Topic 4.2: Circulation Flashcards
Describe how blood flow is controlled in each of the three major types of blood vessels.
Blood flow is controlled in arteries by contraction of smooth muscle in artery walls.
Capillary blood flow is affected by the pressure of arterial supply plus the contraction of precapillary sphincters. Venous blood flow is affected by arterial and capillary blood flow, and valves that prevent blood from flowing backward.
List several specific substances that diffuse across capillary walls.
O2, CO2, glucose, amino acids.
List the major components of blood, along with their functions.
Red blood cells (erythrocytes): Transports O2 and helps transport CO2
White blood cells: Fight infection
- Neutrophils: phagocytizes pathogens
- Eosinophils: phagocytizes antigen-antibody complexes and allergens
- Basophils: releases histamine, which promotes blood flow to injured tissues
-Lymphocytes: responsible for specific immunity
- Monocytes: become macrophages that phagocytize pathogens and cellular debris
Platelets (thrombocytes): Aid clotting
Describe the cellular and molecular events that lead to blood clotting.
- Blood vessel is punctured
- Platelets congregate and form a plug
- Platelets and damaged tissue cells release prothrombin activator, which initiates a cascade of enzymatic reactions
- Fibrin threads form and trap red blood cells.
Identify some types of diseases that would be expected to be treatable with stem cell therapy.
Diabetes
Heart disease
Liver disease
Parkinson’s
Alzheimer’s
Predict the effect on the interstitial fluid if the protein content of the blood was greatly reduced.
If the protein content of the blood was reduced, then the osmotic pressure of the blood would be lowered and less water would move from the interstitial fluid into the blood.
Define blood
Fluid circulated by the heart through a closed system of vessels; type of connective tissue.
Define plasma
In vertebrates, the liquid portion of blood; contains nutrients, wastes, salts, and proteins.
Define formed elements
Portion of the blood that consists of erythrocytes, leukocytes, and platelets (thrombocytes).
Define red blood cells
Erythrocyte; contains hemoglobin and carries oxygen from the lungs or gills to the tissues in vertebrates.
Define erythrocyte
Red blood cell; contains hemoglobin and carries oxygen from the lungs or gills to the tissues in vertebrates.
Define hemoglobin
Iron-containing respiratory pigment occurring in vertebrate red blood cells and in the blood plasma of some invertebrates.
Define white blood cells
Leukocyte, of which there are several types, each having a specific function in protecting the body from invasion by foreign substances and organisms.
Define leukocytes
White blood cell, of which there are several types, each having a specific function in protecting the body from invasion by foreign substances and organisms.
Define neutrophils
Granular leukocyte that is the most abundant of the white blood cells; first to respond to infection.
Define basophils
White blood cell with a granular cytoplasm; able to be stained with a basic dye.
Define eosinophil
White blood cell containing cytoplasmic granules that stain with acidic dye.
Define monocytes
Type of agranular leukocyte that functions as a phagocyte, particularly after it becomes a macrophage, which is also an antigen-presenting cell.
Define dendritic cell
Antigen-presenting cell of the epidermis and mucous membranes.
Define macrophages
In vertebrates, large phagocytic cell derived from a monocyte, that ingests microbes and debris.
Define lymphocyte
Specialized white blood cell that functions in specific defense; occurs in two forms—T lymphocytes and B lymphocytes.
Define platelets
Thrombocyte; component of blood that is necessary for blood clotting.
Define thrombocyte
Platelet; component of blood that is necessary for blood clotting.
Define clotting
Also called coagulation, the response of the body to an injury in the vessels of the circulatory system; involves platelets and clotting proteins.
Define thrombin
Enzyme that is involved in blood clotting; acts on fibrinogen molecules to produce fibrin.
Define fibrin
Protein involved in blood clotting; acts to trap cells to seal wounds in the blood vessels.
Define hemophilia
Genetic disorder that is caused by a deficiency of a clotting factor in the blood.
Define stem cell
Type of cell that acts as a source for other types of cells; capable of continuously dividing.
Define interstitial fluid
Fluid that surrounds the body’s cells; consists of dissolved substances that leave the blood capillaries by filtration and diffusion.
Define lymph
Fluid, derived from interstitial fluid, that is carried in lymphatic vessels.
Name each blood vessel and heart chamber that blood passes through on its journey through the heart and lungs
Blood enters the right atrium,
then the right ventricle, then travels through the pulmonary arteries to the lungs, and through the pulmonary veins back to the left atrium and then left ventricle.
