Prac manual 3.1

What are the two major anatomical divisions of the nervous system?

Central nervous system (CNS) and peripheral nervous system (PNS).

What structures make up the CNS?

Brain and spinal cord.

What structures make up the PNS?

Cranial nerves, spinal nerves, peripheral nerves, and ganglia.

What are the three functional roles of the nervous system?

Monitor internal/external environments, process information, and respond to stimuli.

What is a gyrus?

A raised fold of the cerebral cortex.

What is a sulcus?

A shallow groove between gyri.

What is the central sulcus?

The groove separating the frontal and parietal lobes.

What is the precentral gyrus responsible for?

Primary motor cortex.

What is the postcentral gyrus responsible for?

Primary somatosensory cortex.

What lobes does the lateral sulcus separate?

Temporal lobe from frontal and parietal lobes.

Name the four lobes visible laterally.

Frontal, parietal, temporal, occipital.

What is the corpus callosum?

A large commissural tract connecting the left and right cerebral hemispheres.

What is the cingulate gyrus involved in?

Emotion, learning, and behavior regulation.

What is the parieto-occipital sulcus?

A deep sulcus separating parietal and occipital lobes.

What is the thalamus?

A relay station for sensory information entering the cortex.

What is the hypothalamus?

A control center for autonomic and endocrine functions.

What structures form the brainstem?

Midbrain, pons, medulla oblongata.

What is the optic chiasm?

The crossing point of optic nerve fibers.

What structure lies posterior to the optic chiasm?

Hypothalamus.

What is the internal capsule?

A major white matter pathway carrying ascending and descending fibers.

What are the basal nuclei?

Subcortical grey matter involved in movement regulation.

What is grey matter composed of?

Neuron cell bodies, dendrites, synapses.

What is white matter composed of?

Myelinated axons.

What are projection fibers?

Fibers connecting cortex with lower brain regions/spinal cord.

What are association fibers?

Fibers connecting regions within the same hemisphere.

What are commissural fibers?

Fibers connecting the two hemispheres (e.g., corpus callosum).

What is the purpose of gyri?

To increase cortical surface area for more neurons.

What are the three lobes of the cerebellum?

Anterior, posterior, flocculonodular.

What are cerebellar folia?

The gyri of the cerebellum.

What are the cerebellar peduncles?

White matter tracts connecting cerebellum to brainstem.

List two functions of the cerebellum.

Coordination of movement; maintenance of balance and posture.

What are the three layers of meninges?

Dura mater, arachnoid mater, pia mater.

What is the dura mater?

The tough outer meningeal layer.

What is the arachnoid mater?

A thin avascular membrane with trabeculae.

What is the pia mater?

The delicate layer adhering to the brain surface.

What is the subarachnoid space?

The space between arachnoid and pia containing CSF and blood vessels.

What are arachnoid villi?

One-way valves that return CSF to venous sinuses.

How many ventricles are in the CNS?

Four (two lateral, third, fourth).

Where is CSF produced?

Choroid plexus in all ventricles.

What fills the ventricular system?

Cerebrospinal fluid (CSF).

Describe CSF flow.

Lateral ventricles → 3rd ventricle → cerebral aqueduct → 4th ventricle → subarachnoid space → arachnoid villi → venous sinuses.

What happens if CSF drainage is blocked?

Hydrocephalus; infants develop enlarged head, adults increased intracranial pressure.

What lobe is immediately posterior to the frontal lobe?

The parietal lobe.

What is one function of the frontal lobe?

Voluntary motor control, planning, decision-making, personality, or speech production (Broca's area).

Which two lobes does the central sulcus divide?

The frontal and parietal lobes.

What is the corpus callosum?

A large white-matter tract connecting the left and right cerebral hemispheres.

True or false: Sulci and fissures are different structures; fissures contain meninges and sulci do not.

True.

What are the three parts of the brainstem from superior to inferior?

Midbrain → Pons → Medulla oblongata.

What are three inputs to the hypothalamus?

