Autonomic, Sensory, Motor & Integrative Systems – Review Flashcards

These flashcards cover the autonomic nervous system, sensory receptors and pathways, motor control, sleep, and integrative brain functions to prepare for exams on Chapters 15–17.

What does the autonomic nervous system (ANS) primarily control?

Involuntary body functions such as heart rate, digestion, breathing, and blood pressure.

Which type of sensory receptors monitor internal conditions like blood pressure or CO₂ levels?

Interoceptors.

Name the two major types of interoceptors and the stimuli they detect.

Chemoreceptors detect chemical changes (e.g., CO₂), and mechanoreceptors detect stretch or pressure (e.g., stomach distension).

Somatic vs. autonomic motor pathways: how many motor neurons are found in each?

Somatic pathways have one motor neuron; autonomic pathways have two (preganglionic and postganglionic).

Where are sympathetic pre-ganglionic neuron cell bodies located?

In the lateral horns of spinal cord segments T1–T12 and L1–L2/3 (thoracolumbar outflow).

Why is the sympathetic division called the “thoracolumbar” division?

Because its pre-ganglionic neurons exit the thoracic and lumbar regions of the spinal cord.

Which cranial nerves carry parasympathetic pre-ganglionic fibers?

Cranial nerves III (oculomotor), VII (facial), IX (glossopharyngeal), and X (vagus).

Which spinal cord segments supply sacral parasympathetic outflow?

S2–S4.

Fight-or-flight responses include which cardiovascular change?

Increased heart rate and blood pressure.

Rest-and-digest responses include which gastrointestinal change?

Increased digestive activity and glandular secretions (SLUDD: salivation, lacrimation, urination, digestion, defecation).

What is autonomic tone?

The balance of sympathetic and parasympathetic activity maintained by the hypothalamus.

Which structures receive only sympathetic innervation?

Sweat glands, arrector pili muscles, kidneys, most blood vessels, and adrenal medulla.

What neurotransmitter is released by all autonomic pre-ganglionic neurons?

Acetylcholine (ACh).

Most sympathetic post-ganglionic neurons are classified as what type of neuron?

Adrenergic (they release norepinephrine).

Which cholinergic receptor type is found on all post-ganglionic neurons?

Nicotinic receptors.

Muscarinic receptors can produce what two possible effects on target cells?

Excitation (depolarization) or inhibition (hyperpolarization) depending on the tissue.

Name the two main classes of adrenergic receptors.

Alpha (α) and Beta (β) receptors.

Which adrenergic receptor subtype is primarily responsible for thermogenesis in brown fat?

β3 receptors.

Why do sympathetic effects last longer than parasympathetic effects?

Greater divergence, slower breakdown of norepinephrine, and release of E/NE hormones from adrenal medulla.

Define an autonomic plexus and give one example in the thorax.

A network where sympathetic and parasympathetic fibers mix around major arteries; example: cardiac plexus.

What is the enteric nervous system (ENS)?

A network of ~100 million neurons in the GI tract walls that can operate independently to control digestion.

Which ENS neurons detect stretch and chemical composition of gut contents?

Sensory neurons within enteric ganglia.

Which neurotransmitter do cholinergic sympathetic post-ganglionic neurons to sweat glands release?

Acetylcholine (ACh).

What are the four pathways a sympathetic pre-ganglionic axon can take after entering the sympathetic trunk?

(1) Synapse in the first ganglion, (2) travel up or down before synapsing, (3) pass through to a pre-vertebral ganglion (splanchnic nerve), (4) pass through to the adrenal medulla.

Which branch of the ANS is activated during meditation to slow heart rate?

Parasympathetic division.

What part of the hypothalamus primarily controls sympathetic output?

Posterior and lateral regions.

Name the five components of an autonomic reflex arc.

Receptor, sensory neuron, integrating center, motor neurons (pre- & post-ganglionic), effector.

Define sensation.

The conscious or unconscious awareness of changes in the external or internal environment.

What is meant by receptor selectivity?

Each sensory receptor responds mostly to one specific type of stimulus.

Give two examples of rapidly adapting touch receptors.

Meissner’s corpuscles and hair root plexuses.

Which tactile receptors are slowly adapting and detect fine touch on fingertips and lips?