Predict what might happen to the lungs if the left ventricle was not able to pump blood properly.
If the left ventricle was not contracting strongly, blood would back up into the lung, increasing blood pressure there, resulting in increased fluid leakage from blood vessels in the lung.
Describe the specific cause of each sound of the heart beat.
“Lub”= atrioventricular valves closing
“Dub”= semilunar valves closing
Explain why it is important for the speed and strength of heart contractions to be regulated both intrinsically and extrinsically.
Intrinsic control of the heartbeat is needed to maintain regular coordinated contractions, while extrinsic control allows the heartbeat to change in response to different physiological demands.
Define heart
Muscular organ whose contraction causes blood to circulate in the body of an animal.
Define atrium
Chamber; particularly an upper chamber of the heart, lying above a ventricle.
Define ventricle
Cavity in an organ, such as a lower chamber of the heart or the ventricles of the brain.
Define atrioventricular valve
Heart valve located between an atrium and a ventricle.
Define semilunar valves
Valve resembling a half-moon, located between the ventricles and their attached vessels.
Define pulmonary artery
Blood vessel that transports oxygen-poor blood from the heart to the lungs.
Define pulmonary vein
Blood vessel that transports oxygen-rich blood from the lungs to the heart.
Define cardiac output
Blood volume pumped by each ventricle per minute (not total output pumped by both ventricles).
Define pulse
Vibration felt in arterial walls due to expansion of the aorta following ventricular contraction.
Define cardiac cycle
One complete cycle of systole and diastole for all heart chambers.
Define systole
Contraction period of the heart during the cardiac cycle.
Define diastole
Relaxation period of a heart chamber during the cardiac cycle.
Define pacemaker
Cells of the sinoatrial node of the heart; electrical device designed to mimic the normal electrical patterns of the heart.
Define electrocardiogram (ECG)
Recording of the electrical activity associated with the heartbeat.
Identify which arteries carry O2-poor blood.
Pulmonary arteries
Name the major blood vessels through which blood flows to the lungs and other parts of the body.
Blood flows to the lungs via the pulmonary arteries, and returns to the heart via the pulmonary veins. Blood flows to the body via the aorta, and returns vias the superior and inferior venae cavae.
Describe why blood flows in one direction in an artery versus a vein.
Blood flows in one direction in arteries due to the pressur created from the pumping of the heart, and in veins mainly due too muscle contraction and the presence of valves.
Define pulmonary circuit
Circulatory pathway between the lungs and the heart.
Define systemic circuit
Circulatory pathway of blood flow between the tissues and the heart.
Define the portal system
Pathway of blood flow that begins and ends in capillaries, such as the portal system located between the small intestine and liver.
Define blood pressure
Force of blood pushing against the inside wall of blood vessels.
For question 1-5, match the descriptions to the blood vessels in the key.
Key:
a) venules
b) arteries
c) veins
d) arterioles
e) capillaries
- drain blood from the capillaries
- empty into capillaries
- may contain valves
- muscular vessels that move blood away from the heart
- sites for the exchange of substances between blood and interstitial fluid
- a) venules
- d) arterioles
- c) veins
- b) arteries
- e) capillaries
Which of the following is not a function of blood?
a) regulation of body temperature
b) defense of the body
e) transport of oxygen and carbon dioxide
d) manufacture of hormones
d) manufacture of hormones
Which of the following is/ are formed from megakaryocytes?
a) basophils
b) platelets
c) erythrocytes
d) fibrinogen
b) platelets
Which of the following is not a white blood cell?
a) lymphocyte
b) neutrophil
c) eosinophil
d) basophil
e) all of the above
e) all of the above
Which of the following lists the events of the cardiac cycle in the correct order?
a) both atria contract, then both ventricles
b) both ventricles contract, then both atria
c) left atria and left ventricle contract, then right atria and right ventricle
d) right atria and right ventricle contract, then left atria and left ventricle
a) both atria contract, then both ventricles
An electrocardiogram measures
a) chemical signals in the brain and heart
b) electrical activity in the brain and the heart
c) chemical signals in the heart
d) electrical changes in the wall of the heart
d) electrical changes in the wall of the heart
Blood moving from the left atrium to the left ventricle passes through which of the following valves?
a) bicuspid valve
b) tricuspid valve
c) aortic semilunar valve
d) pulmonary semilunar valve
b) tricuspid valve
