Exam 2- Chapter 13 Flashcards
What are 3 functions of the circulatory system?
- Transportation
- Regulation
- Protection
What does the circulatory system transport?
Respiratory gases, nutrients, and wastes
What does the circulatory system regulate?
Hormones and temperature
How does the circulatory system protect?
Clotting and immune
What are the 2 components of the circulatory system?
- Cardiovascular system
2. Lymphatic system
What are the 2 parts to the cardiovascular system?
- Heart
2. Blood vessels (arteries, arterioles, capillaries, venules, and veins)
What are 3 components to the lymphatic system?
- Lymphatic vessels
- Lymphoid tissues
- Lymphatic organs (spleen, thymus, tonsils, lymph nodes)
When talking about the composition of blood, what are the 4 components?
- Plasma
- Erythrocytes
- Leukocytes
- Platelets (thrombocytes)
Describe the plasma component of blood?
Fluid part of the blood
What is contained within the plasma component of the blood?
- Plasma proteins
2. Serum
What are 2 types of plasma proteins?
- Albumin
2. Globulins
What is albumin?
type of plasma protein; creates osmotic pressure to help draw water from tissues into capillaries to maintain blood volume and pressure
What are globulins?
type of plasma protein; some carry lipids
What are gamma globulins?
specialized globulin; antibodies
What is fribrinogen?
type of gamma globulin; helps in clotting after becoming fibrin
What do erythrocytes carry?
Oxygen
What “standard” cellular structures do erythrocytes lack?
- Nuclei
2. Mitochondria
What is the life span of a erythrocyte?
120 days
What 2 substances do erythrocytes carry?
- Hemoglobin
2. Transferrin
Unlike erythrocytes, what “standard” cellular structures do leukocytes contain?
- Nuclei
2. Mitochondria
What are considered granular leukocytes?
- Neutrophils
- Eosinophils
- Basophils
What are considered aggranular leukocytes?
- Monocytes
2. Lymphocytes
What “standard” cellular structure do platelets (thrombocytes) lack?
Nuclei
What is the life span of platelets (thrombocytes)?
Very short lives (5-9 days)
What is the function of platelets (thrombocytes)?
Clot blood
What do platelets (thrombocytes) need?
Fibrinogen
What is the smallest formed element in the the composition of blood?
platelets (thrombocytes)
What is hematopoiesis?
Process of blood cell formation
What are the two types of hematopoiesis we will be talking about?
- Leukopoiesis
2. Erythropoiesis
What is leukopoiesis?
process of blood formation for WHITE BLOOD CELLS
What two structures are involved in leukopoiesis?
- Red bone marrow
2. Lymphoid tissue
What does leukopoiesis regulate?
Cytokine regulation
What is erythropoiesis?
process of blood formation for RED BLOOD CELLS
In erythropoiesis, what initiates erythropoietin? What is it secreted by?
- Low oxygen levels
2. The kidneys
Where are/What are antigens?
found on the surface of cells to help immune system recognize self cells
What are antibodies secreted by? Why?
- Lymphocytes
2. To respond to foreign cells
What is the ABO system?
Antigens on erythrocyte cell surfaces
What are the 4 possibilities of the ABO system?
- Type A
- Type B
- Type AB
- Type O
What antigen does type A blood have?
Has the A antigen
What antigen does type B blood have?
Has the B antigen
What antigen does type AB blood have?
Has both the A and B antigens
What antigen does type O blood have?
Has neither the A nor the B antigen
In a transfusion reaction what type of antibodies does a patient have?
antibodies against antigens he does not have
What type of antibodies does type A blood have?
Has the anti-B antibody
What type of antibodies does type B blood have?
Has the anti-A antibody
What type of antibodies does type AB blood have?
Has nether the anti-A nor anti-B antibody
What type of antibodies does type O blood have?
Has the anti-A and anti-B antibody
In a transfusion reaction, what happens if a person receives the wrong blood type?
antibodies bind to erythrocytes and cause agglutination.
What can agglutination be used for?
blood typing
What is the Rh factor?
It is antigen D
If a person does have an Rh factor (antigen D), is the person RH positive or negative?
Rh Posiitve
If a person does not have an Rh factor (antigen D), is the person RH positive or negative?
