The Cardio System 5 Flashcards
Blood
Is the only liquid connective tissue in the human body
- 5 times more viscous than water
Blood composition
Formed elements:
- erythrocytes(red blood cells), leukocytes(white blood cells) and platelets
Plasma:
- Blood plasma contains dissolved substances in water
- Sernum: the liquid that remains after the blood has clotted
What is the most abundant solute in our bodies?
Plasma proteins, most of which are produced by the liver
Functions of the body
Transportation
Regulation
Protection
What substances are transported in the blood?
Oxygen, CO2, hormones, nutrients like glucose, electrolytes, proteins and nitrogenous waste
Regulation
In a normal body:
- ph: 7.35-7.45(slightly alkaline)
- volume-5-6L in males, 4-5 L in females
- temp: 37.4 degrees C
Protection
Blood components form clots that protect against excessive blood loss.
• hemostasis (‘haima’:blood; ‘stasis’: halt) is the body response to stop blood loss from damaged blood vessel walls.
Blood components protect against infection.
• white blood cells, complement proteins, and antibodies protect against both viral and bacterial invaders.
Hematopoiesis
Is the formation of blood cells
- after birth and throughout life, this occurs in red bone marrow
- blood cells come form hematopoietic stem cells(HSCs)
Which body activity would get the most affected if a patient lacked an adequate number of erythrocytes(anemia)?
Oxygen transport
Red blood cells(also called erythrocytes)
Are the most abundant formed element:
Males:4.5-6.3 million RBCs/1uL of whole blood
Females: 4.2-5.5 million RBCs/1uL of whole blood
RBCs structure optimizes its function
- flexible: allows movement through capillaries
- does not have a nucleus(anucleate): maximizes space for gas transport
- biconcave shape: increases surface area for O2, CO2 diffusion
Without any organelles, how does ATP production occur in erythrocytes?
glycolysis in the cytoplasm (no need for organelles)
The cytoplasm of Red blood cells contains the protein hemoglobin
Around 250 million per cell
Each hemoglobin contains 4 iron(Fe2+) containing heme groups, each of which binds one oxygen
- O2 loading in true lungs produces oxyhemoglobin
- O2 unloading in tissues produces deoxyhemogloblin or reduced hemoglobin
Cooperative oxygen binding by hemoglobin
As more O2 binds to hemoglobin, its affinity for it also increases
RBC life cycle
Can live up to 120 days
Damaged and old RBCs are removed by macrophages in the spleen, liver and bone marrow
- during this process, hemoglobin will be recycled
True or False
The colour change of skin bruises(from red, purple, brown to yellow) is due to the breakdown of hemoglobin at the injured site
True
Erythropoietin’s
Is the formation of RBCs in bone marrow
Takes about 15 days
Erythropoietin(EPO)
Is a hormone produced by the kidney( and liver to a lesser extent) when they detect oxygen deficiency
Why might synthetic EPO be danergous?
EPO increases the production of RBCs, which will increase the thickness of blood.
• dehydrated athletes will increase even more
Thick blood can increase the risk of clotting, stroke, or even heart failure
Blood typing
An individual’s blood type is determined by the presence or absence of cell surface markers, known as antigens, on red blood cells (RBCs).
There are three important antigens: A, B, and Rh (or D).
• genetically determined → we inherit from our parents
• identify blood cells as “self” (has antigens) or “foreign” (no antigens) to the immune system
• As a result, the immune system develops antibodies against the missing antigen(s)
Affliction
When 1 blood cell type encounters the corresponding antibodies from another blood donor
- can block small blood vessels
- are broken down(hemolysis) by the body
Aggulatuon is used in blood testing
1) slides with anti-A, anti-B, or anti-D antibodies are mixed with a ? blood sample
2) agglutination = presence of antigen
Platelets
Are cell fragments form megakaaryocytes in the bone marrow
- each megakarocyte produces 2000-3000 platelets
- normal range: 150,000 to 400,000 platelets
Platelets play a major role in hemostasisand starts the clotting pathway
they become activated, adhere to the injured vessel wall, and
aggregate to form a platelet plug
• other clotting factors in the plasma work together to reinforce the platelet plug into a stronger fibrin plug
