3.1 Blood Flashcards
Blood is…
A liquid connective tissue
4 Functions of blood
Regulation of homeostasis
Transport
Protection
Hemostasis
What percentage of whole blood does plasma make up?
55%
What is plasma made up of?
92% Water
Colloid with 7% proteins
What are the 4 proteins in plasma?
Liver albumin
Globulins
Fibrinogen
Regulatory
What is plasma
An aqueous solution with electrolytes, nutrients, gases, waste products
A 160 pound person would have how many quarts of plasma?
About 5
What percentage of whole blood do red blood cells make up?
44%
How are red blood cells measured
In a hematocrit analysis
What percentage of whole blood are white blood cells?
1 %
What are white blood cells also called in a hematocrit analysis?
The buffy coat
White blood cells most to least common
Neutrophils Lymphocytes Monocytes Eosinophils Basophils
Hemopoiesis
a.k.a. hematopoiesis
Process of blood cell production
Hemopoietic stem cell
- Red bone marrow
- Self renewal
- Transplantable
What is differentiation of cell sub-types regulated by?
- Growth factors
(e. g. erythropoietin) - “niches”
Myeloid lineage
All stages of origin and development in red bone marrow
What cells are in the myeloid lineage?
Some leukocytes
RBCs
Megakaryocytes (platelets)
Lymphoid
Just origin in bone marrow
What cells are in the lymphoid lineage?
B-lymphocytes, T-lymphocytes and natural killer cells
Where do lymphocytes get their name?
They must migrate within lymphatic system (lymph nodes, spleen, thymus, gland, bone marrow)
Lymphoid leukemia
A liquid timor of cells
Lymphoma
Solid tumor of lymphocytes
Function of Red blood cells
Atmospheric gas transport
Oxygen in blood
99% Carried by hemoglobin in RBCs
1% Dissolved in plasma
CO2 in blood
7% Dissolved in plasma
23% covalently bound to hemoglobin
70% Transported by plasma as bicarbonate ions
How is CO2 converted to bicarbonate (HCO3-)?
Via carbonic anhydrase enzyme expressed in Red blood cells
Does a RBC have a nucleus?
NO
What does oxygen bind to in RBCs?
Iron in heme, turns it bright red
Is heme a protein?
No, the globin that carries heme is a protein
Protein organizes the ____ which organizes the ______ which binds the____
Heme
Iron
Oxygen
What can heme iron also bind?
Carbon monoxide which binds more tightly and prevents oxygen binding
Erythropoiesis
RBC birth
Sensitive to blood oxygen content and hormones
What is the stimulus for erythropoiesis?
Decreased blood oxygen levels
What detects low blood oxygen?
Kindey
What cells release erythropoietin (Epo) into the blood?
Kidney cells
What is the kidney in the RBC life cycle?
Receptor and control center
What does EPO do?
Stimulates red bone marrow to increase the rate of production of erythrocytes
What happens when increased oxygen levels are detected by the kidney?
EPO is inhibited (negative feedback)
How long are RBCs viable for?
~120 days
What happens to the globin (protein part) during death / recycling?
Degraded into AAs
What happens to heme during death / recycle?
Converted to bilirubin, secreted in bile from liver
——> feces
What is an excessive accumulation of bilirubin called?
Jaundice
How can blood not get rejected by all recipients?
RBCs do not have MHCs (Major histocompatibility complex)
Neutrophils
Phagocytize (eat) bacteria, antigen-antibody complexes and other foreign matter, in bloodstream or interstitial spaces
Neutrophils leave circulation (emigrate) and…
Enter tissues at infection site
Basophils
Leave circulation and emigrate into tissues, play a role in inflammatory responses / allergic reactions (pro-inflammatory)
What do basophils produce?
Histamine
Eosinophils leave circulation and..
Enter tissues during inflammatory response
Eosinophils
Destroy inflammatory chemicals like histamine ( anti-inflammatory) ((Help regulate basophils)
Monocytes
Leave circulation an become macrophages; phagocytic cells that reside in tissues.
What are monocytes associated with?
Associated with severe infections
Where do cells from lymphoid lineages migrate?
To lymphatic tissues where they proliferate in response to specific antigens
What do cells in lymphoid lineages mediate?
Acquired immunity (immune memory) specific to a particular antigen
B-cells (lymphocyte)
Recognize foreign protein antigens and produce antibodies which is a part of the humoral defense
Why do vaccines work for your entire life?
Because of B-cells!
T-cells and Natural killer cells
Can directly phagocytize and destroy bacteria or virally infected cells
What does hemostasis prevent?
Hemorrhage: loss of large volumes of blood
3 Steps to hemostasis
- Vascular spasm
- Platelet plug formation
- Coagulation (blood clotting)
What is vascular spasm?
Vasoconstriction of vascular smooth muscle at the site of damage
What triggers vascular spasm at the site of damage?
Release of
- Thromboxanes from activated platelets
- Endothelin from damaged endothelial cells
What are platelets?
Anuclear pieces of megakaryocytes
Thrombopoiesis
-Platelet formation
Thrombocytopenia
Low platelets
Thrombocytosis
High platelets
Step 1 of platelet plug formation
Platelets bind exposed collagen and release thromboxane that recruits and activates other circulating platelets
Step 2 of platelet plug formation
Activated platelets bind soluble fibrinogen in bloodstream
Step 3 of platelet plug formation
Fibrinogen begins to cross-link platelets together to form a jelly-like plug
Coagulation cascade:
Tissue or vessel damage + platelet plug formation recruits..
Clotting factors from the plasma
What are clotting factors?
Enzymes and structural proteins
Stage 1 of the amplification cascade of coagulation
Platelets activate prothrombinase
Stage 2 of the amplification cascade of coagulation
Prothrombin ->thrombin
Stage 3 of amplification cascade of coagulation
Fibrinogen -> Fibrin
Result of amplification cascade
Fibrin matrix + platelets = strong clots
What does heparin do?
Anticoagulant, inhibits thrombin via enzymes
