Physiology chapter 8

List meninges outer to inner.

Dura mater, arachnoid mater, pia mater.

Why is a spinal nerve called mixed?

It carries both sensory and motor axons.

What does the dorsal root carry?

Sensory fibers entering spinal cord.

What does the ventral root carry?

Motor fibers leaving spinal cord.

What do dorsal gray horns process?

Sensory input.

What do ventral and lateral gray horns chiefly send?

Motor output.

What are white columns and what do they contain?

Dorsal, lateral, ventral white matter containing ascending and descending tracts.

What direction do ascending tracts carry information?

Toward the brain; sensory information.

What direction do descending tracts carry information?

Away from brain; motor information.

What information does the dorsal column tract carry?

Touch, pressure, vibration, proprioception.

What information do spinocerebellar tracts carry?

Proprioception to cerebellum.

What information does spinothalamic tract carry?

Pain, temperature, itch, tickle.

Which two corticospinal tracts are direct/pyramidal?

Lateral and ventral corticospinal tracts.

Which motor tracts listed are indirect/extrapyramidal?

Rubrospinal, reticulospinal, vestibulospinal, tectospinal.

List five elements of a reflex arc in order.

Receptor, sensory neuron, integrating center, motor neuron, effector.

What is the route from ventral horn to skeletal muscle?

Somatic motor neuron → ventral root → spinal nerve → skeletal muscle.

How is autonomic motor output organized?

Preganglionic neuron exits CNS → autonomic ganglion → postganglionic neuron → smooth/cardiac muscle or gland.

What four major things protect the brain?

Cranium, meninges, BBB, CSF.

What physical features create the BBB?

Tight junctions in capillaries with astrocyte support and selective transporters.

What produces CSF?

Choroid plexus with ependymal cells and capillaries.

Name the four brain ventricles.

Two lateral ventricles, third ventricle, fourth ventricle.

Where does CSF circulate beyond ventricles?

Subarachnoid space.

What are the functions of CSF?

Mechanical cushioning, chemical protection, nutrient/waste circulation.

Why does interruption of brain blood flow quickly matter?

Neurons need steady oxygen/glucose for aerobic ATP production; slides note impairment after 1-2 min, possible permanent injury after >4 min.

What is CN I and what does it carry?

Olfactory; sensory smell.

What is CN II and what does it carry?

Optic; sensory vision.

What is CN III, its type and function?

Oculomotor; motor; eye movements, pupil constriction, near accommodation.

What is CN IV, its type and function?

Trochlear; motor; eye movement.

What is CN V, its type and function?

Trigeminal; mixed; facial sensation and chewing.

What is CN VI, its type and function?

Abducens; motor; eye movement.

What is CN VII, its type and function?

Facial; mixed; anterior tongue taste, facial expression, salivation and tears.

What is CN VIII, its type and function?

Vestibulocochlear; sensory; hearing and equilibrium.

What is CN IX, its type and function?

Glossopharyngeal; mixed; posterior tongue taste, swallowing/pharynx, parotid secretion, carotid sensory input.

What is CN X, its type and function?

Vagus; mixed; visceral sensation/control, pharynx/larynx and taste from pharynx/epiglottis.

What is CN XI, its type and function?

Accessory; motor; moves head and neck.

What is CN XII, its type and function?

Hypoglossal; motor; tongue movement.

Which cranial nerves group with cerebrum in slides?

I and II.

Which cranial nerves group with midbrain in slides?

III and IV.

Which cranial nerves group with pons in slides?

V, VI, VII, VIII.

Which cranial nerves group with medulla in slides?

IX, X, XI, XII.

What three parts form brainstem?

Midbrain, pons, medulla oblongata.

What are key medullary functions?

Cardiovascular and respiratory control; vomiting, sneezing, coughing, swallowing, hiccup reflexes.

What are key pontine functions?

Relay voluntary movement signals to cerebellum and aid respiratory control.

What do substantia nigra and red nucleus contribute?

Movement regulation in midbrain.

