Circulatory System Quiz

Podcast Beta

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What mechanism is NOT involved in maintaining the forward movement of blood in the superior vena cava?

Valves derived from endothelium and connective tissue of the vein wall

Movement of organs in the thorax during respiration

Contraction of nearby skeletal muscle fibers

Movement of cerebral fluid (correct)

Which statement is true regarding varicose veins?

Varicose veins are caused by a breakdown in venous valves. (correct)

They occur only in deep veins of the legs.

They can only be treated by surgical methods.

Superficial veins are less susceptible to varicosities due to more support.

What is the largest vein in the body?

Pulmonary vein

Inferior vena cava (correct)

Great saphenous vein

Superior vena cava

In systemic circulation, what type of blood is transported away from the left ventricle?

Oxygenated blood Signup and view all the answers

Which vein is the longest in the body and most susceptible to vericosities?

Great saphenous vein Signup and view all the answers

What type of circulation involves the transportation of blood to the lungs?

Pulmonary circulation Signup and view all the answers

Which factor does NOT assist in the movement of blood through the veins?

Gravity Signup and view all the answers

The azygos vein serves as a bypass to which vein?

Inferior vena cava Signup and view all the answers

What is the primary function of the placenta in fetal circulation?

To provide oxygen and nutrients to the fetus Signup and view all the answers

Which blood vessel carries oxygenated blood towards the fetus?

One umbilical vein Signup and view all the answers

What is the consequence of failure to close the Foramen Ovale after birth?

Occurrence of Foramen Ovale syndrome Signup and view all the answers

How does blood flow relate to the pressure in the circulatory system?

Blood flows in the same direction as decreasing pressure gradients Signup and view all the answers

What happens to the Ductus Arteriosus after birth?

It transforms into a fibrous cord Signup and view all the answers

Why is the velocity of blood flow slowest in the capillaries?

To allow for proper exchange of gases and nutrients Signup and view all the answers

What primarily influences venous blood flow?

Skeletal muscle action and respiratory movements Signup and view all the answers

Which of the following statements about fetal circulation is true?

The Foramen Ovale allows blood to bypass the lungs Signup and view all the answers

What is the primary function of capillaries in the circulatory system?

Facilitate nutrient and waste exchange Signup and view all the answers

What physiological feature regulates blood flow into capillaries?

Precapillary sphincters Signup and view all the answers

What triggers the contraction of arterio-venous shunts (AV shunts)?

Thermal, mechanical, and chemical stimuli Signup and view all the answers

Which type of capillaries is characterized by a continuous endothelium and tight junctions?

Continuous capillaries Signup and view all the answers

Which of the following statements about capillary structure is true?

Capillaries have a high surface area to volume ratio Signup and view all the answers

What role does osmotic pressure play in capillary function?

It drives fluid movement across capillary walls Signup and view all the answers

Why is the diameter of a capillary so small?

To allow single-file movement of red blood cells Signup and view all the answers

What effect does contracting precapillary sphincters have on blood flow?

Reduces blood flow into capillaries Signup and view all the answers

What does pulse provide vital information about?

Heart rate, strength of contraction, and rhythmicity Signup and view all the answers

Which artery is most commonly used to take one’s pulse?

Radial artery Signup and view all the answers

What is defined as the difference between systolic and diastolic pressures?

Pulse pressure Signup and view all the answers

Which instrument is necessary for measuring blood pressure?

Sphygmomanometer Signup and view all the answers

What occurs to the artery during the pulse?

It expands and then recoils Signup and view all the answers

What is mean arterial pressure (MAP)?

The average blood pressure in the arteries Signup and view all the answers

Which pressure is first detected when measuring blood pressure and indicates systolic pressure?

The pressure when Korotkoff sounds first appear Signup and view all the answers

What is the purpose of inflating the cuff above systolic pressure?

To block all blood flow temporarily Signup and view all the answers

What is the diastolic pressure defined as?

The pressure at which the last sound is heard Signup and view all the answers

What is the typical value for normal blood pressure referred to as?

120/80 mmHg Signup and view all the answers

How does blood pressure generally change as blood moves away from the left ventricle?