Rh negative
What is an issue with pregnancy and Rh factor?
An Rh− mother exposed to Rh+ fetal blood produces antibodies. This may cause erythroblastosis fetalis in future pregnancies as antibodies cross the placenta and attack fetal RBCs
Blood clotting: What is hemostasis?
cessation of bleeding when a blood vessel is damaged
Damage exposes collagen fibers to blood. What 3 things does the produce?
- Vasoconstriction
- Formation of platelet plug
- Formation of fibrin protein web
Blood clotting- Vessel Walls: What does intact endothelium secrete?
- Prostacyclin
- Nitric oxide
- CD39
Intact endothelium secretes prostacyclin and nitric oxide, which do what 2 things?
- Vasodilate
2. Inhibit platelet aggregation
Intact endothelium also secretes CD39, which does what?
Breaks down ADP into AMP and Pi to inhibit platelet aggregation further
Blood clotting- Platelets: Damaged endothelium exposes collagen. What 3 things then happen?
- Platelets bind to collagen.
- Von Willebrand factor holds them there.
- Platelets recruit more platelets and form a platelet plug by secreting substances
What substances do platelets secrete to help form a platelet plug?
- ADP (sticky platelets)
- Serotonin (vasoconstriction)
- Thromboxane A (sticky platelets and vasoconstriction)
Blood Clotting- Fibrin: How many different pathways convert fibrinogen to fibrin? Name them
2:
- Intrinsic
- Extrinsic
Which pathway of fibrinogen to fibrin is vitamin K needed for?
BOTH
Describe the intrinsic pathway of converting fibrinogen to fibrin.
- Activated by exposure to collagen
- Factor XII activates a cascade of other blood factor
- Calcium and phospholipids (from the platelets) convert prothrombin to the active enzyme thrombin, which converts fibrinogen to fibrin.
What is the extrinsic pathway of converting fibrinogen to fibrin initiated by?
Initiated by tissue factor (factor III)
Which pathway of fibrinogen to fibrin is a more direct pathway?
Extrinsic pathway
Can clotting be prevented with drugs?
YES
What drugs can prevent clotting?
- Calcium chelators
- Heparin
- Coumarin
How do calcium chelators prevent blood clotting?
By using sodium citrate or EDTA
How do heparin prevent blood clotting?
blocks thrombin
How do coumarin prevent blood clotting?
inhibits vitamin K
What does the right atrium of the heart receive?
receives deoxygenated blood from the body
What does the left atrium of the heart receive?
receives oxygenated blood from the lungs
What does the right ventricle of the heart do?
pumps deoxygenated blood to the lungs
What does the left ventricle of the heart do?
pumps oxygenated blood to the body
What does the fibrous skeleton of the heart separate? What does this allow for?
- Separates atria from ventricles
2. The atria to work as one unit, while the ventricles work as a separate unit
What does the fibrous skeleton of the heart form?
annuli fibrosi
What is the function of annuli fribrosi?
hold in heart valves
What is pulmonary circulation between?
between heart and lungs
What is systemic circulation between?
between heart and body tissues
Blood pumps into the lungs via _____ ____.
pulmonary arteries
Blood returns to heart via _____ ____.
pulmonary veins
Blood pumps to body tissues via the _____.
aorta
Blood returns to heart via ____ and ____ ____ ___.
- superior
- Inferior
- venae
- cave
Where are the atrioventricular valves located?
located between the atria and the ventricles
What are the names of the two atrioventricular vales?
- Tricuspid valve
2. Bicuspid valve
Where is the tricuspid valve located?
Between the right atrium and ventricle
Where is the bicuspid valve located?
Between left atrium and ventricle
Where are the semilunar valves located?
located between the ventricles and arteries leaving the heart
What are the names of the two semilunar valves?
- Pulmonary valve
2. Aortic valve
Where is the pulmonary valve located?
between right ventricle and pulmonary trunk
Where is the aortic valve located?
between left ventricle and aorta
What is the cardiac cycle?
Repeating pattern of contraction and relaxation of the heart.
In the cardiac cycle what is systole?
contraction of heart muscles
In the cardiac cycle what is diastole?
relaxation of heart muscles
What are the 5 steps in the cardiac cycle?
