32 Questions
Where does oxygenated blood leave the heart through?
Aorta
What is the function of the capillaries?
To exchange oxygen and nutrients with the body's cells
What is the outermost layer of a blood vessel?
Tunica externa
What is the middle layer of a blood vessel composed of?
A combination of smooth muscle and elastic fibers
What is the function of the tunica externa?
To prevent the vessel from overexpanding
What type of tissue makes up the tunica externa?
Fibrous connective tissue
What is the primary function of arteries in the circulatory system?
To carry oxygenated blood away from the heart
What is the term for the 'enveloping membrane' or layer of tissue in the blood vessel wall?
Tunica
What is the term for a fast heart rate?
Tachycardia
What is the space within the blood vessel where the blood flows?
Lumen
What is the term for the absence of ventricular contraction, also known as cardiac arrest?
Asystole
What is the primary function of veins in the circulatory system?
To carry deoxygenated blood towards the heart
What is the primary function of elastic fibers in blood vessels?
To prevent blood vessel rupture during pulsing when the heart contracts
What is the effect of vasoconstriction on blood pressure?
It increases blood pressure
What is the primary location of vasoconstriction and vasodilation?
Arteries
What is the function of the tunica intima?
To provide a smooth surface for blood flow
What is the effect of vasodilation on blood pressure?
It decreases blood pressure
What is the primary function of smooth muscle in blood vessels?
To regulate blood pressure through contraction and relaxation
What is the primary cause of the 'lub-dub' sounds we hear when auscultating the heart?
The closing of the atrioventricular valves
During which part of the cardiac cycle do the atrioventricular valves close?
Ventricular contraction
What is the term for the cyclical pattern of heart contraction and relaxation in response to electrical changes within the cells?
Cardiac cycle
Which of the following arteries originates from the left ventricle?
Aorta
What prevents blood from flowing back into the ventricles during diastole?
The closure of the semilunar valves
What is the result of high pressure in the blood vessels?
A big number on a blood pressure reading
What is the function of the pulmonary veins?
To carry oxygenated blood from the lungs to the left atrium
What is the definition of systole?
Active contraction of the ventricles
Which type of cardiac muscle cells spontaneously contract?
Automatic cells
Where is the Sinoatrial node located?
At the junction of the cranial vena cava and the right atrium
What is the function of the Atrioventricular node?
To initiate ventricular contraction
Which of the following veins collects blood from the forelegs and head?
Cranial Vena Cava
What is the baseline rate of contraction of the Sinoatrial node?
Not specified
What is the function of the signal sent by the Sinoatrial node?
To initiate atrial contraction
Study Notes
Blood Vessels
- Blood vessels have three layers: Tunica externa (outer connective tissue layer), Tunica media (middle layer with smooth muscle and elastic tissue), and Tunica intima (innermost layer with endothelial cells)
- Arteries carry oxygenated blood away from the heart, except pulmonary arteries, which carry deoxygenated blood to the lungs
- Veins carry deoxygenated blood towards the heart, except pulmonary veins, which carry oxygenated blood from the lungs
Arteries vs Veins
- Arteries have thicker Tunica media for vasoconstriction and vasodilation to regulate blood pressure
- Veins have thinner Tunica media with less smooth muscle, making them less responsive to vasoconstriction and vasodilation
Capillaries
- Smallest blood vessels where gas and nutrient exchange occurs through passive diffusion
- Oxygenated blood flows in and deoxygenated blood flows out
Major Arteries and Veins
- Aorta: largest artery carrying oxygenated blood from the heart to the entire body
- Cranial and Caudal Vena Cavae: largest veins carrying deoxygenated blood from the body back to the heart
- Pulmonary arteries and veins: carry deoxygenated blood to the lungs and oxygenated blood from the lungs, respectively
Heart and Cardiac Cycle
- Sinoatrial (SA) node: pacemaker located at the junction of the cranial vena cava and the right atrium, controlling heart rhythm and rate
- Cardiac cycle: heartbeat consisting of systole (ventricular contraction) and diastole (ventricular relaxation)
- Heart sounds: "lub" (S1) is the closing of the AV valves during ventricular contraction, and "dub" (S2) is the closing of the semilunar valves during ventricular relaxation
Blood Pressure
- Systolic pressure: highest pressure during ventricular contraction (systole)
- Diastolic pressure: lowest pressure during ventricular relaxation (diastole)
- Blood pressure regulation is crucial to maintain a healthy range and prevent high or low pressure.
This quiz covers the structure and functions of the cardiovascular system, including blood vessels, arteries, veins, capillaries, and the heart. It also explores blood pressure and the cardiac cycle.
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