Heart Anatomy, Blood Flow, and Hemostasis Flashcards

Flashcards on heart anatomy and function.

Pericardium

The membrane that directly surrounds the heart and defines the pericardial cavity.

Fibrous pericardium

The sturdy outer layer of the pericardium made of tough, dense connective tissue that protects the heart and maintains its position in the thorax.

Serous pericardium

The inner layer of the pericardium composed of the parietal pericardium and the visceral pericardium (epicardium).

Pericardial cavity

The space between the epicardium and the pericardium, filled with lubricating serous fluid.

Epicardium

The outermost layer of the heart wall, also the innermost layer of the pericardium.

Myocardium

The middle and thickest layer of the heart wall, made largely of cardiac muscle cells.

Endocardium

The innermost layer of the heart wall, lined with endothelium.

Atrioventricular septum

The septum between the atria and ventricles, marked by four openings with valves that ensure one-way flow of blood.

Atrioventricular valves

Valves located between the atria and ventricles.

Semilunar valves

Valves located at the openings that lead to the pulmonary trunk and aorta.

Right Atrium

Receiving chamber for blood returning to the heart from systemic circulation.

Right Ventricle

Receives blood from the right atrium through the tricuspid valve.

Chordae tendineae

Strong strands of connective tissue that attach the flaps of the tricuspid valve to the papillary muscles.

Left Atrium

Receives blood high in oxygen from the pulmonary veins.

Mitral Valve

Guards the opening between the left atrium and ventricle.

Left Ventricle

The major pumping chamber for the systemic circuit, ejects blood into the aorta.

Diffusion

The movement of small molecules, such as gases, lipids, and lipid-soluble molecules, directly through the membranes of the endothelial cells of the capillary wall.

Facilitated diffusion

The movement of glucose, amino acids, and ions through specific channels in the membrane.

Bulk flow

The mass movement of fluids into and out of capillary beds.

Filtration

The movement of fluid from an area of higher pressure in a capillary bed to an area of lower pressure in the tissues.

Reabsorption

The movement of fluid from an area of higher pressure in the tissues into an area of lower pressure in the capillaries.

Hydrostatic pressure

The pressure of any fluid enclosed in a space.

Blood hydrostatic pressure

The force exerted by the blood confined within blood vessels or heart chambers.

Capillary hydrostatic pressure (CHP)

The pressure exerted by blood against the wall of a capillary.

Interstitial fluid hydrostatic pressure (IFHP)

The opposing hydrostatic pressure in the interstitial fluid.

Osmotic pressure

The net pressure that drives reabsorption, the movement of fluid from the interstitial fluid back into the capillaries.

Blood colloidal osmotic pressure (BCOP)

The pressure created by the concentration of colloidal proteins in the blood.

Interstitial fluid colloidal osmotic pressure (IFCOP)

The osmotic pressure in the interstitial fluid.

Net filtration pressure (NFP)

The net filtration pressure, represents the interaction of the hydrostatic and osmotic pressures, driving fluid out of the capillary.

Transcytosis

The movement of substances across a capillary wall endothelial cell by endocytosis and exocytosis.

Cardiac cycle

The period of time that begins with contraction of the atria and ends with ventricular relaxation.

Systole

The period of contraction that the heart undergoes while it pumps blood into circulation.

Diastole

The period of relaxation that occurs as the chambers fill with blood.

End-diastolic volume (EDV)

The volume of blood in the ventricles at the end of diastole.

Stroke volume (SV)

The volume of blood pumped from the heart with each contraction.

End-systolic volume (ESV)

The volume of blood remaining in the ventricle following contraction.

Electrocardiogram (ECG)

A tracing of the electrical signal of the heart.

S1

Sound created by the closing of the atrioventricular valves during ventricular contraction.

S2

Sound of the closing of the semilunar valves during ventricular diastole.

Cardiac output

A measure of the flow of blood expelled from the left or right ventricle into the aorta or pulmonary trunk every minute.

Cardiac index

Measures cardiac output over the person’s weight to judge the effectiveness of the pumping action of the heart in diagnosing cardiac health.

Cardiac reserve

The reserve amount to which cardiac output may potentially increase to reach maximum cardiac output from a resting state to increased activity

Preload

The extent to which the heart stretches before each contraction.

Contractility

The intrinsic strength of each ventricular cardiac muscle fiber.

Afterload

The level of pressure the heart needs to eject blood from the ventricles.

Venous return (VR)

Volume of blood returning to the right ventricle.

Epinephrine and norepinephrine

Hormones released from the adrenal medulla in response to exercise, stress, and excitement which have a stimulatory effect on cardiac muscle fibers, increasing heart rate and contractility

Blood flow

The volume of blood flowing through the vessels of the body in each period of time.

Muscular Pump

Pressure gradient driving the movement of blood from venules to right ventricle

Respiratory Pump

Pressure changes in the thoracic cavity during inhalation and exhalation, promoting venous return to the heart

Circulation time

The time it takes for a drop of blood to pass through the whole of the pulmonary and systemic circulation.

Velocity of blood flow

The speed at which a volume of blood flows through any given tissue.

Blood pressure

The force exerted by blood upon the walls of the blood vessels or the chambers of the heart.

Systolic pressure

The arterial pressure resulting from the ejection of blood during ventricular contraction, or systole.

Diastolic pressure

The arterial pressure of blood during ventricular relaxation, or diastole.

Pulse pressure

The difference between the systolic pressure and the diastolic pressure.

Mean arterial pressure (MAP)

The average pressure of blood flowing through all arteries in the body.

Smaller lumen diameter

Has greater vascular resistance; thus, blood pressure is higher.

Blood viscosity

The thickness of blood and is determined by the number of red blood cells per volume of blood plasma.

