Circulatory System Flashcards
1
Q
Describe arteries
A
They have thick walls composed of elastic and muscular fibers and supporting tissues which branch into arterioles
2
Q
Describe capillaries
A
Capillaries are small vessels that arterioles branch into. They are very narrow, microscopic tubes. The walls are only one cell thick. Gases and small molecules like glucose exchange across the walls of the capillaries.
3
Q
What are sphincter muscles
A
They encircle the entrance to each capillary. In a capillary bed (network of many capillaries), sphincter muscles may be closes off so that more or less blood flows to that area as needed (e.g. more blood flow when working out)
4
Q
What are veins
What do they have
A
Walls are thinner than arterial walls. Veins have valves that allow blood to flow only toward the heart when open and prevent backflow when closed.
5
Q
To which part of the body to the subclavian veins and arteries connect?
A
Heart → shoulder/head
6
Q
To where does the carotid artery connect?
A
Heart → head
7
Q
To where does the jugular vein connect?
A
Head → heart
8
Q
To where does the anterior (superior) vena cava connect?
A
Upper body → heart
9
Q
To where deos the posterior (inferior) vena cava connect?
A
Lower body → heart
10
Q
To where do the pulmonary arteries and veins connect?
A
Heart → lungs
11
Q
To where does the mesenteric artery connect?
A
Heart → digestion tract
12
Q
To where do the hepatic portal vein connect?
A
(O2-poor) villi → liver
13
Q
To where does the hepatic vein connect?
A
Liver → heart
14
Q
To where do the renal artery and vein connect?
A
Heart → kidney
15
Q
To where do the iliac artery and vein connect?
A
Heart → pelvis/legs
16
Q
To where does the aorta connect?
A
Heart → other arteries
17
Q
To where does the coronary artery connect?
A
Heart → heart muscles
18
Q
To where does the coronary vein connect?
A
Heart muscles → heart
19
Q
What three things does blood do?
A
- Transport (gases, waste, nutrients)
- Clotting (to seal injuries)
- Infection fighting
20
Q
What are the two main parts of blood
A
- Plasma (liquid portion of blood) which contains water, organic and inorganic substances (plasma proteins, gases, salts, nutrientsm hormones, waste, etc)
- Formed elements (3 solid parts of blood)
21
Q
What are the three formed elements of the blood?
A
- Red blood cells (erythrocytes) - transport O2 and CO2, have no nuclei (thus unable to repair self), formed in bone marrow, liver, spleen
- White blood cells (leukocytes) - used to fight infections, possess nuclei — some are granular (proteins on outside) while others are agranular (no proteins on outside, made in bone marrow, lymphoid tissues
- Platelets (thrombocytes) - start blood clotting, no nuclei, considered only cell fragments
22
Q
What carries molecules through blood?
A
Proteins in plasma carry molecules (these contribute to blood’s viscosity)
23
Q
What is hemoglobin
A
Hemoglobin is a quaternary protein structure made of 4 amino acid chains. Each chain contains an iron ‘heme’ group which attaches to O2 and carries it through blood
24
Q
Why does O2 easily attach to hemoglobin in the lungs and give it up in other environments
A
The lungs have the perfect conditions for attachment - cool, slightly basic, 37°C, 7.4pH environment
Other areas in the body are warmer and more acidic, 38°C and 7.38pH allowing detachment
25
What is oxyhemoglobin
Hemoglobin with bound O2 (bright red)
26
What is reduced hemoglobin
Hemoglobin that has lost its O2 group (dark purple)
27
What three molecules are required for coagulation
1. Platelets
2. Prothrombin
3. Fibrinogen
28
Where do platelets, prothrombin, and fibrinogen come from
- Platelets come from fragmentation of large cells called megakaryocytes in red bone marrow
- Fibrinogens and prothrombin are plasma proteins manufactured and deposited in the blood by the liver
29
Describe the process of clot formation in four steps
1. Platelets clump at the site of the puncture and partially seal the leak, then platelets and injured tissues release the enzyme prothrombin activator
3. Thrombin acts as an enzyme and severs 2 short amino acid chains from each fibrinogen molecule
4. These activated chains join end to end to form long long ends of fibrin
5. Fibrin threads entangle red cells and platelets in the damaged area and form the framework of the clot
30
Clotting takes place faster at ____ temperatures because....
