Chapter 11.1: Circulatory system

lymphatic system

- RETURN FLUIDS THAT ESCAPED FROM BLOOD VESSELS - contain one way valve - propelled by contraction of smooth muscle as well as skeletal muscle - Produces B and T cells

what are the components of blood?

- plasma - buffy coat - red blood cells (erythrocytes) - white blood cells (leukocytes like granulocytes/Agranulocytes) - platelets (thrombocytes)

In what form is CO2 most predominantly transported in the blood? A. Bicarbonate anion B. Carbonic acid C. Carboxyhemoglobin D. Dissolved CO2 gas

A. Bicarbonate anion. CO2 is able to dissolve in the blood. Once solvated, carbonic anhydrase (an enzyme of red blood cells) takes the dissolved CO2 and converts it to carbonic acid, H2CO3, which quickly dissociates into H+ (proton) and HCO3- (bicarbonate). The bicarbonate buffer system is the main extracellular buffer system of the human body and maintains blood pH levels.

A blood bank accidentally mislabels all of the blood sent to a hospital. Individuals of which blood type would be UNAFFECTED no matter which type of blood they are given?

AB+ Individuals with the blood type AB+ are universal recipients and would be unaffected no matter which type of blood they are given. Individuals with type AB are universal recipients because they have no antibodies to A or B antigens or the Rh antigen in their blood.

blood pressure is high or low in arteries and veins?

Blood pressure is highest in the arteries. It is the lowest in the veins.

Which of the following is true of platelets? A. Contain multiple nuclei B. Cell fragments of old red blood cells C. Megakaryocytes are the precursors to platelets D. Activated platelets release fibrin

C. Megakaryocytes are the precursors to platelets Megakaryocytes are large bone marrow cells that are the precursors to platelets. Fragments of the megakaryocyte break off to form platelets. Platelets are heavily involved in the clotting cascade.

All of the following are components of blood EXCEPT for one. Which is the EXCEPTION? A. Plasma B. Leukocytes C. Thrombocytes D. Erythrocytes E. Adipocytes

E. Adipocytes Adipocytes are a type of cell that stores lipids. They are predominantly found in adipose (fat) tissue and do not flow freely in the blood.

A virus was placed in culture with isolated cells. The virus was observed to replicate in all of the following cells EXCEPT one. Which one is the EXCEPTION? A. Enterocytes B. Leukocytes C. Myocytes D. Gametocytes E. Erythrocytes

Erythrocytes Viruses require a host with replication machinery to reproduce as they lack their own. Erythrocytes or red blood cells are disc-shaped structures that lack a nucleus and many organelles including ribosomes, as shown in the image below. This maximizes their volume available to hold hemoglobin. Since the erythrocyte lacks a nucleus and ribosomes, viral genetic material cannot be replicated in the host nor can viral protein products be produced.

is adipocyte a component of blood?

NO, adipocytes are a type of cell that stores lipids and found in fat tissue.

is podocyte a component of blood?

NO, podocytes are cells in the Bowman's capsule in the kidneys that wrap around the capillaries of the glomerulus.

In which part of the circulatory system would you find the most oxygenated blood?

Pulmonary veins

Rh

Rh, also known as Rhesus Factor, is an antigen that is found on the surface of red blood cells, similar to the A and B antigens. It is a dominant autosomal trait, and its presence is denoted by a positive (+) or Rh+ blood type whereas the lack of this Rh factor is denoted by a negative (-) or Rh- blood type.

The heart rate is directly initiated by the

SA node the site on the heart that has the greatest automaticity. This means that it is always the first place that the heartbeat starts (initiates heartbeat), and is therefore why we refer to it as the 'pacemaker' of the heart.

Atrioventricular node

The AV node is located on the bottom point of the right atrium. The role of AV node is to add a delay to the contraction between the atria and ventricles. This is important because if the atria and ventricles contract at the exact same time, the blood will not flow properly.

blood types? what are the two most important?

a classification of blood, based on the presence and absence of antibodies on the surface of red blood cells. The two most important blood group systems are ABO and Rh. They determine everyone's blood type (A, B, AB and O, with +, − or null denoting Rh status).

Erythroblastosis fatalis is a hemolysis disease of a newborn that can be fatal to the embryo. Which of the following conditions could possibly cause this hemolysis disease?

answer: Rh-negative blood from the mother interacts with Rh-positive blood from the baby Erythroblastosis fetalis is a condition where the immune system of a pregnant mother attacks the red blood cells (erythrocytes) of her fetus and destroys them (hemolysis). This occurs when the blood type of the mother is incompatible with that of the fetus. There are two possible incompatibilities: Rh incompatibility and ABO incompatibility. Out of these two, Rh incompatibility is the most common inducer of erythroblastosis fetalis. Being an antigen, Rh factor can induce an immune response in individuals that have a (-) blood type. Therefore, when an Rh- mother is pregnant with an Rh+ baby, the baby's Rh antigen will be perceived as foreign substance by the mother's immune system, which will start producing antibodies to target and destroy the baby's red blood cells.

