Autonomic Nervous System Flashcards
Organisation of the Nervous System:
The nervous system is broken up in (2)
Peripheral NS and Central NS
Organisation of the Nervous System:
The Peripheral NS is broken up into two divisions. Namely:
Efferent and Afferent Division
The Efferent division is divided into 2 systems. Namely:
Autonomic System and Somatic System
The Autonomic System branches into:
Enteric , Parasympathetic and Sympathetic
What is the most important function of the autonomic nervous system?
To cause consistency of the internal environment. Homeostasis
What are the most important neurotransmitters in the peripheral nervous system?
Acetylcholine and Noradrenaline
What the synapses that synthesises ACTH and NA?
Cholinergic and Adrenergic Synapses.
Acetylcholine is the transmitter at three different sites. Namely:
1) All autonomic ganglia
2) Parasympathetic postganglionic end terminals.
3) Motoric end terminals of skeletal muscle.
The visceral effectors that is acted upon by Acetylcholine is:
Smooth muscle, heart muscle and glands.
The action of ACTH is similar to the plant alkaloid:
Muscarin
The effects of Muscarin are antagonised by the plant alkaloid ________ from Atropa Belladonna.
Atropine
The receptors for ACTH are divided into:
Muscarinic and Nicotinic Receptors.
Where do muscarinic receptors occur?
Parasympathetic postganglionic end terminals.
Where do nicotinic receptors occur?
Autonomic ganglia and Skeletal Muscle Motoric end terminals.
Which transmitter is transmitted at the sympathetic ganglionic end terminals?
Noradrenaline ( Norepinephrine). Adrenaline (Epinephrine) . Dopamine
Where is Adrenaline secreted?
The Adrenal Medulla of Adrenal Gland.
Adrenergic receptors stimulation often causes opposing effects. Adrenergic receptors can be divided into two classes. Namely:
Alpha (a) for Constriction
Beta (B) for dilatation or Relaxation
(except in the heart where B-receptors cause stimulation)
B-receptors of the heart and lungs are divided into B1 and B2. Discuss each division.
B1 is for the heart
B2 is for the lungs and relaxation of vascular muscle.
The sympathetic and Parasympathetic divisions innervate which organs?
Heart Iris Bronchial tree Gastrointestinal tract and sphincters. Salivary glands Urinary bladder Sex organs
Only the Sympthetic division innervate the following organs:
Blood vessels
Spleen
Sweat glands
Pilo-erector muscles
Sympathetic activation of the salivary glands -
Thick mucus-like secretion
Parasympathetic activation causes a high volume watery secretion of the:
Salivary glands
Why do muscarinic agonists have a limited application?
It has a negative effect on the heart, constriction of bronchial muscle and production of high volumes of watery secretions.
How does the sympathetic system prepare the body for increased muscular activity and stress in emergencies?
Heart rate increases as a whole
Muscle blood vessels dilate while skin blood vessels contract; the activity of the GIT decreases; pupils dilate and an increased breakdown of glycogen and fats occurs.
Parasympathetic system is involved in the:
The accumulation, storage and preservation of body supplies - the heart rate decreases; the tonus and peristalsis of the GIT increases, while the sphincters relax; pupils become smaller and accommodation for nearby vision occurs; the smooth muscles of the bronchial tree contracts and glands are stimulated for secretion.
The opposing effects of the sympathetic and parasympathetic systems are _______________
The opposing effects of the sympathetic and parasympathetic systems are reflexively controlled from within the Central Nervous System.
Sympathetic System is also known as the:
Fight or Flight System
The Parasympathetic System is also known as the:
Rest and Digest system.
