Exam II Flashcards
What does the plasma consist of?
Ground Substance (92%)
Dissolved Proteins and Materials (1%)
Hematocrit
ratio of red blood cells in the plasma
Normal Range in hematocrit in men
40%-54%
Normal range of hematocrit in females
37%-47%
Red Blood cells (erythrocytes)
responsible for gas transportation
white blood cells (leukocytes)
fully function to immune system
plates (thrombocytes)
responsible for clotting
Hematopoiesis
formation of blood and it takes place in the marrow
Colony Stimulating factor (CSF
causes a stem cell to commit to one specific leukocyte.
Thrombopoietin (TPO)
causes the stem cell to commit to producing platelets (thrombocytes)
Erythropoietin (EPO)
causes a stem cell to commit to producing a red blood cell (erythrocyte)
Example: occurs during chemotherapy
Understand the role of erythropoietin specifically in RBC production, including what signals its release from the kidneys.
The committed cell becomes a large nucleated erythroblast. During maturation, the cell shrinks and loses its nucleus along with other organelles. This cell is called a reticulocyte, it enters the bone marrow blood vessels and once it matures into a biconcave RBC within 24 hours. The biconcave shape increases cell surface area which increases diffusion/exchange of respiratory gases.
Cytokines
Responsible to help a stem cell commit to produce a certain cell
Explain the initiation and role of vascular spasm in hemostasis
Chemical signals are released by the damaged tissue which causes the damaged blood vessels smooth muscle to vasoconstrict causing reduced blood flow.
What are the processes of hemostasis?
-Vascular Spasm
-Platelet Plug
-Coagulation
Explain the formation of a platelet plug and why it is important.
The damaged tissue exposes collagen, which platets around adhere to it, which results to activated platets called platelet activating factor (PAF). The aggression of platelets form a temporary platelet plug that stop bleeding temporarily.
Understand and be able to explain the basics of the coagulation cascade leading to the formation of a clot.
- Proteins in the blood and released by damaged cells result in a cascade of signals that activate a circulating protein enzyme called Factor X.
- Factor X convers a circulating protein called prothrombin to thrombin, causing two effects which are converting circulating protein called fibroligin ( form clot) and another circulating enzyme Factor XIII(thickness)
Understand the functions of the cardiovascular system
- Circulate and distribute nutrients (oxygen, glucose, proteins)
- Remove waste ( Co2, waste products)
- Communication (circulate hormones and other signals)
- Regulation (temperature, muscle activity)
- Protection (antibodies, platelets, immune system)
Know the pathways of blood flow in the body (be able to trace a red blood cell as it moves through the circulatory system)
Inferior/Superior Vena Cava, Right atrium, tricuspid valve, right ventricle, pulmonary semilunar valve, pulmonary trunk, pulmonary arteries, lungs, pulmonary vein, left atrium, mitral/bicuspid valve, left ventricle, aortic semilunar valve, aorta, body
Atrioventricular valves (tricuspid, mitral,bicuspid)
control one way movement of blood from the atria to the ventricles. Help stay In place by papillary muscles pulling on choradae tendinae. Keep from blowing out under pressure.
Semilunar valve (aortic and pulmonary valve)-
Semilunar valve (aortic and pulmonary valve)- control one way flow from ventricles to body via loop. Shape helps them not prolapse.
Fossa Ovalis
whole in the heart to let blood be pumped by surpassing lungs, but closes when born
Ligamentum arteriosum
ligament that anchors the aorta to pulmonary trunk to make sure it stays in place, useful in fetal development but no longer has use after birth.
Know what the coronary circulation is and what its function is.
Circulation of blood in the arteries and veins that supply the heart muscle. It needs uninterrupted supply of oxygen and nutrients if not it will die.
RCA supplies the
posterior interventricular artery
Right atrium
Left Atrium (partial)
Right ventricle
Left ventricle (very little)
1/3 septum
SA/AV node
LCA supplies the
circumflex artery and anterior interventricular septum (including the following)
Left ventricle
Left Atrium
Right Atrium (little)
2/3 of septum
atherosclerosis
arterial disease that begins with plaque of cholesterol followed by inflammation of arterial wall, Leads to increase systolic blood pressure
Myocardial infarction
the coronary vessel is blocked by either blood clot or debris of atherosclerotic plaque. Blood supply to the heart is stopped.
Important features of cardiomyocytes
- Smaller fibers than skeletal muscle but larger than smooth
- High branched
- Intercalated disk between adjacent cells
- SR smaller -Ca from outside and from SR
- Very oxidative
- Cannot perform anaerobic metabolism -require oxygen supply
- Capable of grades contraction
Be able to describe, in detail, myocardial E-C coupling
Contraction
1. Action potential enters the sacromela from adjacent cells
2. Voltage-gated Calcium (Ca2+) channels open, allowing calcium to enter cells.
3. Calcium induces calcium release through the ryanodine receptor channels (Ryr)
4. Calcium release causes the release of calcium
5. Summed calcium create a calcium signal
6. Calcium ions then binds with tropin to initiate contraction
Relaxation
1. Calcium unbinds from tropin
2. Calcium is pumped back into the sarcoplasmic reticulum for storage
3. Calcium is exchanged with Sodium (Na+) by the NCEX antiporter
4. Sodium gradient is maintained by the Na+ K+ ATP phase
the role of calcium in myocardial contractility
Calcium helps activate signal for the heart to contract causing the pump.
Where do cardiomyocytes get the calcium, they need for contraction?
Myocardiocytes get their calcium for the contraction from the intercalated disk.
Myocardial Cell Action Potential Process
Phase 4: Resting Membrane Potential - 90 mv
Phase 0: Depolarization: Voltage Na channels open
Phase 1: Initial Repolarization: Voltage Na channels close, and Fast K channels open
Phase 2: Plateau Phase: Voltage Ca channels open, K channels slowly decrease due to Ca
Phase 3: Rapid Repolarization: Voltage Ca channels close, slow K channels open.
What is the role/importance of plateau phase in contractile cells
- Brings calcium into the cell for contraction and preloads AP (refractory period) to allow the heart fill with blood.
- No tetanus occurs here.
True or False: cardiac auto rhythmicity is the unstable pacemaker potential
True
- Be able to trace electrical conduction through all parts of the heart. What are the pathways and the structures involved?
- SA node depolarizes (electrical signal moves from cell to cell via gap junctions
- Wave of Depolarization spreads through the atria – atria contract (special conductive internodal pathway is crucial)
- Electrical connection from atria to ventricle blocked except at the AV node (conduction slows down through AV node aka AV node delay; provides time for atrial contraction and ventricular filling)
- Depolarization continues down the septal conduction system ( First through AV bundle-bundle of his; Next through L and R bundle branches; Finally though small Purkinjie Fibers in walls of ventricles; Wave of depolarization spreads through ventricles (from apex to base)
- Ventricles Contract: (bottom to top, wringing twisting- spiral muscle arrangement) (artia replorize)
- Ventricles Repolarize in opposite direction ( last to polarize is first to depolarize)
Describe what “heart block” is and what effect it has on the coordination of contractions between the atria and ventricles.
Heart Block is known as conduction disorder. If electrical signals cant move from atria to ventricles, blood is not being pumped correctly
Understand what an electrocardiogram represents.
Electrocardiogram is the activity of the heart, not action. Can reflect specific part of the heart depolarizing and repolarizing.
IMPORTANT: Does NOT show contraction, rather the mechanical events.
P wave
atrial depolarization
QRS complex
ventricular depolarization
T wave
ventricular repolarization