Purkinje fibers

branch across the ventricles of the heart. They help to ensure that the right and left ventricles contract in a coordinated fashion.

Blood can be best described as what type of tissue?

connective tissue

arteries

contain smooth muscles that can contract or relax, changing their diameter in response to hormones. Their main role is to carry and distribute oxygenated blood to the tissues of the body

A decreased concentration of blood plasma proteins would result in: A. Greater lymph volume B. Blood volume increase C. Decreased hydrostatic pressure D. Greater oncotic pressure E. More white blood cells

greater lymph volume When blood reaches the capillary beds, it is the hydrostatic pressure in the vessels that pushes out some of the plasma into the interstitial space (the space between cells). However, some of this fluid returns to circulation due to oncotic pressure, also known as colloid osmotic pressure. This balance of filtration due to hydrostatic pressure and reabsorption due to oncotic pressure is illustrated below.

ABO blood group

involves two antigens and two antibodies found in human blood. The two antigens are antigen A and antigen B. The two antibodies are antibody A and antibody B. The antigens are present on the surface of the red blood cells and the antibodies are present in the serum. All human beings can be classified into 4 groups, those with antigen A (group A), those with antigen B (group B), those with both antigen A and B (group AB) and those with neither antigen (group O)

left atrium and left ventricle

left atrium: accepts oxygen-rich blood returning from the lungs via the pulmonary veins. It pumps blood through the bicuspid valve and into the left ventricle. left ventricle: pumps oxygenated blood through the aortic semilunar valve into the aorta for systematic circulation

Which chamber of the heart directly pumps the highest concentration of oxygenated blood for distribution to the rest of the body?

left ventricle

In the fetal circulatory system, the ductus venosus allows blood to bypass which of the following?

liver As oxygenated and nutrient-rich blood returns to the fetus from the placenta via the umbilical vein, half enters the ductus venosus. This bypasses the liver as blood returns to the heart. The liver in adults acts to filter and detoxify the blood but is not fully functional during early development.

Pulmonary circulation

moves oxygen-poor (deoxygenated) blood to the lungs in order for it to become oxygen-rich (oxygenated) Deoxygenated blood enters the vena cava → right atrium → tricuspid valve → right ventricle → pulmonary semilunar valve → pulmonary arteries → lungs (blood becomes oxygenated) → pulmonary veins → left atrium

Systematic circulation

moves oxygen-rich (oxygenated) blood to the body tissues in order for these tissues to use the oxygen and nutrients contained in the blood. Left atrium → bicuspid/mitral valve → left ventricle → aortic semilunar valve → aorta → body tissues

Bundle of His

receives the electrical signal from the AV node and carries the signal to the base of the heart through the right and left bundle branches. It is located in the interventricular septum between the ventricles. The bundle of His carries the signal to the Purkinje fibers, which contracts the ventricles

right atrium and right ventricle

right atrium: accepts oxygen-poor blood returning from the body via the superior and inferior vena cava. It pumps blood through the tricuspid valve and into the right ventricle. right ventricle: pumps oxygen-poor blood through the pulmonary semilunar valve and into the pulmonary arteries.

Blood is PUMPED into the pulmonary circuit of the circulatory system by which chamber of the heart?

right ventricle the pulmonary circuit pumps deoxygenated blood through the pulmonary arteries to capillaries in the lungs to facilitate gas exchange. The pulmonary arteries leave from the right ventricle. The capillaries are in close contact with lung alveoli, where the blood becomes reoxygenated. The pulmonary veins then return the oxygenated blood to the heart so that it can be pumped through the systemic circuit.

intercalated discs

serve as contact points between adjacent cardiomyocytes that connect heart cells. They allow the cardiac muscle cells to have automaticity.

All of the following are true of the lymphatic system EXCEPT one. Which is the EXCEPTION? A. Contain one way valves B. Drains into the digestive system C. Propelled by contraction of smooth muscle as well as skeletal muscle D. Produces B and T cells E. Returns fluids that escaped from blood vessels

B. Drains into the digestive system Certain lymphatic capillaries (lacteals) absorb dietary fats in the villi of the small intestine. These lacteals transport fat FROM the digestive system to rest of the body, not towards the digestive system.

In which part of the circulatory system would you find the most deoxygenated blood? A. Aorta B. Pulmonary artery C. Pulmonary vein D. Superior vena cava E. Arteriole

B. Pulmonary artery The pulmonary arteries are the final vessel before blood reaches the lungs and is reoxygenated. Therefore, the most deoxygenated blood would be expected to be seen here. Alternatively, the pulmonary veins would contain the most oxygenated blood.

