Chapter 7: The Cardiovascular System Flashcards
The _____________ system consists of a muscular 4-chambered heart, blood vessels, and blood.
Cardiovascular system
The _____________ consists of arteries, capillaries, and veins.
Vasculature
The right side of the heart accepts deoxygenated blood returning from the body and moves it to the lungs by way of the pulmonary arteries; this constitutes the first pump (______________ circulation)
Pulmonary circulation
The second pump is the left side of the heart, which receives oxygenated blood from the lungs by way of the pulmonary veins and forces it out to the body through the aorta (___________ circulation).
Systemic circulation
The _________ are thin-walled structures where blood is received from either the venae cavae or the pulmonary veins.
Atria
The ____________ carry deoxygenated blood entering the right side of the heart.
Venae cavae
The ____________ carry oxygenated blood entering the left side of the heart.
Pulmonary veins
The atria contract to push blood into the ____________.
Ventricles
The ventricles are far more muscular than the __________, allowing for more powerful contractions that are necessary to push blood through the rest of the body.
Atria
The atria are separated from the ventricles by the ___________________.
Atrioventricular valves
The ventricles are separated from the vasculature by the ___________________.
Semilunar valves
The cave between the right atrium and the right ventricle is known as the _____________ (three leaflets).
Tricuspid valve
The valve between the left atrium and the left ventricle is known as the ____________ or _____________ (two leaflets).
Mitral/Bicuspid valve
The valve that separates the right ventricle from the pulmonary circulation is known as the __________________.
Pulmonary valve
The contraction of cardiac muscle originates in an electrical impulse that occurs at the _______________ node, which generates 60-100 signals per minute without requiring any neurological input. This small collection of cells is located in the wall of the right atrium.
Sinoatrial (SA) node
As the depolarization wave spreads from the SA node, it causes the two ___________ to contract simultaneously.
Atria
While most ventricular filling is passive (that is, blood moves from the atria to the ventricles based solely on ventricular relaxation), _____________ (contraction) results in an increase in atrial pressure that forces a little more blood into the ventricles.
Atrial systole
The additional volume of blood from the atrial systole is called the _______________ and accounts for about 5-30 percent of cardiac output.
Atrial kick
From the SA node and two atria, the signal reaches the _________________, which sits at the junction of the atria and ventricles.
AV node (atrioventricular node)
The signal is delayed in ___________ to allow the ventricles to fill completely before they contract.
AV node
After the AV node, the signal then travels down the _____________ and its branches (the _______________).
Bundle of His
Purkinje fibers
The bundle of His and its branches are embedded in the ______________ (wall).
Interventricular septum
The valve that separates the left ventricle from the aorta is known as the ______________.
Aortic valve
The ____________ distribute the electrical signal through the ventricular muscle.
Purkinje fibers
The heart muscle cells are connect by _____________, which contain many gap junctions directly connecting the cytoplasm of adjacent cells. This allows for coordinated ventricular contraction.
Intercalated discs
The heart’s electrical impulses can be detected on the body’s surface by placing electrodes on the skin on opposite sides of the heart. A recording of these currents is called an _______________.
Electrocardiogram (ECG or EKG)
The ________ wave in an EKG occurs immediately before the atria contract.
P-wave
The _____________ occurs in an EKG just before the ventricles contract.
QRS complex
The _________ wave in an EKG represents ventricular depolarization.
T-wave
______________ nervous system signals speed up the heart rate and increase the contractility of cardiac muscle.
Sympathetic nervous system
______________ nervous system signals slow down the heart.
Parasympathetic nervous system
The parasympathetic nervous system signals are provided by the _____________ nerve.
Vagus nerve
During _____________, ventricular contraction and closure of the AV valves occurs and blood is pumped out of the ventricles.
Systole
During _____________, the ventricles are relaxed, the semilunar valves are closed, and blood from the atria fills the ventricles.
Diastole
The _____________ is the total blood volume pumped by a ventricle in a minute.
Cardiac output
The _____________ is the volume of blood pumped per beat.
Stroke volume
The _________ sound, _______, is produced when the 2 AV valves close at the start of systole to prevent back flow into the atria.
