lecture 5 - blood

Question 1

• Describe the major functions of each component of the cardiovascular system - blood

Answer 1

o Blood -> Helps regulate body temperature.
Maintains body pH.
Regulates fluid volume – is a fluid reserve. Prevents infection – works as part of the immune system to fight against things that should not be there.
Prevents loss of blood via clotting – uses clotting to help prevent the loss of blood. Transportation – transports nutrients, waste products (Carbon dioxide), hormones, and oxygen

Question 2

• Describe the major functions of each component of the cardiovascular system - heart

Answer 2

• pumping blood, circulating oxygenated blood to the body, returning deoxygenated blood to the heart, regulating blood pressure, maintaining blood flow directions

Question 3

• Describe the major functions of each component of the cardiovascular system - blood vessels

Answer 3

• transporting blood, oxygen and nutrient delivery, waste removal, maintaining blood pressure and flow, exchange of gases and nutrients, temperature regulation, supporting the immune system

Question 4

Describe the general composition of blood (e.g., plasma, formed elements).

Answer 4

Is a connective tissue that developed form mesenchyme and has three components
 Plasma (albumin, fibrinogen, hormones, electrolytes, nutrients, wastes)
 Serum = plasma – clotting factors
 Cells – called the formed elements of blood
 Erythrocytes (white blood cells), leukocytes (red blood cells), platelet (thrombocyte)
 Fibers (fibrin, which is usually dissolved in the blood) -> typically in an off state while in the blood so that the blood can flow. It is present as pieces of the fiber so that it can assemble into the fiber when needed (clotting)

Question 5

the general composition of formed elements

Answer 5

red blood cells (transport of oxygen and carbon dioxide)
white blood cells (immune system)
platelets (blood clotting)

Question 6

define hematocrit and identify the components in the layers

Answer 6

Hematocrit – the % of red blood cells in the total blood
 The deepest layer has erythrocytes because they will sink and accumulate. The next layer on top of the bottom one is the WBCs and platelets which could be compared to oil separating from liquid and sitting on top. ON top of that you have all the rest of the fluid (plasma)

Question 7

Describe the composition of blood plasma.

Answer 7

Blood plasma is pale yellow and is what remains in the body after the red blood cells are removed. (55% of total blood volume). Water makes up 90% of it and acts as a solvent. Proteins make up 7% of plasma. Electrolytes make up about 1% of the volume

Question 8

list the major types of plasma proteins, their functions, and sites of production

Answer 8

Albumin – one of the proteins which maintains osmotic pressure, and helps keep fluid within the bloodstream
Globulins – are involved in the immune functions (antibodies) and transporting substances like lipids and metals. Is a protein
Fibrinogen – another protein, is essential for blood clotting. Is usually dissolved in pieces and can become strands to clot.
- Several other proteins that are either enzymes, regulatory proteins.

Question 9

Compare and contrast the morphological features and general functions of the formed elements (i.e., erythrocytes, leukocytes, platelets).

Answer 9

Erythrocytes – are biconcave disc shaped which helps increase surface area for gas exchange and allows for flexibility. Are relatively small, lack a nucleus, and their cytoplasm is filled with hemoglobin. The general functions are oxygen transport and carbon dioxide transport
Leukocytes – all have a nucleus, but their shape can range from spherical to lobed or irregular. Larger than erythrocytes and oversee playing a key role in the immune systems job in defending the body against infection and foreign invaders.
Platelets – thrombocyte – are small, smallest ones, and have no nucleus. There main functions are blood clotting and platelet plug formation (release of chemicals to trigger a clotting cascade to form a fibrin clot.

Question 10

Describe the structure and function of hemoglobin

Answer 10

o Hemoglobin is made up of four subunits, two of which are alpha globin and the other two being beta globin. All four subunits contain iron at the core which can bind to oxygen. Each subunit also contains a heme pigment.
o Functions of hemoglobin: oxygen transport, carbon dioxide transport. The structure allows for gas exchange and transport, which also ensures that things like iron are recycled and utilized in the body effectively.

Question 11

Describe the locations of hematopoiesis (hemopoiesis) and the significance of the hematopoietic stem cell (HSC).