Blood pressure decreases Signup and view all the answers

What directly affects the peripheral resistance of blood vessels?

Blood vessel diameter Signup and view all the answers

What happens to blood pressure when resistance increases?

Blood pressure increases Signup and view all the answers

Which factor decreases blood viscosity?

Increased plasma volume Signup and view all the answers

How does vessel elasticity relate to blood pressure?

Decreased elasticity causes increased blood pressure Signup and view all the answers

Which hormone can cause vasoconstriction and impact blood pressure?

Aldosterone Signup and view all the answers

What is the primary function of the tunica externa in blood vessels?

It binds the vessels to surrounding tissue structures. Signup and view all the answers

Which property of arteries is primarily responsible for absorbing the shock of ventricular contractility?

Elasticity of the artery Signup and view all the answers

What happens to the lumen size of an artery during vasoconstriction?

It decreases significantly. Signup and view all the answers

Which type of blood is carried by the pulmonary artery in post-natal life?

Deoxygenated blood Signup and view all the answers

What controls the contraction and relaxation of arterioles?

Primarily autonomic control Signup and view all the answers

What process allows arteries to assist in forward blood flow after ventricular contraction?

Pulsatile flow Signup and view all the answers

Which feature is NOT indicative of arterioles compared to larger arteries?

They contain a thicker tunica media. Signup and view all the answers

What is the effect of norepinephrine on blood pressure in relation to arterioles?

Triggers vasoconstriction and increases blood pressure. Signup and view all the answers

What primarily regulates blood flow entering a capillary?

Precapillary sphincters Signup and view all the answers

How does the structure of capillaries facilitate the exchange of materials?

They have a single layer of simple epithelium. Signup and view all the answers

What type of stimuli can influence the contraction of arterio-venous shunts?

Thermal, mechanical, and chemical stimuli Signup and view all the answers

What happens to blood flow when precapillary sphincters contract?

Blood flow decreases meaningfully. Signup and view all the answers

Which of the following accurately describes capillaries?

Their small diameter limits blood flow to single red blood cells. Signup and view all the answers

Which factor is NOT involved in the movement of fluid across capillary walls?

Blood viscosity Signup and view all the answers

What characteristic of capillaries makes them suitable for nutrient and waste exchange?

Their thin walls allowing for easy diffusion. Signup and view all the answers

Which of the following statements about capillary distribution is true?

Capillary density increases in tissues with high metabolic demand. Signup and view all the answers

What occurs to blood pressure as blood moves away from the left ventricle?

Blood pressure decreases gradually Signup and view all the answers

Which factor directly decreases peripheral resistance in blood vessels?

Increased blood vessel diameter Signup and view all the answers

What relationship does blood viscosity have with blood pressure?

Increased viscosity requires more pressure to maintain flow Signup and view all the answers

Which environmental factor influences vasoconstriction significantly?

Norepinephrine release Signup and view all the answers

How does aging specifically affect blood vessels and blood pressure?

Decreases vessel elasticity, increasing blood pressure Signup and view all the answers

Which hormone is specifically associated with increasing blood pressure through vasoconstriction?

Angiotensin II Signup and view all the answers

What effect does an increase in plasma volume have on blood viscosity?

Decreases blood viscosity Signup and view all the answers

What is the primary characteristic of laminar flow in blood vessels?

Blood in contact with the vessel wall moves slowly Signup and view all the answers

What condition is characterized by inflammation of a vein often leading to pain and lameness in a limb?

Thrombophlebitis Signup and view all the answers

Which term describes a significant decrease in blood pressure upon standing or changing posture?

Orthostatic Hypotension Signup and view all the answers

What medication type works by preventing blood platelets from sticking together?

Antiplatelets Signup and view all the answers

Which phenomenon is primarily triggered by cold temperatures or emotional stress, leading to reduced blood flow in extremities?

Reynaud's Disease Signup and view all the answers

What is the common term for medications that decrease the coagulating ability of the blood?

Anticoagulants Signup and view all the answers

Which condition is defined as pain and lameness in the limbs due to inadequate blood circulation?

Claudication Signup and view all the answers

What is the primary underlying mechanism for orthostatic hypotension?