First sound, S1
The _________ sound, _______, is produced when the two semilunar valves close at the end of systole to prevent back flow into the ventricles.
Second sound, S2
During periods of exercise or rest, the ______________ nervous system will increase (sympathetic) or decrease (parasympathetic) cardiac output, respectively.
Autonomic nervous system
Blood travels away from the heart in ____________, the largest o which is the aorta (in the systemic circulation).
Arteries
Arteries then undergo further divisions and name changes as they divert blood to specific tissues and organs until, upon reaching their target, they branch into ____________, which ultimately lead to capillaries that perfuse the tissues.
Arterioles
On the venous side of a capillary network, the capillaries join together into __________, which join to form veins.
Venules
All blood vessels are lined with _______________ cells.
Endothelial cells
_____________ are highly muscular and elastic, creating tremendous resistance to the flow of blood.
Arteries
_____________ are vessels with a single endothelial cell layer and are so small that red blood cells must pass through the capillaries in a single-file line.
Capillaries
_____________ are thin-walled, inelastic vessels that transport blood to the heart.
Veins
_____________ are smaller venous structures that connect capillaries to the larger veins of the body.
Venules
Failure of the venous valves can result in the formation of __________ veins, which are distended where blood has pooled.
Varicose veins
The ________________ returns blood from portions of the body above the heart.
Superior vena cava (SVC)
The ________________ returns blood from portions of the body below the heart.
Inferior vena cava (IVC)
Right atrium ————–> right ventricle —————> pulmonary artery -> lungs -> pulmonary veins -> left atrium ————–> left ventricle —————> aorta -> arteries -> arterioles -> capillaries -> venues -> veins -> venae cavae -> right atrium
- Tricuspid valve
- Pulmonary valve
- Mitral valve
- Aortic valve
In the ___________ portal system, blood leaving capillary beds in the walls of the gut passes through the hepatic portal vein before reaching the capillary beds in the liver.
Hepatic portal system
In the ____________ portal system, blood leaving the capillary beds in the hypothalamus travels to a capillary bed in the anterior pituitary to allow for paracrine secretion of releasing hormones.
Hypophyseal portal system
In the _____________ portal system, blood leaving the glomerulus travels through an efferent arteriole before surrounding the nephron in a capillary network called the vasa recta.
Renal portal system
____________ is the liquid portion of blood, an aqueous mixture of nutrients, salts, respiratory gases, hormones, and blood proteins.
Plasma
All blood cells are formed from ________________, which originate in the bone marrow.
Hematopoietic stem cells
The _____________ or ____________ is a specialized cell designed for oxygen transport.
Erythrocyte
Red blood cell
Each erythrocyte contains about 250 million molecules of _____________, each of which can bind four molecules of oxygen.
Hemoglobin
Red blood cells are ___________ or indented on both sides, which serves a dual purpose. This shape assist them in traveling through tiny capillaries. It also increases the cell’s surface area, which increases gas exchange.
Biconcave
____________ cells are unique in that, when thy mature, the nuclei, mitochondria, and other membrane-bound organelles are lost.
Red blood cells
Red blood cells do not carry out oxidative phosphorylation to generate ATP; rather, they rely entirely on _____________ for ATP, with lactic acid (arising from fermentation) as the main byproduct.
Glycolysis
_____________ measures the quantity of hemoglobin in the blood, giving a result in grams per decilitre. A normal range is considered to be between 13.5-17.5 g/dL for males and between 12-15 g/dl for females.
Hemoglobin
____________ is a measure of how much of the blood sample consists of red blood cells, given as a percentage. A normal range is considered to be between 41-53% for males and between 36-46% in females.
Hematocrit
_____________ or ____________ usually comprise less than 1% of total blood volume. They are a crucial part of the immune system, acting as our defenders against pathogens, foreign cells, cancer, and other materials not recognized as self.
White blood cells, leukocytes
The granular leukocytes or ____________ (neutrophils, eosinophils, basophils) are so named because they contain cytoplasmic granules that are visible to microscopy.
