Nervous system - organization
CNS: brain, spinal cord
Somatic: conscious, voluntary
Autonomic: automatic, involuntary
Nervous system - functions
Sensory/afferent: impulses to CNS from receptors
Motor/efferent: impulses from CNS to effector organs
Central nervous system
Brain and spinal cord
Integrating and command centers
Interpret incoming sensory information and issue instructions
Peripheral nervous system
Link all parts of the body by carrying impulses
Star-shaped with swollen ends
Protect neurons from harmful substances in blood
Help control chemical environment in brain
Circulate cerebrospinal fluid
Protective cushion around CNS
Line cavities of brain and spinal cord
Cerebrum - parietal lobe
Somatic sensory area
Posterior to central sulcus
Interprets impulses from sensory recetpros
Recognize pain, coldness, touch
Cerebrum - frontal lobe
Primary motor area
Anterior to central sulcus
Conscious movement of skeletal muscles
Diencephalon - hypothalamus
Regulates body temperature, water balance, metabolism
Center for drives and emotions
Pituitary gland: produces hormones
Mammilary bodies: reflex centers
Brain stem - medulla oblongata
Most inferior of brain stem
Controls heart rate, blood pressure, breathing, swallowing, vomiting
Posterior to pons and medulla, anterior to cerebellum
Dorsally from occipital lobe
Timing for skeletal muscle activity
Controls balance and equilibrium
Contains less protein, more vitamin C
Watery cushion protects nervous system from blows and trauma
Least permeable capillaries in body
Separates neurons from bloodborne substances
Useless against fats, respiratory gases, fat-soluble molecules
Meninges - dura mater
Surrounds brain, attached to inner surface of skull
Meninges - pia mater
Clings tightly to surface of brain and spinal cord
Reflexes - reflex arc
Sensory receptor reacts to stimulus
Effector organ eventually stimulated
Sensory and motor neurons connect the two
Integration center: synapse between sensory and motor neurons
Reflexes - autonomic
Activity of smooth muscles, heart, glands
Digestion, elimination, blood pressure, sweating
Secretion of saliva, changes in size of eye pupil
Fibers arise from olfactory receptors in nasal mucosa and synapse with olfactory bulbs.
Carries impulses for sense of smell.
Fibers arise from retina of eye and form optic nerve. The two optic nerves from optic chiasma by partial crossover of fibers.
Carries impulses for vision.
Fibers run from the midbrain to the eye.
Supplies motor fibers to four of the six muscles that direct the eyeball, to the eyelid, and to the internal eye muscles controlling lens shape and pupil size.
Fibers run from the midbrain to the eye.
Supplies motor fibers for one external eye muscle.
Fibers emerge from the pons and form three divisions that run to the face.
Conducts sensory impulses from the skin of the face and mucosa of the nose and mouth; also contains motor fibers that activate the chewing muscles.
Fibers leave the pons and run to the eye.
Supplies motor fibers to the lateral rectus muscle, which rolls the eye laterally.
Fibers leave the pons and run to the face.
Activates the muscles of facial expression and the lacrimal and salivary glands; carries sensory impulses from the taste buds of anterior tongue.
Fibers run from the equilibrium and hearing receptors of the inner ear to the brain stem.
Vestibular branch transmits impulses for the sense of balance, and cochlear branch transmits impulses for the sense of hearing.
Fibers emerge from the medulla and run to the throat.
Supplies motor fibers to the pharynx that promote swallowing and saliva production; carries sensory impulses from taste buds of the posterior tongue and from pressure receptors of the carotid artery.
Fibers emerge from the medulla and descend into the thorax and abdominal cavity.
Fibers carry sensory impulses from and motor impulses to the pharynx, larynx, and the abdominal and thoracic viscera; most motor fibers are parasympathetic fibers that promote digestive activity and help regulate heart activity.
Fibers arise from the medulla and superior spinal cord and travel to muscles of the neck and back.
Mostly motor fibers that activate the sternocleidomastoid and trapezius muscles.
Fibers run from the medulla to the tongue.
Motor fibers control tongue movements; sensory fibers carry impulses from the tongue.
Spinal nerve plexuses - brachial
C5-C8 and T1
Axillary: deltoid muscle of shoulder
Radial: triceps and extensor muscles of forearm
Medial: flexor muscles of forearm and some muscles of hand
Spinal nerve plexuses - lumbar
Femoral: lower abdomen, buttocks, anterior thighs, skin of anteromedial leg and thigh
Obturator: adductor muscles of medial thigh and small hip muscles, skin of medial thigh and hip joint
Spinal nerve plexuses - sacral
L4-L5 and S1-S4
Sciatic: lower trunk and posterior surface of thigh
Common fibular: lateral aspect of leg and foot
Tibial: posterior aspect of leg and foot
Superior and inferior gluteal: gluteus muscles of hip
ANS - sympathetic
Pounding heart, rapid breathing, cold skin, prickly scalp, dilated eye pupils
Increase heart rate, blood pressure, blood glucose levels