... warmer temperatures because it is controlled by enzymes. The fibrin clot is only a temporary repair. Eventually enzymes called plasmin destroy the fibrin network and restores plasma fluidity
31
What does the lymph system do?
Fight infections (by cleansing lymph and production of lymphocytes)
Abosorbtion of fat (from intestine and transport to blood)
Transport of excess tissue fluid back to cardiovascular system
32
Which vessel collects and drains the upper right portion of the body
The Right Lymphatic Duct drains the upper right body and enters into the right subclavian vein
33
Which vessel drains the rest of the body
The Thoracic Duct drains the rest of the body and drains into the left subclavian vein
34
What are lymphocytes
White blood cells made in bone marrow that are part of the lymph system
Some lymphocytes produce antibodies
35
What are lacteal
The lymphatic vessels of the small intestine which absorb digested fats
36
What are lymph nodes
Small oval structures that occur along strategic places on lymph vessels
They produce/store lymphocytes and filler lymph of damaged cells and debris
37
What is the spleen
Located behind the stomach / next to spine
Contains WBCs and stores blood
38
What is the thymus
Located in the upper thoracic cavity
Functions to produce/mature some lymphocytes
39
What is innate immunity
What does it consist of
Body responds to a wide variety or microbes
It consists of external barriers formed by the
- skin
- mucous membrane
- set of interncal cellular/chemical defenses like WBCs / lymphocytes
40
Which vein does not involve the heart in transport of blood
Hepatic portal vein
41
Which artery and vein are opposite for direction of O2 rich and O2 poor blood transport
Pulmonary artery and vein
42
What is aquired immunity (specific)
It can distinguish between one inducing agent and another by WBCs (lymphocytes)
43
What are the 2 general responses to aquired immunity
1. Humoral response
2. Cell-mediated response
44
Describe the humoral response
Cells derived from B cells secrete defensive proteins called antibodies that bind to microbes and target for elimination
45
Describe the cell mediated response
Cytotoxic lymphocytes directly destroy infected body cells, cancer cells, or foreign tissues
46
What is an antigen
Any pathogen that elicits a lymph reaction
47
Both B cells and T cells are made in the bone marrow. Where do each mature
B cells mature in the bone marrow
T cells mature in the thymus
48
Where are the B and T cells concentrated
Spleen
Lymph nodes
Lymphatic tissues
49
What are antigen-specific receptors
Receptors embedded in the plasma membrane of B and T cells how they recognize antigens
50
Describe B cells role in humoral immunity
B cell activation and clonal selection and results in the production of anibodies that circulate in the blood plamsa and lymph
51
Describe T cells role in cell mediated immunity
Activation and clonal selection of cytotoxin - T cells allow these cells to directly destroy certain target cells
52
What are T-dependent antigens
Harmful antigen that can only be defeated by both T and B cells. The T cells help activate the B cells which produce the required antibodies to defeat the antigen
53
What are T-independent antigens
Antigens with polysaccharieds on their surfaces. These can be immediately recognized by B cells for destroyal.
54
How do antibodies help to dispose of antigens in three ways
1. Antibodies bind to proteins on the surface of a virus, blocking the virus's ability to infect a hose
2. Antibodies enhance macrophage attachment to and phagocytosis of the microbes
3. Antibodies can cause agglutination (clumping) of bacteria / viruses, making them easier targets for phagocytes
55
What is immunology memory
The immune system's ability to generate secondary immune response
It is based on long living B and T cell's memory
56
What is active immunity
Immunity that comes from recovering from an infection
May be aquired through immunization
57
Vaccines can be made from 5 things...
