Autonomic Nervous System Flashcards
What does the ANS regulate?
Involuntary functions:
- Circulation
- Respiration
- Metabolism
- Secretion
- Body temperature
- Reproduction
Where are the ANS control centres located?
Hypothalamus & brainstem (from where signals are sent)
What is the ANS composed of?
Motor neurones that innervate:
- Smooth muscle
- Cardiac muscle
- Glands
(Effectors)
What are the (2) neurone pathways that the ANS uses?
- Preganglionic neuron
- Postganglionic neuron
What is info integrated from in the ANS for autoregulation?
- Peripheral afferents
- CNS receptors
Where are preganglionic neurons located?
Brain or spinal cords
Where does the brain and spinal cord’s myelinated axons synapse?
Peripheral ganglia
What divisions can the ANS be divided into?
- Sympathetic
- Parasympathetic
Describe the axons and what they innervate in postganglionic neurons?
Postganglionic neurons have unmyelinated axons that innervate target organs.
Where does the sympathetic nervous system (SNS) originate from?
The thoracic & lumbar spinal cord
Where do preganglionic axons terminate?
In the sympathetic chain ganglia or prevertebral ganglia in the abdomen
What does the sympathetic nervous system (SNS) do?
Prepares the body for stressful situations (fight-or-flight response)
What are the neurotransmitters in the sympathetic nervous system (SNS)?
Preganglionic:
- Acetylcholine (Ach)
Postganglionic:
- Norepinephrine (Noradrenaline)
What does the parasympathetic nervous system (PNS) do?
Maintains homeostasis & vital functions
(Rest & Digest)
Where does the parasympathetic nervous system (PNS) receive signals from?
- Brainstem (cranial nerves III, VII, IX, X)
- Sacral spinal cord
What is a major preganglionic nerve of the parasympathetic nervous system (PNS)?
Vagus nerve (CN X)
What does the Vagus nerve (CN X) control?
- Heart
- Lungs
- Digestive tract
What is a neurotransmitter of the parasympathetic nervous system (PNS)?
Both pre and postganglionic:
- Acetylcholine (ACh)
What is the name for disorders/dysfunction of the ANS?
Dysautonomia
What are some common neurological conditions of the ANS?
- Parkinson’s disease
- Multiple System Atrophy (MSA)
- Stroke
- Multiple Sclerosis (MS)
- Guillian-Barre Syndrome (GBS)
What are some cardiovascular S&S of ANS dysfunction?
- Orthostatic hypotension
- Hypertension
- Tachycardia or Bradycardia
What are some gastrointestinal S&S of ANS dysfunction?
- Gastroparesis (delayed gastric emptying)
- Constipation
- Diarrhoea
- Faecal incontinence
What are some urinary S&S of ANS dysfunction?
- Retention
- Incontinence
- Recurrent UTIs
What are some thermoregulatory S&S of ANS dysfunction?
- Excessive sweating (Hyperhidrosis)
- Reduced or absent sweating (Anhidrosis)
- Heat intolerance
