BN Ch.23 The Hematologic and Lymphatic Systems

Question 1

Describe the principal functions of blood and its homeostatic mechanisms.

Answer 1

Transportation, Regulation, and Protections.

Question 2

Identify the plasma proteins and their functions. ( 4 groups of plasma proteins)

Answer 2

• Albumin:
  
  • Largest group accounts for 50-60% of plasma proteins.
  • Maintains
    
    • osmotic pressure,
    • blood pressure, and
    • circulating fluid volume.
• Fibrinogen:
  
  • Essential for blood clotting.
• Prothrombin
  
  • Essential for blood clotting.
• Globulin (alpha & beta):
  
  • Formulated in the liver and act as carriers for molecules, such as fats.
  • Gamma globulins are antibodies.

Question 3

Describe the structure and function of red blood cells, white blood cells, and platelets.

Answer 3

• Red blood cells: (erythro=red, cyte=cell)
  
  • Most numerous in body, made in bone marrow, very fragile, last about 120 days
  • Erythropoiesis begins in kidney cells with secretion of erythropoietin which stimulates bone marrow to produce RBCs, about 120 to 180 million RBCs produced every minute.
  • Macrophages in the liver and spleen ingest old, used RBCs and salvage iron, which is transported to bone marrow to make new RBCs.
  • Each BC contains more than 250 million molecules of the compound hemoglobin. (Hgb or Hb)
  • As RBCs move through capillaries, oxygen transfer occurs.
  • Pulse oximetry indirectly measures arterial oxygen content.
  • Specific blood tests: RBC count, hematocrit, hemoglobin, glycosylated Hgb (HA1C, A1C)
    
    • Functions:
      
      • Transports oxygen.
      • Produces and releases ATP.
      • Releases substances which assist in dilation of blood vessels.
      • Stores iron in the body.
      • Participates in the immune response and acid-base balance.
      • Influences specific gravity of blood.
• White blood cells: (leuko=white, cyte=cell)
  
  • Constitute about 1% of blood volume in healthy adult.
  • Formed in bone marrow: hematopoietic stem cell.
  • Defends the body against disease organisms, toxins, irritants, and other foreign materials.
  • Abnormal number or character of leukocytes often indicates disease.
  • A reduced number of leukocytes is called leukopenia, may be caused by disease or certain medications.
  • Pus which forms in wounds contains abnormally large number of leukocytes.
  • Fixed leukocytes: Kupffer cells, histiocytes, mast cells, microglia
• Platelets/ thrombocytes: (thromobo= clot, cyte=cell)
  
  • Smallest of the elements formed by the blood
  • Formed in red bone marrow by megakaryocytes
  • Essential in blood clotting
  • Stimulate contraction of blood vessels, from hemostatic plug, clump together, combine with plasma to speed blood coagulation.
  • Are fragments of larger cells
  • Lack nuclei
  • Capable of ameboid movement

Question 4

Discuss the importance of chemotaxis and phagocytosis in fighting invading organisms and other foreign materials.

Answer 4

• Chemotaxis: Neutrophils can move away from blood vessels and travel directly to sites of infections or damaged tissues because of their attraction to specific chemicals.
• Phagocytosis: Engulfing and devouring invaders.

Question 5

Briefly describe the mechanism of blood clotting.

Answer 5

• Hemostasis:
  
  • Cessation of bleeding
• Hemostatic initial response:
  
  • Vascular spasm (vasoconstriction), platelet plug formation, and blood clotting
• Clotting:
  
  • Protects the body from losing vital plasma fluid and blood cells by sealing off broken blood vessels.
    **Cascade of events leads to clotting
• Vitamin K:
  
  • Necessary for formation of prothrombin and other clotting factors.
  • Thrombus: stationary clot.
  • Embolus: cloth that circulates.

Question 6

Identify the four blood groups and define the term Rh factor. Explain the concept of universal donor and universal recipient.

Answer 6

• Human blood falls into one of four inherited (genetic) groups (blood types):
  
  • A, B, AB, and O
• Rh factors are inherited antigens.
• The Rh system is named after the rhesus monkey used in early experiments.
  
