Lecture 6: Brain & Spinal Cord Overview

These question-and-answer flashcards cover major anatomical structures, physiological functions, and clinical points from Lecture 6 on the brain, brainstem, spinal cord, meninges, and cerebrospinal fluid.

Where is the medulla oblongata located within the brainstem?

It is the lowest and most posterior part of the brainstem, continuous with the spinal cord.

What ventricular cavity lies within the medulla?

The fourth ventricle.

Why must all nerve tracts between the brain and spinal cord pass through the medulla?

Because the medulla is the direct continuation of the spinal cord into the brainstem.

What is the primary role of the reticular formation?

Receiving sensory information and influencing the level of arousal to keep the cerebrum conscious and alert.

Name three vital centers housed in the medulla oblongata.

Cardiac centers (heart rate), vasomotor centers (blood pressure), and respiratory centers (breathing control).

Which reflex centers are located in the medulla?

Vomiting, sneezing, coughing, and swallowing reflex centers.

What structure acts as a “bridge” on the anterior brainstem superior to the medulla?

The pons.

List two functional centers found in the pons.

Respiration centers and sleep centers.

Which short brainstem segment contains the cerebral aqueduct?

The midbrain.

What do the four rounded bodies (colliculi) in the midbrain control?

Reflex centers for visual and auditory reflexes.

Between which two major brain parts is the diencephalon located?

Between the cerebrum and the midbrain.

What cavity lies within the diencephalon?

The third ventricle.

What is the main relay station for all sensory information except smell?

The thalamus.

How does the thalamus influence sensory awareness?

It ‘gates’ sensory input, deciding which signals reach the cerebrum for conscious perception.

Which diencephalic structure links the nervous and endocrine systems?

The hypothalamus.

Name two hormones produced by the hypothalamus and released by the pituitary.

Antidiuretic hormone (ADH) and oxytocin.

Which hypothalamic nucleus acts as a master biological clock?

The suprachiasmatic nucleus.

Give three homeostatic functions regulated by the hypothalamus.

Fluid balance/thirst, body temperature, appetite & satiety (food intake).

What are the two main hemispheres of the cerebellum called?

The right and left cerebellar hemispheres.

What type of matter forms the cerebellar cortex?

Gray matter (neuronal cell bodies).

Where are the basal nuclei located and what is their role?

Within the cerebral white matter; they help regulate automatic movements.

Which structure connects the right and left cerebral hemispheres?

The corpus callosum.

Which sulcus separates the frontal lobe from the parietal lobe?

The central sulcus.

What kinds of activities are handled by cerebral association areas?

Intellect: thought, reasoning, judgment, decision making, learning, memory, and language.

Name the primary motor area in the frontal lobe.

The precentral gyrus.

Which frontal-lobe region is essential for speech production?

Broca’s area.

Where is the primary somatosensory area located?

In the postcentral gyrus of the parietal lobe.

Which lobe houses the primary visual cortex?

The occipital lobe.

What is the main auditory processing lobe of the brain?

The temporal lobe (primary auditory and auditory association areas).

Which brain system is chiefly involved in emotion and memory?

The limbic system.

What role does the hippocampus play?

Formation and retrieval of memories.

What is the amygdala’s primary function?

Evaluating sensory information for emotional relevance, especially fear and survival.

Define synaptic plasticity.

The ability of synapses to be modified during learning and remembering.

How do most mood-altering drugs affect the brain?

By changing dopamine or other neurotransmitter levels.

List the two principal functions of the spinal cord.

Transmit information to/from the brain and control reflexes.

Where does the adult spinal cord typically end?

At the level of the second lumbar vertebra (L2).

What type of information is carried by ascending tracts?

Sensory information traveling up to the brain.

Describe a reflex action.

A predictable, automatic response to a specific stimulus.

Name the five basic steps in a reflex pathway.

Stimulus reception, sensory transmission to CNS, integration, motor transmission, and response.

What three neuron types are involved in a withdrawal reflex?

Sensory neurons, interneurons, and motor neurons.

List the three layers of meninges from outermost to innermost.

Dura mater, arachnoid, pia mater.

Where does cerebrospinal fluid (CSF) circulate outside the ventricles?

In the subarachnoid space around the brain and spinal cord.

What produces most CSF?

The choroid plexuses projecting from the pia mater into the ventricles.

Give two protective or supportive functions of CSF.

Acts as a shock absorber and serves as a medium for nutrient/waste exchange.

What condition results from abnormal CSF flow causing ventricular enlargement?

Hydrocephalus.

Why is a lumbar puncture typically performed between L3 and L4 (or L4 and L5)?

To access the subarachnoid space for CSF sampling without risking damage to the spinal cord (which ends at L2).

What medical procedure involves injecting anesthetic into the subarachnoid space?

A spinal (or epidural) anesthesia to block sensory transmission.

Which brainstem component contains respiratory, cardiac, and vasomotor centers?

The medulla oblongata.

What are the two main cavities found in the cerebrum called?

The lateral ventricles.

Which white-matter tract links the hippocampus to the hypothalamus?

The fornix.