- Ventricles begin contraction, pressure rises, and AV valves close (lub).
- Pressure builds, semilunar valves open, and blood is ejected into arteries.
- Pressure in ventricles falls; semilunar valves close (dub).
- Pressure in ventricles falls below that of atria, and AV valve opens. Ventricles fill.
- Atria contract, sending last of blood to ventricles
What are heart sounds produced by?
Produced by closing valves
What is the “lub” sounds of the heart produced by? When does it occur?
- Closing of AV valves
2. Occurs at ventricular systole
What is the “dub” sounds of the heart produced by? When does it occur?
- Closing of semilunar valves
2. Occurs at ventricular diastole
What is a heart murmur?
Abnormal heart sounds produced by abnormal blood flow through heart
What are many heart murmur’s caused by?
Many caused by defective heart valves
What is mitral stenosis?
Type of heart murmur; mitral valve calcifies and impairs flow between left atrium and ventricle
What can a mitral stenosis result in?
pulmonary hypertension
What are incompetent valves?
Can result in heart murmurs; valves that do not close properly
What can incompetent valves be due to?
May be due to damaged papillary muscles
What are septal defects? What is a result of this?
- Can result in heart murmurs; Holes in interventricular or interatrial septum
- Blood crosses sides
What are 3 things that can cause heart murmurs?
- Mitral stenosis
- Incompetent valves
- Septal defects
Cardiac muscle cells are interconnected by gap junctions called ____ ____.
intercalated discs
Electrical activity of the heart:
- Once stimulation is applied, it flows from ___ __ ___.
- The area of the heart that contracts from one stimulation event is called a ________.
- The atria and ventricles are separated electrically by the ___ ____.
Electrical activity of the heart:
- Once stimulation is applied, it flows from cell to cell.
- The area of the heart that contracts from one stimulation event is called a myocardium.
- The atria and ventricles are separated electrically by the fibrous skeleton.
What is the sinoatrial node of the heart also known as? Where in the heart is it located?
- Pacemaker
2. Right atrium
Describe the pacemaker potential?
slow, spontaneous depolarization
When talking about the electrical activity of the heart, what happens at −40mV?
voltage-gated Ca2+ channels open, triggering action potential and contraction
What happens with the opening of voltage gated K+ channels?
Repolarization occurs
Cardiac muscle cells have a resting potential of what?
-90mV
How are cardiac muscle cells depolarized to threshold?
threshold by action potentials from the SA node
How do action potentials spread in cardiac muscles cells?
Action potentials spread via intercalated discs (gap junctions)
In cardiac muscle cells what conduct stimulation to ventricles?
AV node at base of right atrium and bundle of His
Where does the bundle of His divide into bundle branches?
In the interventricular septum
What do the bundle branches in the interventricular septum become? What do they stimulate?
- Purkinje fibers
2. Stimulate ventricular contraction
How fast/slow do action potentials from the SA node spread?
Action potentials from the SA node spread rapidly: 0.8–1.0 meters/second
How fast/slow do action potentials from the AV node spread? What does this account for?
- At the AV node, things slow down: 0.03−0.05 m/sec
2. This accounts for half of the time delay between atrial and ventricular contraction.
How fast/slow do action potentials from the bundle of His spread?
The speed picks up in the bundle of His, reaching 5 m/sec in the Purkinje fibers
How long after the atria do the ventricles contract?
Ventricles contract 0.1–0.2 seconds after atria
Why can’t the atria and ventricles sustain a contraction?
Because the atria and ventricles contract as single units
How long is the refractory period of cardiac muscles cells and why?
Because the action potential of cardiac cells is long, they also have long refractory periods before they can contract again
List the 6 steps to myocardial action potentials.
- Cardiac muscle cells have a resting potential of −90mV.
- They are depolarized to threshold by action potentials from the SA node.
- Action potentials spread via intercalated discs (gap junctions)
- AV node at base of right atrium and bundle of His conduct stimulation to ventricles
- In the interventricular septum, the bundle of His divides into bundle branches.
- Branch bundles become Purkinje fibers, which stimulate ventricular contraction.
Describe the 4 steps in conduction of impulses.
