ALL Study Notes UofA

Autonomic Nervous System (ANS)

Involuntary system regulating internal body functions.

Homeostasis

Maintaining internal environment stability in the body.

Fight or Flight Response

Emergency activation mechanism during stress.

Rest and Digest

Housekeeping functions like digestion and relaxation.

Central Nervous System (CNS)

Brain and spinal cord; neural control center.

Peripheral Nervous System (PNS)

Nerves outside CNS; connects body to CNS.

Afferent Division

Carries sensory information to the CNS.

Efferent Division

Transmits commands from CNS to effectors.

Somatic Nervous System

Controls voluntary movements of skeletal muscles.

Autonomic Motor Division

Targets smooth muscle, cardiac muscle, and glands.

Sympathetic Division

Prepares body for stressful situations.

Parasympathetic Division

Promotes rest and energy conservation.

Enteric Nervous System

Regulates gastrointestinal functions independently.

Smooth Muscle

Involuntary muscle in hollow organs.

Cardiac Muscle

Muscle tissue found in the heart.

Sensory Receptors

Detect environmental changes and send signals.

Somatic Sensory Information

Touch, pain, and temperature sensations.

Visceral Sensory Information

Sensations from internal organs.

Special Sensory Information

Includes visual, olfactory, and auditory sensations.

Effectors

Muscles and glands executing CNS commands.

Involuntary Control

Functions not under conscious awareness.

Afferent neuron

Relays sensory information to the CNS.

Efferent neuron

Relays motor commands from the CNS.

Nerve

Group of nerve fibers in the PNS.

Neuron

Basic nerve cell in the nervous system.

Cranial Nerves

12 nerves emerging directly from the brain.

Vagus nerve

Cranial nerve 10, important for parasympathetic function.

Spinal Nerves

31 pairs of mixed nerves in the body.

Somatic Nervous System (SNS)

Controls voluntary movements via skeletal muscles.

Autonomic Nervous System (ANS)

Controls involuntary functions in smooth and cardiac muscles.

Preganglionic neuron

First neuron in the autonomic chain.

Postganglionic neuron

Second neuron in the autonomic chain.

Ganglia

Clusters of neuronal cell bodies outside the CNS.

Acetylcholine (ACh)

Neurotransmitter for somatic muscle contraction.

Myelination

Insulation of axons to increase conduction speed.

Sympathetic Nervous System

Activates fight-or-flight responses in emergencies.

Parasympathetic Nervous System

Promotes rest-and-digest activities.

Mixed nerves

Nerves containing both afferent and efferent fibers.

Synapse

Junction where two neurons communicate.

Collateral ganglia

Ganglia located in front of the vertebral column.

Celiac ganglion

Collateral ganglion innervating abdominal organs.

Superior mesenteric ganglion

Collateral ganglion for intestines and colon.

Inferior mesenteric ganglion

Collateral ganglion for pelvic organs.

Thoracolumbar division

Sympathetic division originating from thoracic and lumbar regions.

Ganglion location in PSNS

Ganglia near or within target organs.

Neurotransmitter in ANS

Can be ACh, norepinephrine (NE), or epinephrine (E).

Short axon in SNS

Allows for rapid and direct control of muscles.

Long axon in PSNS

Connects CNS to ganglia near target organs.

Inhibition of skeletal muscle

No command sent from CNS prevents contraction.

Somatic Nervous System (SNS)

Controls voluntary movements to skeletal muscles.

Autonomic Nervous System (ANS)

Controls involuntary actions to smooth and cardiac muscles.

Myelination

Insulation of axons affecting conduction speed.

Acetylcholine (ACh)

Neurotransmitter for skeletal muscle contraction.

Sympathetic Nervous System

Thoracolumbar division controlling fight or flight response.

Parasympathetic Nervous System

Rest and digest system, promotes relaxation.

Mixed nerves

Contain both afferent and efferent fibers.

Neurotransmitter

Chemical messenger between neurons.

Synapse

Junction where neurons communicate.

Superior mesenteric ganglion

Collateral ganglion supplying the intestines.

Inferior mesenteric ganglion

Collateral ganglion innervating pelvic organs.

Ventral root

Pathway carrying motor information from the spinal cord.

Dorsal root

Pathway carrying sensory information to the spinal cord.

Short axon

Characteristic of SNS preganglionic neurons.

Long axon

Characteristic of PSNS preganglionic neurons.

Mass discharge

Activation of multiple organs in SNS response.

Sympathetic preganglionic fiber

Nerve fiber originating from the spinal cord.

Sympathetic ganglion

Cluster of nerve cell bodies in the sympathetic nervous system.

Collateral ganglion

Ganglion located away from the spinal cord.

Splanchnic nerve

Nerve that innervates abdominal organs.

Communicating rami

Connections between spinal nerves and ganglia.

White ramus communicans

Branch carrying myelinated preganglionic fibers.

Grey ramus communicans

Branch carrying unmyelinated postganglionic fibers.

Synapse

Connection point between two neurons.

Preganglionic neuron

Neuron that transmits signals from the spinal cord.

Sympathetic Pathways

Nerve fibers travel through rami for communication.

Rami

Structures allowing nerve fibers to communicate.

Sympathetic Nervous System

Dominates during fight or flight response.

Adrenal Medulla

Releases epinephrine and norepinephrine into blood.

Epinephrine

Hormone released by adrenal medulla, 80% of secretion.

Norepinephrine

Hormone released by adrenal medulla, 20% of secretion.

Preganglionic Neurons

Neurons originating in the CNS, short axon.

Postganglionic Neurons

Neurons that innervate target tissues, longer axon.

Parasympathetic Nervous System

Dominates during rest and digest response.

Craniosacral Origin

Preganglionic fibers originate from brainstem and sacral regions.

Vagus Nerve

Carries 75% of all parasympathetic fibers.

Terminal Ganglia

Ganglia located close to innervated organs.

Dual Autonomic Innervation

Most organs receive both sympathetic and parasympathetic input.

Sympathetic Tone

Background activity level of the sympathetic system.

Parasympathetic Tone

Background activity level of the parasympathetic system.

Antagonistic Effects

Opposing actions of SNS and PSNS on organs.

Cooperative Effects

Both systems work together for complex responses.

Cholinergic Fibers

Release acetylcholine (ACh) as neurotransmitter.

Adrenergic Fibers

Release norepinephrine (NE) as neurotransmitter.

Chemical Transmitters

Substances released by neurons to communicate.

Acetylcholine (ACh)

Major transmitter at all autonomic ganglia.

Acetylcholinesterase

Enzyme that breaks down ACh in synapse.

Varicosity

Swelling along axon where neurotransmitter is released.

Sympathetic Innervation

Only innervation for adrenal medulla and blood vessels.

Sweat Glands

Receive only sympathetic innervation for activation.

Blood Vessel Innervation

Most receive sympathetic innervation; exceptions exist.