Central Nervous System Flashcards
Telencephalon
Part of the forebrain (prosencephalon). Consists of cerebrum, hippocampus, basal ganglia, and amygdala
Cerebrum
Divided into R and L hemispheres connected by corpus callosum. Outer surface is gray matter and inner surface is white matter
Left Hemisphere
Language, sequence and perform movements, logical, rational, express positive emotions, process verbally coded information
Right Hemisphere
Non-verbal processing and communication, concept comprehension, hand-eye coordination, spatial relationships, kinesthetic awareness, negative emotions, body image awareness
Hippocampus
Within lower temporal lobe. Responsible for process of forming and storing new memories. Possesses importance in learning language.
Basal Ganglia
Gray matter masses located deep within the white matter of the cerebrum and include the caudate, putamen, globus pallidus, substantia nigra, and subthalamic nuclei.
Responsible for voluntary movement, regulation of autonomic movement, posture, muscle tone, and control of motor responses.
Basal ganglia dysfunction associated with Parkinsons’ disease, Huntington’s, Tourette’s syndrome, ADD, OCD, and addictions.
Amygdala
Nucleus located within the temporal lobes of each hemisphere. Responsible for emotional and social processing. Involved with fear and pleasure, arousal, processing of memory, and formation of emotional memories.
Diencephalon
Part of the forebrain. Located beneath cerebral hemispheres and contains the thalamus, hypothalamus, subthalamus, and epithalamus.
Major motor and sensory tracts synapse here. Acts as an interactive site between CNS and endocrine system; complements limbic system.
Thalamus
Relay or processing station for majority of info that goes to cerebral cortex. Receives info from cerebellum, basal ganglia, and all sensory pathways except for olfactory tract. Thalamus relays info to appropriate associated cortex. Damage can produce thalamic pain syndrome where there is spontaneous pain on contralateral side of body.
Hypothalamus
Receives and integrates info from ANS and regulates hormones. Controls hunger, thirst, sexual behavior, and sleep. Regulates body temp, adrenal glands, pituitary glands, and other vital activities. Lesions may produce obesity, sexual disinterest, poor temp control, and diabetes.
Subthalamus
Located between thalamus and hypothalamus. Regulates movements produced by skeletal muscles. Associated with basal ganglia and substantia nigra.
Epithalamus
Primarily represented in pineal gland, which secretes melatonin and is involved in circadian rhythms, regulation of motor pathways, and emotions. Associated with limbic system and basal ganglia.
Midbrain (Mesencephalon)
One of three components of the brainstem. Connects forebrain to hindbrain and functions as a relay area for info passing from cerebrum, cerebellum, and spinal cord. Reflex center for visual, auditory, and tactile responses. Includes tectum (superior and inferior colliculi) and tegmentum (cerebral aqueduct, periaqueductal gray, reticular formation, substantia nigra, red nucleus)
Hindbrain (Rhombencephalon)
Consists of cerebellum, pons, and medulla oblongata. Pons and medulla oblongata are part of brainstem and control vital functions.
Cerebellum
Responsible for fine tuning movement and maintaining posture and balance by controlling muscle tone and positioning of extremities in space. Controls ability to perform rapid alternating movement. Consists of 2 hemispheres and divided into anterior, posterior, and flocculonodular lobes. Damage to cerebellum will produce ipsilateral symptoms. Symptoms include ataxia, nystagmus, tremor, hypermetria, poor coordination, and poor postural reflexes, balance, and equilibrium.
Pons
Regulates respiration rate and orientation of head in relation to visual and auditory stimuli. CN V-VIII originate from pons.
Medulla Oblongata
Influences autonomic nervous activity and regulation of respiration and heart rate. Reflex centers for vomiting, coughing, and sneezing in medulla. Damage to motor tracts within medulla produces contralateral impairment. Responsible for relaying somatic sensory info from internal organs and control of arousal and sleep. CN IX-XII originate from here.
Brainstem
Consists of midbrain, pons, and medulla oblongata. Acts as a relay center, sending messages between cerebral cortex and body. Regulates HR and RR. Majority of CN originate in this area.
Anterior cerebral artery (ACA)
Supply: Anterior frontal lobe and medial surface of frontal and parietal lobes.
Expected Impairments: Contralateral LE motor and sensory involvement, loss of behavioral inhibition, neglect, aphasia, apraxia
Middle cerebral artery (MCA)
Most common site of CVA
Supply: Outer cerebrum, basal ganglia, internal capsule, putamen, pallidum, lentiform nucleus.
Expected Impairments: Contralateral motor and sensory loss of face and UE with less involvement of LE, Wernicke’s aphasia in dominant hemisphere, homonymous hemianopsia, apraxia.
Posterior cerebral artery (PCA)
Supply: Portion of midbrain, subthalamic nucleus, thalamus, basal nucleus, inferior temporal lobe, occipital and occipitoparietal cortices.
Expected Impairments: Contralateral pain and temperature sensory loss, contralateral hemiplegia, ataxia, athetosis or choreiform, thalamic pain syndrome, homonymous hemianopsia, visual agnosia, memory impairment.
Vertebral-basilar artery
Supply: Midbrain, superior cerebellum, thalamus, occipital cortex.
Expected Impairments: Hemiplegia or tetraplegia, loss of consciousness, inability to speak or swallow, locked-in syndrome, vertigo, nystagmus, ataxia.
Meninges
Consists of 3 layers of connective tissue that protect the brain from contusion and infection. There are blood vessels and CSF within meninges.
Dura mater – outermost layer
Arachnoid mater – impermeable, surrounds brain in loose manner
Pia mater – covers the contours of brain; forms the choroid plexus in the ventricular system
Meningitis Symptoms
Fever, headache, vomiting; stiff/painful neck; pain in lumbar area and posterior thigh; Brudzinski’s sign (flexion of neck facilitates flexion of hips and knees); Kernig’s sign (pain with hip flexion combined with knee extension); sensitivity to light. Lumbar puncture to diagnose.
Ventricular System
Protects and nourishes brain
Comprised of 4 fluid-filled cavities
Each ventricle contains choroid plexus that makes CSF
Excess fluid in ventricles is termed hydrocephalus and excess fluid in spinal cord called syringomyelia
CSF provides cushion and mechanical buoyancy/support. Helps remove metabolites.
Blood Brain Barrier
Consists of meninges, protective glial cells, and capillary beds of the brain. Exchanges nutrients between the CNS and vascular system. Protects the brain by restricting certain molecules from crossing.