Limbic system, retina, blood chemistry, brainstem autonomic centers.

What is one output from the hypothalamus?

Autonomic nervous system, pituitary gland (hormonal control).

What is the function of the hypothalamus?

Regulates homeostasis: temperature, hunger, thirst, autonomic function, endocrine control.

List two functions of the hypothalamus.

Temperature regulation; control of pituitary hormones; hunger/thirst regulation; circadian rhythms.

What are the adjacent structures of the thalamus in a coronal view?

Medially: third ventricle; Laterally: internal capsule; Superiorly: lateral ventricles; Inferiorly: hypothalamus.

Where are the sensory and motor homunculi located?

Sensory: postcentral gyrus; Motor: precentral gyrus.

What are the functional areas of the frontal lobe?

Primary motor cortex, premotor cortex, prefrontal cortex, Broca's area.

Where is the frontal lobe located?

Anterior portion of the cerebrum, in front of the central sulcus.

What are the functional areas of the parietal lobe?

Primary somatosensory cortex, sensory integration.

Where is the parietal lobe located?

Posterior to the central sulcus, superior to the lateral sulcus.

What are the functional areas of the occipital lobe?

Primary visual cortex and visual association areas.

Where is the occipital lobe located?

Posterior region of the cerebrum.

What are the functional areas of the temporal lobe?

Hearing, memory, language comprehension (Wernicke's area).

Where is the temporal lobe located?

Inferior to the lateral sulcus.

What is the function of the insular cortex?

Taste, visceral sensation, emotion, self-awareness.

Where is the insular cortex located?

Deep within the lateral sulcus.

Compare and contrast the left and right hemispheres.

Left: language, logic, analytical tasks; Right: spatial awareness, creativity, emotion.

What is the diencephalon?

Region containing the thalamus, hypothalamus, epithalamus.

What is the function of the thalamus?

Relay station for all sensory information (except smell) to the cortex.

What are two similarities between the cerebrum and cerebellum?

Both have hemispheres; both have cortex and white matter; both have gyri/sulci (folia in cerebellum).

What are two differences between the cerebrum and cerebellum?

Cerebellum has three lobes (not four); cerebellum lacks a corpus callosum.

What are two functions of the cerebellum?

Coordination of movement; balance; muscle tone regulation.

What are four sources of information that feed into the cerebellum?

Vestibular system, spinal cord proprioception, cerebral cortex, visual system.

Describe the location of the cerebellum.

Posterior cranial fossa, inferior to occipital lobes, posterior to brainstem.

What is the overall function of the brainstem?

Controls vital functions (breathing, heart rate), reflexes, consciousness, and houses cranial nerve nuclei.

List four functions of the brainstem.

Cardiovascular control, respiratory control, consciousness/alertness, reflexes (swallowing, coughing).

Describe the location of the brainstem relative to the skull and CNS.

Sits in the posterior cranial fossa; connects cerebrum to spinal cord.

What structure connects the brainstem with the cerebrum?

Cerebral peduncles.

What structure connects the brainstem with the cerebellum?

Cerebellar peduncles.

What is the function of arachnoid villi?

Reabsorb CSF into venous circulation.

What fills the ventricular system?

CSF.

Where is CSF produced?

Choroid plexus in all ventricles.

Is CSF present in the spinal cord?

Yes, in the central canal and subarachnoid space.

How many ventricles are in the CNS?

Four.

What is one function of CSF?

Cushioning, nutrient transport, waste removal.

What are the consequences of blocked CSF drainage?

Hydrocephalus; infants → enlarged head; adults → increased intracranial pressure.

What are the three layers of meninges and where are they found?

Dura (outer), arachnoid (middle), pia (inner).

What are three features of the dura mater?

Tough, vascular, forms dural folds and venous sinuses.

What are the contents of the subarachnoid space?

CSF, arteries, veins, arachnoid trabeculae.

What are two unique features of spinal meninges?

Dura is a single layer (not double); epidural space contains fat and venous plexus.