Central Nervous Sytem
about 100 billion multipolar neurons The Brain about 100 billion multipolar neurons
Divided into 4 major sections Brain stem Cerebellum Diencephalon Cerebrum
Protective covering meninges
Meningitis Infection and swelling of the meninges (membrane that surrounds brain and spinal cord) Can be viral or bacterial
Blood-brain barrier
Infections Shingles- infection of peripheral nervous system by herpes zoster virus Pain, skin discoloration, line of skin blisters Poliomyelitis- poliovirus attacks neuron cell bodies Fever, headaches, stiff neck and back, pain and weakness Can cause paralysis
Cerebrospinal fluid provides protection, maintains proper ion concentration for the CNS, and provides a pathway to the blood for waste
Brain Stem Connects cerebrum and diencephalon to the spinal cord Midbrain- reflexes Pons- breathing Medulla oblongata- heart rate, breathing, blood pressure Reticular formation- arousal (comatose state)
Cerebellum Anterior and posterior lobes Coordination of desired movements Regulates posture and balance Cognitive and language processing
Diencephalon Located between cerebral hemispheres and above the midbrain Contains: Thalmus- relay station for sensory impulses Hypothalmus- maintains homeostasis by regulating: Heart rate Temperature Water/ electrolyte balance Hunger Glandular secretions Sleep link
- Epithalamus- superior and posterior to Contains pineal gland- secretes hormone melatonin (endocrine)
Diencephalon
Cerebrum Divided into 2 cerebral hemispheres by the corpus callosum Convolutions- ridges of the brain (gyri) Sulcus- shallow groove Fissure- deep groove
The Basal Ganglia (caudate nucleus, putamen, globus pallidus) act as a relay station for motor impulses travelling from the cerebral cortex to the spinal cord link
Parkinson's Disease Progressive disorder of CNS Usually seen around age 60 Changes in substantia nigra and basal ganglia Too little dopamine produced (neurotransmitter) Too much acetylcholine produced
The cerebral cortex interconnects with the basal ganglia, the thalmus and the hypothalmus to form the Limbic System Controls emotional experience and expression link
Lobes of the cerebrum (higher brain function) Frontal Parietal Temporal Occipital Insula
Covered in a thin layer of gray matter called the Cerebral Cortex Motor area (mostly frontal) Sensory area (mostly parietal) Association areas (throughout cerebrum) Frontal- concentration, problem solving, planning Parietal- compose speech, touch sensation Temporal understand speech, reading, music Occipital- analyzing visual patterns
patb
can map somatosensory areas (lips and hands large area, trunk and limbs small area)
Sensory and Motor areas of the cerebral cortex link
Alzheimer's Disease Afflicts about 11% of population over 65 Deterioration of mind Loss of neurons in specific regions Abnormal plaque deposits Tangled protein filaments in neurons Diagnosis difficult
Huntington Disease link Devastating, degenerative brain disorder for which there is, at present, no effective treatment or cure Genetic- autosomal dominant (50% chance to pass to children) link
frog bird cat
Electroencephalogram (EEG) link
Spinal Cord Injury Damaged by compression (tumor, herniated disc, blood clots, penetrating wounds, traumatic events) Can lead to paralysis Monoplegia- one extremity Paraplegia- both lower extremities Quadriplegia- both upper and lower extremities
Multiple Sclerosis Progressive destruction of myelin sheaths of neurons in CNS Form scleroses (hardened scars or plaques) Slows conduction Average onset age 33 Progressive loss of function interspersed with remission periods
Peripheral nervous system Nerve structure- very similar to structure of muscle!! link
Cranial nerves I - Olfactory II - Optic III - Oculomotor IV - Trochlear V - Trigeminal VI - Abducens VII - Facial VIII - Auditory IX - Glossopharyngeal X - Vagus XI - Accessory XII - Hypoglassal
Spinal nerves and plexuses (tangled networks of axons)