Karteikarten
Nervous and Hormonal Control of the Circulation
Karten in diesem Stapel (32)
- 1Why does the circulation need to be controlled?To regulate TPR and therefore BP
- 2Is it intrinsically or extrinsically controlled?Extrinsically
- 3TPR and BP can be controlled by release of _____________ and ___________.Neurotransmitters,
hormones - 4How is the release of neurotransmitters mediated?Baroreceptors and chemoreceptors in vessels send signals to the hypothalamus, which signals the RVLM to send excitatory signals to the thoracic spinal cord to stimulate the sympathetic fibres to the heart, vessels and adrenal medulla.
- 5In blood vessels, sympathetic _____________ fibres exist in the T. ___________. On these fibres are ______ ___ ___________, and it is from here that ___ is released.vasoconstrictor,
adventitia,
strings of varicosities,
NA - 6How does this achieve vascular tone?Low frequencies of NA are constantly being released, meaning the vessel is always in a slightly constricted state. This way it can be constricted more or relaxed according to need.
- 7Where does the NA bind to?Alpha 1 adrenergic receptors on vascular smooth muscle.
- 8Give 2 reasons why this is helpful to meet the body's needs.1. Ensures that the brain and myocardium are always well perfused
2. Can direct blood flow to certain areas of the body and away from others. - 9How might this be useful in maintaining blood volume, for example?If pre-capillaries are constricted, the capillary pressure will decrease and favour fluid reabsorption from the interstitial fluid, thus increasing blood volume.
- 10Which other nerves can affect blood vessels but are less common?Vasodilator nerves
- 11What are the 3 types of vasodilator nerves?1. Parasympathetic
2. Sympathetic
3. Sensory (nociceptor C fibres) - 12Where are parasympathetic vasodilator fibres found, and which neurotransmitters activate them? (3)1. Salivary glands - ACh on M receptors, VIP on NANC receptors
2. Pancreas/intestinal mucosa - VIP on NANC receptors
3. Erectile tissue - NO and VIP on NANC receptors - 13Where are sympathetic vasodilator fibres found, and which gland are they associated with? (1)Skin - sweat glands
- 14When sensory vasodilator fibres are activated, what is this in response to and what happens at the area?Trauma - redness and swelling
- 15What is their mechanism of action?Activates the C-fibre axon reflex. Causes release of substance P and dengranulation of mast cells to release histamine, which causes vasodilation and increases vessel permeability.
- 16Name 4 hormones which help control circulation1. Adrenaline
2. Angiotensin II
3. Atrial Natriuretic Peptide
4. Vasopressin (ADH) - 17When and from where is adrenaline released?Released from the adrenal medulla in response to: 1. exercise
2. Fear, fight or flight
3. hypotension
4. hypoglycaemia - 18Which receptors does adrenaline have higher affinity for?beta adrenergic
- 19Where are there beta 2 receptors that allow dilatation? (3)Skeletal muscle, myocardium and liver
- 20Which receptors cause vessel constriction?Alpha 1 adrenergic
- 21What is the effect of adrenaline? (4)1. Increased HR
2. Increased CO
3. Slight increased BP
4. Decreased TPR - 22What causes secretion of Renin from the kidneys? (2)1. Sympathetic stimulation
2. Low renal blood flow - 23What does Renin do?converts angiotensinogen to Ang I, which gets converted by ACE to Ang II in lungs.
- 24What does Ang II do? (3)1. Increases sympathetic drive
2. Causes thirst
3. Stimulates production of aldosterone from adrenal cortex - 25What does aldosterone do?Retains Na+ and water, so blood volume increases, causing CVP to increase and thus increasing SV (Starling's Law), CO and BP.
- 26Where is vasopressin (ADH) secreted from?Posterior pituitary gland
- 27What stimulates the secretion of ADH? (2)1. Switching on of CVLM in response to low blood pressure and volume signals hypothalamus
2. Osmoreceptors detect low blood volume and signal hypothalamus - 28What effect does ADH have? (2)Increases water reabsorption so increases blood volume and thus BP. Also raises BP by causing vasoconstriction.
- 29Where is ANP released from?Atrial myocytes
- 30What stimulates its release? (2)1. High BP
2. High blood volume - 31What receptor does ANP bind to?Natriuretic Peptide Receptors
- 32What effect does ANP have?1. Increases Na+ and water excretion
2. Vasorelaxation (by cGMP)
3. Increases permeability
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- Beschreibung
- Degree CVS1 Karteikarten am Nervous and Hormonal Control of the Circulation, erstellt von Hannah Tribe am 30/04/2014.
- Erstellt von
- Hannah Tribe · Apr 2014
- Aktualisiert
- 19 Feb 2016
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- 50
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