Structural and Functional Organization of Blood Flashcards
What kind of tissue is blood, and what are its functions?
Liquid connective tissue surrounded by extracellular matrix.
Transportation, regulation, and protection.
Describe “Transportation”
Blood transports O2 from the lungs to cells in the body, and CO2 from cells in the body to the lungs.
It also carries waste from the GI tract to body cells, heat and waste products away from cells, and hormones from endocrine glands to other body cells.
Describe “Regulation”
Blood helps regulate the pH of body fluids.
- Water in plasma has heat absorbing, coolant properties, and can variate its flow rate through the skin to help adjust pressure.
- Blood osmotic pressure also influences the water content of cells.
Describe “Protection”
Blood clots in response to an injury which protects against excessive blood loss.
WBCs protect against disease via phagocytosis and producing proteins called antibodies.
Blood contains additional proteins, called interferons and complement, which also help protect against disease.
What is the temperature and pH of blood?
38C/100.4F
Slightly alkaline, ranges from 7.35-7.45.
It constitutes 8% of the total body weight, and is denser and more viscous than water.
What is the average blood volume for males and females?
Males: 5-6L
Females: 4-5L
The difference is due to body size.
What two portions is whole blood composed of, and what are their percentages?
55% blood plasma, a liquid extracellular matrix that contains dissolved substances.
45% formed elements, which are cells and cell fragments.
- More than 99% of the formed elements are RBCs.
- The remaining 1% consists of WBCs and platelets.
What is hematocrit?
The percentage of RBCs within total blood volume.
It is expressed as a percentage.
Males: 42%-52%.
Females: 37%-47%.
What is the Buffy Coat?
It is made up of WBCs and platelets (the <1% of total blood volume).
It is a very thin layer that lies between packed RBCs and blood plasma in centrifuged blood.
What is blood plasma composed of?
91.5% water, 7% proteins, 1.5% solutes.
Proteins in the blood are synthesized by the liver.
The most plentiful plasma proteins are albumins, which account for 54% of all plasma proteins.
What are RBCs composed of?
RBCs (aka erythrocytes) contain hemoglobin, which is an O2 carrying protein.
Hgb is a pigment that makes blood red.
It also transports 23% of the CO2 in blood.
A healthy adult male has 5.4 million RBC/uL of blood, and a female has 4.8 million.
RBCs only live for 120 days.
How are WBCs different compared to RBCs, and what do they do?
WBCs (leukocytes) have a nuclei and a full complement of other organelles. They do not have Hgb.
The average content is 5,000-10,000/uL and are classified as either granular or agranular, depending on whether they contain cytoplasmic granules.
They live for a few hours to a few days.
They combat pathogens and other foreign substances in the body.
What are the granular and agranular WBCs?
Granular:
- Neutrophils
- Eosinophils
- Basophils
Agranular:
- Lymphocytes
- Monocytes
Neutrophils
50-70% of all WBCs - they are the most abundant.
They destroy bacteria with lysozyme, defensins, and strong oxidants.
Eosinophils
1-5% of WBCs.
They suppress the effects of histamine in allergic reactions and can destroy parasitic worms.
Basophils
0-1% of WBCs.
They release heparin, histamine and serotonin which intensifies inflammatory response in allergic reactions.
Lymphocytes
T cells, B cells and Natural Killer Cells, constitutes 20-40% of WBCs.
They mediate immune response, including antigen antibody reaction.
- B cells transform into plasma cells that secrete antibodies.
- T cells attack viruses, cancer cells and transplanted tissue cells.
- NKC attack a wide variety of microbes and some tumor cells.
Monocytes
1-6% of WBCs.
They are phagocytic and will transform into a fixed histiocyte or a wandering macrophage.
How many platelets per uL are in blood, what do they do, and how long do they live?
150K-400K/uL
They form a platelet plug during hemostasis, release chemicals for vascular spasm and blood clotting.
They live for 5-9 days.
What is the primary site of hemopoiesis?
Red bone marrow
What cells have the capacity to develop into different cell types?
Pluripotent Stem Cells.
They will differentiate into either Myeloid or Lymphoid cells.
What cells can myeloid cells differentiate into?
Red cells Platelets Eosinophils Mast cells Basophils Neutrophils Monocytes
They mature in red bone marrow.
What cells can lymphoid cells differentiate into?
T cells, B cells, NKCs. They mature in the lymphatic tissues.
What do you call immature neutrophils?
Bands.
> 10% is considered abnormal and may be due to a left shift. This is because the body has been fighting an infection so long that the bone marrow cannot keep up and starts to send out immature neutrophils to fight infection.
A left shift is a poor prognosis.
What is the most immature myeloid cell?
Blast cells. These are associated with myeloid disorders like cancer.
Hemostasis
A sequence of responses that stops bleeding when blood vessels are injured.
What are the three mechanisms that can reduce blood loss from blood vessels?
Vascular spasm
Platelet plug formation
Blood clotting
Vascular spasm
Smooth muscle contracting in response to damage to a blood vessel.
It reduces blood loss for several minutes to several hours while other hemostatic mechanisms begin to work.
Platelet Plug Formation
Platelets change drastically and quickly when they come into contact with damaged blood vessels. They come together to form a plug that helps fill the gap in the injured vessel wall.
Lots of stickiness is involved here.
