Circulatory System Flashcards
(108 cards)
1
Q
Arteries vs. Veins
A
Arteries carry blood under high pressure away from the heart, while veins return the blood to the heart after its pressure has been reduced in the capillaries. Arteries differ from veins in that they have a thicker, more flexible wall designed to handle the high pressure, while veins have a thinner wall and larger lumen to accommodate a greater volume of slower moving blood. Both have three layered walls. The inner layer, or endothelium, of both is a layer of smooth cells that minimizes friction on the flowing blood, but in arteries it is often folded like an accordion during diastole, allowing it to stretch during systole. The middle layer, which is made up of smooth muscle and elastic fibres, is much thicker in arteries, allowing it to expand as a pulse goes through and to contract afterwards, pushing the blood forward. The outer layer, which consists of both elastic and rigid connective tissues, provides protection against ballooning and rupture.
Veins have internal valves, which are lacking in arteries. These valves produce a one way flow when the veins are squeezed, allowing muscular action such as walking and breathing to pump blood toward the heart.
2
Q
Arteries (arterioles)
A
A blood vessel that carries blood under high pressure away from the heart. It exerts pressure with its thick walls so high pressure doesn’t burst the walls. Pressure is the force caused when a molecule hits a wall, the # times it hits a wall is proportional to pressure/force.
Arteries branch so that they can send blood to different parts of the body.
3
Q
Arteriole
A
The smallest artery, that gives rise to capillaries
4
Q
Capillary
A
A tiny blood vessel consisting of only one layer of epithelial cells, where exchange of materials occurs. It is the thinnest structure that carries blood cells . The size of vessel gets smaller as it branches. It is very low in pressure, and allows efficient exchange by diffusion.
5
Q
Capillary bed
A
An anastomosing network of capillaries that supplies a particular tissue
6
Q
Venule
A
The smallest vein, collecting blood from capillaries
7
Q
Vein
A
Any blood vessel that carries low-pressure blood back toward the heart. It is looser to expand more and stores great quantities of blood.
8
Q
History
A
Hippocrates was the first physician to view the body as a whole. This dates back to the Greeks and Romans: Hippocrates and Galen. They had similar views on what the circulatory was. At the time they believed the body contained fluids known as humorous, there were 4 of them. If you had an imbalance of these fluids in your body, it meant you sick. This is how surgical techniques like blood letting were introduced. The Hippocratic oath is something all doctors take promising that if anyone is sick, they will treat them.
William Harvey is a doctor who first correctly described that blood circulated through the body. His conclusions were based on vivisection. Blood is circulated, not consumed by the body.
9
Q
Cardio
A
Heart
10
Q
Vascular
A
Vessels
11
Q
Vivisection
A
learning exploratory surgeries on the living
12
Q
Disection
A
Surgery done on the dead
13
Q
Systems in the Body
A
Since the systems are subjected to natural selection over time and have evolved to gain their structure and function through NS and other agents of evolution, all of them solve a problem in the environment. There is a challenge in the environment that is posed that the systems we have in our bodies will address. This is related to what cells need from the environment.
14
Q
Cellular Respiration
A
Cells need oxygen and glucose to produce energy.
15
Q
Unicellular organisms
A
Do not have a circulatory system so they use diffusion
16
Q
Multicellular Organisms
A
Diffusion is too slow to supply substances like glucose and oxygen to all of the cells in the deep layers of the skin. This is why we have different systems.
17
Q
Functions of the System
A
- Transport
* O2, CO2, hormones and wastes, nutrients moved around efficiently - Regulation
* helps control pH and body temperature (homeostasis) - Protection
* from blood loss through clotting, and against infection by pathogens
18
Q
Pathogens
A
disease causing organisms (bacteria, fungi, virus)
19
Q
Homeostasis
A
the ability to maintain a constant internal environment in response to environmental changes
20
Q
Main Components of the System
A
- Pathway of transport -> Blood Vessels
- Pump to move medium along pathway -> Heart
- Medium/Substance that carries things -> Blood
Not all organisms have the exact 3 components, but everything needs a pathway, a medium of transport (like hemolymph), and a pump to move substance around a circuit.
21
Q
Structure of Blood Vessels:
Direction of Blood
A
Artery: away from heart
Vein: back to heart
22
Q
Structure of Blood Vessels:
Lumen
A
Artery: small
Vein: large
23
Q
Structure of Blood Vessels:
Wall thickness
A
Artery: thicker
Vein: thinner
24
Q
Structure of Blood Vessels:
Valves and Muscles Around
A
Artery: no valves or muscles
Vein: present
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Structure of Blood Vessels:
Tunica Interna
Artery: folds
Vein: no folds
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Structure of Blood Vessels:
Tunica Intermedia
Artery: thicker/more muscles
Vein: thinner/less muscle
Arteries need thicker muscle layers because high pressure would rip the thinner walls.
