Chapter 14: The Brain and Cranial Nerves (Anatomy & Physiology) – Practice Flashcards

A comprehensive set of Q&A flashcards covering the major topics from the notes on the brain and cranial nerves.

What are the three major divisions of the brain ?

Forebrain, cerebellum, and brainstem.

Which part of the brain is the largest portion of the forebrain with 83% of brain volume?

The cerebrum

What are gyri

Gyri are thick folds on the cerebrum surface.

What is the deep groove that separates the cerebral hemispheres called?

The longitudinal cerebral fissure.

What is the corpus callosum?

A thick bundle of nerve fibers at the bottom of the longitudinal fissure that connects the cerebral hemispheres.

Where is the cerebellum located and how is it separated from the cerebrum?

Located in the posterior cranial fossa; separated from the cerebrum by the transverse cerebral fissure.

What are the main components of the brainstem?

Midbrain, pons, and medulla oblongata.

What is gray matter and what does it include?

Gray matter contains nerve cell bodies, dendrites, and synapses; includes the cortex and nuclei.

What is white matter and what is its role?

White matter consists of tracts (bundles of axons) that connect brain regions and link to the spinal cord.

What does the neural crest give rise to?

The two inner meninges (arachnoid and pia) and most of the peripheral nervous system, among other structures.

List the three meninges from outermost to innermost.

Dura mater, arachnoid mater, and pia mater.

What are the dural venous sinuses and their function?

Spaces that collect blood circulating through the brain, e.g., superior sagittal sinus and transverse sinus.

Is there an epidural space in the cranium?

No unlike the spinal cord

What are the folds of the dura mater

Falx cerebri, tentorium cerebelli, and falx cerebelli

What is arachnoid mater and what is the subarachnoid space?

A transparent membrane over the brain; the subarachnoid space between arachnoid and pia is filled with CSF and blood vessels.

What is meningitis?

Inflammation of the meninges, often Pia and arachnoid

Name the internal ventricles

Two lateral ventricles; third ventricle ; fourth ventricle. They connect via interventricular foramen, cerebral aqueduct, and central canal.

Where is CSF produced and what cells modify it?

Produced by the choroid plexus and modified by ependymal cells.

What are the main functions of CSF?

Buoyancy, protection, and chemical stability; it cushions the brain and helps remove wastes.

What is the brain barrier system (BBS) and its two main entry points?

Regulates which substances reach brain tissue; entry points are the blood–brain barrier and the blood–CSF barrier at the choroid plexus.

What composes the blood–brain barrier and how is it formed?

Tight junctions between endothelial cells; astrocytes induce endothelial cells to form these tight junctions, making the barrier selectively permeable.

What is the blood–CSF barrier and where is it formed?

Formed by tight junctions between ependymal cells at the choroid plexus, allowing exchange between brain tissue and CSF.

What are Circumventricular organs (CVOs)?

where the barrier is absent, allowing direct blood access to the brain to monitor variables like glucose and pH; can be routes for pathogens

What is a stroke and what are the two main types?

Cerebral vascular accident; hemorrhagic stroke, and ischemic stroke

From which embryonic vesicle does the medulla oblongata develop?

The myelencephalon (hindbrain).

What are the key features of the medulla oblongata?

Begins at the foramen magnum; pyramids and olives; cranial nerves VIII (part), IX, X, XII

What are the pyramids and olives in the medulla?

Pyramids are anterior ridges containing corticospinal tracts; olives are lateral bulges containing sensory pathways.

Which cranial nerves begin or end in the medulla?

Cranial nerves VIII (part), IX, X, and XII.

What are the main features of the pons?

anterior bulge; contains cerebellar peduncles and cranial nerves V–VIII; houses reticular formation

What are cerebellar peduncles?

Three pairs of stalks (inferior, middle, superior) connecting the brainstem to the cerebellum, carrying signals to/from the cerebellum.

What are the primary functions of the midbrain?

Connects hindbrain to forebrain; contains the cerebral aqueduct, tectum with superior and inferior colliculi, and cerebral peduncles (tegmentum, substantia nigra, cerebral crus).

What is the tectum and its bulges?

The roof-like part of the midbrain; contains the superior colliculi (visual tracking) and inferior colliculi (auditory relay).

What is the reticular formation and where is it located?

A loose network of gray matter running vertically through all levels of the brainstem into the upper spinal cord; occupies space between white tracts and brainstem nuclei.

Name two key functions of reticular formation nuclei.

Somatic motor control (tone, posture), gaze centers, integration of sensory stimuli for motor coordination; central pattern generators for breathing and swallowing; cardiovascular control; sleep and consciousness; habituation.

What is the cerebellum and why is it important?

Largest part of the hindbrain; contains more than half of brain neurons; coordinates motor activity, maintains posture, and contributes to nonmotor functions like texture perception and spatial awareness.

What are the major cerebellar features (vermis, folia, arbor vitae, peduncles)?

Vermis connects the hemispheres; folia are the surface folds; arbor vitae is the branching white matter; peduncles (inferior, middle, superior) connect to brainstem.

