.
Central Nervous System (CNS) - Answer Brain and Spinal Cord
Encased in bone, sheathed in meninges
Peripheral Nervous System (PNS) - Answer Nerves outside CNS; Somatic and Autonomic
Hindbrain - Answer Ancient, posterior part of brain consisting of medulla, pons, and
cerebellum
Raphe System - Answer Core strip of cells through hindbrain and midbrain, involved in sleep
Cerebellum ("little brain") - Answer Hindbrain structure for guided, timed movements and
attention shifting
Organizes sensory input to guide movement, modified by learning
Brainstem - Answer Structure along the center-most section of the brain including hindbrain
(except cerebellum), midbrain, and diencephalon of forebrain
Midbrain - Answer Central structures above hindbrain
Proportionally larger and more important in simpler animals
Tectum ("roof"/"plate tectonics" in geology) - Answer Midbrain structure involved in sensory
processes
Includes superior (visual- including "blindsight") and inferior (auditory) colliculi
Forebrain - Answer Anterior portion of brain
Diencephalon (in brainstem) and telencephalon
,Limbic System ("border") - Answer Set of forebrain structures involved in motivation and
emotional expression
Includes hippocampus, amygdala, cingulate gyrus, olfactory bulb
Hippocampus ("seahorse") - Answer Part of limbic system, involved in memory formation
and spatial mapping
Amygdala ("almond") - Answer Part of limbic system (at end of hippocampus), involved in
anger/fear and recognizing emotions in others
Cingulate Gyrus - Answer Part of limbic system, "re-entrant" layer (just under cortex)
between cortex and lower systems, for +/- evaluation
Cerebral Cortex ("bark") - Answer Outermost forebrain structure, 6 layered, highly
convoluted (gyri/bulges and sucli/folds)
4 lobes, central sulcus divides parietal from frontal, lateral sulcus divides frontal from temporal
Bell-Magendie Law - Answer Governs directions of info flow in/out of the spinal cord
Sensory in via dorsal root, motor out via ventral root
Note: for sense organs and muscles in the head, cranial nerves of PNS serve this function
Grey Matter - Answer area of the spinal cord (center) consisting of soma and dendrites,
including inter-neurons
White Matter - Answer area of the spinal cord consisting of myelinated axons, ascending and
descending tracks to/from brain, surrounded by grey matter
Central Canal - Answer tube through core of spinal cord containing fluid (cerebral spinal
fluid)
Meninges - Answer - three-layered protective covering that surrounds CNS
- Dura Mater (tough mother): thick outer layer immediately under the bone
- Arachnoid Mater (spider mother): spiderweb-like layer (subarachnoid space filled with CSF)
- Pia Mater (pious mother): pliant inner layer, conforms to brain and spine surface, includes
blood vessels
,-Meningitis: inflammation of meninges
Ventricles - Answer - four hollow chambers (plus aqueducts) in brain that produce the
cerebral spinal fluid that feeds, cleans, and cushions brain
- 2 lateral and 3rd ventricles in forebrain, cerebral aqueduct in midbrain, 4th ventricle in
hindbrain
-CSF drain into subarachnoid space of meninges and central canal of spine
-Hydrocephalus (water on brain):flow from ventricles blocked, may be surgically drained
Blood Vessels - Answer -Complex web of arteries (incoming) and veins (outgoing) that feed
(glucose) and cleanse brain
-Brain is under 2% body weight but uses 20% of body's continuous blood supply
Cerebral Spinal Fluid - Answer -fluid, produced by ventricles, found within spinal cord and in
covering around CNS
-drawn into subarachnoid space of meninges and central canal of spine
-helps cushion and support (float) jellylike brain, protect spinal cord, and provide a reservoir of
hormones and nutrition
Blood-Brain Barrier - Answer -semi-permeable barrier, controls what chemicals enter brain,
created by closing gaps between capillaries' endothelial cells
-neural functioning depends on regulation of chemistry of intra- and extra-cellular fluids
-protects brain from infection (brain lacks body's immune system and cellular regeneration)
-Glia Cells (astrocytes) help create BBB
-Passive transport: small, uncharged (O2, CO2), and fat-soluble molecules
-Active transport for others (glucose) (energetic, protein-mediated)
-Weaker in medulla (lets some toxins past - vomiting)
Somatic Nervous System - Answer - part of the PNS that is responsible for body's interaction
with the external environment
- 31 pairs spinal nerves and 12 cranial nerves
- spinal: sensory (body's surface, skeletal muscle feedback) and motor (skeletal muscles)
- cranial: sensory (visual, auditory, taste, smell, tactile for face, and some organ feedback) and
motor (eye movement, facial expression, chew and swallow, speech, neck muscles, some
organs)
Autonomic Nervous System - Answer - the part of the PNS that is responsible for assessing
and maintaining the body's internal environment
, - 2 parts (sympathetic and parasympathetic always active, activity is complimentary)
Sympathetic Nervous System - Answer - the part of the ANS that produces the "fight or
flight" response
- ganglia near spinal cord, form tightly-knit chain, activity tightly coordinated
- adrenal glands, sweat glands, liver, blood vessels, and hair follicles work through this system
exclusively (not parasympathetic)
Parasympathetic Nervous System - Answer - the part of the ANS that facilitates relaxation
and replenishment ("rest and digest")
- ganglia not near spinal cord, but near target organs, activity not as coordinated as sympathetic
Parasympathetic Rebound - Answer extreme compensatory response of one system to
extreme activation of the other- can lead to fainting, ulcers, and voodoo death
Neurons - Answer cells in the nervous system responsible for information transmission
Ribosomes - Answer organelles in a cell that are the site of protein production, crucial to
much neural functioning
Mitochondria - Answer organelles in a cell that are the source of energy (ATP) to power
active (rather than passive) functions in cell
Glial Cells (glia=glue) - Answer - cells in the nervous system responsible for support, feeding,
recycling, development, etc.
- non-neural cells, do not participate in information transfer
- physically and chemically buffer and support neurons
- much smaller that neurons, less than 50% of brain weight
- can regenerate (runaway regeneration="glioma" brain tumor)
Astrocyte - Answer provide nutrients to neurons, blood brain barrier, recycle NT, remove
waste, etc.
Microglia - Answer proliferate in areas of brain damage, remove toxic material
Myelination - Answer whole shwann cells wrap around axon in PNS, arms of an
Oligodendrocyte in CNS