27
Structure of Blood Vessels:
Tunica Externa
Artery: thicker
Vein: thinner
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Epithelial Cells
Specialized cells that surround tissue
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Tunica Interna
The inner layer has flat, smooth, flat epithelial cells and is known as the endothelium on a thin layer of connective tissue. Has the lowest amount of friction and is quite strechy. Produces protein elastic collagen. In arteries, this layer is folded like an accordion so it can expand for pressure/
30
Tunica Intermedia
Surrounding layer of smooth muscle can stretch to accommodate passing blood, or contract to resist blood flow. Blood won't travel as far with low pressure. Covered in connective tissue.
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Tunica Externa
This is a layer of connective tissue produced by elastic and rigid collagen proteins. This has a stretch limit. The tough layer will prevent walls from ballooning when pressure is high.
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Varicose veins
abnormal valve during atrial contraction
33
Open circulatory system
- most common in invertebrates
- haemolymph is the transport medium (from open-ended vessels to cavities)
- transports nutrients by diffusing in cells
- gases are not transported
Insects and crustaceans have an open circulatory system, in which the blood (technically called haemolymph) leaves the blood vessels and surrounds the tissues. They lack a venous system. They lack a lung or gill, and distribute gases by a series of tubes
34
Tracheal System
system of tubes that carry air for each cell of the body, the circulatory system is not responsible for transporting gases
35
a) Superior (anterior)
b) Inferior (posterior)
c) Dorsal (back)
d) Ventral (front)
36
Closed circulatory system
- keeps everything inside of the veins
- when you close vessels, you can control substances and you will have more efficiency because you control directions of fluid and send things to certain places
- you can generate pressure so the system doesn't need to work as hard
more loops=more oxygen=more efficient
37
One loop and two loop systems
Fish and their relatives have a heart that is a single pump, and their blood flows through first the gills and then the body systems. This “single loop system” is efficient, except that the movement of blood through the gill capillaries slows it down and reduces blood pressure to the other organs. Blood pressure is required for rapid delivery of resources.
The higher vertebrates (mammals, birds, crocodiles, probably dinosaurs) have a “double loop system” in which the heart consists of two parallel pumps. One pump sends deoxygenated blood to the lungs, and returns it to the other pump, which sends it to the body systems. Thus, every system gets high pressure, oxygenated blood
38
The heart of a mammal has ______ chambers. The chambers that produce the main pumping action of the heart are called \_\_\_\_\_\_\_\_\_\_.
The heart of a mammal has \_\_\_\_4\_\_ chambers. The chambers that produce the main pumping action of the heart are called \_\_\_\_\_ventricles\_\_\_\_\_.
39
A membrane sac called the __________ surrounds the heart.
A membrane sac called the \_\_\_\_\_pericardium\_\_\_\_\_ surrounds the heart.
40
The main artery leaving the left side of the heart is called the \_\_\_\_\_. The first branches from it are the coronary arteries, which supply blood to the \_\_\_\_\_\_\_\_\_\_.
The main artery leaving the left side of the heart is called the \_\_\_aorta\_\_. The first branches from it are the coronary arteries, which supply blood to the \_\_\_\_\_\_heart muscle (myocardium)\_\_\_\_.
41
How does a heart valve work? How do the chordae tendineae contribute to this function?
Valves are one-way gates that open if there is pressure on one side and close if there is pressure on the other side. They typically consist of two or more flaps of tissue.
The chordae tendineae are tough bands of connective tissue that attach the AV valves (tricuspid and bicuspid) to the opposite wall of the ventricle. They help to pull the AV valves open when the ventricle relaxes, but their main function is to support the AV valves during ventricular systole (contractions) so they don’t get blown inside out.
42
The Heart
The heart is mostly muscle and the pump part of the circulatory system. It moves blood by contracting. Its longest length is when its relaxed and when it contracts it gets shorter. When it contracts the volume inside lowers so that pressure is higher so blood can be pumped around. The function of the heart is to pump blood.
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Coronary
takes blood to all the muscles of the heart
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Types of muscles
cardiac muscle, skeletal muscle, smooth muscle
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cardium
heart muscles
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inner layer of heart
endocardium
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middle layer of heart
myocardium
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outer layer of heart
Pericardium. There are two layers to the pericardium because the fluid helps protect and prevent friction as the heart moves and the sac surrounds it.