What are the two major regions of the forebrain and what do they enclose/develop into?

Diencephalon (encloses the third ventricle) and Telencephalon (develops into the cerebrum).

Which three components make up the diencephalon and what is a key feature of the thalamus?

Thalamus, hypothalamus, epithalamus; the thalamus is the gateway to the cerebral cortex and relays most sensory input to the cortex.

What are the main roles of the hypothalamus?

Autonomic and endocrine control; homeostasis; attaches to the pituitary via the infundibulum; visceral and behavioral regulation.

What are the components and functions of the epithalamus?

Pineal gland (endocrine) and habenula; part of the roof of the third ventricle; involved in circadian and emotional regulation.

What are the components of the cerebrum and its gross anatomy features?

Telencephalon; two hemispheres separated by the longitudinal fissure; corpus callosum; gyri and sulci increase cortical surface.

What are the five lobes of the cerebrum and their general functions?

Frontal (motor, planning, mood), Parietal (general senses, taste), Occipital (primary visual), Temporal (hearing, memory, emotion), Insula (taste, language integration).

Describe the cerebral white matter and its three main tracts.

White matter contains glia and myelinated axons; three types of tracts are projection, commissural, and association tracts.

What is the corpus callosum and what is its role?

The major commissural tract that connects the two cerebral hemispheres, enabling interhemispheric communication.

What are the basal nuclei and their components?

Masses of gray matter deep in white matter: caudate nucleus, putamen, globus pallidus; collectively called the corpus striatum; lentiform nucleus = putamen + globus pallidus.

What is the limbic system

Emotion and learning center

what are the limbic systems key components?

ingulate gyrus, hippocampus, amygdala, fornix, and connections to thalamic nuclei.

What are the two major types of brain waves and

Alpha waves , Beta waves , Theta , Delta

What stages characterize sleep and what EEG changes occur?

Stages 1-4 of non-REM sleep with progressively slower waves, culminating in deep sleep; REM sleep occurs periodically with EEG resembling wakefulness and vivid dreams.

What is the master biological clock that helps regulate sleep–wake cycles?

The suprachiasmatic nucleus (SCN) of the hypothalamus.

How is waking initiated and what is orexin's role?

Waking is initiated by orexins (neuropeptides from the hypothalamus) that activate the reticular activating system

Cognition and which brain areas primarily support it?

largely supported by widely distributed association areas in the cortex (about 75% of brain tissue).

How are memory and memory-related regions organized in the brain?

Hippocampus is crucial for memory consolidation; cerebellum for motor learning; amygdala for emotional memory.

What regions are involved in language and how do Wernicke and Broca areas interact?

Wernicke area (posterior language area) processes language comprehension; Broca area (inferior frontal) plans speech production; they communicate to generate spoken language.

What is cerebral lateralization and the typical language dominance?

Left hemisphere is typically categorical (language, sequential thought); right hemisphere is often representational (spatial, music). Lateralization is not absolute and varies among individuals.

cranial nerve 1, CN I

Olfactory (smell, sensory)

Which cranial nerves are purely sensory,

Purely sensory: CN I, CN II, CN VIII. Motor: CN III, CN IV, CN VI, CN XI (primarily motor).

Which nerve passes through the cribriform plate to reach the olfactory bulb?

Olfactory nerve (CN I).

Which nerve transmits vision from the retina to the brain?

Optic nerve (CN II).

Which nerve controls most of the eye’s movements and raises the eyelid?

Oculomotor nerve (CN III).

Which nerve innervates the mandible and carries major sensory input from the face?

Trigeminal nerve (CN V) with ophthalmic, maxillary, and mandibular divisions.

Which nerve provides facial motor control and taste sensation from the anterior two-thirds of the tongue?

Facial nerve (CN VII).

Which nerve is primarily responsible for hearing and balance?

Vestibulocochlear nerve (CN VIII).

what are sulci

sulci are shallow grooves between gyri

which nerves are primarily motor?

CN III, CN IV, CN VI, CN XI

which nerves are primarily mixed

Mixed: CN V, CN VII, CN IX, CN X.

cranial nerve 2 II?

Optic (vision, sensory)

cranial nerve 3 III?

Oculomotor (eye movement, motor)

cranial nerve 4 IV?

Trochlear (eye movement, motor)

cranial nerve 5 V?

Trigeminal (facial sensation and chewing; mixed)

cranial nerve 6 VI?

Abducens (eye movement, motor)

cranial nerve 7VII?

Facial (facial expression and taste anterior 2/3; mixed)

cranial nerve 8 VIII?

Vestibulocochlear (hearing and balance; sensory)

cranial nerve 9 IX?

Glossopharyngeal (taste, swallowing, sensory; mixed)

cranial nerve 10 X?

Vagus (parasympathetic to organs, motor; mixed)

cranial nerve 11 XI

Accessory (neck/shoulder movement; motor)

cranial nerve 12 XII

Hypoglossal (tongue movement; motor)