Granulocytes
The ______________, which do not contain granules that are released by exocytosis, consist of lymphocytes and monocytes.
Agranulocytes
____________ are important in the specific immune response, the body’s targeted fight against particular pathogens, such as viruses and bacteria.
Lymphocytes
Some _____________ act as primary responders against an infection, while others function to maintain a long-term memory bank of pathogen recognition.
Lymphocytes
Lymphocytes that mature in the bone marrow are referred to as __________.
B-cells
Lymphocytes that mature in the thymus are called ___________.
T-cells
____________ are responsible for antibody generation.
B-cells
____________ kill virally infected cells and activate other immune cells.
T-cells
____________ phagocytize foreign matter such as bacteria.
Monocytes
Most organs of the body contain a collection of monocytes; once they leave the bloodstream and enter an organ, monocytes are renamed ____________.
Macrophages
In the central nervous system, the macrophages are called ___________.
Microglia
In the skin, macrophages are called _______________.
Langerhans cells
In the bones, macrophages are called _____________.
Osteoblasts
_____________ or ____________ are cell fragments that assist in blood clotting and are present in the blood at high concentration.
Thrombocytes
Platelets
Thrombocytes are cell fragments or shards released from cells in bone marrow known as ______________.
Megakaryocytes
The production of blood cells and platelets is called ____________, and is triggered by a number of hormones, growth factors, and cytokines.
Hematopoiesis
______________ is secreted by the kidney and stimulates mainly red blood cell development.
Erythropoietin
______________ is secreted by the liver and kidney and stimulates mainly platelet development.
Thrombopoietin
Red blood cells express surface proteins called _________.
Antigens
The two major antigen families relevant for blood groups are ______________ and ______________.
ABO antigens
Rh factor
People with type O blood are considered _____________ because their blood will not cause ABO-related hemolysis in any recipient.
Universal donors
People with type AB blood are considered ____________ because they can receive blood from all blood types: no blood antigen is foreign to AB individuals, so no adverse reactions will occur upon transfusion.
Universal recipients
Research has demonstrated that ____________ bacterium that inhabit the colon may have proteins that match the A and B alleles. This would serve as a source of exposure and would allow. one to develop anti-A or anti-B antibodies prior to exposure to another person’s blood.
E. coli
__________________ happens in any subsequent pregnancy in which the fetus is Rh+ will present a problem because maternal anti-Rh antibodies can cross the placenta and attack the fetal blood cells, resulting in hemolysis of the fetal cells.
Erythroblastosis fetalis
When an Rh- woman is pregnant with her first Rh+ fetus, the risk of erythroblastosis fettles in subsequent Rh-mismatched pregnancies can usually be avoided by giving the Rh- mother ______________ during pregnancy and immediately after delivery.
Rh-immunoglobulin (RhoGAM)
Blood pressure is a measure of the force per unit area exerted on the wall. of the blood vessels and is measured wth a _________________.
Sphygmomanometer
____________ is expressed as a ratio of the systolic (ventricular contraction) to diastolic (ventricular relaxation) pressures.
Blood pressure
Blood pressure gradually drops from the arterial to venous circulation, with the largest drop occurring across the ____________. This is critical because the capillaries are thin-walled and unable to withstand the pressure of the arterial side of the vasculature.
Arterioles
Normal blood pressure is considered to be between ____________ and ____________.
90/60 and 120/80
The longer a blood vessel is, the (more?/less?)____________ resistance it offers.
More
The larger the cross-sectional area of a blood vessel, the (more?/less?)___________ resistance it offers.
Less
____________ can contract to limit the amount of blood entering a given capillary bed (much like increasing resistance will decrease current flow to a given branch in a circuit).
Arterioles
Opening capillary beds will (increase?/decrease?)___________ vascular resistance (like adding another resistor in parallel) and, assuming the body can compensate, increase cardiac output.
Decrease
Blood pressure is regulated using ______________ in the walls of the vasculature.
Baroreceptors
______________ are specialized neurons that detect changes in the mechanical forces on the walls of the vessel.
Baroreceptors
When the blood pressure is too low, ____________ can stimulate the sympathetic nervous system, which causes vasoconstriction, thereby increasing the blood pressure.
