Nervous System

Peripheral Nervous system – messages via spinal and cranial nerves Central nervous system Sensory nerves - carry sensory info to brain and spinal cord somatic sensory nerves - FROM skin, muslces, joints, special senses visceral sensory nerves - FROM body organs Motor nerves - from CNS to effectors Somatic motor nerves - (controls movement) TO skin, skeletal muscles, tendons -voluntary Autonomic motor nerves -(controls body function) To smooth muscle, cardiac muscle, organs, glands - involuntary Parasympathetic division "rest and digest" "normal state" Sympathetic division "Fight or flight" Brain Spinal cord Peripheral Nervous system – messages via spinal and cranial nerves

Resting Potential

Action Potential

Action Potential

Propagation of Action Potential

Synaptic Integration

Cerebrum meninges corpus callosum Diencephalon Brain stem Cerebellum skull meninges pituitary gland fourth ventricle spinal cord Cerebrum Diencephalon Cerebellum hypothalamus midbrain pons Brain stem b. Cerebral hemispheres lateral ventricle third pineal gland corpus callosum thalamus (surrounds the third ventricle) medulla oblongata

Spinal Cranial Nerve artery and vein single nerve fiber bundle of nerve fibers

Somatic Nervous system pin dorsal root ganglion central canal white matter sensory receptor (in skin) gray matter Dorsal dorsal horn cell body of sensory neuron axon of sensory neuron cell body of interneuron axon of motor neuron effector (muscle) ventral root cell body of motor neuron ventral horn Ventral

Autonomic Nervous system ganglion inhibits tears inhibits salivation stimulates tears constricts pupils slows heart sympathetic ganglia vagus nerve Sympathetic Division Parasympathetic Division dilates pupils stimulates salivation cranial nerves speeds heart cervical dilates air passages stimulates liver to release glucose constricts bronchioles stimulates gallbladder to release bile adrenal secretion increases activity of stomach and pancreas increases intestinal activity inhibits activity of kidneys, stomach, and decreases intestinal activity urination inhibits sacral causes orgasmic contractions erection of genitals lumbar thoracic Acetylcholine is neurotransmitter. Norepinephrine is neurotransmitter.

Autonomic motor pathways    Somatic Motor Pathway Autonomic motor pathways Sympathetic motor pathway Parasympathetic motor Control Vol/invol invol involuntary # of neurons/message 1 2 (preganglionic shorter than post) 2 (preganglionic longer than post) Loctn of motor fiber Most cranial nerves and all spinal nerves Thoracic-lumbar spinal nerves Cranial and sacral spinal nerves Neurotransmitter acetylcholine Norepinephrine (NE) Acetylcholine (Ach) effectors Skeletal muscle, skin, tendons Smooth & cardiac muscle, glands, & organs