If a woman has circulating anti-A, anti-B, and anti-Rh antibodies, what is her blood type? A. Type AB- B. Type AB+ C. Type O- D. Type O+

C. Type O- A person will produce antibodies to non-self antigens. If a person has circulating anti-A, anti-B, and anti-Rh antibodies, she cannot have these blood cell surface antigens - otherwise she'd mount an immune response to her own blood. Therefore, she cannot have either A or B, or Rh blood cell surface antigens. If she does not have A or B blood cell surface antigens, she has type O blood. In addition to the A and B blood cell surface antigens, another blood cell surface protein is the Rhesus factor (Rh). You either have the Rh or do not have the Rh. So you are either Rh positive (+) or Rh negative (-). This is where (+) and (-) designations in blood typing come from. Because she produce antibodies to Rh, she cannot have Rh antigens. Therefore, she must be O-.

A patient with colon cancer undergoes a surgical procedure to have a lymph node examined. The purpose of this examination is to: A. Check the immune response B. Test for lymphomas C. Directly sample interstitial fluid D. Check where cancer cells have travelled E. Sample cancerous DNA

Check where cancer cells have travelled A biopsy is the removal of a sample of tissues for diagnostic purposes. In removing a tumor, it is also common to biopsy a lymph node to test for metastasis, the spread of cancerous tissue from one area to another. To get a better understanding of this, the image below illustrates how cancer cells can originate from a tumor but can colonize and spread to other areas.

Which part of the heart pumps oxygenated blood into the systemic circulation? A. Right atrium B. Right ventricle C. Left atrium D. Left ventricle

D. Left ventricle The left ventricle is the most muscular chamber of the heart. It forcefully ejects oxygenated blood through the aortic semilunar valve into the aorta for circulation to the rest of the body, i.e. systemic circulation. Pulmonary circulation moves oxygen-poor blood to the lungs in order for it to become oxygen-rich, whereas systemic circulation moves oxygen-rich blood to the body tissues in order for these tissues to use the oxygen and nutrients contained in the blood.

All of the following contribute to the circulation of lymph throughout the body EXCEPT one. Which one is the EXCEPTION? A. Location of re-entry B. Smooth muscle contractions C. Skeletal muscle contractions D. Lymph node contractions E. Lymphatic valves

Lymph node contractions the heart pumps blood throughout the body, and it pumps so powerfully that it actually squeezes some lymph out of the capillaries. The lymphatic system collects excess fluid in the interstitial space and returns this to the circulatory system.The lymphatic system is able to pump this lymphatic fluid in one direction due to the following reasons: 1. Point of re-entry - Lymph is intelligent about where it reenters the high-pressure system. It particularly reenters at the very end of the venous circulation system as the pressure there is much lower than the pressure in the arteries or capillaries. 2. Lymphatic valves - There are structures within the lymph vessels that prevent fluid from going back. 3. Smooth and Skeletal muscle contractions - These initiate motion and drive the fluid in one direction.

does the left ventricle receive blood through the tricuspid calve?

NO, the right ventricle does Blood returning from the body enters the heart into the right atrium via the superior and inferior vena cava. It then flows into the right ventricle through the tricuspid valve, and then through the pulmonary valve and pulmonary arteries to receive oxygen from the pulmonary circulation. This blood returns to the heart through the pulmonary veins, into the left atrium, and then through the mitral (aka bicuspid) valve into the left ventricle. Blood from here is pumped to the systemic circulation through the aortic valve and out the aorta. Since the left ventricle must create enough force for blood to be pushed out to the entire body, it has a thick muscular wall.

A man with type A+ blood had children with a woman with type AB- blood. All of the following are possible blood types they could have EXCEPT one. Which one is the EXCEPTION? A. A- B. B+ C. AB- D. B- E. O+

O+

signal pattern

SA node -> AV node -> bundle of His -> Purkinje fibers

In which part of the circulatory system would you find the most deoxygenated blood?

The pulmonary arteries are the final vessel before blood reaches the lungs and is reoxygenated. Therefore, the most deoxygenated blood would be expected to be seen here.

A mother has blood type B and the father has a blood type of AB. All of the following can be a possible blood type of their child EXCEPT one. Which one is the EXCEPTION?

Type O The blood types result from the antigens expressed on red blood cells' plasma membranes. People with type A blood express the A antigen, type B express the B antigen, type AB express both A and B antigens, and type O do not express A or B antigens. As most evident by type AB blood expressing both A and B antigens, the IA and IB alleles are codominant in that they can be expressed together. However, both IA and IB alleles are dominant to the recessive i allele which does not produce antigens. we can see that the offspring cannot possibly have type O blood. Therefore, Type O, is the correct answer.

Sinoatrial node

the SA node is the site on the heart that has the greatest automaticity. This means that it is always the first place that the heartbeat starts (initiates heartbeat), and is therefore why we refer to it as the 'pacemaker' of the heart. It sends a signal to contract both atria to send blood to the ventricles. It also sends a signal to the AV node to initiate contraction.

The blood type that has the lowest chance of causing a transfusion reaction when donated is...

type O Universal donors are individuals who have no surface antigens present on their red blood cells and have Type O blood type. Such blood types can be administered to everyone due to the fact that there are no surface antigens that can be detected and identified as foreign by the blood acceptor's immune system. Therefore, these individuals are unable to cause transfusion reactions when they donate their blood to a donor.