Test #2 Flashcards
What is plasma composed of?
Proteins 7%
- albumins 58%
- globulins 38%
- fibrinogen 4%
Some hormones, enzymes are proteins too.
Water 91%
Other solutes 2%
What is the composition of blood?
Plasma 55%
Formed elements 45%
Rbcs
Buffy white coat - platelets and wbcs
What is the function of albumin?
Osmotic or oncotic pressure (mostly found in capillaries)
Buffer
Transport of fatty acids, drugs, thyroid hormones, and bilirubin
Determines blood viscosity along with other proteins
What is the function of globulins?
Main transporter of thyroid hormones, thyroid building globulin and other lipid-soluble hormones, iron lipids and has to do with immunity
What is the function of fibrinogen?
Blood clotting
What is the difference between blood, plasma and serum?
Blood is plasma and formed elements together
Plasma is just the liquid part of blood
Serum is plasma without its clotting factors
Describe the formed elements?
Red blood cells (erythrocytes)
Biconcave disks, have hemoglobin, no organelles,
Does not us O2 for energy
White blood cells (leukocytes)
Platelets (thrombocytes)
These are fragments of megakarotinocytes,
Release chemicals for blood clotting, many
Many growing factors released too
No nucleus, but have mitochondria
Described the formed elements that are white blood cells, what are the two types?
Granulocytes - have large granules and multi-lobed nuclei (neutrophils, eosinophils, basophils)
Agranulocytes- small granules in the cytoplasm and nuclei that aren’t lobed (lymphocytes and monocytes)
Describe the different types and granulocytes.
Neutrophils - first responders in immune response (60%-70%)
Eosinophils - these reduce inflammation, increase with allergies (2%-4%)
Basophils - release histamine and increase inflammatory response (.5%-1%)
Describe the different types of agranulocytes.
Monocytes - these become macrophages
Lymphocytes - Immunity
What are the three ways our body can arrest bleeding?
- Vascular spasm - the constriction of the damaged blood vessels. Small vessels can be occluded this way. Thromboxanes from platelets and endothelin from damages endothelial cells cause this.
- Platelet plug formation
- Coagulation or blood clotting followed by clot retraction.
What is the importance of vitamin k and calcium in coagulation?
Vitamin k is used for the synthesis of clotting factors.
Calcium is used as a cofactor of the many factors in the blood clotting cascade.
What is the intrinsic pathway of blood clotting?
In intrinsic, clotting starts when inactive factor XII in blood plasma comes in contact with a damaged blood vessel.
What enzyme dissolutes a clot and how does it work?
The process is called fibrinolysis, plasmin is used to dissolve the clot by hydrolysing the fibrin clot.
What are the functions of the heart?
Generating blood pressure
Routing blood by separating pulmonary and systemic circulations
Ensuring one way blood flow
Changing supply by changing contraction rate and force for supply needs at changing metabolic rates
Also has been found to have endocrine function by making atrial natriuretic peptide
Where is the heart located?
The heart is in the mediastinum in the thoracic cavity.
What are the definitions of a artery and a vein?
Arteries take blood away from the heart and veins take blood to the heart.
When is the myocardium nurtured?
Diastole
Would a more proximal or distal blockage create a more severe myocardial infarction?
Proximal.
What makes a valve open or close?
Pressure. (Higher to lower)
What causes blood to move through the heart?
Differences in pressure.
What contacts are important for the electric conduction of the heart and ultimately the contraction?
The intercalated disks are specialized contacts that allow the cells to be interdigited, desosomes hold cells together, gap junctions allow for the transfer of action potentials.
What are the differences between skeletal and cardiac muscle?
Cardiac muscle is involuntary and has the ability to conduct its own action potentials, it has intercalated disks and gap junctions that make the muscle slower to propagate, but have a long plateau phase
What ion is responsible for the plateau phase of the cardiac muscle action potential?
Calcium
What is the primary pacemaker of the heart?