- Action potentials from the SA node spread rapidly. (0.8–1.0 meters/second)
- At the AV node, things slow down (0.03−0.05 m/sec)
- This accounts for half of the time delay between atrial and ventricular contraction. - The speed picks up in the bundle of His, reaching 5 m/sec in the Purkinje fibers
- Ventricles contract 0.1–0.2 seconds after atria.
What is an electrocardiogram, and how does it work?
This instrument records the electrical activity of the heart by picking up the movement of ions in body tissues in response to activity
What does a P wave mean in an electrocardiogram?
atrial depolarization
What does a QRS wave mean in an electrocardiogram?
ventricular depolarization
What is the S-T segment in an electrocardiogram?
plateau phase
What does a T wave mean in an electrocardiogram?
ventricular repolarization
At what wave does the “lub” sound occur?
after the QRS wave
At what wave does the “dub” sound occur?
beginning of the T wave
What are the 5 types of blood vessels?
- Arteries
- Arterioles
- Capillaries
- Venules
- Veins
The walls of arteries and veins have how many tunics, or coats?
3
What are the names of the 3 tunics (coats) of the walls of arteries/veins? (from inner to outer)
- Tunica intima
- Tunica media
- Tunica externa
What is the inner tunic layer (tunica intima) of arteries/veins composed of?
composed of simple squamous endothelium on a basement membrane and connective tissue
What is the middle tunic layer (tunica media) of arteries/veins composed of?
composed of smooth muscle tissue
What is the outer tunic layer (tunica externa) of arteries/veins composed of?
composed of connective tissue
Where are elastic arteries located?
closer to the heart
Describe elastic arteries.
allow stretch as blood is pumped into them and recoil when ventricles relax
Where are muscular arteries located?
farther from the heart
Describe muscular arteries.
have more smooth muscle in proportion to diameter; also have more resistance due to smaller lumina
What is the diameter of arterioles?
20−30 µm in diameter (micrometer)
What are the smallest blood vessels?
Capillaries
What is the diameter of capillaries?
7−10 µm in diameter (micrometer)
What is the structure of capillaries?
Single layer of simple squamous epithelium tissue in wall
What happens in the capillaries?
Gases and nutrients are exchanged between the blood and tissues
Blood flow to capillaries is regulated by what two things?
- Vasoconstriction and vasodilation of arterioles
2. Precapillary sphincters
What are the 3 types of capillaries?
- Continous capillaries
- Fenestrated capillaries
- Discontinuous capillaries
Continous capillaries:
- How are adjacent cells arranged?
- Where are these type of capillaries found?
- Close together
- Muscles
- Adipose Tissue
- CNS (add to BBB)
Fenestrated capillaries:
- Structure?
- Where are these type of capillaries found?
- Have pores in vessel wall
- Kidneys
- Intestines
- Endocrine glands
Discontinuous capillaries:
- How are adjacent cells arranged?
- Where are these type of capillaries found?
- What do they allow for?
- Have gaps between cells
- Bone marrow
- Liver
- Spleen
- Allow passage of proteins
Which has higher pressure, veins or arteries?
Arteries
What is the pressure of veins vs arteries?
Veins: 2 mmHg
Arteries: 100 mmHg
What is the function of veins?
Return blood to the heart
What are 3 ways the veins help return blood to the hear?
- Skeletal muscle pumps
- Venous valves
- Breathing
How do skeletal muscle pumps help return blood to the heat?
Muscles surrounding the veins help pump blood
How do venous valves help return blood to the heat?
Ensure one-directional flow of blood
How does breathing help return blood to the heat?
Flattening of the diaphragm at inhalation increases abdominal cavity pressure in relation to thoracic pressure and moves blood toward heart.
When you breathe does the diaphragm flatten or round?
Flatten
What contributes to 50% of the deaths due to heart attack and stroke?
Atherosclerosis
Generally, what is going on with atherosclerosis?
Plaques protrude into the lumen and reduce blood flow.
What do the plaques in atherosclerosis form in response to?
damage done to the endothelium of a blood vessel.
What are 4 causes for atherosclerosis?
- Smoking
- High blood pressure
- Diabetes
- High cholesterol
Name the 3 steps in development of atherosclerosis.
- Lipid-filled macrophages and lymphocytes assemble at the site of damage within the tunica intima.
- Next, layers of smooth muscle are added.
