Chapter 10-11 - Circulatory and Blood & Immune Systems Flashcards
1
Q
What is an artery? What is it made of?
A
A blood vessel that carries blood away from the heart. It has thick walls composed of distinct layers. The outer and inner layers are mostly composed of connective tissue. The middle layers are made up of muscle fibres and elastic connective tissue.
2
Q
What causes blood to enter the artery? What happens to the artery?
A
A heart contraction makes blood surge from the heart into the arteries. Arteries stretch to accommodate inrush of blood.
3
Q
What are arterioles? What are they composed of?
A
Smaller arteries. It has thick walls composed of distinct layers, the outer and inner layers are mostly connective tissue. The middle layer is composed of elastic fibres and smooth muscle.
4
Q
What is a pulse? Where can you find your pulse?
A
Change in the diameter of the arteries following heart contractions. Your pulse can be felt near the wrist or on either side of your neck.
5
Q
What is the autonomic nervous system?
A
The part of the nervous system that controls the motor nerves that regulate equilibrium and the diameter of the arterioles, and that is not under conscious control.
6
Q
What is vasoconstriction and what causes it?
A
The narrowing of blood vessels, allowing less blood into the tissues. It’s caused by a nerve impulses which causes smooth muscles in the arterioles to contract.
7
Q
What is vasodilation and what causes it?
A
The widening of blood vessels, allowing more blood into the tissues. It’s caused by the relaxation of the smooth muscles which causes a dilation of the arterioles.
8
Q
What does vasodilation permit?
A
Permits the cells in the localized area to perform energy-consuming tasks.
9
Q
What is atherosclerosis? What is formed?
A
A degeneration of blood vessels caused by the accumulation of fat deposits in the inner wall. Calcium and other minerals deposit on top of the lipid, forming plaque. (A form of arteriosclerosis)
10
Q
What is arteriosclerosis?
A
A group of disorders that cause the blood vessels to thicken, harden, and lose their elasticity. They can narrow arteries and lead to high blood pressure.
11
Q
What happens when plaque accumulates too much in the artery during atherosclerosis?
A
Blood clots form in the blood vessel when plaque gets too big and it bursts through the wall of the artery and it can block the artery and cut off blood flow.
12
Q
What is an aneurysm? Why are they dangerous?
A
A bulge in the weakened wall of a blood vessel, usually an artery. They can lead to the rupture of blood vessels and causes a hemorrhage. (Escape of blood from a ruptured blood vessel)
13
Q
What is the function of capillaries?
A
Sites of fluid and gas exchange between blood and body cells.
14
Q
What are capillaries composed of?
A
A single layer of cells which is ideal for diffusion. They are between 0.4 and 1.0mm long with a diameter less than 0.005mm, which causes red blood cells to travel in a single file line.
15
Q
What is the advantage and disadvantage of a capillaries structure?
A
Adv: Small distance for diffusion of gases and nutrients.
Dis: Capillary beds are easily damaged.
16
Q
What determines whether a capillary is open?
A
Pre-capillary sphincter muscles regulate the movement of blood from the arterioles into capillaries.
17
Q
What are the two methods to keep blood flowing one way back to the heart in veins? Explain them.
A
One way valves and skeletal muscles.
Valves: open in one direction, steering blood towards the heart. They restrict blood from flowing in the other direction.
Skeletal muscles: Venous blood pressure increases when skeletal muscles contract and push against the vein. Muscles bulge when they contract, thereby reducing the vein’s diameter. Pressure in veins increase and valves open.
18
Q
How does pressure help flow blood towards the heart?
A
Nerve impulses causes smooth muscles in the walls of veins to contract, increasing fluid pressure during times of stress. Increased pressure drives more blood into the heart.
19
Q
What are the roles of the veins?
A
Carries blood towards the heart in low-pressure canals, and act as blood reservoirs. (About 65% of blood volume can be found in veins.)
20
Q
What are varicose veins and what causes them?
A
Disorder where the surface veins gradually become larger and begin to bulge. Caused by damaged valves and excessive blood pooling.
