Neuroanatomy Study Guide PDF

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Neuroanatomy Study Guide for exam 3...

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Neuroanatomy Study Guide What are the parts of a neuron? -cell body -dendrites -axons, covered in myelin How do neurons function? -chemical transmitters are released by the axon of one neuron and travel across the synaptic cleft where it stimulates the dendrite of a second neuron. -This causes a change in the neuron's electrical charge and may create an action potential. What are the types of neurons? -sensory, receive input -motor, connect to muscles and glands -interneurons, connect neurons What makes up gray matter? -glial cells -neurons What makes up white matter? -axons What structures are included in the CNS? -brain -brainstem -cerebellum -spinal cord What makes up the PNS? -somatic nervous system -autonomic nervous system What is the somatic nervous system? -perceive sensory stimuli and volitional motor What is the autonomic nervous system? -self-regulation

What are the components of the skull? -8 plates -cranial vault, space inside skull -foramen magnum, opening for brain stem to pass to spinal cord What makes up the vertebrae? -protects and supports the spinal cord -cervical: 1-7 -thoracic: 8-19 -lumbar: 20-24 -sacral: 25-29 -coccygeal: 30-33 What are ventricles? -4 cavities filled with cerebrospinal fluid connected by narrow channels What is the diencephalon? -top of the brainstem -thalamus: major relay station for motor and sensory info -basal ganglia: controls major muscle groups of trunk and limbs What makes up the brain stem? -communicative link between brain and spinal cord -midbrain (mesencephalon): arousal, temp regulation, CN3-4 -pons: breathing, CN5-7 -medulla: regulates BP and breathing, CN 8-12 What are the lobes of the brain? -frontal: planning, executive function, and volitional behavior -parietal: perception, integration, and mediation of touch, body awareness, and visuospatial information -temporal: perception and processing of auditory stimuli -occipital: vision What is the function of the cerebellum? -regulates rate, range, direction, and force of movement -damage = ataxia

What makes up the spinal cord? -outer layer of white matter and core of grey matter -anterior horns: motor neurons -posterior horns: sensory neurons

What are the membranes of the meninges? -dura mater: outer membrane; tough but elastic; adheres to inner surface of skull -arachnoid: web-like tissue to create subarachnoid space filled with CSF -pia mater: fragile membrane that adheres tightly to the brain What are the components of the cerebrum? -2 hemispheres divided by longitudinal fissure -Gyri: ridges -sulci: valleys -fissures: deep valleys -central sulcus: divides anterior and posterior -lateral cerebral fissures: divides ventral and dorsal; sylvian fissure What are the motor pathways? -corticospinal tract -cerebral cortex to motor neurons in spinal cord, which controls muscles responsible for voluntary movement of trunk and limbs -corticobulbar tract -cerebral cortex to motor neurons in spinal cord, which controls muscles responsible for voluntary movement of head and neck -vestibulospinal tract -cerebral cortex to motor neurons in brain stem, which controls muscles responsible for quick movement in response to sudden changes in body position

Sensory pathways: -nerves serving pain and temperature share common pathways to thalamus -proprioception and stereognosis: brain stem to cerebellum and parietal nerve

Motor systems: -pyramidal system i. ii.

Imitates most skilled volitional actions Pyramidal neurons in cortex to spinal cord neurons

-vestibular-reticular system iii. Balance and orientation of body iv. Neurons of brain and cerebellum -extrapyramidal system v.

Indirect system in subcortical area of CNS adjusts muscle tone and postures needed for volitional movements Volitional movements:

-activation of cortical region prepares system for movement -premotor cortex creates coded instructions -primary motor cortex sends command to nerves -vestibular nuclei, midbrain, and reticular formation adjust and posture before and during movement -cerebellum modulates rate, force, and direction -extrapyramidal system adjusts muscle tone and posture to make smooth and continuous movement

Fiber tracts: -projection fibers -long distance carriers from brain to brainstem and spinal cord or from peripheral sensory nerves to brain via spinal cord -commissural fibers -regional carriers between hemispheres -corpus callosum -largest and most important -anterior and posterior commissures association fibers: -connect cortical areas within a hemisphere -fasciculus a. Connects two different lobes -unicate b. Frontal and temporal -congulum c. Frontal and parietal -arcuate d. Temporal and frontal (important for speech and language) B. Blood supply i.

Anterior system 1. Common carotid, internal carotid, anterior and middle cerebral 2. supplies forebrain, most of cortex, basal ganglia, thalamus, deep structures ii. Posterior system 1. Subclavian, vertebral, basilar, posterior cerebral 2. Supplies posterior cortex, midbrain, brainstem iii. From basilar, can go to superior cerebellar artery, anterior inferior cerebellar artery, and posterior inferior cerebellar supplies medulla, pons, midbrain, cerebellum iv. Anterior cerebral supplies midline v. Middle important for speech and language

Cranial nerves: Olfactory (S) vi.

Smell, taste II Optic (S)

vii. Vision III Oculomotor (M) viii.

Eye movement IV Trochlear (M)

ix.

Eye movement V Trigeminal (B)

x. xi.

Sensation from face Motor to masseters, palate, and pharynx VI Abducens (M)

xii. Eye movement VII Facial (B) xiii. Sensation from anterior tongue xiv. Motor to facial muscles VIII Acoustic (S) xv. Hearing and balance IX Glossopharyngeal (B) xvi. Sensation from posterior tongue, soft palate, pharynx xvii. Motor to pharynx X Vagus (B) xviii. Sensation from viscera xix. Motor to larynx, pharynx, viscera XI Accessory (M) xx. Larynx, chest, shoulders XII Hypoglossal (M) xxi.

Tongue movement

Spinal Nerves: Cervical – 8 Thoracic – 12 Lumbar – 5 Sacral – 5 Coccygeal – 1...