- Finally, a cap of connective tissue covers the layers of smooth muscle, lipids, and cellular debris.
What do Low-density lipoproteins (LDLs) do?
Low-density lipoproteins (LDLs) carry cholesterol to arteries
People who consume or produce a lot of cholesterol have ____ LDLs.
more
This high LDL level is associated with increased development of _______.
atherosclerosis
What do High-density lipoproteins (HDLs) do?
carry cholesterol away from the arteries to the liver for metabolism
What do HDLs do to defend against developing plaques?
takes cholesterol away from the macrophages in developing plaques because of their original function—-(carrying cholesterol away from the arteries to the liver for metabolism)
What kind of drugs (give on example) increase HDL levels?
Statin drugs (e.g., Lipitor)
What type of disease is atherosclerosis now believed to be?
inflammatory disease
What is a better predictor for atherosclerosis than LDL levels?
C-reactive protein (a measure of inflammation)
What may be a future treatment for atherosclerosis?
Antioxidants
What is ischemia?
condition characterized by inadequate oxygen due to reduced blood flow
What is the most common cause of ischemia?
Atherosclerosis
What is angina pectoris?
The increased increased production of lactic acid and resulting pain associated with ischemia.
With ischemia, eventually a necrosis of some areas of the heart occurs. What does this lead to?
myocardial infarction (heart attack)
What does myocardial infarction mean?
heart attack
How can you detect ischemia using an electrocardiogram ?
Depression of the S-T segment of an electrocardiogram
What is another way to detect ischemia besides using an electrocardiogram?
Plasma concentration of blood enzymes (Creatine phosphokinase, lactate dehydrogenase, troponin I, and troponin T)
What does a heart arrhythmia mean?
Abnormal heart rhythms
What is bradycardia?
type of heart arrhythmia; slow heart rate, below 60 bpm
What is tachycardia?
type of heart arrhythmia; fast heart rate, above 100 bpm
When is bradycardia, and tachycardia considered normal? Not normal?
These heart rhythms are normal if the person is active, but not normal at rest
What can abnormal tachycardia be due to do?
Abnormal tachycardia can occur due to drugs or fast ectopic pacemakers.
What does flutter mean?
extremely fast (200−300 bpm) but coordinated contractions
What does fibrillation mean?
uncoordinated pumping between the atria and ventricles
When does ventricular tachycardia occur?
occurs when pacemakers in the ventricles make them contract out of synch with the atria
Is ventricular tachycardia dangerous? What can it lead to?
This condition is very dangerous and can lead to ventricular fibrillation and sudden death.
What are the two types of fibrillation?
- Ventricular fibrillation
2. Atrial fibrillation
What is happening with ventricular fibrillation? How can the victim die?
- Ventricles can’t pump blood
2. Victim dies without CPR and/or electrical defibrillation to reset the heart rhythm
What can atrial fibrillation be a result from?
atrial flutter
What is going on in atrial fibrillation?
- Atrial muscles cannot effectively contract
2. AV node can’t keep pace with speed of atrial contractions, but some stimulation is passed on.
How much does atrial fibrillation reduce cardiac output by?
Only reduces cardiac output by 15%
What is atrial fibrillation associated with increased risk of?
Associated with increased risk of stroke and heart failure
What are 3 functions of the lymphatic system?
- Transports excess interstitial fluid (lymph) from tissues to the veins
- Produces and houses lymphocytes for the immune response
- Transports absorbed fats from intestines to blood
What are the two types of vessels of the lymphatic system?
- Lymphatic capillaries
2. Lymph ducts
Which is smaller lymphatic capillaries or lymph ducts?
lymphatic capillaries
Where are lymphatic capillaries found?
Within most organs
What can enter lymphatic capillaries?
- Interstitial fluids
- Proteins
- Microorganisms
- Fats
What are lymph ducts formed by?
merging capillaries
What are lymph ducts similar in structure to?
veins
Where is lymph filtered through?
Lymph nodes
What are the organs of the lymphatic system?
- Tonsils
- Thymus
- Spleen
* *Lymph nodes**
What are the sites of lymphocyte production?
- Tonsils
- Thymus
- Spleen
(organs of the lymphatic system besides the lymph nodes if those even count)