Answer 11

• the process of which blood cells are formed in the bone marrow
  Primarily occurs in the hematopoietic tissues, and changes throughout development. In prenatal development will be in the yolk sac then the liver then the spleen and lymph nodes. In early development post-natal it goes to the bone marrow.
• The hematopoietic stem cell is critical for hematopoiesis to fully work. One HSC has the ability to divide and produce more cells which allows it to ensure that there is an eternal production of new ones so that there can be RBC production forever.

Question 12

Explain the basic process of erythropoiesis and regulation through erythropoietin (EPO).

Answer 12

The process by which red blood cells are produced in the bone marrow
Erythropoiesis is promoted by erythropoietin (EPO), and primarily occurs in the bone marrow. This process ensures that there is an adequate supply of health red blood cells that facilitate transport of red blood cells throughout the body
 The steps: the process begins in the hematopoietic stem cells which are in the bone marrow, and then there is the development of the proerythroblasts (the large nucleated cells that eventually become mature red blood cells). Then erythroblasts are formed, which take several forms until it moves on to the reticulocyte. Once the reticulocyte becomes fully functioning it becomes a mature erythrocyte and become the anucleate biconcave cell that is optimized for gas transport.

Question 13

Explain the role of surface antigens on erythrocytes in determining blood groups

Answer 13

The blood groups system is based on the presence of absence of the surface antigens and are responsible for if the immune system sees it as “self” or “non self”

Question 14

List the type of antigen and the type of antibodies present in each ABO blood type.

Answer 14

ABO = A, B, AB, O
A – the RBCs have A antigens on their surface and the persons immune system will produce antibodies against B antigens.
- A+ can receive A+, A-, O+, O- and can give to A+ and AB+
- A- can receive A-, O- and can give to both As and Abs
B – have B antigens on their surface and produce antibodies against A antigens.
- B+ can receive both Bs and Os and can give to B+ and AB+
- B- can receive B- and O- and can donate to both Bs and Abs
- AB – has both A and B antigens but does not produce any antibodies. This means that AB can receive blood from everyone and can give to AB+
- AB- can give to both ABs and receive from all -s
O- have not antigens and have both antibodies which makes O- the universal donor. Can only receive blood from O-
- O+ can receive from all Os and give to all positives

Question 15

Describe how the presence or absence of Rh antigen results in blood being classified as positive or negative.

Answer 15

o If an individual has the Rh antigen on their RBs they are considered Rh-positive. This means they do not produce antibodies against the Rh factor, but their blood still contains the Rh protein.
o However, if individuals do not have the Rh antigen, then they are considered Rh negative. This means that if they are exposed to Rh+ blood then their immune system may produce antibodies against the antigen which will cause issues further down the road in further exposures.
o The Rh antigen is inherited from both parents, if at least one passes on the positive the child will be positive, if both pass on negative the child will be negative. However, if a mom is Rh negative but baby is Rh positive the body may recognize it and try to produce antibodies against the baby which can harm the baby.

Question 16

Describe the development and clinical significance of anti-Rh antibodies.

Question 17

Predict which blood types are compatible and what happens when the incorrect ABO or Rh blood type is transfused.

Answer 17

o When the incorrect blood type is transfused often the body will reject the transfused blood cells which will lead to the destruction of the blood cells. This can lead to a transfusion reaction which can in very severe cases lead to death.
o When it comes to Rh blood, a Rh negative person should only receive Rh negative blood because if they have a positive one then their body will start to produce anti-Rh antibodies and can cause bad reactions. Rh positive individuals can receive Rh positive or negative blood.

Question 18

Explain the basic process of leukopoiesis.

Answer 18

The production of white blood cells, which occurs in the bone marrow and includes many kinds of white blood cells. The process is largely regulated by cytokines and growth factors
- The steps: Hematopoietic stem cell begins in the bone marrow and differentiates with the colony stimulating factors, and interleukins, which then give rise to the lineage of leukopoiesis until they differentiate, mature, and are released into the bloodstream.

Question 19

List the five types of leukocytes in order of their relative prevalence in normal blood and describe their major functions.

Answer 19

Neutrophil
Lymphocyte
Monocyte
Eosinophil
Basophil

Question 20

the breakdown products of hemoglobin

Answer 20

bilirubin - is a pigment that is yellow and should be removed by the liver, if there is too much of it, it causes jaundice
urobilin - yellow, in our urine
stercobilin - brown, in our feces

Question 21

the significance of a reticulocyte

Answer 21

Reticulocyte – an immature red blood cell that is released from the bone marrow and out into the bloodstream. It does not have a nucleus and over a period of 1-2 days will eventually become fully functioning erythrocytes.

