NEUROLOGIC SYSTEM

• Central nervous system- encompasses the brain and spinal chord, which are covered by meninges, three layers of connective tissue that protects and nourish the CNS.
• Brain - located in the cranial cavity, it has 4 major divisions.
• 4 major divisions of the brain

  Cerebrum

  Diencephalon

  Brain stem

  Cerebellum
• Gray matter - rims the surface of the cerebral hemisphere, forming the cerebral cortex
• Diencephalon - lies beneath the cerebral hemisphere and consist of the thalamus and hypothalamus
• Thalamus - responsible for screening and directing the impulses to specific areas in the cerebral cortex.
• Hypothalamus- is responsible for regulating many body functions, including water balance, appetite, vital signs, sleep cycle, pain perception, and emotional status.
• Brain stems- located between the cerebral cortex and the spinal cord, it consist of mostly nerve fibers and has 3 parts.
• Brain stems 3 parts;

  Midbrain

  Pons

  Medulla oblongata
• Midbrain- serves as relay center for ears and eye reflexes and relays impulses between the higher cerebral centers, and the lower pons, medulla, cerebellum and spinal cord.
• Pons - links the cerebellum to the cerebrum and the midbrain to the medulla. It is responsible for various reflex actions.
• Medulla oblongata- contains the nuclei for cranial nerves, and has centers thay control and regulates respiratory, functions, and heart rate and force, and blood pressure.
• Cerebellum - located behind the brain stem and under the cerebrum, also has 2 hemisphere. DOES NOT INITIATE MOVEMENTS. primary function includes coordination, and smoothing of voluntary movements, maintenance of equilibrium, and maintenance of muscle tone.
• Spinal cord- conducts sensory impulses up ascending tracts to the brain, conduct motor impulses down descending tracts tp neurons that stimulates glands and muscles throughout the body. And is responsible for simple reflex acitivity.
• Neural pathway - senspry impulses travel to the brain by way of two discending neural pathways.
• 2 Àscending neural pathways

  Spinothalamic tract

  Posterior columns
• Peripheral nervous system - carrying information to and from the CNS, the peripheral nervous system consist of 12 pairs or cranial nerves and 31 spinal nerves
• PNS is categorized as two types of fibers

  Somatic

  Autonomic
• Somatic fibers - carry CNS impulses to voluntary skeletal muscles
• Autonomic fibers - carry CNS impulses to smooth, involuntary muscles(in the heart and glands)
• Somatic nervous system - mediates conscious or voluntary activities
• Autonomic nervous system - mediates unconscious or involuntary activites
• Cranial nerves - 12 pairs evolves from the brain or brain stems and transmits motor or sensory messages.
• Spinal nerves - comprising 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal nerves
• The sensory of each spinal nerves innervates an area of the skin called DERMATOME
• Autonomic nervous system - peripheral nerve special function associated with autonomic activities. Impulses are carried by both cranial and spinal nerves
• Autonomic nervous system- maintains the internal homeostasis of the body incorporate the sympathetic and parasympathetic nervous systems
• Sympathetic nervous system - (fight or flight system) is activated during stress and elicits responses.
• Parasympathetic nervous system - functions to restore and maintain normal body functions.
• 12 cranial nerves

  Olfactory

  Optic

  Oculomotor

  Trochlear

  Trigeminal

  Abducens

  Facial

  Acoustic, vestibulocochlear

  Glossopharyngeal

  Vagus

  Spinal accessory (accessory)

  Hypoglossal
• Cerebrovascular disease(CVD)- has neurologic effects but the cause is vascular
• Eyetic - brief, repititive, stereotyped, coordinated movements occuring at irregular intervals
• Choreiform movements of the hands - brief, rapid, jerky, irregular, and unpredictable. They occur at rest or interrupt normal coordinated movements.
• Resting (static) tremors - are most prominent at rest, and may decrease or disappear with voluntary movement
• Postural tremor- appears when affected part is actively maintaining posture
• Intention tremor of a pointed finger- intention tremors, absent at rest, appears with activity and often get worst as the target is near.
• Athetosis- athetoid movements are slower, more twisting and writhing than choreiform movements, and have a larger amplitude..most commonly involve the face and the distal extremitiea
• Cerebellar ataxia- wide-based staggering, unsteady gait.
• Parkinsonian gait- shuffling gait, turns accomplish in very stiff manner. Stooper - over posture with flexed hips and knees
• Scissors gait - stiff, short gait, thighs overlap each other with each step. Seen with partial paralysis of the legs