What do superior and inferior colliculi process?

Superior: visual reflexes; inferior: auditory reflexes.

What does cerebellum compare?

Intended movement from cerebrum versus actual movement from proprioceptors.

What does cerebellum do with movement mismatch?

Sends corrective feedback to smooth and coordinate movement; helps posture/balance.

What are three diencephalon components?

Thalamus, hypothalamus, epithalamus/pineal gland.

What does thalamus do?

Relays most sensory input to cortex and motor information from basal nuclei/cerebellum.

Name hypothalamic functions.

Controls ANS and hormones, emotion, hunger/satiety/thirst, temperature and circadian rhythms.

What do suprachiasmatic nuclei help regulate?

Circadian rhythms using visual input.

What does pineal gland secrete and regulate?

Melatonin; sleep/wake cycle.

What are gyri and sulci?

Gyri are raised cortical folds; sulci are grooves.

What three broad structural layers/components of cerebrum are listed?

Cerebral cortex (gray), underlying white matter, deep basal nuclei (gray).

Where is primary somatosensory cortex?

Postcentral gyrus of parietal lobe.

What does primary somatosensory cortex process?

Touch, pressure, vibration, temperature, pain, proprioception.

Where is primary visual cortex?

Occipital lobe.

Where is primary auditory cortex?

Temporal lobe.

Where is gustatory cortex?

Insula.

Where is olfactory cortex?

Inner temporal lobe.

Where is primary motor cortex and what does it do?

Precentral gyrus, frontal lobe; controls voluntary contractions contralaterally.

What is Broca's area's role and location?

Speech articulation/motor plan in frontal lobe.

What does Wernicke's area do?

Interprets meaning of written or spoken words.

What does somatosensory association cortex do?

Builds/uses memories of somatic sensations.

What does visual association cortex do?

Interprets/evaluates what is seen.

What does facial recognition area do?

Recognizes people by faces.

What does auditory association cortex do?

Recognizes sounds.

What does orbitofrontal cortex do for sensory input?

Identifies and discriminates smells.

What does common integrative area do?

Combines sensory input to form thoughts.

What does prefrontal cortex contribute?

Personality, intellect and complex learning.

What does premotor cortex contribute?

Stored patterns/planning for complex movements.

Name five basal nuclei network structures in slides.

Caudate, putamen, globus pallidus, subthalamic nucleus, substantia nigra.

What are three functions of basal nuclei?

Initiate movement, suppress unwanted movement, maintain tone.

What is limbic system broadly associated with?

Emotional processing: pleasure, fear, anger, affection, pain and related states.

What does reticular activating system do?

Supports wakefulness, alertness, awareness.

What two sleep states are listed?

REM and NREM (slides list four NREM stages).

Trace a spoken word to a spoken response.

Primary auditory cortex → Wernicke's → Broca's → primary motor cortex → speech muscles.

Trace a written word to a spoken response.

Primary visual cortex → Wernicke's → Broca's → primary motor cortex → speech muscles.

Where does mesolimbic dopamine pathway originate and project?

Ventral tegmental area → nucleus accumbens, limbic and prefrontal regions.

What is associative learning?

Connecting two stimuli or events, e.g. Pavlovian conditioning.

What is nonassociative learning?

Change in response after repeated exposure to one stimulus.

What is habituation?

Decreased response to repeated irrelevant stimulus.

What is sensitization?

Increased response to repeated noxious stimulus.

What is declarative/explicit memory?

Consciously recallable/verbalizable facts and experiences.

What is semantic memory?

Facts, names, objects, general knowledge.

What is episodic memory?

Personal autobiographical events.

What is nondeclarative/procedural memory?

Implicit skills, habits, procedures; associated with basal nuclei, cerebellum, premotor cortex.

What distinguishes short- from long-term memory?

Short term seconds-minutes; long term days-years.

What is consolidation and which structure is crucial for declarative memories?

Short-to-long-term stabilization; hippocampus.

What does neural plasticity mean?

Functional and structural changes in neurons and synaptic connections.