Type I cutaneous mechanoreceptors (Merkel discs).

Which temperature range activates warm receptors?

25–45 °C (77–113 °F).

What type of nerve fibers carry fast pain?

Myelinated A fibers.

Referred pain from a heart attack is commonly felt where?

Left arm or jaw.

What proprioceptor detects muscle length and helps initiate the stretch reflex?

Muscle spindle.

Which proprioceptor prevents tendon damage by causing muscle relaxation when tension is high?

Tendon organ (Golgi tendon organ).

How many neurons carry conscious somatic sensory signals to the cortex?

Three: first-order, second-order, and third-order neurons.

Which pathway carries pain and temperature to the cerebral cortex?

Anterolateral (spinothalamic) pathway.

Which tract carries proprioceptive information to the cerebellum, not the cortex?

Spinocerebellar tracts.

What is the main direct (pyramidal) pathway for skilled limb movement?

Lateral corticospinal tract.

Which indirect (extrapyramidal) tract helps maintain posture and balance via vestibular input?

Vestibulospinal tract.

What role do basal nuclei play in movement?

Initiate and terminate movements, suppress unwanted motions, regulate muscle tone, and influence cognition/emotion.

Which brain region monitors movement and provides corrections for coordination and balance?

Cerebellum.

What system keeps you awake and alert?

Reticular Activating System (RAS).

List the four stages of NREM sleep in order.

Stage 1 (transition), Stage 2 (light), Stage 3 (moderately deep), Stage 4 (deepest).

During which sleep type do most dreams occur?

REM (Rapid Eye Movement) sleep.

Differentiate learning from memory.

Learning is acquiring new information or skills; memory is the storage and retrieval of that information.

Give an example of immediate, short-term, and long-term memory.

Immediate: recalling a word you just read; Short-term: remembering a phone number for minutes; Long-term: knowing how to ride a bicycle.

Which cranial nerve carries the majority of parasympathetic output to thoracic and abdominal organs?

Vagus nerve (cranial nerve X).

What is divergence in the sympathetic division, and why is it important?

One pre-ganglionic fiber synapses with 20+ post-ganglionic neurons; it produces widespread, simultaneous responses.

Which autonomic neurotransmitter is broken down quickly by acetylcholinesterase, limiting its effects?

Acetylcholine.

Which neurotransmitters/hormones bind to adrenergic receptors?

Norepinephrine (from neurons and adrenal medulla) and epinephrine (from adrenal medulla).

What is the function of β1 adrenergic receptors in the heart?

Increase heart rate and force of contraction.

What is the primary chemical released by tissue injury that stimulates nociceptors?

Prostaglandins (among others such as kinins and K⁺).

Why doesn’t the brain itself feel pain?

The brain lacks nociceptors; however, surrounding meninges and blood vessels do have them.

Which sensory receptors adapt slowly, ensuring continuous awareness of stimulus (e.g., pain)?

Slowly adapting receptors such as nociceptors and proprioceptors.

What is the main excitatory neurotransmitter at neuromuscular junctions in the somatic system?

Acetylcholine acting on nicotinic receptors at motor end plates.

What does the autonomic nervous system (ANS) primarily control?

Involuntary body functions such as heart rate, digestion, breathing, and blood pressure.

Which type of sensory receptors monitor internal conditions like blood pressure or CO₂ levels?

Interoceptors.

Name the two major types of interoceptors and the stimuli they detect.

Chemoreceptors detect chemical changes (e.g., CO₂), and mechanoreceptors detect stretch or pressure (e.g., stomach distension).

Somatic vs. autonomic motor pathways: how many motor neurons are found in each?

Somatic pathways have one motor neuron; autonomic pathways have two (preganglionic and postganglionic).

Where are sympathetic pre-ganglionic neuron cell bodies located?

In the lateral horns of spinal cord segments T1–T12 and L1–L2/3 (thoracolumbar outflow).

Why is the sympathetic division called the “thoracolumbar” division?

Because its pre-ganglionic neurons exit the thoracic and lumbar regions of the spinal cord.

Which cranial nerves carry parasympathetic pre-ganglionic fibers?

Cranial nerves III (oculomotor), VII (facial), IX (glossopharyngeal), and X (vagus).

