Day 2.2 Flashcards
what is the blood composition?
55%: plasma
1%: buffy coat
45%: erythocytes
what is blood plasma composed of?
-55% of whole blood
-least dense component
-Straw colored, viscous
-90% water
-10% solutes
nutrients
gases
salts
hormones
proteins
what are the major categories of plasma proteins?
- Albumins
smallest and most abundant
contribute to viscosity and osmolarity
influence blood pressure, flow, and fluid balance - Globulins (antibodies)
provide immune system functions - Fibrinogen
Precursor of fibrin threads that help form blood clots
Serum: Identical to plasma except for the absence of fibrinogen
what are the functions of albumins?
smallest and most abundant
contribute to viscosity and osmolarity
influence blood pressure, flow, and fluid balance
what are the functions of globulins?
(antibodies)
provide immune system functions
what are the functions of fibrinogen?
Precursor of fibrin threads that help form blood clots
what are the formed elements?
-originate in bone marrow (hematopoiesis)
-do not divide
-survive in the blood only a few days
what are the three clases of formed elements?
Erythrocytes
Leukocytes
Platelets
Name the formed elements of blood
what is hematopoiesis?
Blood Cell Formation
Where does hematopoiesis occur?
Occurs in red bone marrow
Red bone marrow of axial skeleton, girdles and
proximal epiphyses of humerus and femur
what cells are involved with hematopoiesis?
Hemocytoblasts
Hematopoietic stem cells (pluripotent stem cells)
Give rise to all formed elements
Hormones and growth factors push the cell toward a specific pathway of blood cell development
what are structural characteristics of erythrocytes?
Biconcave discs
Anucleate Hemoglobin (Hb)
what is the formation of red blood cell production?
Erythropoiesis
what is used to stimulate erythropoiesis?
Erythropoietin (EPO)
Direct stimulus for erythropoiesis
Released by the kidneys in response to hypoxia
what are the functions of erythrocytes?
RBC: dedicated to respiratory gas transport
Hemoglobin binds reversibly with oxygen
what makes up hemoglobin?
Hemoglobin consists of globin (two
alpha and two beta polypeptide
chains) and four heme groups
what respiratory gases does erythocytes transport?
Oxygen:
98.5 % in hemoglobin (binds with iron of heme group)
1.5 % dissolved in plasma.
The association of O2 and hemoglobin is affected by:
pH
Temperature
pO2 and pCO2
Carbon dioxide:
7 % dissolved in plasma,
23 % in hemoglobin (binds with globin)
70 % as bicarbonate ions (HCO3−)
Name the RBC stages
hemopoietic stem cell
erythocyte (CFU)
erythoblast
reticulocyte
erythocyte
how is erythropoiesis controlled?
Hormonal Control of Erythropoiesis
regulated by the liver and kidneys
what is the process of the destruction of erythocytes?
what is agglutination?
Antibody molecule binding to antigens
Causes clumping of red blood cells
what is a universal donor?
-Type O: most common blood type
-Lacks RBC antigens
-Donor’s plasma may have both antibodies against recipient’s RBCs (anti-A and anti-B)
what is a universal recipient?
-Type AB: rarest blood type
-Lacks plasma antibodies; no anti-A or anti-B
ABO group
Label the correct plasma antibodies and the blood that can be recieved
what is a transfusion reaction?
-donor RBCs agglutinated by recipient plasma, which can lead to blockages of small vessels
what is the Rh group?
-Rh (C, D, E) agglutinogens discovered in rhesus monkey in 1940:
-Rh D is the most reactive and a patient is considered blood type Rh+ if having D antigen on RBCs
-Rh frequencies vary among ethnic groups
what types of wbc?
Granulocytes
Neutrophils (50 – 70%)
Eosinophils (2 – 4%)
Basophils (0.5 – 1%)
Agranulocytes
Lymphocytes (25 – 45%)
Monocytes (3 – 8%)
Name the wbc type
what are agranulocte cells?
-Lymphocytes (25% to 33%)
Variable amounts of bluish cytoplasm (scanty to abundant); ovoid/round, uniform dark violet nucleus
-Monocytes (3% to 8%)
Usually largest WBC; ovoid, kidney-, or horseshoe-shaped nucleus
what are granulocyte cells?
-Neutrophils (60% to 70%): polymorphonuclear leukocytes
Barely visible granules in cytoplasm; three- to five-lobed nucleus
-Eosinophils (2% to 4%)
Large rosy-orange granules; bilobed nucleus
-Basophils (less than 1%)
Large, abundant, violet granules (obscure a large S-shaped nucleus)
WBC pathway
what is thrombopoiesis?
Platelet formation
Formation is regulated by thrombopoietin
what is hemostasis?
The cessation of bleeding
Stopping potentially fatal leaks
Hemorrhage: excessive bleeding
what are the hemostatic mechanism?
Vascular spasm
Platelet plug formation
Blood clotting (coagulation)
Label the circulation of the heart
Label the heart in the mediastinum
Label the components of the heart
Label the heart in a superior view
Label the layers of the heart
List the layers of the heeart from most superficial to deepest
Pericardium:
Fibrous pericardium
Serous pericardium
2a) Parietal pericardium
- Pericardial cavity (filled with pericardial fluid)
2b) Visceral pericardium (same layer as epicardium)
Heart wall:
Epicardium (same layer as visceral pericardium)
Myocardium
Endocardium
what are the functions of the heart valves?
ensure unidirectional blood flow through the heart
what are the valves of the heart?