21
Q
What is the pericardium?
A
The fluid-filled membrane that surrounds and bathes the heart, preventing friction between its outer wall and covering the membrane.
22
Q
What is the septum?
A
A wall of muscle that separates the right and left sides of the heart.
23
Q
What is the pulmonary circulatory system?
A
The system of blood vessels that carries deoxygenated blood to the lungs and oxygenated blood back to the heart.
24
Q
What is the systemic circulatory system?
A
The system of blood vessels that carries oxygenated blood to the tissues of the body and deoxygenated blood back to the heart.
25
What is an atrium?
(plural: atria) A thin-walled chamber of the heart that receives blood from veins.
26
What is a ventricle?
A muscular, thick-walled chamber of the heart that delivers blood to the arteries.
27
From what system does the right atrium receive blood from?
The systemic system.
28
From what system does the left atrium receive blood from?
The pulmonary system.
29
What is the atrioventricular valve (AV)? What is it composed of?
A heart valve that prevents the back flow of blood from a ventricle into an atrium. AV separates the atria from the ventricles. It is supported by bands of connective tissue called chordae tendine.
30
What is the semilunar valve? What shape are they?
A valve that prevents the back flow of blood from an artery into a ventricle. Semilunar valves separate ventricles from arteries. Valves are half-moon shaped (semilunar).
31
What is the superior vena cava?
Vein that carries deoxygenated blood from the head and upper body to the right atrium.
32
What is the inferior vena cava?
Vein that carries deoxygenated blood from all veins below the diaphragm to the right atrium.
33
What is the aorta?
The largest artery in the body that crries oxygenated blood to the tissues.
34
What is the coronary artery?
An artery that supplies the cardiac muscle with oxygen and nutrients. It branches form the aorta.
35
What is angina?
Chest pain that occurs when too little oxygen reaches the heart.
36
What is the SA node? What are its functions?
The sinoatrial node is a small mass of tissue in the right atrium that originates the impulses stimulating the heartbeat. It sets the heart's tempo or beat rate. It also acts as a pacemaker, setting the rhythm of about 70 beats/min.
37
What is the AV node? What are its functions?
The atrioventricular node is a small mass of tissue in the right atrioventricular region through which impulses from the sinoatrial node are passed to the ventricles. It serves as a conductor, passing nerve impulses via two large nerve fibers (Purkinje) through the septum to the ventricles.
38
What are Purkinje fibers?
A nerve fiber that branches and carries electrical impulses throughout the ventricles.
39
What is the sympathetic nervous system? What are its functions?
A division of the autonomic nervous system that prepares the body for stress. The system increases heart rate which increases blood flow to tissues, enabling the body to meet increased energy demands.
40
What is the parasympathetic nervous system?
A division of the autonomic nervous system that returns the body to normal resting levels following adjustment to stress.
41
What is tachycardia? How does it occur?
When heart rate exceeds 100 beats/min. This can result from exercise or drugs such as caffeine or nicotine.
42
What is the myogenic muscle?
A muscle that contracts without external nerve stimulation. (Automatic: Ex. cardiac muscle)
43
What is cardiac catheterization? What instrument does it need? Where does it go?
A method of detecting coronary artery blockage. A catheter is used, which is a small, thin hollow tube. It is passed into an artery in the groin.
44
What can be taken with the catheter and what does it determine?
Blood samples can be taken with the catheter to determine how oxygen is in the blood in different chambers.
45
What are the lubb-dubb sounds caused by?
The closing of heart valves.
46
What is diastole? What happens to the atria during diastole?
Relaxation (dilation) of the heart. The atria and ventricles are relaxed and when the atria are relaxed, they fill with blood.
47
What is systole? What happens to the atria during systole?
Contraction of the heart, during which blood is pushed out of the heart. The atria contracts, increasing fluid pressure and forcing the AV valves open.
48
What creates the lubb sound?
Blood flows from the atria to the ventricles. Ventricles contract and the pressure forces the AV valves shut which produces a heavy lubb sound.
49
What creates the dubb sound?
Closing of the semilunar valves create a dubb sound.