  • The most commonly found Rh factor and the one most likely to cause a transfusion reaction is abbreviated D (Duffy).
  • Blood is tested for the presence of D antigen.
  • If the blood contains D factor, the person is said to be Rh-positive ( Rh or D ); if this factor is absent, the person is Rh-negative ( Rh− ).
• Blood group AB is known as the universal recipient because people of this group may receive red blood cells from donors of any ABO group in an extreme emergency.
• Blood group O is known as the universal donor because these red blood cells may be given to people of any ABO group in an extreme emergency.

Question 7

Describe lymphatic circulation and the filtration role of lymph nodes.

Answer 7

• Lymphatic circulation:
  
  • Lymph only carries fluid away from tissues.
  • Lymph capillaries drain into larger lymph vessels.
  • Upper right quadrant drains into right lymphatic duct; rest into thoracic duct, then into left subclavian vein.
  • Lymph enters lymph nodes through afferent lymph vessels, leaves lymph nodes through efferent lymph vessels toward the bloodstream.
• Filtration role:
  
  • Filters and destroys pathogens and other foreign substances in blood.
  • Filtering out and destroying pathogens; may appear swollen and painful during infections.
  • Lymph nodes may either filter out cancer or spread to other body sites

Question 8

Describe the circle of Willis and the blood–brain barrier, including the function of each.

Answer 8

• Several arteries come together in the brain to form the circle of Willis. The arterial circle helps maintain and protect cerebral blood flow.
• The circle of Willis helps provide uninterrupted blood supply to the brain.
• The blood–brain barrier protects the brain from harmful substances.

Question 9

Explain the process of hepatic portal circulation.

Answer 9

• An efficient detour in venous return, directed at transporting raw materials (carbohydrates, fats, and proteins) from digestive organs to the liver.

Question 10

Discuss changes in the hematologic and lymphatic systems related to aging.

Answer 10

Question 11

__________ a glycoprotein-type hormone,
stimulates the stem cells of bone marrow to
produce the red blood cells.

Answer 11

Erythropoietin

Question 12

The functions of the __________ system include transportation of nutrients and oxygen to the cells, blood volume regulation, and production of blood cells and antibodies.

Answer 12

Hematologic

Question 13

The formation of blood cells originating in
__________ cells in red bone marrow is called hematopoiesis or hemopoiesis.

Answer 13

Stem

Question 14

Vitamin _________ is necessary for the formation of prothrombin and other clotting
factors.

Answer 14

K

Question 15

A bacterial infection would most likely
produce an increase in __________
which are considered to be first in the line of defense against bacteria.

Answer 15

neutrophils

Question 16

Engulfing of particulate matter

Answer 16

Phagocytosis

Question 17

Engulfing of extracellular fluid materials

Answer 17

Pinocytosis

Question 18

Formation of red blood cells

Answer 18

Erythropoiesis

Question 19

Consist of monocytes and lymphocytes

Answer 19

Agranulocytes

Question 20

Consists of the basophils, neutrophils, and eosinophils

Answer 20

Granulocytes

Question 21

Write the correct sequence of production and
circulation of blood through the body in the
boxes provided below.

1. Blood carries out the transportation of
   oxygen, carbon dioxide, nutrients, heat,
   waste products, and hormones.
2. Blood is carried through a closed system of vessels pumped by the heart.
3. Lymph nodes, spleen, and thymus contribute to additional production and maturation of agranular white blood cells.
4. Blood in the general (systemic) circulation returns to the right atrium of the heart.
5. The red bone marrow manufactures all blood cells

Answer 21

5. The red bone marrow manufactures all blood cells
6. Lymph nodes, spleen, and thymus contribute
7. Blood is carried through a closed system of vessels pumped by the heart.
8. Blood carries out the transportation of
   oxygen, carbon dioxide, nutrients, heat,
   waste products, and hormones.
9. Blood in the general (systemic) circulation returns to the right atrium of the heart.

Question 22

What is the difference between the
hematologic system and the lymphatic
system?