Baroreceptors
______________ can sense when the osmolarity of the blood is too high, which could indicate dehydration.
Chemoreceptors
Dehydration promotes the release of _____________ hormone (_____ or _____________), a peptide hormone made in the hypothalamus but stored in the posterior pituitary, which increases the reabsorption of water, thereby increasing blood volume and pressure (while also diluting the blood).
Antidiuretic hormone (ADH or vasopressin)
Low perfusion to the juxtaglomerular cells of the kidney stimulates _____________ release through the renin-angiotensin-aldosterone system; ____________ increases the reabsorption of sodium and, by extension, water, thereby increasing the blood volume and pressure.
Aldosterone
Within the heart, specialized atrial cells are able to secrete a hormone called _________________ (_____). This hormone aids in the loss of salt within the nephron, acting as a weak natural diuretic with loss of fluid.
Atrial natriuretic peptide (ANP)
Regardless of the substance being exchanged in the blood, there is one fundamental concept to be considered in this process: _________________. In each case, one side of the capillary wall has a higher concentration of a given substance than the other.
Concentration gradient
Oxygen is carried primarily by _______________ in the blood.
Hemoglobin
______________ is protein composed of four cooperative units, each of which has a prosthetic heme group that binds to an oxygen molecule.
Hemoglobin
The binding or releasing of oxygen to or from the iron atom in the heme group is an ________________ reaction.
Oxidation-reduction reaction
The level of oxygen in the blood is often measured as the partial pressure of O2 within the blood, or _________. A normal _________ is approximately 70-100 mmHg.
PaO2
____________ is the percentage of hemoglobin molecules carrying oxygen, which is easily measured using a finger probe. Most healthy people have an _____________ above 97%.
Oxygen saturation
As the first oxygen binds to a heme group in the alveolar capillaries, it induces a conformation shift in the shape of hemoglobin from ________ to relaxed.
Taut
The positive-feedback phenomenon in the binding and removal of oxygen molecules from hemoglobin subunits (resulting in conformational changes) is a form of allosteric regulation referred to as ________________ and results in the classic sigmoidal (S-shaped) oxyhemoglobin dissociation curve.
Cooperative binding
______________ gas, like oxygen gas, is non polar and therefore has low solubility in the aqueous plasma; only a small percentage of the total ______________ being transported in the blood to the lungs will be dissolved in the plasma.
Carbon dioxide (CO2)
Carbon dioxide can be carried by ____________, but ___________ has a much lower affinity for carbon dioxide than for oxygen.
Hemoglobin
The vast majority of CO2 exists in the blood as the ______________.
Bicarbonate ion/HCO3-
When CO2 enters a red blood cell, it encounters the enzyme _______________, which catalyzes the combination reaction between carbon dioxide and water to form carbonic acid (H2CO3).
Carbonic anhydrase
Increased carbon dioxide production will cause a right shift in the bicarbonate buffer equation, resulting in increased _______________ (decreased pH).
Hydrogen ions
As carbon dioxide production increases, the hydrogen ions in the bicarbonate buffer equation bind to hemoglobin. The decreased hemoglobin affinity for oxygen can be seen in the oxyhemoglobin curve as a shift to the right; this is known as the _____________.
Bohr effect
The following occur during exercise:
- ______________ PaCO2
- ______________ [H+] (decreased pH)
- ______________ temperature
- Increased PaCO2
- Increased [H+] (decreased pH)
- Increased temperature
Fetal hemoglobin (HbF) has a higher affinity for oxygen than adult hemoglobin (HbA), and therefore has a (left?/right?)________-shifted curve compared to adult hemoglobin.
Left-shifted curve
Other causes of a right shift in the oxyhemoglobin curve include increased temperature and increased _____________________ (____________), a side product of glycolysis in red blood cells.
2,3-biphosphoglycerate (2,3-BPG)
A left shift in the oxyhemoglobin curve may occur due to ______________ temperature, ______________ PaCO2, ______________ [H+], ____________ pH, and _______________ 2,3-BPG.
