Mod 6: Neurology

2 major components of nervous system

central nervous system and peripheral nervous system

CNS made up of (broadly)

brain and spinal cord

PNS made up of (broadly)

ganglia and nerves

CNS structures (5)

cerebral cortex, cerebellum, diencephalon, brainstem, spinal cord

PNS structures (w #s)

12 pairs of cranial nerves and 31 pairs of spinal nerves

Cerebrum

higher functions (cognition, language, memory) & Integrates sensorimotor functions and perception

Limbic system

Regulates motivational and emotional states

Basal ganglia 

regulates motor movements and muscle tone

Thalamus

Mediates sensation to cerebral cortex

Hypothalamus

Regulates body functions such as temperature, satiation, water balance, emotional behavior, sexual response

Cerebellum

Regulates coordination of skilled movements

Midbrain

Mediates auditory and visual reflexes, Maintains cortical arousal, Houses cranial nerve nuclei

Pons

Houses cranial nerve nuclei

Medulla (5)

Regulates respiration, phonation, heartbeat, blood pressure & reflexes

Glial cells (Glue) make up half of ——-, and provide ———-

brain tissue 50%, support and nutrients to the neurons

Interneurons 

communicate between neurons

Motor neuron

Bipolar neuron that activate muscular or glandular responses, usually long myelinated axon

Arcuate fasiculus - connects

frontal lobe gyri to temporal, parietal and occipital lobes

Cerebellum - think

coordination, integrates somatic information, vestibular function, muscle and joint sense, and perception of body in space

posterior frontal lobe 

motor speech and planning

OOO, To Touch And Feel Very Green Vegetables, AH

Olfactory, Optic, Occulomotor, Trochlear, Trigeminal, Abducens, Facial, Vestibulocochlear, Glossopharyngeal, Vagus, Accessory, Hypoglossal

olfactory (function)

sense of smell

optic (function)

sense of vision

occulomotor (function)

eye movement

trochlear (function)

eyes down

trigeminal (function)

sense of touch to face/muscle of chewing

abducens (function)

lateral eye movement

facial (function)

muscles of face and sensation of ear canal, taste anterior 2/3 of the tongue

vestibulocochlear (function)

hearing and vestibular mechanism of ear

glossopharyngeal (function)

afferent for posterior 1/3 of the tongue, relfexes swallow, vomit, gag

vagus (function)

efferent larynx, afferent pharynx, trachea, esophagus, thorax and abdomen

accessory (function)

neck and shoulder movements

hypoglossal (function)

tongue muscles

What is the primary function of the cerebellum?

Coordination of movement, balance, and fine motor skills (NOT motor speech or planning).

Which brain area is responsible for motor speech production and planning?

The posterior frontal lobe (including the primary motor cortex and Broca's area).

What is the key difference between the cerebellum and the posterior frontal lobe?

• Cerebellum = coordination of movement.

• Posterior frontal lobe = motor speech production and planning.

5 steps of reflex arc

1. receptor 2. sensory neuron 3. control center (CNS) 4. motor neuron (efferent neuron) 5. effector

in step 1 of reflex arc, receptor

Detects the stimulus (change in the environment) and sends signal to sensory neuron.

in step 2 of reflex arc, sensory neuron (afferent neuron)

Carries impulse from receptor to control center (CNS), Travels through dorsal root of the spinal cord.

in step 3 of reflex arc, control center (CNS)

spinal cord processes signal, sends instruction to motor neuron. involves interneurons for comm

in step 4 of reflex arc, motor neuron (efferent neuron)

carries response signal from CNS to the effector

in step 5 of reflex arc, effector (interneuron/relay neuron)

causes muscle or gland to respond to the stimulus

how many spinal nerves

31

five regions of spine

cervical, thoracic, lumbar, sacral and coccygeal

cervical, thoracic, lumbar, sacral and coccygeal - how many nerves in each

8, 12, 5, 5, 1

somatic nervous system in charge of

voluntary control of skeletal muscles and sensory information

autonomic nervous system in charge of

involuntary, unconscious bodily functions like heart rate, digestion, breathing

name the main fissures (3)

longitudinal, lateral, central

what is anterior to the central fissure?

primary motor cortex

what is superior to the lateral/sylvian fissure?

Frontal lobe (anteriorly) and Parietal lobe (posteriorly).

what is inferior to the lateral fissure?

temporal lobe

location of longitudinal fissure

between the right and left hemispheres of the brain. down through the brain until it reaches the corpus callosum

What is the primary function of the cortical system?

Higher-level conscious processing, including thought, sensory perception, voluntary motor control, language, and memory.

What is the primary function of the subcortical system?

Automatic, fundamental processes such as emotion regulation, motor coordination, arousal, and memory encoding.

name the parts of a neuron

cell body (soma), dendrites, axon, axon terminals, myelin sheath, nodes of ranvier, nucleus

How do nodes of Ranvier assist in neural signal transmission?

gaps in myelin sheath, allow for faster signal transmission enabling ion flow and saltatory conduction.

function of the myelin sheath

speeds up transmission of electrical impulses, insulates axon and allows faster signal movement.

axon terminals in communication between neurons?

release neurotransmitters to pass signals to other neurons or muscles at the synapse.

What is the axon responsible for in a neuron?

transmits electrical impulses away from the cell body

role of dendrites in a neuron?

receive electrical signals from other neurons and bring them toward the cell body.

projection fibers

connect cortex to brainstem/spinal column

association fibers

connect regions within same hemisphere

commisural

connects left and right (corpus callosum)