50
What causes heart murmurs?
Occurs when valves don't close completely. Blood leaks past the closed heart valve because of an improper seal.
51
What is foxglove and what is it used for?
Foxglove is a garden plant. An ingredient called digitalis initiates strong, regular heart contractions and is used to treat congestive heart failure.
52
What is nitroglycerin and what is it used for?
Nitroglycerin is an explosive used to prevent heart attacks as it relaxes smooth muscle and dilates blood vessels.
53
What are beta-blockers and what are they used for?
Beta-blockers are drugs important for people with irregular heartbeats or who display the effects of high blood pressure.
54
What is epinephrine and how do beta-blockers affect it?
Epinephrine is a stress hormone. It attaches to receptors on the heart and blood vessels, increasing heart rate and narrowing blood vessels. Both effects can increase blood pressure. Beta-blockers tie up receptor sites that accept epinephrine.
55
What are the two types of beta-receptors?
Beta 1 and Beta 2. Beta 1 is found on the surface of the cardiac muscle and affects the speed and strength of heart contractions and directly influences blood pressure. Beta 2 is found primarily in the blood vessels and the bronchioles leading into the lungs.
56
What is arrhythmia and what causes it?
An irregular heartbeat caused by a blocked coronary artery.
57
What is ventricular fibrillation? How does the heart respond to it?
When cells within the ventricle responds to toxins and begins to contract wildly. As the heart fibrillates, blood is not pumped in a coordinated fashion and the heart responds by beating faster.
58
What is cardiac output? What factors affect cardiac output?
The amount of blood pumped from the heart each minute. Stroke volume and heart rate affect cardiac output.
59
What is special about the amount of blood pumped when measuring cardiac output?
Unless dysfunction occurs, the amount of blood pumped from the right side of the heart is equal to the amount of blood pumped from the left side of the heart.
60
What is stroke volume? How is a contraction related to stroke volume? What is the average stroke volume?
The quantity of blood pumped with each beat of the heart. The stronger the heart contraction, the greater the stroke volume.
61
What is heart rate?
The number of times the heart beats per minute.
62
What is the equation for calculating cardiac output?
= stroke volume x heart rate
= 70 mL/beat x 70 beats/min
= 4900 mL/min
63
What is blood pressure? What factors does it depend on?
The force of blood on the walls of the arteries. It depends on two factors: cardiac output and arteriolar resistance.
64
How is cardiac output related to blood pressure?
Increase of cardiac output will increase blood pressure.
65
How is the diameter of the arteriole regulated?
Regulated by smooth muscles.
66
What device is used to measure blood pressure?
A sphygmomanometer is used to measure blood pressure. (Cuff with air bladder)
67
How is blood pressure measured?
Non-SI units of millimeters of mercury, or mmHg.
68
What is hypertension and what causes it?
Hypertension is high blood pressure or the silent killer. It is caused by increased resistance to blood flow, which results in a sustained increase to blood flow.
69
What does low blood pressure induce? Why is this a problem for some tissues?
Low blood pressure reduces the capacity to transport blood. This is a problem acute for tissues in the head, where blood pressure works against the force of gravity.
70
What is systolic blood pressure?
Pressure exerted by the blood during ventricular contraction. (Avg. < 120 mmHg)
71
What is diastolic blood pressure?
Pressure exerted by the blood flowing into the artery during ventricular relaxation/filling. (Avg. < 80mmHg)
72
What is hypertension? What causes it?
The silent killer. It is high blood pressure caused by increased resistance to blood flow, which results in a sustained increase in blood flow.
73
What does low blood pressure do? Why is this a problem for certain tissues?
Reduces capacity to transport blood. It is a problem for tissues in the head because blood pressure works against the form of gravity.
74
What can high blood pressure lead to?
The weakening/rupture of an artery.
75
What is thermoregulation?
Maintenance of body temperature within a range that enables cells to function efficiently.
76
How does the body adjust to a decrease in environmental temperatures?
Increasing rate of cellular respiration to generate heat.
77
What is the hypothalamus?