Inadequate autonomic response to posture changes Signup and view all the answers

What term describes the closure or obstruction of a blood vessel's lumen?

Occlusion Signup and view all the answers

How does an increase in hematocrit affect blood viscosity?

It increases viscosity Signup and view all the answers

What physiological mechanism causes baroreceptors to signal a decrease in heart rate?

Increased blood pressure stretching the receptor walls Signup and view all the answers

What is a consequence of increased stroke volume (SV) on cardiac output (Q)?

Q increases linearly with SV Signup and view all the answers

Which factor does NOT affect blood pressure regulation?

Body temperature fluctuations Signup and view all the answers

How does an increase in venous return affect cardiac output?

It increases cardiac output due to increased preload Signup and view all the answers

What directly influences the frequency of action potentials sent by baroreceptors?

The stretch of the receptor wall due to blood pressure Signup and view all the answers

What physiological state occurs during erythrocytosis?

Increase in RBC count Signup and view all the answers

Which would NOT likely result in a decrease in blood volume?

Hydration through intravenous fluids Signup and view all the answers

Where does gas exchange take place?

capillary Signup and view all the answers

What is the first way veins get forward flow to the heart?

hydrostatic pressure Signup and view all the answers

Which of the following has the highest pressure? (vein)

Digital vein Signup and view all the answers

Which of the following has the lowest pressure?

Digital Artery Signup and view all the answers

What 4 things is Blood pressure characterized by?

<ol> <li>Systolic Pressure</li> <li>Diastolic Pressure</li> <li>Pulse Pressure</li> <li>Mean Arterial Pressure</li> </ol> Signup and view all the answers

What is the normal blood pressure?

120/80 mmHg Signup and view all the answers

What is normal pulse pressure?

40 mm/hg Signup and view all the answers

what is the correct formula for Mean Arterial Pressure

MAP=DBP + 1/3 PP Signup and view all the answers

Blood pressure is greater in .................. as opposed to .................

arteries, veins Signup and view all the answers

As blood moves away, blood pressure

decreases Signup and view all the answers

What 4 things affect blood pressure?

Peripheral Resistance, blood viscosity, volume of blood, cardiac output = Q=HR x SV Signup and view all the answers

If peripheral resistance increases, blood pressure

increases Signup and view all the answers

A decreases of elasticity is a ............... of Blood Pressure?

increase Signup and view all the answers

Hematocrit is the ................... of Red Blood cells in whole blood.

percentage Signup and view all the answers

Any factor that will increase hematocrit will ..................... viscosity.

increase Signup and view all the answers

Which of the following makes up the formed elements?

RBC Signup and view all the answers

An increase of plasma in the blood will ................... viscosity.

decrease Signup and view all the answers

Erythrocytosis is the .............. of RBC production. Whereas Erythropenia is the .............. of RBC production.

excess, lack Signup and view all the answers

How can Stroke Volume be increased or decreased?

<ol> <li>Preload</li> <li>Amount of Venous Return</li> </ol> Signup and view all the answers

Chemoreceptors response to partial pressure of which 3 elements?

<ol> <li>Co2</li> <li>H+ (ph)</li> <li>Oxygen 02</li> </ol> Signup and view all the answers

What are the 2 short term methods to regulate Blood Pressure?

Baroreceptors and Chemoreceptors Signup and view all the answers

Which of the following mechanisms are used to regulate long term BP?

renin Signup and view all the answers

Whenever Blood pressure decreases, the ............ secrete renin into blood. Renin activates a conversion of Angiotensin to .................... Angiotensin then travels to the ................. and becomes angiotensin ...........

kidneys, angiotensin 1, lungs, 2 Signup and view all the answers

What does Angiotensin 2 do?

vasoconstriction which increases Blood Pressure Signup and view all the answers

Aldosterone stimulates the .................... to reabsorb .................. water follows which results in the increase of water volume which ................. blood pressure.

kidneys, sodium, increases Signup and view all the answers

What 3 things comes off the Aorta?

