The circulatory system delivers ___ and nutrients needed for metabolic processes to the tissues, carries ____ products from the tissues to the kidneys and other excretory organs for elimination, and circulates electrolytes and ___ needed to regulate body
oxygen, waste, hormones
The circulatory system can be divided into two parts: the ____ circulation and the ____ circulation.
pulmonary, systemic
The ____ circulation consists of the right heart, the pulmonary artery, the pulmonary capillaries, and the pulmonary veins.
pulmonary
The ____ circulation consists of the left heart, the aorta and its branches, the capillaries that supply the brain and peripheral tissues, and the systemic venous systems and the vena cava.
systemic
The ____ pressure of the pulmonary circulation allows blood to move through the lungs more slowly, which is important for gas exchange.
low
The ____ function as collection chambers for blood and the _____ are the main pumping chambers of the heart.
atria, ventricles
Because it is a closed system, the effective function of the circulatory system requires that the outputs of both sides of the heart pump the ____ amount of blood over time.
same
Blood flow in the circulatory system depends on a blood ____ that is sufficient to fill the blood vessels and a ____ difference across the system that provides the force to move blood forward.
volume, pressure
The term ____ refers to the principles that govern blood flow in the circulatory system.
hemodynamics
Because flow is directly related to the radius, small changes in vessel radius can produce ____ changes in flow to an organ or tissue.
large
____ is the resistance to flow caused by the friction of molecules in a fluid.
Viscosity
____ blood flow may predispose to clot formation as platelets and other coagulation factors are exposed to the endothelial lining of the vessel.
Turbulent
Wall tension is inversely related to wall thickness, such that the _____ the vessel wall, the lower the tension.
thicker
The total quantity of blood that can be stored in a given portion of the circulation for each millimeter rise in pressure is termed compliance, and reflects the ____ of the blood vessel.
distensibility
The ____ and ____ valves control the movement of blood out of the ventricles.
aortic, pulmonic
The electrical activity, recorded on the electrocardiogram, _____ the mechanical events of the cardiac cycle.
precedes
The aorta is highly _____ and as such stretches during systole to accommodate the blood that is being ejected from the left heart during systole.
elastic
____ is marked by ventricular relaxation and filling.
Diastole
The difference between the end-diastolic and end-systolic volumes (approximately 70 mL) is called the ____.
stroke volume
The stroke volume divided by the end-diastolic volume is the ____ fraction.
ejection
The efficiency of the heart as a pump often is measured in terms of the ____ or the amount of blood the heart pumps each minute.
cardiac output
The ____ refers to the maximum percentage of increase in cardiac output that can be achieved above the normal resting level.
cardiac reserve
The ___ mechanism allows the heart to accommodate various levels of venous return.
Frank-Starling
The ____ determines the frequency with which blood is ejected from the heart.
heart rate
The outermost layer of a vessel, the ____ is composed primarily of loosely woven collagen fibers.
tunica adventitia
The middle layer of a vessel, the _____, is largely a smooth muscle layer.
tunica media
The innermost layer of a vessel, the _____ consists of a single layer of flattened endothelial cells.
tunica intima
The ____ represents the energy that is transmitted from molecule to molecule along the length of the vessel.
arterial pressure pulse
With peripheral arterial disease, there is a delay in the transmission of the reflected wave so that the pulse _____ in amplitude.
decreases
Pressure in the right atrium is called the ____.
central venous pressure
____ in the veins of extremities prevent retrograde flow with the help of skeletal muscles that surround and intermittently compress the leg veins to move blood forward to the heart.
Valves
______ of blood flow is mediated by changes in blood vessel tone due to changes in flow through the vessel or by local tissue factors.
Autoregulation
An increase in local blood flow is called _____.
hyperemia
In the heart and other vital structures, ______ channels exist between some of the smaller arteries.
anastomotic
The term _____ refers to the functions of the smallest blood vessels, the capillaries, and the neighboring lymphatic vessels.
microcirulation
Water-filled junctions, called the ______, join the capillary endothelial cells and provide a pathway for passage of substances through the capillary wall.
capillary pores
The key factor that retrains fluid loss from the capillaries is the _______ pressure generated by the plasma proteins.
colloidal osmotic
The neural control centers for the integration and modulation of cardiac function and blood pressure are located bilaterally in the _____.
medulla oblongata
The neural control of the circulatory system occurs primarily through the _____ and ______ divisions of the autonomic nervous system.
sympathetic, parasympathetic
When the intracranial pressure rises to levels that equal intra-arterial pressure, blood vessels to the vasomotor center become compressed, initiating the central nervous system ischemic response. This is known as the ___.
Cushing Reflex
Diastole
Resting phase of cardiac cycle
Pericardium
Sac that covers the heart
End-diastolic volume
Volume in heart following passive filling phase
Preload
Ventricular filling
Myocardium
muscular wall of heart
Cardiac output
heart rate x stroke volume
Heart valves
semilunar and atrioventricular
End-systolic volume
residual blood volume following contraction
Systole
contractile phase of cardiac cycle
Afterload
resistance to ejection of blood from heart
What are the factors involved in regulating the flow of blood and how are they related?
The most important factors governing the flow of blood in the cardiovascular system are pressure, resistance, and flow. Blood flow (F) through a vessel or series of blood vessels is determined by the pressure difference (? P) between the two ends of a ves
The velocity of blood in the circulatory system varies considerably between large vessels and capillaries. Normally, when fluid flows from a large vessel to a smaller vessel, the velocity increases, but this does not occur in the circulatory system. Why a
This is because, even though each individual capillary is very small, the total cross-sectional area of all the systemic capillaries greatly exceeds the cross-sectional area of other parts of the circulation. Because of this large surface area, the slower
What is the importance of the Frank-Starling mechanism?