Region of a vertebrate's brain responsible for coordination many nerve and hormone functions.
78
What happens when sensors in the brain detect a rise in body temperature?
A nerve impulse is coordinated within the hypothalamus, and a signal is released to the sweat glands to initiate sweating. The evaporation of perspiration from the skin causes cooling.
79
What is the response of the circulatory system to exercise?
Sympathetic nerves stimulate adrenal glands. Epinephrine (adrenaline) is released from adrenal glands and travels in the blood to other organs of the body. Red blood cells increase from the spleen which increases oxygen delivery.
80
How does the body respond to cold?
Thermoreceptors in the skin send a message to the hypothalamus which sends messages to the organs and tissues to increase body temp. Nerves to the arterioles of the skin cause vasoconstriction which reduces heat loss and maintains heat in the core of the body.
81
What causes goosebumps?
When there is cold, nerve messages are carried to the smooth muscles that surround the hair follicles causing the hair to stand on end. The erect hair traps warm, still air next to the surface of your skin and helps reduce heat loss.
82
What causes shivering?
Hypothalamus sends nerve messages to initiate shivering. Shivering response is a rhythmic contraction of skeletal muscles. Cycles of rapid muscle contractions between 10-20 times per min generate heat production by increasing metabolism.
83
What is hypothermia?
Condition in which the body's core temperature falls below the normal range. A drop in a few degrees can lead to a coma or possibly death.
84
What is ECF?
Extracellular fluid is fluid that occupies the spaces between cells and tissues: includes plasma and interstitial fluid.
85
What two forces regulate the movement of water between the blood and ECF? How does water move between the two?
Fluid pressure and osmotic pressure. Fluid pressure is high at the arteriole end (35mmHG) and low at the venous end (15mmHg) which creates pressure on the inner wall of the capillary. ECF has low pressure so, through osmosis, water moves from high pressure (in the capillary/blood) to an area of low pressure (ECF).
86
What is filtration?
The selective movement of materials through capillary walls by a pressure gradient.
87
In what ways are capillaries selectively permeable?
Large materials such as proteins, red blood cells, and white blood cells remain in the capillary.
88
What is absorption?
The movement of fluid into the capillaries.
89
What is the average osmotic pressure?
25mmHg.
90
How do hemorrhages upset balances between fluid pressure and osmotic pressure?
Low fluid pressure, normal osmotic pressure. Excessive bleeding causes loss in blood volume and blood pressure and many proteins are lost so there is no force driving fluid from the capillaries into the ECF.
91
What is osmotic pressure?
Pressure that draws water back into the capillary.
92
How does starvation upset balances between fluid pressure and osmotic pressure?
Normal fluid pressure, low osmotic pressure. Plasma proteins help draw fluids from the tissues and ECF into the capillaries. Decrease in concentration of plasma proteins lower osmotic pressure, decreasing absorption.
93
How does inflammation upset balances between fluid pressure and osmotic pressure?
Normal fluid pressure, low osmotic pressure.
94
What is lymph?
The fluid found in lymph vessels that contain some proteins that have leaked through capillary walls.
95
What happens when there is an accumulation of proteins in the ECF?
Osmotic pressure would decrease and tissues would swell.
96
What is a lymph node?
A mass of tissue that stores lymphocytes and removes bacteria and foreign particles from the lymph.
97
What is the lymphatic system?
Where proteins are drained from the ECF and returned to the circulatory system by the lymphatic system. Lymph is transported in open-ended lymph vessels that are similar to veins. This low pressure system operates by slow muscle contractions against the vessels which have flap-like valves that prevent back flow. Lymph is returned to the venous system via right and left subclavian veins.
98
What is a lymphocyte?
A white blood cell that produces antibodies.
99
Where are lymph nodes and what are their function?
Located along the lymph vessel. Nodes house white blood cells that filter out bacteria present through the process of phagocytosis. Nodes also filter out damaged cells and debris from the lymph and stores lymphocytes.
100
What are the lymphoid organs?
Red bone marrow, the spleen, and the thymus gland.
101
What is the function of red bone marrow? Where is it found?