1. Killed microbes
2. Inactivated bacterial toxins
3. Parts of microbes
4. Viable but weakened microbes
5. Genes encoding microbe proteins
58
What is passive immunity
The short-term immunity which results from the introduction of antibodies from another person or animal (e.g. breastfeeding mother passes antibodies to child)
59
What is the major portion of the heart called
The myocardium
60
What contains the heart
The pericardial sac
61
The right side of the heart pumps blood ______ while the left side of the heart pumps blood ______.
Right side → lungs
Left side → everywhere else
Each side of the heart has two chambers
62
What is the septum
It divides the heart into right and left
63
What is the atrium
The small chamber on top
64
What is the ventricle
The large chamber on the bottom (left ventricle is much bigger than the one on the right)
65
What are valves
The control the flow of blood between chambers and prevents backflow (they are found between the atria and ventricles)
66
What is the tricuspid valve
Separates the right atrium from the right ventricle
67
What is the bicuspid (mitral) valve
Separates the left atrium from the left ventricle
68
What is the chordae tendinae
Strong fibrous strings that support valves and prevent from inverting
It is attached to muscular projections of ventricular wall
69
What is the semilunar valve
Valve in each ventricle between it and attached to blood vessels
Blood flows through it on the way out of the heart
70
What is the pulmonary semilunar valve
Valve in the right ventricle
71
What is the aortic semilunar valve
Valve in the left ventricle
72
What is the first step on the path of blood throught the heart
1. O2-poor blood enters through the right atrium through superior and inferior vena cava
73
What is the second step on the path of blood throught the heart
2. The right atrium contracts forcing blood through the tricuspid valve and into the right ventricle
74
What is the third step on the path of blood throught the heart
3. The right ventricle contracts sending blood through the pulmonary semilunar valve and into the pulmonary trunk
75
What is the fourth step on the path of blood throught the heart
4. The pulmonary trunk divides into pulmonary arteries taking O2-poor blood to capillaries in lungs
76
What is the fifth step on the path of blood throught the heart
5. At the lungs, CO2 diffuses out of blood, O2 diffuses in. (Blood is now oxygenated)
77
What is the sixth step on the path of blood throught the heart
6. The O2-rich blood feeds into pulmonary veins which takes it from lungs to left atrium
78
What is the seventh step on the path of blood throught the heart
7. The left atrium contracts forcing blood through the mitral valve into left ventricles
79
What is the eighth step on the path of blood throught the heart
8. The left ventricle contracts, forcing blood through the aortic semilunar valve into the aorta
80
What is the ninth step on the path of blood throught the heart
9. Aorta divides into smaller arteries, carrying O2 rich blood to tissues
81
The heartbeat we hear comes in 2 phases. What are these
1. The atria contract as ventricles relax (closing of atrioventricluar valves)
2. The ventricles contract as atria relax (closing of semilunar valves)
82
What does systole mean
Contraction of heart muscles
83
What does diastole mean
Relaxation of heart muscles
84
What is the cardiac cycle
Pulse (heartbeats)
85
What is the sinoatrial node
Located in the upper back wall of the right atrium
It initiates the heartbeat by sending out a signal automatically every .85 seconds to make the atria contract
86
What is the atrioventricular node
Located in the base of the right atrium near the septum
It sends its signal along fibers to the atria and the AV node
When pulse sent by SA node reaches AV node, AV node sends out signal along special conducting fibers called purkinje fibers
87
What do purkinje fibers do
Purkinje fibers take messages to the ventricles and cause them to contract. This action begins at the base of the heart and moves like a wavelength. This is because the purkinje fibers first stimulate cardiac muscle at the base of the heart
88
What is the medulla oblangata
The heart-rate control center of the brain which can speed up or slow down the heart rate according to the prevailing stimuli received by autonomic nervous system
Factors like stress, O2 levels, bpressure determine how autonomic system will affect heart rate
