Skip to main content
Indietro

Efferent Division and Autonomic Nervous System - Anatomy & Physiology

I pulsanti di controllo sono stati cambiati in modalità "navigazione".
1/20

Termini in questo insieme (20)

  • What are the two main subdivisions of the autonomic nervous system (ANS)?

    The sympathetic and parasympathetic divisions, distinguished anatomically by ganglia location and functionally by their activity during stress or rest.

  • What is the hallmark of autonomic nervous system control?

    Antagonistic control, where sympathetic and parasympathetic divisions have opposite effects on target organs to maintain balance.

  • Describe the two-neuron efferent pathway in the autonomic nervous system.

    It consists of a preganglionic neuron (from CNS to ganglion) and a postganglionic neuron (from ganglion to target tissue).

  • Where are the ganglia located in the sympathetic and parasympathetic divisions?

    Sympathetic ganglia are near the spinal cord (paravertebral or prevertebral), parasympathetic ganglia are near or within the target organs.

  • What neurotransmitter is released by all preganglionic neurons in the ANS?

    Acetylcholine (ACh) is released by both sympathetic and parasympathetic preganglionic neurons.

  • What neurotransmitters are released by postganglionic neurons in the sympathetic and parasympathetic divisions?

    Sympathetic postganglionic neurons mostly release norepinephrine, parasympathetic postganglionic neurons release acetylcholine (ACh).

  • What are cholinergic synapses and their receptor subtypes?

    Synapses using acetylcholine as neurotransmitter; receptor subtypes are nicotinic and muscarinic receptors.

  • Where are adrenergic receptors found and what is their function?

    On target tissues of sympathetic postganglionic neurons; they bind norepinephrine and mediate varied responses depending on receptor subtype.

  • What is the role of varicosities and synapses en passant in the ANS?

    They allow neurotransmitter release along the length of postganglionic axons, enabling diffuse and widespread effects on target tissues.

  • How do autonomic reflexes support homeostasis?

    By adjusting organ function automatically in response to internal changes, maintaining stable internal conditions.

  • Which brain regions control autonomic reflexes?

    The medulla oblongata directs many autonomic reflexes; the hypothalamus controls higher-level autonomic regulation.

  • Give examples of antagonistic control by the ANS.

    Sympathetic increases heart rate; parasympathetic decreases it. Sympathetic dilates pupils; parasympathetic constricts pupils.

  • How does adrenergic stimulation vary among different tissues?

    Responses depend on receptor subtype (alpha or beta); e.g., beta receptors increase heart rate, alpha receptors cause vasoconstriction.

  • What distinguishes the anatomical location of sympathetic vs parasympathetic ganglia?

    Sympathetic ganglia are close to the spinal cord; parasympathetic ganglia are located near or inside the target organs.

  • What neurotransmitter is used at all autonomic ganglionic synapses?

    Acetylcholine (ACh) is used at synapses between preganglionic and postganglionic neurons in both divisions.

  • What is the functional significance of the two-neuron efferent pathway in the ANS?

    It allows signal modulation at the ganglion and enables widespread or targeted control of organs.

  • How do sympathetic and parasympathetic divisions differ in their general effects?

    Sympathetic prepares body for 'fight or flight'; parasympathetic promotes 'rest and digest' activities.

  • What is the role of the hypothalamus in autonomic control?

    The hypothalamus integrates autonomic functions and coordinates responses to maintain homeostasis.

  • What types of receptors do postganglionic parasympathetic neurons act on?

    They act on muscarinic cholinergic receptors on target tissues.

  • What is the significance of synapses en passant in the ANS?

    They allow neurotransmitter release at multiple points along an axon, enabling broad influence over target tissues.