Where all types of blood cells are produced. Stem cells, which are found in marrow, divide at incredible rates and differentiate into different types of white blood cells to meet the needs of the body. Found mainly in bones of children. In adults, it is found in the cranium, sternum, ribs, spinal column and long bones of arms and legs.
102
What is the spleen, where is it located, and what are its functions?
A lymphoid organ that acts as a blood reservoir and a filtering site for lymph. It is located at the upper left side of the abdominal cavity, just below the diaphragm. It is supplied with blood sinuses which allow the spleen to hold 150mL of blood. It released red blood cells in response to low blood pressure or when love oxygen levels drop.
103
What is the thymus gland, where is it located, and what are its functions?
A lymphoid organ in which T lymphocytes mature. The gland gets smaller with age. It is located in front of the trachea, just above the heart. T cells that are released from the thymus gland have been selected to ensure they will not initiate an immune system response against the body's own proteins.
104
What are the components of blood?
55% plasma, 45% red blood cells (erythrocytes), and < 1% white blood cells (leukocytes) and platelets.
105
What is hematocrit?
Percentage of red blood cells in the blood.
106
What is plasma and what does it contain?
The fluid portion of the blood, which is about 90% water, allowing it to be described as a fluid tissue. It contains blood proteins, glucose, vitamins, minerals, dissolved gasses, and waste products of cellular metabolism. Large plasma proteins help maintain homeostasis.
107
What are albumins?
Large plasma proteins that establish an osmotic pressure that draws water back into the capillaries and helps maintain body fluid levels.
108
What are globulins?
Large plasma proteins that provide protection against invading microbes.
109
What are fibrinogens?
Large plasma proteins that are important for blood clotting.
110
What are erythrocytes? What colour are they and why?
Red blood cells that contain hemoglobin and carry O2. Hemoglobin increases the oxygen-carrying ability of blood by 70. Oxyhemoglobin gives it its red colour, and since hemoglobin always changes shapes, the reflection of blue light explains why blood looks blue in the veins.
111
What is the shape of red blood cells?
Biconcave discs approx. 7 um in diameter which provides greater surface area for gas exchange. They have a lifespan of about 120 days because they are bigger than capillaries, so they are constantly being reformed and begin to wear down.
112
Why don't red blood cells have a nucleus?
Young cells lose their nuclei as they are discharged into the bloodstream because it allows more room for the cell to carry hemoglobin which increases oxygen-carrying abilities.
113
What happens when blood cells break down?
Hemoglobin is released. Iron is recovered and stored in the liver and bone marrow for production of new red blood cells. Heme is transformed into bile pigments.
114
How are levels of red blood cells maintained?
Maintained by specialized white blood cells that are found in the spleen and liver. They monitor the age of red blood cells and remove debris from the circulatory system.
115
What is anemia and what causes it? What are symptoms of anemia?
The reduction in blood oxygen due to low levels of hemoglobin or poor red blood cell production. The most common cause is hemorrhage. Other causes include physical injury, ulcer bleeding, hemorrhage in lungs due to tuberculosis, or iron deficiency. It causes low energy levels.
116
What percentage of blood has to be lost in order for the body to stop coping?
More than 40%.
117
What is a leukocyte? What are its functions? How are they normal cells?
A white blood cell. Some leukocytes destroy invading microbes by phagocytosis: they squeeze out of capillaries and engulf the microbe. Then enzymes are released that digest both the microbe and the leukocyte. Other leukocytes form proteins called antibodies which interfere with invading microbes and toxins. They do contain a nucleus.
118
What is a granulocyte? Where are they produced?
Type of leukocyte. It is classified according to small granules in the cytoplasm that become visible when stained. Produced in bone marrow.
119
What are agranulocytes? Where are they produced?
A type of leukocyte that does not have granules in the cytoplasm. They are produced in bone marrow but modified in lymph nodes.
120
What are platelets and how are they formed?
(AKA thrombocytes) A component of blood responsible for initiating blood clotting. They are produced from large nucleated cells in bone marrow. Small fragments of the cytoplasm break from the large megakaryocyte (large cell in bone marrow) to form platelets.
