What are arteries responsible for?
Transport blood away from the heart into the lungs (for oxygenation) or to body tissues.
What is systemic circulation?
The exchange of nutrients and wastes between the blood and the cells throughout the body (oxygenated blood to the rest of the body).
What is pulmonary circulation?
The exchange of O2 and CO2 in the lungs (receives deoxygenated blood from the body and sends it to the lungs for oxygenation).
What are the three layers veins and arteries are made of?
1. Tunica intima - endothelial, inner layer
2. Tunica media - smooth muscle (controls diameter and lumen size)
3. Tunica adventitia/externa - outer CT layer, contains elastic and collagen fibers
What are the 3 steps of hemostasis?
1. In small bv the vessel vasoconstricts to decrease blood flow and to allow the formation of a platelet plug.
2. Platelets adhere to tissue, if bv is small platelet plug is formed.
3. In larger vessels clotting factors are released for coagulation.
What are some features of an rbc?
- biconcave
- no nucleus
- lifespan is approx. 120 days
- obligate in the bone marrow
Which leukocytes are granulocytes and agranulocytes?
Granulocytes:
- neutrophils
- basophils
- eosinophils
Agranulocytes:
- monocytes
- lymphocytes
Are platelets cells?
No, they're fragments with no nucleus.
Describe blood clotting/coagulation?
1. damaged tissue and platelets release clotting factors such prothrombin activator (PTA).
2. PTA is converted to thrombin - an anticoagulant.
3. fibrinogen --> fibrin threads from thrombin
3. fibrin mes traps cells --> forms a clot
4. clot pulls at the edges of damaged tissue, sealing it
What vitamin is necessary for the synthesis of clotting factors and where are they made?
liver; vit. k
How does the body balance forming unnecessary clots?
antithrombin III (inhibitor) circulates in the blood
O2 deficits from anemia can lead to:
- less energy in cells
- tachycardia
- cracked lips
- dysphagia
- angina if severe
What is iron deficiency anemia?
Insufficient iron in the body --> impairement of hemoglobin synthesis (reduces the amount of O2 transported).
What is pernicious/megaloblastic anemia?
Very large, immature erythrocytes --> carry less hemoglobin and shorter lifespan which means the bone marrow is constantly producing them instead of mature rbcs.
What causes pernicious/megaloblastic anemia?
Vitamin B12 deficiency due to lack of intrinsic factor produced in the glands of the gastric mucosa.
What is aplastic anemia?
Impairment/failure in bone marrow --> loss of stem cells and pancytopenia. May be temporary or permanent.
What is SICKLE CELL ANEMIA?
Genetic condition --> leads to abnormal hemoglobin. When deoxygenated it turns into a sickle shape. 20 day lifespan.
What does prostaglandin do?
Prevents platelets from sticking to undamaged tissue.
What does iron deficiency anemia do to RBCs?
Turns them into microcytic (smaller) and hypochromic (less red/paler) RBCs.
Hyper-segmented neutrophils appear in ___.
pernicious anemia
What are some symptoms of pernicious anemia?
- general signs of anemia
- tongue enlarged
- ataxia
- burning in the extremities (B12 helps in the myelination of nerves, deficiencies cause neuropathies)
When testing for pernicious anemia, how may the RBCs look?
- macrocytic or megablastic
- reduced in numbers
- bone marrow is hyperactive
How do you treat pernicious anemia?
- prophylaxis
- B12 injections
What are the two hemolytic anemias?
- Sickle cell
- Thalassemia
Why is the sickle cell bad for our RBCs?
It can't hold as much oxygen, and they're far too large. This means they can cause obstructions, leading to multiple infarctions.
Name some signs and symptoms of sickle cell anemia?
- general signs of anemia
- hyperbilirubinemia - jaundice
- splenomegaly (because the spleen is working overtime)
- infarctions
- infections
What is thalassemia?
A genetic defect where the amount of hemoglobin synthesized is reduced and can then induce anemia and hemolysis.
What are the signs and symptoms of thalassemia?
- hyperactive bone marrow
- increased cardiac workload --> heart failure
What are some warning signs of a possible blood-clotting disorder?
- persistent bleeding from gums
- petechiae
- anemia
- coughing up blood
- feeling faint
Describe the three different types of hemophilias.
Hemophilia A: deficit in a clotting factor, inherited in men through transferred by X-linked recessive trait.
Hemophilia B: "Christmas Disease", similar to A.
Hemophilia C: a milder form.
Name some signs and symptoms of hemophilia.
- prolonged/severe hemorrhage following minor trauma
- persistent oozing
- hematomas (bubble of blood) are common
- blood appearing in urine or feces
What is VON WILLEBRAND DISEASE?
A hereditary clotting/bleeding disorder. Where the body has a deficiency of the von Willebrand factor which is important for blood clotting proteins. It's signs and symptoms are similar to hemophilia but milder.
What is disseminated intravascular coagulation?
A life threatening condition that involves excessive bleeding and clotting. The excessive clotting can cause multiple thromoboses and infarctions, but because of that it also consumes all the available clotting factors and platelets. This over consumption can lead to hemorrhage.
What are the signs and symptoms of disseminated intravascular coagulation?
- low plasma fibrinogen
- thrombocytopenia (indicates that they're being used and consumed from all the clotting)
- prolonged bleeding
- low bp and shop
- petechiae/ecchymosis
What is thrombophilia?
A group of disorders that are either inherited or acquired. It increases abnormal clotting --> deep vein thrombosis, pulmonary embolism or PVD.
What is polycythemia vera?
A neoplastic disorder that increases the production of RBCs, thrombocytes and granulocytes. This leads to an increased blood volume and viscosity, which can lead to infarctions.
What is the difference between acute leukemia (ALL/AML) and chronic leukemia (CLL/CML)?
Acute: cells are found in the bone marrow and peripheral circulation, occurs in kids/young adults.
Chronic: insidious onset with milder symptoms and better prognosis, typically in older people.
As leukemic cells proliferate in the bone marrow, what else might it do?
It suppresses the production of other normal cells (RBCs) --> anemia, thrombocytopenia and normal functioning WBCs. Not only that but the bone marrow will become crowded leading to severe bone pain.
What are some complications of leukemia?
- opportunistic infections (pneumonia)
- sepsis
- liver failure
- renal failure
- hemorrhage
What is multiple myeloma?
A neoplastic disease which increase the production of malignant plasma cells in the bone marrow. These cells will eventually replace the bone marrow and erode the bone --> impaired production of RBCs and antibodies.