CH. 5 Flashcards
What is the cardiovascular system?
Consists of the heart, which pumps blood, and the blood vessels, through which the blood flows
What are the functions of the cardiovascular system?
Transport, homeostasis, protection
What is the lymphatic system?
Assists the cardiovascular system, collects excess interstitial fluid and returns it to the cardiovascular syste
Describe the two parts of the cardiovascular system?
The heart, which pumps blood, and the blood vessels, which carry the blood
Summarize the functions of the cardiovascular system
Generates blood pressure, transports blood, promotes gas exchange at the capillaries, and regulates blood flow as needed
Explain how the lymphatic system interreacts with the cardiovascular system
Lymphatic vessels collect excess interstitial fluid and return it to the cardiovascular system
What is an artery?
A blood vessel that transports blood away from the heart
Describe the structure of an artery
Well suited for the transport of blood leaving heart under pressure, the arterial wall has three layers. The inner is the endothelium which is surrounded by a middle layer of smooth and elastic tissue which is surrounded by the artery’s outer layer of connective tissue.
What are arterioles?
Small arteries barely visible to the naked eye, the middle layer is mostly composed of smooth muscle, muscle fibers encircle the arteriole.
Describe arterioles functions
The constriction or dilation of arterioles controls blood pressure. When arterioles constrict, blood pressure rises. Dilation of arterioles causes blood pressure to fall
What are capillaries?
Arterioles branch into these, they are the smallest of the blood vessels. It is an extremely narrow, microscopic tube with a wall composed only of endothelium, which is formed by a single layer of epithelial cells with a basement membrane
Describe veins
Blood vessels that return blood to the heart
What are Venules
Are small veins that drain blood from the capillaries and then join to form a vein. These allow blood to flow only toward the heart when open and prevent backward flow of blood when closed.
List and describe the different types of blood vessels
Arteries carry blood from the heart to smaller vessels called arterioles. These lead to capillaries where gas exchange occurs. Venules carry blood from the capillaries to the veins, which carry blood back to the heart
Describe how each blood vessel contributes to the flow of blood in the body
Arteries have thick muscular walls that are elastic and carry blood at higher pressure. Arterioles, which have thinner walls, receive blood from arteries and the blood pressure drops. Capillaries have thin walls made up of a single layer of epithelium and carry blood at lower pressure. Venules receive blood from the capillaries and move it to the veins at low pressure blood back to the heart
Explain why the structure of the veins is different from that of the arteries
Veins carry blood at a lower pressure and therefore have thinner walls than arteries, as well as less muscle and elastic fibers. In addition, veins have valves to help move the blood back to the heart
Describe the heart
A cone-shaped, muscular organ located between the lungs directly behind the sternum (breastbone). The heart is tilted so that the apex (the pointed end) is oriented to the left side of the body
Myocardium
Major portion of the heart, is the interior wall of tissue consisting largely of cardiac muscle tissue
What of the following are part of the electrical conduction system within the heart?
- QRS node
- Purkinje fibers
- AV node
- Chordae tendineae
- SA node
- Purkinje fibers
-AV node
-SA node
What is the natural pacemaker of the heart, which regulates the heartbeat?
SA node
The heart rate of a healthy adult human at rest is normally ?
60 to 80 beats per minute
Select all examples of external controls that regulate the heartbeat.
- Sympathetic stimulation
- Atrioventricular (AV) node
- Epinephrine and norepinephrine
- sympathetic stimulation
- Epinephrine and norepinephrine
What is the function of the atrioventricular (AV) node?
Conduct an electrical impulse into the ventricles
Another name for the pacemaker of the heart is the _________ node.
Sinoatrial (SA)
The major actions of the hormone’s epinephrine and norepinephrine on the heart is to cause the heart to ______.
Contract faster and stronger
The second sound of the heartbeat (“dub”) occurs when __________.
the ventricles relax, causing the semilunar valves to close
A patient enters the hospital complaining of chest pain. Which test will the doctor most likely perform to analyze the electrical activity of the heart?
ECG (electrocardiogram)
External control of the heart is maintained by nervous stimulation and by chemicals called
_______, such as epinephrine and norepinephrine, which are released from the adrenal glands.
hormones
Which of the following is the application of a strong electrical current to the chest to reset coordinated beating of the heart?
Defibrillation
Select all of the following that are part of the electrical conduction system within the heart.
- QRS node
- AV node
- Purkinje fibers
- Chordae tendineae
- SA node
- AV node
- Purkinje fibers
- SA node
Blood pressure is highest in which blood vessel?
The aorta
Extrinsic control of the heart includes the action of which two hormones, released from the adrenal medulla?
- Norepinephrine
- Growth hormone
- Insulin
- Thyroxine
- Epinephrine
- Nonrepinephrine
- Epinephrine
The rhythmic expansion and recoil of an arterial wall can be felt as a _________.
pulse
What does an electrocardiogram record?
Changes in electrical activity of the heart during the cardiac cycle
Blood pressure is most commonly measured by wrapping a blood pressure cuff, or sphygmomanometer, around which part of the body?
Arm
Which of the following refers to uncontrolled irregular activity of the ventricles?
Ventricular fibrillation
The highest arterial pressure reached as blood is ejected from the heart is called _______.
Systolic pressure
Low blood pressure is called _________.
Hypotension
The majority of arteries and veins transport blood to all the body systems and are therefore part of the ________ circuit.
Respitory