121
What is thrombus?
A blood clot that forms within a blood vessel and blocks it, which restricts blood flow.
122
What is embolus?
A blood clot that dislodges and is carried by the circulatory system to another part of the body, that can lodge in and block a vital organ.
123
What is artificial blood made of?
Fluosol which contains fluorine.
124
What is agglutination?
The clumping of blood cells caused by antigens and antibodies. Agglutinated blood can't pass through capillaries and prevents the delivery of oxygen and nutrients.
125
What is an antigen?
A substance, usually protein, that stimulates the formation of an antibody.
126
What is an antibody?
A protein formed within the blood that reacts with an antigen.
127
What is the body's first line of defense?
Skin and mucous defend against viral and bacterial invaders.
128
What is lysozyme, where is it found, and what does it do?
An antimicrobial enzyme secreted in human tears, saliva, mucous secretions, and perspiration, destroys the cell walls of bacteria, killing them.
129
What is the body's second line of defense?
Leukocytes/white blood cells that may engulf invading microbes or produce antibodies.
130
What is phagocytosis?
The process by which a white blood cell engulfs and chemically destroys a microbe.
131
What is a macrophage and what is its role? How are macrophages created?
A phagocytic white blood cell found in lymph nodes, bone marrow, and the spleen and liver. Macrophages extend long protrusions called pseudopods that attach to invading microbes and the macrophage devours it and itself. Macrophages are made from monocytes that have migrated from the blood into the tissues.
132
What are neutrophils?
White blood cells that are attracted to chemical signs given off by cells that have been damaged by microbes and in a process of chemotaxis, the neutrophils make their way to the microbe and engulf it. Finally, they release lysosomal enzymes that digest both the microbe and the neutrophil.
133
What is pus?
A thick liquid composed of protein fragments from digested leukocytes and microbes.
134
What is the inflammatory response?
Localized nonspecific response triggered when tissue cells are injured by bacteria or physical injury, characterized by swelling, heat, redness, and pain.
135
What is the third line of defense?
The immune system.
136
What is a complement protein?
A plasma protein that helps defend against invading microbes by tagging the microbe for phagocytosis, puncturing cell membranes, or triggering the formation of a mucous coating.
137
What are lymphocytes?
A type of white blood cell that produces antibodies. (Part of the immune response)
138
What is a T cell and how are they created? What are its functions?
A lymphocyte, manufactured in the bone marrow and processed in the thymus gland. Its function is to seek out the intruder and signal the attack. Once a T cell finds the invaders by its antigen markers, another T cell passes this info onto the antibody-producing B cell.
139
What is a B cell and how is it created? What are its functions?
A lymphocyte, made and processed in bone marrow, that produces antibodies. B cells multiply and produce molecular weapons: antibodies. Each B cell produces a single type of antibody, which is displayed along its cell membrane.
140
What are helper T cells? What are their functions?
A T cell with receptors that bind fragments to antigens Releases lymphokine and activate killer T cells.
141
What is lymphokine? What does it do?
A protein produced y the T cells that acts a chemical messenger between other T cells and B cells. Lymphokine causes B cells to divide into identical cells called clones.
142
What is a killer T cell and what is its function?
A T cell that destroys microbes, body cells infected with viruses, and mutated cells by puncturing cell membranes once a viral coat is found attached to the cell membrane, the T cell attacks the infected cell. Killer T cells also destroy mutated cells that could be cancerous.
143
What is a memory B cell and what is its function?
A B cell that retains information about the shape of an antigen. It remains after the battle, and if subsequent infection occurs, the memory B cells identify the invader and quickly mobilize antibody-producing B cells.
144
What are suppressor T cells and what are their functions?
A T cell that turns off the immune system. to ensure that there a number of antibodies containing the invading antigen to guard the site. Phagocytes survey the area and clean up debris.
145
Define pluripotent cell. What is an example of one?
A cell that is capable of developing into a number of specialized cells such as a neuron or muscle cell. Stem cells are pluripotent cells.