Ascending Aorta, Arch of Aorta, Descending Aorta Signup and view all the answers

Which wall of the Artery is in contact with blood?

tunica intima Signup and view all the answers

Which part wall of artery is innervated by the ANS?

tunica media Signup and view all the answers

What is the only artery that carries poorly oxygenated blood in post-natal life?

Pulmonary artery Signup and view all the answers

What kind of tissue is the tunica intima?

epithelium Signup and view all the answers

What kind of tissue is the tunica media?

Smooth muscle Signup and view all the answers

Arteries are ...................... pressure ..................... capacity/volume

high, low Signup and view all the answers

The ability to contract an artery comes from the tunica .................. because of the smooth muscle tissue

media Signup and view all the answers

What type of capillaries have porous walls that allow nutrients, water, and water-soluble waste products to exit the capillary lumen?

Fenestrated capillaries Signup and view all the answers

Which type of capillaries control bulk transport?

Vesicular capillaries Signup and view all the answers

Veins are .............. volume, ............... pressure

high, low Signup and view all the answers

Which of the following are required to maintain forward flow due to hydrostatic pressure in the Superior Vena Cava? (Select all that apply)

Contraction of skeletal muscle fibers Signup and view all the answers

What is the largest vein in the body?

Vena cava Signup and view all the answers

What vein is a bypass to the inferior vena cava?

Azygos vein Signup and view all the answers

What is the longest vein in the human body?

Saphenous vein Signup and view all the answers

What are the two types of circulatory routes?

Systemic and pulmonary circulation Signup and view all the answers

Which circulatory route loses CO2 and becomes O2?

Pulmonary Signup and view all the answers

What is the term that involves partial or complete blockage of one or more of the coronary arteries and their branches?

clinical coronary occlusion Signup and view all the answers

Where does the right coronary artery branch into?

posterior interventricular and marginal arteries Signup and view all the answers

Where does the left coronary artery branch into?

circumflex and anterior interventricular Signup and view all the answers

What branches off the ascending aorta?

Left and Right Coronary arteries Signup and view all the answers

What is the medical term for a blockage by a blood clot that impedes blood flow?

Thrombus Signup and view all the answers

Clots can either be .........

Clots can be digested by enzymes Signup and view all the answers

Which condition consists of fatty deposits in blood vessels?

Atherosclerotic plaques Signup and view all the answers

Where does the oxygenation of fetal blood flow take place?

Placenta Signup and view all the answers

The one umbilical vein transports .............. blood .............. the fetus and away from the placenta.

oxygenated, toward Signup and view all the answers

The 2 umbilical arteries transport .............. blood ................. from the fetus and to the placenta.

deoxygenated, away Signup and view all the answers

What are 2 non-functional structures that shunt blood through the heart and bypass the lungs?

Foramen ovale (FO) and ductus arteriosus Signup and view all the answers

The foramen ovale closes shortly after birth and is referred to as the?

Fossa ovalis Signup and view all the answers

Study Notes

Tunica Externa

The outermost layer of blood vessels, primarily composed of collagenous connective tissue and varying amounts of elastic fibers.
Its main function is to bind the vessel to surrounding tissues.

Lumen of an Artery

The hollow center of an artery through which blood flows.

Elasticity of Arteries

Arteries expand to accommodate blood flow during ventricular contraction.
This expansion and subsequent recoil help absorb the shock of ventricular contraction and facilitate pulsitile blood flow (forward movement).
Arteries are characterized by high pressure and low capacity/volume.

Contractility of Arteries

Smooth muscle tissue surrounding the tunica media layer gives arteries the ability to contract.
Contraction of this smooth muscle narrows the lumen.
Vasoconstriction: decrease in lumen size.
Vasodilation: increase in lumen size.

Pulmonary Artery

The only artery that carries deoxygenated blood in post-natal life.

Arterioles

The smallest vessels with three layers: intima, media, and adventitia.
Media and adventitia layers disappear as they branch into capillaries, leaving only the tunica intima.
Walls are similar in thickness to the diameter of the lumen.
Primarily responsible for directing and diverting blood flow.

Autonomic Control of Arterioles

Sympathetic control: Norepinephrine causes vasoconstriction and increased blood pressure.
Parasympathetic control: Acetylcholine causes vasodilation and decreased blood pressure.