49
Atria
the receiving chamber
50
pericarditis
swelling of the heart
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Pulmonary circuit
It goes from the right side of the heart carrying oxygen-poor blood up towards the lungs and returns back to the heart with oxygen-rich.
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pulmonary
lungs
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Systemic circuit
It gets pumped through the whole body. It carries blood away from your heart, delivers it to most of your organs and tissues, and returns it to your heart again. Blood returns to the body in veins, the vena cava.
54
Largest vein in the body
vena cava
55
The right side of the heart pumps __________ blood.
The right side of the heart pumps oxygen-poor blood.
56
The left side of the heart pumps __________ blood.
The left side of the heart pumps oxygen-rich blood.
57
Chordae Tendineae
Attaches to muscles to help vavlves stay in place when force of blood is strong.
58
Why is a cardiac muscle cell contractile?
It is contractile because there is a presence of two motor proteins called actin and myosin. The proteins pull each other together.
59
How a muscle is polarized
It happens when the inside fo the cell is more -ve than the outside. This is how signalling is controlled. Because they need to tell the cells to contract, otherwise the heart won't coordinate contractions and blood will not be pushed through the heart.
60
Depolarization
Th atria/ventricles contract in direction of blood flow. The polarized membrane is a way the muscle acts for signalizing. The presence of a high concentration of Ca2+ ions is what makes the outside +ve. Ca is too polar to get through the lipid layer of the membrane. The protein channels on the membrane (now selectively permeable) open up and let calcium in. This is called depolarization, as the charge is reversed.
61
How does a cardiac muscle get its signals?
They are the only cells in the body that are self-excitable. They can spontaneously open calcium channels. This is a unique feature as it does not actually need communication from the nervous system to tell the doors to open. If the brain and the heart are not communicating, the heart will function as long as nutrients are supplied. There are 2 ways a cardiac muscle cell gets signals. If the doors haven't opened in a certain amount of time they will open up, or it can actually open doors if it gets signaling from neighboring cells. There are intercalated discs between cells that create a wave of contractions. It signals through the branch evenly in all directions. A cardiac muscle cell will be able to contract every 1.5s unless a signal is received to do so sooner.
62
Cardiac muscle cells are...
contractile, self-excitable, autorhythmic, and non-
fatiguing
It does not get tired because of an abundance of myoglobin that binds oxygen. O2 is needed for cellular respiration for energy. The heart is also the first stop on the systemic circuit.
63
What is the sequence of events (filling, contraction, valve movement) that occurs during a single beat of the heart?
Atria fill – AV valves open – atria contract – ventricles fill – AV valves close as ventricles contract – semilunar valves open as ventricles contract – semilunar valves close as ventricle begins to relax.
64
The phase of the heartbeat when the ventricles relax and fill with blood is called ventricular \_\_\_\_\_\_\_. During this phase, blood pressure in the arteries is _______________ (higher/lower). The phase when the ventricles contract is called \_\_\_\_\_\_\_\_\_\_\_.
The phase of the heartbeat when the ventricles relax and fill with blood is called ventricular \_\_\_\_diastole\_\_\_. During this phase, blood pressure in the arteries is \_\_\_\_\_\_\_\_high\_\_\_\_\_\_\_ (higher/lower).
The phase when the ventricles contract is called \_\_\_\_\_\_\_systole\_\_\_\_.
65
What is the pacemaker, and how does it function?
The SA pacemaker is a cluster of cardiac cells that discharges spontaneously at about 60-70 times per minute. It initiates the contraction of the muscles in the atria, starting a wave that spreads over the entire heart muscle. In this way, it controls the heart rate. The pacemaker can be adjusted by signals from nerves that originate in the brain. One set of nerves releases epinephrine (adrenalin) and speeds up the pace maker. The other releases acetylcholine and slows down the pacemaker.
The AV node acts as a secondary pacemaker. It will cause the ventricles to beat at about 40 beats per minute, even if the SA node fails.
66
Describe the sequence of events that makes up a mammalian heart beat
1. Atria contracts to help push blood into ventricles because for the heart to pump efficiently you want to pump as much blood around the body with the fewest amount of contractions to conserve energy
2. Ventricles contract bottom up
3. Depolarization/ relaxation phase where both sets of muscles have stopped contracting and refill with blood
67
LUBDUB sound
LUB (first heart sound louder): AV valves (tricuspid and bicuspid valves) snap shut avoiding back flow
DUB (second heart sound weaker): semilunar valves (aortic valve and pulmonary valve) snap shut avoiding
back flow
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systole
contraction
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diastole
relaxation
70
Who invented first stethoscope
Rene Laennec
71
Who invented first ECG
Willem Einthoven
72
SA node
Sino atrial node is a natural pacemaker (one signal every 0.8 sec), starts in right atrium
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AV nod
Atrio ventricular nod, secondary pacemaker, in some situations, starts in septum
74
Relate the traces of the ECG to the events in the heart
P wave:
- SA node signaling
- Atria cells - depolarization
- Interval before the next wave (AV node delays
its signal)
QRS wave (or QRS complex):
- AV node signaling (Q)
- Ventricular cells: depolarization (R-S)
T wave:
Repolarization of ventricles (refilling with blood)
75
Vasodilation
the dilatation of blood vessels, which decreases blood pressure
76
Vasoconstriction
the constriction of blood vessels, which increases blood pressure.