Atrioventricular (AV) valves
Semilunar (SL) valves
when do AV valves open and close?
-AV valves open; atrial pressure greater than ventricular pressure
-AV valves closed; atrial pressure less than ventricular pressure
When do SL valves open and close?
As ventricles
contract ,
intraventricular
pressure rises,
blood is pushe
what is the blood flow path?
- Blood enters right atrium from superior and inferior venae cavae.
- Blood in right atrium flows through right AV valve into right ventricle.
- Contraction of right ventricle forces pulmonary valve open.
- Blood flows through pulmonary valve into pulmonary trunk.
- Blood is distributed by right and left pulmonary arteries to the lungs, where it unloads CO_2 and loads O_2.
- Blood returns from lungs via pulmonary veins to left atrium.
- Blood in left atrium flows through left AV valve into left ventricle.
- Contraction of left ventricle (simultaneous with step 3) forces aortic valve open.
- Blood flows through aortic valve into ascending aorta.
- Blood in aorta is distributed to every organ in the body, where it unloads O_2 and loads CO_2
- Blood returns to right atrium via venae cavae.
Name the major coronary arteries
Name the major cardiac veins
Name the structures of cardiac muscle
Label the structure of the cardiac muscle
what is the Intrinsic Conduction System?
-Coordinates the heartbeat:
-Composed of an internal pacemaker and nerve-like conduction pathways through myocardium
-Depolarization of the heart is rhythmic and spontaneous
-About 1% of cardiac cells have automaticity (are self-excitable)
-Gap junctions ensure the heart contracts as a unit
what are the steps of the intrinsic conduction system?
- SA node fires.
- Excitation spreads through atrial myocardium.
- AV node fires.
- Excitation spreads down AV bundle.
- Subendocardial conducting network distributes excitation through ventricular myocardium.
what is the extrinsinc regulation of the heart
-The vagus nerve
(parasympathetic)
decreases heart rate
-Sympathetic cardiac
nerves increase heart rate
and force of contraction
what is Electrocardiogram?
Electrocardiogram (ECG or EKG) the action potentials generated by nodal and contractile cells detected, amplified and recorded by electrodes on arms, legs, and chest
what are the waves in ecg?
P wave: depolarization of SA node
QRS complex: ventricular depolarization
T wave: ventricular repolarization
what does a normal ecg look like?
what is the process of an ecg?
- atria begins depolarizing
- atrial depolarization complete
- ventricular depolarization begins at apex and progresses superiorly as atria repolarize
- ventricular depolarization complete
- ventricular repolarization begins at apex and progresses superiorly
- ventricular repolarization complete, heart is ready for the next cycle
what is a cardiac cycle?
one complete contraction and relaxation of all four chambers of the heart
what are the cycles of events in the heart?
Systole: contraction
Diastole: relaxation
Although “systole” and “diastole” can refer to contraction and relaxation of either type of chamber, they usually refer to the action of the ventricles
what is the operation of the heart valves?
- atrioventricular valves open
- atrioventricular valves closed
- semilunar valves open
- semilunar valves closed
what does the cardiac cycle look like?
what is cardiac output?
Volume of blood pumped by each ventricle in one minute
what is the equation for cardiac output?
CO = heart rate (HR) x stroke volume (SV)
HR = number of beats per minute
SV = volume of blood pumped out by a ventricle with each beat
CO sometimes also called Q
Examples of cardiac output
what is tachycardia?
Tachycardia — resting adult heart rate above 100 bpm
Stress, anxiety, drugs, heart disease, or fever
Loss of blood or damage to myocardium
what is bradycardia?
Bradycardia — resting adult heart rate of less than 60 bpm
In sleep, low body temperature, and endurance-trained athletes
what do chronotropic agents go?
Positive chronotropic agents — factors that raise the heart rate
Negative chronotropic agents — factors that lower the heart rate
what is stroke volume?
Volume of blood ejected from each ventricle per beat.
what is end diastolic volume?
EDV: End Diastolic Volume
Volume of blood in ventricle at the end of ventricular relaxation
what is end systolic volume?
ESV: End Systolic Volume
Volume of blood in ventricle at the end of ventricular contraction
how does preload affect SV?
The amount of tension in ventricular myocardium immediately before it begins to contract
Frank-Starling law of the heart: SV proportional to EDV
Ventricles eject almost as much blood as they receive (output = input)
Increased preload = increased SV
Increased venous return = increased EDV = increased SV
how does contractility affect SV?
how hard the myocardium contracts for a given preload
independent of muscle stretch and EDV
Impacts ESV
Increased contractility = increased SV
Positive inotropic agents increase contractility
Hypercalcemia can cause strong, prolonged contractions and even cardiac arrest in systole
Catecholamines increase calcium levels
Negative inotropic agents reduce contractility
Hypocalcemia can cause weak, irregular heartbeat and cardiac arrest in diastole
Hyperkalemia reduces strength of myocardial action potentials and the release of 〖𝐶𝑎〗^(2+) into the sarcoplasm
how does afterload affect SV?
Sum of all forces opposing ejection of blood from ventricle
Pressure that must be overcome for ventricles to eject blood
Impacts ESV
Hypertension increases afterload, resulting in increased ESV and reduced SV
Increased afterload = decreased SV