Which spinal cord segments supply sacral parasympathetic outflow?

S2–S4.

Increased heart rate and blood pressure.

Fight-or-flight responses include which cardiovascular change?

Rest-and-digest responses include which gastrointestinal change?

Increased digestive activity and glandular secretions (SLUDD: salivation, lacrimation, urination, digestion, defecation).

What is autonomic tone?

The balance of sympathetic and parasympathetic activity maintained by the hypothalamus.

Which structures receive only sympathetic innervation?

Sweat glands, arrector pili muscles, kidneys, most blood vessels, and adrenal medulla.

What neurotransmitter is released by all autonomic pre-ganglionic neurons?

Acetylcholine (ACh).

Most sympathetic post-ganglionic neurons are classified as what type of neuron?

Adrenergic (they release norepinephrine).

Which cholinergic receptor type is found on all post-ganglionic neurons?

Nicotinic receptors.

Muscarinic receptors can produce what two possible effects on target cells?

Excitation (depolarization) or inhibition (hyperpolarization) depending on the tissue.

Name the two main classes of adrenergic receptors.

Alpha (α) and Beta (β) receptors.

Which adrenergic receptor subtype is primarily responsible for thermogenesis in brown fat?

β3 receptors.

Why do sympathetic effects last longer than parasympathetic effects?

Greater divergence, slower breakdown of norepinephrine, and release of E/NE hormones from adrenal medulla.

Define an autonomic plexus and give one example in the thorax.

A network where sympathetic and parasympathetic fibers mix around major arteries; example: cardiac plexus.

What is the enteric nervous system (ENS)?

A network of ~100 million neurons in the GI tract walls that can operate independently to control digestion.

Which ENS neurons detect stretch and chemical composition of gut contents?

Sensory neurons within enteric ganglia.

Which neurotransmitter do cholinergic sympathetic post-ganglionic neurons to sweat glands release?

Acetylcholine (ACh).

What are the four pathways a sympathetic pre-ganglionic axon can take after entering the sympathetic trunk?

(1) Synapse in the first ganglion, (2) travel up or down before synapsing, (3) pass through to a pre-vertebral ganglion (splanchnic nerve), (4) pass through to the adrenal medulla.

Which branch of the ANS is activated during meditation to slow heart rate?

Parasympathetic division.

What part of the hypothalamus primarily controls sympathetic output?

Posterior and lateral regions.

Name the five components of an autonomic reflex arc.

Receptor, sensory neuron, integrating center, motor neurons (pre- & post-ganglionic), effector.

Define sensation.

The conscious or unconscious awareness of changes in the external or internal environment.

What is meant by receptor selectivity?

Each sensory receptor responds mostly to one specific type of stimulus.

Give two examples of rapidly adapting touch receptors.

Meissner’s corpuscles and hair root plexuses.

Which tactile receptors are slowly adapting and detect fine touch on fingertips and lips?

Type I cutaneous mechanoreceptors (Merkel discs).

Which temperature range activates warm receptors?

25–45 °C (77–113 °F).

What type of nerve fibers carry fast pain?

Myelinated A fibers.

Referred pain from a heart attack is commonly felt where?

Left arm or jaw.

What proprioceptor detects muscle length and helps initiate the stretch reflex?

Muscle spindle.

Which proprioceptor prevents tendon damage by causing muscle relaxation when tension is high?

Tendon organ (Golgi tendon organ).

How many neurons carry conscious somatic sensory signals to the cortex?

Three: first-order, second-order, and third-order neurons.

Which pathway carries pain and temperature to the cerebral cortex?

Anterolateral (spinothalamic) pathway.

Which tract carries proprioceptive information to the cerebellum, not the cortex?

Spinocerebellar tracts.

What is the main direct (pyramidal) pathway for skilled limb movement?

Lateral corticospinal tract.

Which indirect (extrapyramidal) tract helps maintain posture and balance via vestibular input?

Vestibulospinal tract.

What role do basal nuclei play in movement?

Initiate and terminate movements, suppress unwanted motions, regulate muscle tone, and influence cognition/emotion.

Which brain region monitors movement and provides corrections for coordination and balance?

Cerebellum.