77
The major systemic artery rises from the ________ ventricle and is called the \_\_\_\_\_\_\_\_. The major veins of the systemic system are called the \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_.
The major systemic artery rises from the \_\_\_\_left\_\_\_\_ ventricle and is called the \_\_\_\_aorta\_\_\_\_. The major veins of the systemic system are called the \_\_\_\_\_\_\_vena cava\_\_\_\_\_\_.
78
Arteries of the systemic circulatory system carry _____________ blood.
Arteries of the systemic circulatory system carry \_\_\_\_\_\_\_\_\_oxygenated\_\_\_\_ blood.
79
A branch at the very beginning of the aorta diverts blood from the systemic circulatory system to __________ circulation, which supplies the heart muscle.
A branch at the very beginning of the aorta diverts blood from the systemic circulatory system to \_\_\_\_\_\_coronary\_\_\_\_ circulation, which supplies the heart muscle.
80
Blood Presssure
The amount of force applied to a given area of a blood vessel wall as the blood flows past it.
81
How is blood pressure measured, and what fo the measurements mean?
A sphygmomanometer measures the systolic and diastolic force acting on the wall of an artery, such as the brachial artery.
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Arteries
Accessory structures:
Function:
Blood pressure (high or low, decreasing rapidly):
Source of pumping action:
Oxygenation (high or low):
Arteries
Accessory structures: none
Function: carry high pressure blood away from heart
Blood pressure: high and pulsing
Source of pumping action: heart
Oxygenation: high
83
Capillaries
Accessory structures:
Function:
Blood pressure (high or low, decreasing rapidly):
Source of pumping action:
Oxygenation (high or low):
Capillaries
Accessory structures: precapillary sphincters & arterio-venous shunt
Function: pick up and delivery of resources and wastes
Blood pressure: dropping, no pulse
Source of pumping action: heart
Oxygenation: declining
84
Veins
Accessory structures:
Function:
Blood pressure (high or low, decreasing rapidly):
Source of pumping action:
Oxygenation (high or low):
Capillaries
Accessory structures: valves to direct flow of blood
Function: carry low-pressure blood back to heart
Blood pressure: low, no pulse
Source of pumping action: surrounding muscles
Oxygenation (high or low): low
85
How blood is moved back to the heart in the veins
Skeletal muscles squeeze on the veins, generating pressure. The one-way valves in the veins prevent the blood from moving backwards, while the muscular pressure pushes the blood towards the heart. The most important movements in keeping the blood moving toward the heart are the movements of breathing, which change the pressure on the posterior vena cava and pump blood uphill from the lower body. (Of course, blood from the upper body can use gravity as well to flow back to the heart.)
86
Functions of a Cardio-Vascular System
1. Transport - transports oxygen and carbon dioxide, nutrients, hormones, and wastes
2. Regulation - blood helps regulate pH, body temperature
3. Protection - protects against blood loss through clotting and foreign pathogens
87
What is blood made of?
55% plasma, 44% blood, 1% wbc+ platelets
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What is Plasma Made of
Water makes up 90% of plasma. The function of it is that you need volume when the heart is pumping so we can generate pressure. It's a very good solvent and polar so it can transport a lot.
Plasma proteins make up 7%. These molecules have a lot of functions. Albumin helps maintain blood volume by maintaining a concentration by creating osmotic gradients to suck water back in. Antibodies produced by WBC and fight infections. Fibrinogen helps clotting. PP are found in plasma so it has access to whole body.
Majority of things transported is found in plasma. The function of salts is to maintain BP and muscle contraction. It also makes sure that not too much osmosis happens. Gases for cellular respiration. Nutrients as energy sources. Nitrogen wastes through kidneys.
89
Red Blood Cells
Erythrocytes: Transport O2 and help transport CO2
Since they are small they are more efficient of diffusing oxygen in, SA/V
Bends and twists to get through capillary, flexible
Has a protein called hemoglobin that is very strong to bind O2.