Question 22

AB+

Answer 22

has the A and B antigen as well as the Rh antigen

Question 23

AB-

Answer 23

has the A and B antigen but no Rh antigen

Question 24

Rh inheritance and pregnancy

Answer 24

The Rh antigen is inherited from both parents, if at least one passes on the positive the child will be positive, if both pass on negative the child will be negative. However, if a mom is Rh negative but baby is Rh positive the body may recognize it and try to produce antibodies against the baby which can harm the baby.

Question 25

neutrophil

Answer 25

The most abundant type of leukocyte. Is granulated with a multi lobed nucleus that looks like many circular pieces connected by a line. Is the 1st defender for our immune system that is especially working against bacterial infections.

Question 26

lymphocyte

Answer 26

Is a WBC which has a very large nucleus that takes up almost all of the cells. This cell makes antibodies and is direct cell mediated to kill virus infected cells and tumor cells.

Question 27

monocyte

Answer 27

Are very large and have a bean or kidney shaped nucleus. Are WBCs that go into the body and become macrophages to fight infection. Can also regulate inflammation, heal wounds, maintain homeostasis and the immune response, and disorders although not as important

Question 28

eosinophil

Answer 28

Has a nucleus that is shaped like an earmuff, and its main function if to fight against parasitic worms. (shellfish poison as well) Essentially helps with the immune response against parasites and regulating allergic responses. Can also help with inflammation and damage to the body.

Question 29

basophil

Answer 29

The least abundant WBC, there is a nucleus, but you cannot see it. Basophils in the body mainly help with inflammation, allergic reactions through releasing histamine, and preventing blood clots.

Question 30

Describe the vascular phase of hemostasis, including the role of endothelial cells.

Answer 30

o Vascular spasm – when the injury causes the vessels to twitch or constrict o Platelet plug – when the platelets stick to the collagen fibers that are exposed under the epithelium o Coagulation – where thrombin activates fibrinogen to turn on and turn into fibrin to reinforce the clot

Question 31

Describe the role of platelets in hemostasis and the steps involved in the formation of the platelet plug.

Answer 31

o Platelets work by forming a platelet plug at the site of the injury to then help reduce blood loss by creating a temporary covering before a more permanent one is formed o The platelets first stick to the exposed collagen, then change shape and activate other platelets. This leads to the platelets binding to each other through the fibrinogen bridges to stabilize and form a plug. This creates a temporary but effective seal.

Question 32

Describe the basic steps of coagulation resulting in the formation of the insoluble fibrin clot.

Answer 32

o Coagulation is when blood changes form a liquid to a gel to form a clot to seal a wound and prevent further blood loss. o First the vasoconstriction stage occurs which activates the damaged vessels to interact to constrict. Next coagulation is triggered through the extrinsic (outer) pathway then goes to the intrinsic pathway. This all leads to the activation of thrombin which in turn activates fibrinogen to help form the mech fibrin to clot and restabilize the body.

Question 33

Explain how the positive feedback loops in the platelet and coagulation phases promote hemostasis.

Answer 33

o First the platelets are activated and recruited to come to the exposed collagen on the injury site and become activates to recruit additional platelets to the injury site for repairing. Next the amount of platelets is intensified and used to increase the amount of platelets coming to the site (aggregation) to then form the temporary plug. o In the coagulation phase thrombin will intensify the reaction by activating the coagulation or clotting factors to enhance further production which creates a cascade which drives the levels to increase and get worse before eventually the fibrin will stabilize the clot.

Question 34

Explain the importance of vitamin K in blood clotting.

Answer 34

Vitamin K is important for blood clotting because it helps the liver to produce the proteins the body needs and uses for blood to clot. Deficiency could lead to bleeding issues. Without vitamin K the body would not be able to make some of the necessary clotting factors that the blood needs to be able to actually clot int eh body.

Question 35

Describe the process of fibrinolysis

Answer 35

Fibrinolysis is the natural process of the breakdown of blood clots that is done to prevent them from growing and blocking blood vessels. - First the system is activated, next it is started through plasmin digesting the clots and fibrinogen. Then lysis causes the network to be degraded and the components are released into the blood system broken down smaller.