The anatomic arrangement of the actin and myosin filaments in the myocardial muscle fibers is such that the tension or force of contraction depends on the degree to which the muscle fibers are stretched just before the ventricles begin to contract. The ma
How is blood vessel diameter controlled?
Sympathetic innervation via ?-adrenergic receptors is excitatory in that they produce vasoconstriction; ?-adrenergic receptors are inhibitory in that they produce vasodilation. Smooth muscle contraction and relaxation also occur in response to local tissu
What are the factors that travel in the bloodstream that will regulate blood flow? Indicate if each factor is a dilator or a vasoconstrictor.
1. Norepinephrine - potent vasoconstrictor
2. Epinephrine - mild vasoconstriction or dilation depending on the receptor type found in target tissue.
3. Angiotensin II - powerful vasoconstrictor
4. Histamine - powerful vasodilator and can increase permeabi
Blood volume is dictated by age and body weight. Neonates have a higher blood volume per kilogram than do adults. What is the blood volume range per kilogram in an adult?
The total blood volume is a function of age and body weight, ranging from 85 to 90 mL/kg in the neonate and from 70 to 75 mL/kg in the adult.
Resistance to flow is determined by the blood vessels and the blood vessel itself. An equation has been developed for understanding the relationship between the diameter of the blood vessel, the viscosity of the blood, and resistance. What is the equation
Poiseuille's Law. The blood vessels and the blood vessel itself constitute resistance to flow. A helpful equation for understanding the relationship between resistance, blood vessel diameter (radius), and blood viscosity factors that affect blood flow was
The dispensability of the blood vessel is the major factor in which of the vessel's characteristics?
Compliance. Compliance refers to the total quantity of blood that can be stored in a given portion of the circulation for each millimeter rise in pressure. Compliance reflects the distensibility of the blood vessel. Wall tension, laminar blood flow, and r
When intracranial pressure (ICP) equals intracranial pressure, the central nervous system ischemic response is initiated. This response is directed at raising arterial pressure above intracranial pressure (ICP), thereby re-establishing blood flow to the v
Cushing Reflex. The Cushing reflex is a special type of central nervous system reflex resulting from an increase in intracranial pressure. When the intracranial pressure rises to levels that equal intra-arterial pressure, blood vessels to the vasomotor en
The troponin complex is one of a number of important proteins that regulate actin-myosin binding. Troponin works in a striated muscle to help regulate calcium-mediated contraction of the muscle. Which of the troponin complexes are diagnostic of a myocardi
Troponin T and Troponin I. In clinical practice, the measurement of the cardiac forms of troponin T and troponin I are used in the diagnosis of myocardial infarction. Troponin C is not diagnostic of a myocardial infarction. Troponin A is not one of the tr
The stroke volume is the amount of blood ejected with every contraction of the ventricle. It is broken down into quarters. What is the approximate amount of the stroke volume per quarter?
60%, 20%, 20%, and little blood. Approximately 60% of the stroke volume is ejected during the first quarter of systole, and the remaining 40% is ejected during the next two quarters of systole. Little blood is ejected from the heart during the last quarte
Downstream peripheral pulses have a higher pulse pressure because the pressure wave travels faster than the blood itself. What occurs in peripheral arterial disease?
The pulse decreases rather than increases with amplitude. With peripheral arterial disease, there is a delay in the transmission of the reflected wave so that the pulse decreases rather than increases in amplitude.
Cardiac output (CO) is used to measure the efficiency of the heart as a pump. What is the equation used to express CO?
CO = SV X HR. The efficiency of the heart as a pump often is measured in terms of cardiac output (CO) or the amount of blood the heart pumps each minute. The CO is the product of the stroke volume (SV) and the heart rate (HR), and can be expressed by the
As the needs of the body change, the heart's ability to increase output necessarily needs to change too. This ability in the heart depends on what factors?
Cardiac contractility, Heart Rate, Preload, and Aferload.The heart's ability to increase its output according to body needs mainly depends on four factors: the preload, or ventricular filling; the afterload, or resistance to ejection of blood from the hea
Nitroglycerin is the drug of choice in treating angina. What does nitroglycerin release into the vascular smooth muscle of the target tissues?
Nitric oxide. The fact that nitric oxide is released into the vessel lumen (to inactivate platelets) and away from the lumen (to relax smooth muscle) suggests that it protects against both thrombosis and vasoconstriction. Nitroglycerin, which is used in t
Colloidal osmotic pressure acts differently than the osmotic effects of the plasma proteins. What is its action?
Pulls fluid back into the capillary. The osmotic pressure caused by the plasma proteins in the blood tends to pull fluid from the interstitial spaces back into the capillary. This pressure is termed colloidal osmotic pressure to differentiate the osmotic
The lymph system correlates with the vascular system without actually being a part of the vascular system. Among other things, the lymph system is the main route for the absorption of fats from the gastrointestinal system. The lymph system empties into th
Junctions of the subclavian and internal jugular veins. The lymph capillaries drain into larger lymph vessels that ultimately empty into the right and left thoracic ducts. The thoracic ducts empty into the circulation at the junctions of the subclavian an
The heart and blood vessels receive both sympathetic and parasympathetic innervation from neural control. What controls the parasympathetic-mediated slowing of the heart rate?
The cardioinhibitory center. The medullary cardiovascular neurons are grouped into three distinct pools that lead to sympathetic innervation of the heart and blood vessels and parasympathetic innervation of the heart. The first two, which control sympathe