Blood
What is the name of the immature red blood cell?
reticulocyte
What is hemostasis?
Stoppage of blood flow
The tricuspid valve prevents backflow of blood into what structure?
Right atrium
What is the formula for calculating cardiac output?
CO = Heart Rate x Stroke Volume
Your friend has sadly been diagnosed with lymphoid leukemia. If you were to look at their blood sample, what would indicate this diagnosis?
An abundance of irregular lymphocytes
What are the granulocyte WBCs and their functions?
Neutrophil: kill bacteria
Eosinophil: attack objects coated with antibodies/parasitic worms
Basophil: promote inflammation/allergic responses
What occurs during the vascular phase of hemostasis, and what activates this response?
Vascular spasms (contraction of smooth muscle fibers to significantly reduce blood flow)
Activated by direct injury to smooth muscle, chemical release (serotonin, thromboxane), and nociceptors
During ventricular ejection, what is the status of the heart valves?
The AV valves are closed, and the semilunar valves are open.
What are the sources of resistance in blood vesels?
Blood viscosity (relatively constant, related to thickness)
Total vessel length (longer vessel, greater R)
BV diameter (smaller diameter, greater R)
A patient with high blood pressure is told to take baby aspirin every morning. Why? What chemical does aspirin inhibit, and what does this chemical do?
Aspirin inhibits thromboxane, which is released by platelets. Thromboxane stimulates vascular spasms and the attraction of more platelets to the site of injury. Patients with high blood pressure are at risk for stroke or heart attack, so sometimes they are told to take baby aspirin to prevent blood clotting.
What are the three products of RBC breakdown, and what do we do with each?
globin -> amino acids: recycled to make proteins
heme -> iron: recycled to make more RBCs
heme -> bilirubin: excreted in urine & feces
During the platelet phase, what do platelets release that specifically attracts more platelets to the site of injury?
ADP (adenosine diphosphate)
What is stroke volume?
It is the difference between end diastolic volume and end systolic volume. It is the amount of blood pumped out of the ventricles per beat.
List the following blood vessels in order of increasing pressure (lowest - highest)
pulmonary artery, venules, systemic arteries, veins
veins, venules, pulmonary arteries, systemic arteries
A patient comes into your clinic, and after some testing and examination, you determine that this patient has atherosclerosis (their arteries have become less compliant). What issues does this pose for the patient? What can this lead to?
If arteries are rigid, they cannot expand to accommodate blood flow, so blood pressure increases (high BP). This can also lead to heart attack or stroke.
Ellie has type O+ blood. Her friend Jordan has type AB- blood. Could Ellie donate her RBCs to Jordan? Whoy or why not?
Ellie cannot donate RBCs to Jordan. Although Ellie has no A or B antigens, she does have Rh antigens. Because Jordan is Rh negative, he could have Rh antibodies which would cause an agglutination reaction upon encountering Ellie's Rh positive blood. Thus, Rh + individuals cannot donate RBCs to Rh - individuals.
What is the role of thrombin (a clotting factor) in the coagulation phase?
Thrombin converts fibrinogen (soluble fibrin) into insoluble fibrin which is essential to clotting.
What is the path of electrical signals of the heart?
SA node -> AV node -> AV bundle/bundle branches -> Purkinje fibers
How could you achieve the same flow in a dilated blood vessel and constricted vessel (assuming they are the same vessel type) without changing vessel diameter?
Increase the change in pressure/pressure gradient in the constricted vessel. A greater pressure gradient means greater flow.
Since constricted vessels have greater resistance than dilated vessels and vessel diameter is not changing, the only way to achieve the same flow in the vessels is to increase the pressure gradient in the constricted vessel.
You take a patient's heart rate and monitor their EKG. You note that they have a heart rate of 55bpm and no p waves. What is the diagnosis? What part of the heart's ICS system is malfunctioning?
This is junctional rhythm. The absence of p waves indicates that the SA node is not firing, so the AV node has taken over. The AV node has a slower rhythm than the SA node, hence the slower heart rate.
Describe the life cycle of a RBC. Your response must include:
- the name of the process of creating RBCs, how long RBCs live, the name of the cell that breaks down RBCs, components that are recycled and excreted
BIRTH: Erythropoiesis occurs in red bone marrow; after 5-7 days, RBCs are released into the blood as reticulocytes
LIFE: Reticulocytes pick up oxygen and become mature RBCs and circulate in blood for ~120 days
DEATH: RBC dies and undergoes phagocytosis in spleen/liver/red bone marrow by macrophages
RECYCLE: Hemoglobin breakdown: Globin -> amino acids (recycled for proteins); Heme -> iron (recycled for future RBCs!) & bilirubin (excreted in urine & feces, gives it color!)
What are the three main steps of clot retraction and removal? Include the important components of each step.
Platelets draw the edges of the wound together using actin and myosin
Platelet derived growth factor (PDGF) stimulates vessel wall to rebuild
Plasminogen is converted to plasmin to dissolve the clot
How do actions potentials of autorhythmic (intrinsic conduction system) cells compare to contractile cells?
Autorhythmic cells do not maintain a stable resting membrane. Contractile cells require a stimulus from an adjacent cell to depolarize to action potential, but the autorhythmic cells are able to do this spontaneously as they drift towards the threshold (although autorhythmic cells can also depolarize as a result of an action potential arriving from an adjacent cell).
What are the two factors that control arterial blood pressure?
1) How much elastic arteries can be stretched/how compliant they are
2) The volume of blood forced into the arteries (if vessel diameter remains constant, and blood volume in the arteries increases, then blood pressure will increase)
You measure a patient's heart rate (75bpm), end diastolic volume (140mL), and end systolic volume (70 mL). What is their stroke volume? What is their cardiac output in mL/min?
SV = EDV - ESV = 140 - 70 = 70 mL/beat
CO = HR x SV = 75 x 70 = 5250mL/min