- Decreased temperature
- Decreased PaCO2
- Decreased [H+]
- Increased pH
- Decreased 2,3-BPG
The bicarbonate buffer system is important because it links the respiratory and __________ systems.
Renal system
If an individual hyperventilates, excess CO2 will be blown off, shifting the bicarbonate buffer system to the left and decreasing the concentration of protons. This leads to an increase in pH, or what is known as ______________. The kidney can compensate for this change by increasing excretion of bicarbonate, which brings the pH back to normal.
Respiratory alkalosis
In renal tubular acidosis type I, the kidney is unable to excrete acid effectively. This leads to a buildup of protons in the blood (___________), which causes the buffer system to shift to the left.
Metabolic acidosis
Carbohydrates and amino acids are absorbed into the capillaries of the small intestine and enter the systemic circulation via the _________________ system.
Hepatic portal system
Fats are absorbed into lacteals in the small intestine, bypassing the hepatic portal circulation to enter systemic circulation via the ________________.
Thoracic duct
When released from intestinal cells, fats are packaged into ______________, which are water-soluble.
Lipoproteins
Hormones enter the circulation in or near the organ where the hormone is produced. This usually occurs by ______________, allowing for secretion of hormones into the bloodstream.
Exocytosis
Once hormones reach their target tissues, they can activate cell-surface receptors (___________ hormones) or diffuse into the cell to activate intracellular or intranuclear receptors (___________ hormones).
- Peptide hormones
- Steroid hormones
_____________ pressure is the force per unit area that the blood exerts against the vessel walls.
Hydrostatic pressure
_____________ pushes fluid out of the bloodstream and into the interstitium through the capillary walls, which are somewhat leaky by design.
Hydrostatic pressure
_____________ pressure is the “sucking” pressure generated by solutes as they attempt to draw water into the bloodstream.
Osmotic pressure
Because most of the osmotic pressure is attributable to plasma proteins, it is usually called the ____________ pressure.
Oncotic pressure
At the arteriole end of a capillary bed, hydrostatic pressure (pushing fluid out) is much (larger?/smaller?)_______________ than oncotic pressure (drawing fluid in), and there is a net efflux of water from the circulation.
Larger
At the venule end of the capillary bed, hydrostatic pressure (pushing fluid out) has dropped (above?/below?)__________ oncotic pressure (drawing fluid in), and there is a net influx of water back into the circulation.
Below
The balance of the hydrostatic and osmotic pressures (opposing pressures), also called ______________, is essential for maintaining the proper fluid volumes and solute concentrations inside and outside the vasculature.
Starling forces
Accumulation of excess fluid in the interstitium results in a condition called __________.
Edema
Most lymphatic fluid (lymph) is returned to the central circulatory system by way of a channel called the ____________.
Thoracic duct
___________ are composed of both coagulation factors (proteins) and platelets, and they prevent (or at least minimize) blood loss.
Clots
When the endothelium of a blood vessel is damaged, it exposes the underlying connective tissue, which contains collagen and a protein called _____________.
Tissue factor
________________, most of which are secreted by the liver, sense tissue factor and initiate a complex activation cascade.
Coagulation factors
The end point of the complex activation cascade is the activation of prothrombin to form thrombin by ________________.
Thromboplastin
Thrombin can convert fibrinogen into _____________.
Fibrin
______________ ultimately forms small fibers that aggregate and cross-link into a woven structure, like a net, that captures red blood cells and other platelets, forming a stable clot over the area of damage.
Fibrin
A clot that forms on a surface vessel that has been cut is called a _________.
Scab
______________ formation, or blood clotting, occurs when blood vessels are injured.
Thrombus formation
Blood clotting begins when platelets attach to the matrix that becomes exposed when the endothelial cells lining blood vessels are disrupted. This attachment then activates quiescent ____________ molecules, causing them too adhere to circulating proteins - including fibrinogen, which forms bridges to additional platelets.
alpha IIa beta 3 integrin molecules
The clot will have to be broken down. This task is accomplished predominantly by ___________.
Plasmin
Plasmin is generated from ________________.
Plasminogen
