Introduction to ANS Flashcards
What are the differences between the autonomic and voluntary somatic nervous system?
Autonomic: Regulates body activities that are generally not under conscious control
Voluntary: Regulates body activities that are generally under conscious control
What are the Functions of ANS?
- Control of:
- smooth muscle: visceral, vascular
- heart rate and force
- exocrine secretions, some endocrine
- homeostasis
What are the effectors of SNS and ANS?
SNS: Skeletal muscles
ANS: Smooth muscle, cardiac muscle and glands
Somatic
- Effectors
- Control Type
- Neural Pathway
- Action of Effectors
- Neurotransmitters
- Effectors: Skeletal muscles
- Control Type: Voluntary
- Neural Pathway: One neuron from CNS synapses directly on skeletal muscles
- Action of Effectors: Excitatory
- Neurotransmitters: ACh
Autonomic
- Effectors
- Control Type
- Neural Pathway
- Action of Effectors
- Neurotransmitters
- Effectors: Cardiac & smooth muscle, glandular epithelium, lipid cells
- Control Type: Involuntary
- Neural Pathway: One neuron from CNS synapses in a ganglion with a second neuron
- Action of Effectors: Excitatory or inhibitory
- Neurotransmitters: ACh or NA
What are the differences in regulation by sympathetic and parasympathetic nervous system?
Sympathetic:“fight or flight”
Parasympathetic: keeping body energy use low (rest)
What are the D activities of parasympathetic nervous system?
- Digestion, defacation, diuresis
- Illustrated by an individual who relaxes after a meal
- Lowered blood pressure and heart/respiratory rate
- High GIT activity
- Warm skin, constricted pupils
What are the E activities of sympathetic nervous system?
- Exercise, excitement, emergency, embarrassment
- Promotes adjustments during exercise (blood flow to organs reduced, muscles increased)
- Activity illustrated by a person who is threatened
- heart rate increases, rapid breathing
- cold, sweaty skin, pupils dilate
What is the role of the hypothalamus in ANS regulation?
- Mediator
- Centres of hypothalamus control:
- heart activity, blood pressure
- body temperature, water balance, endocrine activity
- emotional stages and biological drives
- reactions to fear from ‘fight or flight’
What is the function of adrenal gland?
- Can cause body-wide release of A and NA in an extreme emergency
- Synapse in the gland
What are the neurotransmitters of ANS for preganglionic axons?
- ACh for both branches (cholinergic)
What are the neurotransmitters of ANS for postganglionic axons?
- Sympathetic: NA (adrenergic)
- Parasympathetic: ACh (cholinergic)
What are the functions of two cholinergic receptors?
- Mediate actions of parasympathetic nervous system
- Actions on ion channels could modulate nerve activity
