The Circulatory System Flashcards
What are the two systems that make up the circulatory system?
Cardiovascular and lymph
What are the functions of the circulatory system?
Distribution of gases and other molecules
Chemical signalling
Thermoregulation
Mediate inflammation and host defence responses
What is the cardiovascular system composed of?
Arteries
Heart
Veins
What are the two main circulations of the cardiovascular system?
Pulmonary circulation
Systemic circulation
What is the direction of blood flow in pulmonary circulation?
Right ventricle to lungs to left atrium
What is the direction of blood flow in systemic circulation?
Left ventricle to capillary beds of organs and tissues to right atrium
What is the direction of blood flow starting at the right atrium?
RA RV Lungs LA LV Body RA
What is systole?
Contraction
What is diastole?
Relaxation
Which artery carries blood away from the left ventricle?
Aorta
Which artery carries blood away from the right ventricle?
Pulmonary trunk
Which vein carries blood to the left atrium?
4 pulmonary veins
Which vein carries blood to the right atrium?
Superior and inferior vena cavae
What are the three layers of the heart?
Epicardium
Myocardium
Endocardium
Where are the layers of the heart located?
Epicardium is external
Myocardium is middle
Endocardium is internal
Which chamber of the heart has the thickest later of muscle?
Left ventricle
Which chamber of the heart forms the posterior surface of the heart?
Left atrium
Which chamber of the heart forms the most anterior surface of the heart?
Right ventricle
Where is the pulmonary valve located?
Between the right ventricle and the pulmonary trunk
Where is the tricuspid valve located?
Between the right atrium and the right ventricle
Where is the mitral valve located?
Between the right ventricle and the pulmonary trunk
Where is the aortic valve located?
Between the left ventricle and the aorta
What is the route of electrical conduction in the heart?
Starts in the SA node - both atria contract
Travels ot AV node
Travels down right and left bindles in inter ventricular septum
Spreads out to myocardium through connecting fibres - both ventricles contract
What are the three layers of most blood vessels from internal to external?
Tunica intima
Tunica media
Tunica adventitia
What are each of the three layers of most blood vessels made of?
Tunica intima - endothelium
Media - smooth muscle and elastic fibres
Adventitia - connective tissue
What shape are the lumens of arteries and veins?
A - round
V - Squashed
Do arteries carry oxygenated or deoxygenated blood?
Oxygenated
What do arteries split into?
Branches
What is it called when an artery divides into 2 or 3?
Bi or trifurcation
What is the region of the body supplied by a single artery and its branches called?
Territory
Are arteries typically located deeper or closer to the surface than veins?
Deeper
Which terms indicate that an artery will definitely divide again?
Common
Trunk
What are vasodilation and contraction?
Relaxation/constriction of the smooth muscle and widening of the lumen to increase/reduce blood flow to the organ or tissue supplied
What is sympathetic tone?
Background low level contraction of smooth muscle in arterioles
What are the effects of increasing or decreasing sympathetic tone?
Increasing - further constrict
Decreasing - further dilate
Why would vasodilation of arterioles occur?
Reduce blood flow following an injury
What is anastomosis?
Arteries connect without an intervening capillary network to provide an alternative route for blood to flow when a blockage occurs
What is a collateral circulation?
An alternative route in an anastomosis
What is the disadvantage of anastomosis?
Collaterals bleed from both sides of a cut
What is an end artery?
The only arterial blood supply so a given area of the body
What does an untreated occlusion of an end artery result in?
Infarction of its territory
What does infarction mean?
Irreversible cell death due to hypoxia (lack of oxygen)
What is elastic recoil for?
To maintain peripheral flow when the heart relaxes
What are the four parts of the aorta in order?
Ascending aorta
Arch of the aorta
Thoracic aorta
Abdominal aorta
How many branches does the ascending aorta have and what are they called?
2
Left coronary artery
Right coronary artery
How many branches does the arch of the aorta have and what are they called from left to right?
3
Brachiocephalic trunk
Left common carotid artery
Left subclavian artery
How many branches does the thoracic aorta have?
Numerous
How many branches does the abdominal artery have?
3 unpaired midline branches
3 paired, bilateral branches
What is the order of the changing name of the upper limb’s artery?
Subclavian artery
Auxillary artery
Brachial artery
Radial/Ulnar artery
What type of blood do veins carry?
De-oxygenated
Are veins or arteries pulsatile?
Arteries
Are veins or arteries high pressure?
Arteries
Do veins or arteries have valves?
Veins
What is venous blood pumped back to the heart by?
Venous valves
Skeletal muscle pump
Accompanying veins
What is the skeletal muscle pump
Contraction of skeletal muscles in the lower limb
How do accompanying veins pump blood back towards the heart?
Small veins run in pairs or more with an artery.
The arterial pulsations push venous blood along
What are the two sets of veins?
Superficial
Deep
What are the two main venous systems?
Hepatic portal venous system
Systemic venous system
Where does the hepatic portal venous system drain venous blood from and to?
Absorptive parts of the GI tract to the liver
Where does the systemic venous system drain venous blood from and to?
All organs other than the GI tract to the superior/inferior vena cavae
What are capillaries lined by?
A single layer of epithelium
What can flow through a capillary?
One red blood cell at a time
What do capillaries allow for exchange of?
Gases
Metabolites
Waste products
What do lymphatic capillaries collect?
Tissue fluid/lymph fluid
When is tissue fluid called lymph fluid?
Once it is in the lymphatic capillaries
Where do lymphatics carry lymph through and what do these contain?
Lymph nodes
White blood cells to filter foreign particles and fight infection
Where is lymph returned to?
The central veins in the root of the neck
Where does the right/left lymphatic duct drain lymph into?
The right/left venous angle
What do superficial lymphatics drain into?
Deep lymphatics