Factors Affecting Arteriole Smooth Muscle Contraction

Epinephrine (sympathetic stimulation).
Angiotensin (details discussed later).
Atrionatremic factor (ANF): regulates heart blood pressure.
Kinins: released at wound sites.
Histamine: released during tissue injury and immune reactions.

Capillaries

Smallest and most numerous blood vessels.
Composed of a single layer of simple epithelium (tunica intima) with a basement membrane.
Their thin walls allow exchange of nutrients and waste between blood and tissue cells.
Diameter is small enough for only one red blood cell to pass through at a time.

Capillary Distribution

Varies with metabolic demand.
Skeletal muscle, liver, and kidney have the most extensive capillary networks.

Movement into Capillaries

Controlled by hydrostatic pressure and osmotic pressure, allowing for bulk flow and simple diffusion of water.

Precapillary sphincters: control the flow of blood into capillaries.

          - Sphincter contraction reduces blood flow.
          - Sphincter relaxation increases blood flow.

Movement between Arterial and Venous Sides

Controlled by Arterio-Venous Shunts (AV shunts) or Metarterioles.
Contraction of smooth muscle in these shunts allows blood to bypass tissue bed and be directed elsewhere.

AV Shunt Responsiveness

Respond to thermal stimuli, mechanical stimuli, and chemical stimuli, regulating their opening and closing.

Types of Capillaries

Classified by the morphology of their endothelial cells.

Blood Pressure

The force exerted by blood against the walls of blood vessels.
Pulse pressure is the difference between systolic and diastolic pressure.
Highest in elastic arteries and lowest in large veins.

Factors Affecting Blood Pressure

Directly related to blood pressure:
- Peripheral resistance: friction between blood and vessel walls. - Blood flow is faster in the center of the vessel due to less resistance, creating laminar flow.
- Blood viscosity: thickness of blood. - Increased plasma volume (water) decreases viscosity. - Increased hematocrit (percentage of red blood cells) increases viscosity.
- Volume of blood: average adult volume is 5 liters. - Increased volume increases blood pressure.
- Cardiac output: amount of blood pumped per minute. - Increased heart rate or stroke volume increases cardiac output and blood pressure.

Regulation of Blood Pressure

Short-term mechanisms: baroreceptors and chemoreceptors.
Long-term mechanisms: (details not covered in this text).

Baroreceptors

Located in the aortic arch and carotid sinus.
Respond to changes in pressure by stretching their walls.
Increased pressure: sends action potentials to the medulla oblongata, decreasing heart rate and causing vasodilation.
Decreased pressure: decreases action potentials to the medulla oblongata, increasing heart rate and causing vasoconstriction.

Chemoreceptors

Sensitive to changes in blood oxygen, carbon dioxide, and pH.
Stimulate changes in heart rate, respiration, and blood vessel diameter.

Occlusion

Closure or obstruction of a lumen, such as in a blood vessel.

Hypotension

Low blood pressure, often used to describe an acute drop in blood pressure.

Orthopstatic Hypotension

Excessive lowering of blood pressure upon assuming an upright position, often a sign of disease.

Phlebitis

Inflammation of a vein.

Phlebotomy

Incision into a vein.

Reynaud's Disease

Vascular disorder, common in women, characterized by bilateral attacks of ischemia, usually affecting fingers and toes.

Thrombophlebitis

Inflammation of a vein accompanied by clot formation.

Superficial Thrombophlebitis

Affects veins under the skin, especially in the calf.

Anticoagulants

Reduce the coagulating ability of blood.
Examples: heparin, citrate, Coumadin, Hirudin.
Help prevent clot formation and enlargement.

Antiplatelets

Prevent blood clots by stopping platelets from sticking together.
Example: aspirin.
Used in patients with heart attack, TIA (transient ischemic attacks), and plaque buildup.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge on the human circulatory system, focusing on veins, blood flow, and fetal circulation. This quiz covers various aspects, including the mechanisms involved in blood movement and key anatomical features. Challenge yourself with questions about the functions of different blood vessels and their roles in circulation.