SA node pacemaker cells
What happens if the primary pacemaker fails? (60-100)
The AV node will take over (40-60) and if that fails the purkinje fiber will take over (30-40)
What channels open/close during the three phases of the SA node action potential?
Pacemaker potential
- a few sodium channels are open, potassium channels that were open during repolarization of last AP are closing, calcium channels begin to open
Depolarization - calcium channels are open and potassium channels are closed
Repolarization- calcium channels close and potassium channels open
How does the pacemaker potential reach its threshold?
Through the nongated sodium channels.
When the aortic valve opens its means that the pressure in the left ventricle is higher than which blood pressure?
Systolic
What are the definitions of mean arterial pressure?
Average blood pressure in the arteries.
What is total peripheral resistance?
Determined by the diameter of blood vessels, the total resistance against which blood must be pumped.
Cardiac output?
The amount of blood pumped by the heart per minute.
Stroke volume?
Volume of blood pumped per heart beat
Heart rate?
Number of heart beats per minute
Frank sterling law and heart muscle? Intrinsic regulation.
At optimal stretch, the heart pumps the most blood per stroke, if stretched too far the heart can’t pump efficiently.
Extrinsic regulation of the heart?
Sympathetic control: supplied by cardiac nerves, increases rate and force of contraction, dilates coronary arteries (fight or flight), neurotransmitter is norepinephrine, binds with beta andrenergic receptors.
Parasympathetic control: supplied by vagus nerve, decreases heart rate only, acetylcholine is the neurotransmitter, binds with muscarinic cholingeric receptors
Hormonal control: epinephrine secreted by the adrenal medulla increases heart rate and contractility RELATED TO SYMPATHETIC STIMULATION
What are the basic structures of blood vessels?
Three layers: tunica adventitia- outer layer that connects with connective tissue
Tunica media- vascular smooth muscle (constricts and dilates)
Tunica intima - endothelial lining (inner layer)
The VASA VASORUM IS THE BLOOD VESSELS THAT SUPPLY THE WALLS OF ARTERIES AND VEINS
Do all vessels have the three layers of tissue?
No, capillaries and venules don’t have all three layers.
Capillary cells are simple squamous epithelium with a basement membrane
Venules are the same and have some smooth muscle cells as well
What is the importance of arterioles in blood pressure regulation?
The constriction and dilation of them is the main point of regulating resistance, in turn regulates systemic blood pressure
What is the predominant layer in large veins?
The tunica adventitia is the predominant layer, the middle layer isn’t as important because of the low pressure and the inner layer is thin and allows its elasticity
Why are valves important in veins?
These are important to prevent back flow, these fail in varicose veins
More valves in lower extremities than upper because of gravity
Atherosclerosis vs arteriosclerosis
Arteriosclerosis is the degeneration in arteries that makes them less elastic
Atherosclerosis is the deposition of plaque on the walls which can lead to many issues including thrombi
Different control of blood in tissues
Local: proportional to metabolic needs of tissues, pressure can regulate this
Nervous (sympathetic)- routes blood flow and maintains pressure (arteriole diameter)
Hormonal control: epinephrine from adrenal MEDULLA, angiotensin II and vasopressin (ADH) are a consequence
ONLY PRESSURE IN LOCAL AND BOTH PRESSURE AND FLOW IN NERVOUS AND HORMONAL
What is the extrinsic pathway of blood clotting?
Clotting starts when thromboplastin is released outside the blood plasma in the damaged tissue.
How is the process regulated?
Through positive and negative feedback systems.
Positive feedback is important for fast coagulating and negative is important in preventing clotting or stopping process when bleeding is arrested.
Steps 5-7 of coagulation cascade?
- Prothrombin is converted to thrombin by prothrombinase.
- Fibrinogen is converted to fibrin by thrombin.
- Thrombin activates clotting factors, which promotes formation of a clot and stabilizes fibrin clot.