Systemic vascular resistance (SVR)

The combined effect of the vascular resistance of all systemic vessels.

Cardiovascular center in the medulla oblongata of the brainstem

A region that receives input from sensory receptors and higher brain centers; closely regulates the cardiovascular system through a series of autonomic reflexes

Autonomic nervous system (ANS)

Closely regulates the cardiovascular system through a series of autonomic reflexes.

Baroreceptors

Mechanoreceptors situated in the walls of the carotid sinus and aortic arch. Detect changes in blood pressure

Proprioceptors

Monitor the position of the limbs. They detect changes in joint angles and muscle length and tension at the onset of exercise

Chemoreceptors

Sensory receptors close to the baroreceptors of the carotid sinus and aortic arch. They monitor chemical changes in the blood.

Hormonal Regulation of Blood Pressure and Flow

A negative feedback systems exist that control the short- and long-term homeostasis of blood pressure via hormones.

Renin-angiotensin-aldosterone (RAA) System; Renin

In response to a fall in blood volume or decreased blood flow to the kidneys, the juxtaglomerular cells of the kidneys secrete the hormone enzyme _ into the bloodstream

Epinephrine and Norepinephrine

During stress, in response to sympathetic stimulation, the adrenal medulla releases and into the bloodstream.

Atrial Natriuretic Peptide (ANP)

Released from atrial cells, causes vasodilation which decreases blood pressure. It also reduces total blood volume by promoting the loss of salt and water in the urine.

Erythropoietin

In response to low levels of oxygen in the blood, the kidneys release _. This glycoprotein hormone stimulates the bone marrow to produce more red blood cells, which increases the oxygen-carrying capacity of the blood.

Shock

The body goes into a state of _ when the cardiovascular system fails to supply enough oxygen and nutrients to tissues in order to meet cellular metabolic needs.

Hypovolemic shock

The most common form of shock resulting from sudden blood loss.

Cardiogenic shock

Results from damage to the heart, causing it to fail to pump efficiently.

Vascular shock

Results from poor circulation due to extreme vasodilation.

Obstructive shock

Results from a blockage stopping the flow of blood through a portion of the circulatory system.

Vascular spasm

The contraction of the smooth muscle in the blood vessel wall.

Platelet plug

An aggregation of platelets that functions as a temporary seal against blood loss.

Coagulation

The formation of a blood clot.

Anticoagulants

Substances that inhibit blood clotting.

Vitamin K

The fat-soluble vitamin required by the liver for the synthesis of various clotting factors.

Thrombosis

The clotting of a vessel that has not ruptured.

Embolus

A piece of debris traveling in the blood.

Erythrocytes

Also known as red blood cells; these are the most abundant cells in blood and are thin, disc-shaped cells, about 7.5μm in diameter. Primarily responsible for oxygen exchange.

Hematocrit

The percentage of blood volume containing red blood cells (RBCs).

Hemoglobin

A molecule consisting of a protein called globin, made up of four polypeptide chains, and an organic molecule, heme, with an iron at the center, which weakly binds reversibly to oxygen molecules

Fe3+; Iron

A part of hgb which immediately binds to a transporter protein; then travels to the liver, where it detaches from transferrin and attaches to ferritin and hemosiderin, which store it until it is needed

Leukopoiesis

The process by which white blood cells (leukocytes) are developed from stem cells in red bone marrow developed from stem cells in red bone marrow.

Granular Leukocytes (Granulocytes)

Leukocytes (WBCs) that are a type of white blood cell containing specialized enzyme-filled granules within their cytoplasm; examples include neutrophils, eosinophils, and basophils

Neutrophils

are most abundant, accounting for up to 50–70% of white blood cells. Function due to their abundance and mobility, neutrophils are often the first cells at the site of inflammation. They are attracted to pathogens and inflamed tissues by the chemicals they secrete, which include toxins, kinins, and colony-stimulating factors

Eosinophils

account for 2–4% of white blood cells. Eosinophil granules contain enzymes such as antihistamines, which, when released, counteract the effects of histamine during inflammatory reactions. They also have the capacity to phagocytize antigen-antibody complexes, pathogens, and parasites, commonly associated with allergies and asthma

Totipotent stem cell

This stem cell gives rise to all cells of the human body.

Basophils

are the least abundant of all white blood cells, making up less than 1% of white blood cells. Granules contain heparin, histamine, and serotonin, which are inflammatory chemical messengers released at sites of inflammation, eliciting allergic reactions

Agranular Leukocytes (Agranulocytes)

A type of white blood cell containing large nuclei and small cytoplasmic granules not visible under a light microscope. There are two types: lymphocytes and monocytes

Lymphocytes

There are various types that are mainly involved in specific immune responses such as with infections or cancers

Natural killer cells (NK cells)

A type of lymphocytes that provide a generalized, nonspecific immunity. These attack tumor cells and virus-infected cells because they are capable of recognizing “non-self” proteins

T lymphocytes (T cells)

A type of lymphocytes that are mainly involved in specific immune responses for virus-infected cells, fungi, cancer cells, and some bacteria

B lymphocytes (B cells)

A type of lymphocytes that are mainly involved in specific immune responses for antibody-mediated immune response, producing antibodies against antigens to destroy bacteria, especially memory cells stimulated by a vaccine

Monocytes

A type of leukocytes that engulf and remove cellular debris and microbes by phagocytosis or differentiate in the tissues into macrophages and dendritic cells involved innate/adaptive responses, and activate lymphocytes

Blood Groups; marker; plasma; erythrocytes

Blood groups are determined by the presence or absence of specific molecules on the membranes of _

Antigens

_ are substances that may trigger a defensive response from leukocytes of the immune system if the body does not recognize the antigen as belonging to the "self."