90
White blood cells
Leukocytes: fight infections
Granular- basophils, eosinophils, neutrophils
Agranular- lymphocytes, monocytes
91
Neutrophils
Most abundant, Fight infections, are a neutral colour when stain, phagocytize (eat) pathogens
Neutrophil will change shape of cell to get pathogen into the membrane, cell will then digest it and remove the waste. Dies once it phagocytizes. (Flattens itself, squeezes through capillaries and cells to reach the layer of skin to fight bacteria)
92
Eosinophils
Phagocytize parasitic worms, proteins (antigen-antibody complex) and allergens, pick up red stain
Sometimes the proteins they respond to are not harmful, allergens (allergies).
93
Basophils
Least abundant, Related to allergic reactions, blue
Release chemical substance called histamine. Creates more blood flow and swelling response to infection.
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Monocyte
Put a small protein on the surface of the cell that a particular bacteria is in the body, helper of a lymphocyte
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Lymphocyte
More will be kept around if a specific pathogen comes, these cells require a lot of energy so that is why we don’t keep them in abundance. We are only immune to pathogens in our environment, we have the ability to detect a certain bacteria or virus.
Produce antibodies.
96
Platelet
Used to be in a megakaryocyte, each thrombocyte is filled with a protein called thromboplastin/ prothrombin activator as it activates clotting mechanisms
Clot blood to prevent blood from leaking out of your body
97
Granular cells that phagocytize foreign cells in the blood are called\_\_\_\_\_.
Granular cells that phagocytize foreign cells in the blood are called\_\_\_neutrophils\_\_.
98
Cells that migrate outside the blood and ingest foreign cells are called _______ and \_\_\_\_\_\_.
Cells that migrate outside the blood and ingest foreign cells are called \_\_\_\_monocytes\_\_\_ and \_\_\_macrophages\_\_\_.
99
Cells that induce allergic responses are _________ and \_\_\_\_\_\_\_\_\_\_\_\_\_.
Cells that induce allergic responses are \_\_\_\_\_eosinophils\_\_\_\_ and \_\_\_\_\_\_basophils\_\_\_\_\_\_\_.
100
WBC’s that produce antibodies to fight disease organisms are called \_\_\_\_\_\_\_\_\_\_\_\_.
WBC’s that produce antibodies to fight disease organisms are called \_\_\_\_\_\_\_lymphocytes\_\_\_\_\_.
101
Steps in Blood Clotting
1. Puncture of the vessel
2. This is a cascade reaction because there are a lot of steps and very fast. You get more control over the body having multiple steps. Each step can be controlled or switched off. You are using enzymes again and again so you do not need to create new molecules each time. Blood leaks out of wound but when platelets get exposed to air their chemistry changes and their membranes become sticky and stick to each other and walls of the vessel. This helps reduce blood flow. Releases prothrombin activator. This causes the fibrinogen to become the fiber threads. The fibers form over the cut and act as net until it dries out and forms a solid mass called a scab. It is a barrier so nothing can go in or out and cause an infection. You are also not losing any more blood.
102
The lymphatic System
The lymphatic system is an network of
vessels and nodes that collects lymph from the
spaces between the cells and empties it into the venous circulation just before it enters the heart. It has vessels that connects with the subclavian vein so that it can put the fluid back into the blood. The lymph nodes play another role in protecting the body against infection are important sites of lymphocyte formation.
103
Lymphatic: What is in the plasma?
water
rbc’s
wbc’s
proteins
nutrients
salts
oxygen
104
Lymphatic: What is in the tissue fluid?
water
some wbc’s
nutrients
salts
oxygen
wastes
105
Lymphatic: What is in the lymph duct?
water
wbc’s
wastes
salts
106
How does water potential differ at the beginning and end of a capillary?
The blood in the capillaries is hypertonic to the tissue fluid because plasma proteins remain in the blood as solutes, so there is always osmotic pressure pulling water into the capillary. Blood pressure is high at the beginning of the capillary pushing fluids out of the blood but drops by the end. Fluid leaves the capillary at the beginning but is drawn in at the end.
107
What is the main purpose of the lymphatic system?
To recover fluids lost from the blood
108
Lymph passes through small swellings in the lymphatic system, called \_\_\_\_\_\_\_\_\_\_\_\_\_. These contain large numbers of _____________ that defend against disease-causing organisms that have made it into the body.
Lymph passes through small swellings in the lymphatic system, called \_\_\_\_\_\_\_lymph nodes\_\_\_\_\_\_. These contain large numbers of \_\_\_\_\_\_\_lymphocytes (WBC’s)\_\_\_\_\_\_ that defend against disease-causing organisms that have made it into the body.
