Lecture 8 - Cardiovascular System Flashcards
What is the function of the Cardiovascular system impacted by
Endocrine System
Nervous system
Kidneys
What are the 2 loops in the cardiovascular system
Systemic
Pulmonary
What does the systemic loop do
carries blood to from the heart to themajor parts of the body and back to the heart
Blood leaves the left ventricle via the aorta
Branches to form systemic arteries
Branch to form the microcirculation: Arterioles, capillaries, venules
What do the venules that form veins ultimately form
Inferior Vena Cava - Collects blood from below heart
Superior Vena Cava - Collects blood from above the heart
What is the job of the Pulmonary loop
carries oxygen-poor blood to the lungs and
back to the heart.
Blood leaves right ventricle: pulmonary trunk
Dividing into pulmonary arteries – take blood to both lung
What are the 5 types of blood vessels
Arteries
Arterioles
Capillaries
Venules
Veins
What is the exception to the rule “arteries carry oxygenated blood and veins carry deoxygenated blood”
the pulmonary arteries
- carry deoxygenated blood to the lungs
- here they collect oxygenated blood and
- the pulmonary veins carry oxygenated blood to the heart
What is the pressure in a blood vessel
Pressure is the force exerted and we measure this in mm Hg
What is flow in blood vessels
Flow is the volume moved and it is measured in mL/min
What is the resistance in a blood vessel
Resistance is how difficult it is for blood to flow between two points at any given
pressure difference
What are 3 things that contribute to the resistance in blood vessels
Blood viscosity
Total Blood Vessel length
Blood Vessel diameter
Where are elastic/conduit arteries located
These vessels are near the heart and carry blood for
circulation eg. the aorta
What are some features elastic/conduit arteries
Large lumen vessels (low resistance) that contain more elastin
than the muscular arteries.
Allows them to be “pressure reservoirs”
‒ expand and contract (recoil) as blood is ejected by the
heart. This allows blood flow to be continuous.
What are muscular arteries and their key traits
These arteries deliver blood to specific organs (mesenteric artery, renal artery etc.).
They have proportionally the most smooth muscle and are very active in vasoconstriction.
These arteries can play a large role in the regulation of blood pressure
What is compliance
how easily a structure stretches
What are some factors affecting pressure in an elastic container
How much water you put in it
How easily the walls of the balloon (eg.) can stretch
What is systolic blood pressure
Maximal arterial pressure reached during peak ventricular ejection
What is diastolic blood pressure
Minimal arterial pressure reached just before ventricular ejection
What is pulse pressure
Difference between systolic and diastolic pressure
What is intrinsic tone
Arterioles have basal level of contraction
How is smooth muscle regulated
Autonomically by local or extrinsic control
How does the dilation/contraction of arterioles affect minute-to-minute blood flow
If they contract, blood flow is diverted away from their tissues
If they Dilate, then blood flow to the tissue increases
What is an example of local control of resistance
Response to local metabolic or local blood flow changes
eg.Blood flow increases to an organ due to an increase in metabolism (eg. exercising skeletal muscle)
Response to injury - local inflammation Is characterised by increased blood flow
What are some examples of extrinsic control of resistance
Hormones
Sympathetic nerves
What does Epinephrine do
vasodilates or constricts
depending on the tissue
What does angiotensin II do
Constricts most arterioles
What does Vasopressin do
Constricts most arterioles
What is the affect of symapthetic nerves on arterioles
Always some sympathetic tone, this can be
reduced resulting in vasodilation, by
withdrawing sympathetic activity
What are the 3 types of capillary
Continuous capillary: found in skin, muscle, most
common kind have tight junctions.
Fenestrated capillary: more permeable —
intestines, hormone-producing tissues, kidneys,
etc.
Sinusoidal capillary: only one with an incomplete
basement membrane; these are found in the liver,
bone marrow and lymphoid tissues.
What is angiogenesis
Capillaries develop and grow (through muscle adaptation or tumours)