Answer 22

• The hematologic system consists of the components of the blood (i.e., plasma and formed elements) and the bone marrow, the primary organ that manufactures blood cells.
• The function of the hematologic system involves the removal of hematologic waste products, the delivery of nutrients and oxygen to cells, blood volume regulation, blood cell and antibody production, and blood coagulation.
• The lymphatic system consists of the lymphatic vessels and tissues.
• The lymphatic system transports dietary fats to the blood, drains interstitial fluid, helps protect the body from infection, and provides immunity.
• It also returns any excess proteins that may escape from the blood vessels to the systemic circulation

Question 23

What are antibodies?

Answer 23

Antibodies are materials synthesized by the body in response to antigens or foreign invaders, thus immunizing the body against infection and disease

Question 24

What is the function of the iron in
hemoglobin?

Answer 24

• As blood passes through the lungs, the iron in hemoglobin picks up oxygen in a loose chemical combination.
• When hemoglobin is saturated with oxygen, the blood is bright red.
• As blood circulates through the capillaries, the hemoglobin gives its oxygen to various cells of the body and picks up their carbon dioxide.
• The deoxygenated blood is much darker in color.

Question 25

What is the difference between white blood
cells (WBCs) and red blood cells (RBCs)?

Answer 25

• RBCs are flattened biconcave discs, and mature RBCs do not have a nucleus, so they cannot reproduce.
  
  • About 25 trillion RBCs are found in the body, produced by the stem cells in the red bone marrow.
  • Iron in the hemoglobin of the RBC picks up oxygen in the lungs and exchanges it for carbon dioxide at the cellular level.
• WBCs are ameboid and contain nuclei.
  
  • WBCs also assist in repairing damaged tissues.
  • Sometimes they die during this activity and collect with bacteria to form pus.
  • WBCs are of two types, granular and agranular.

Question 26

What is hemostasis?

Answer 26

• Hemostasis is the cessation of bleeding.
• When damage or rupture occurs to blood vessels, hemostatic responses such as vasoconstriction, platelet plug formation, and blood clotting take place to stop the bleeding.
• This requires quick and controlled responses to stop blood loss

Question 27

A client visiting a healthcare clinic for a complete blood count test seeks information on the composition and function of blood.

a. What is the primary objective of blood?

Answer 27

• The primary objective of blood is to maintain a constant environment for the rest of the body’s tissues.
• Blood maintains homeostasis via its viscosity (thickness), its ability to carry dissolved substances, and its ability to move to all body parts.

Question 28

What are the components of blood?

Answer 28

• Blood is composed of both plasma and formed elements.
• Plasma is 90% water.
• Its remaining 10% consists primarily of plasma proteins but also includes:
  
  • Salts (electrolytes),
  • Nutrients,
  • Nitrogenous waste products,
  • Gases,
  • Hormones, and
  • Enzymes.

Question 29

A nurse is educating a client on the difference
between blood and other connective tissues.

a. Why is blood considered a connective
tissue?

Answer 29

• Blood is considered a connective tissue because almost all of it is made of cells that share many characteristics with other connective tissues in terms of origin and development.

Question 30

How is blood different from other connective tissues?

Answer 30

Blood differs from other connective tissues because its cells are not fixed but move freely in the liquid portion of the blood (plasma).

Question 31

During a lecture on the lymphatic system,
the nurse explains to student nurses the constituents of lymph and the networking of
lymphatic vessels.

a. What are lymphatic vessels?

Answer 31

• The lymphatic vessels are thin-walled vessels with one-way valves that prevent backflow of lymph fluid.
• They are located both superficially and deeper in the body.
• Most lymphatic vessels are located near the venous system and are named according to their body location.
• Lymphatic vessels begin as a network of tiny closed-ended lymphatic capillaries in spaces between cells.
• These capillaries have a unique structure that allows interstitial fluid to flow into them but not out.

Question 32

What is known as the lymph?

Answer 32

The excess fluid and certain other waste products that collect in the capillaries form the thin, watery, colorless liquid known as lymph.

Question 33

How does the lymphatic fluid move
through the body?

Answer 33

• Lymph fluid is propelled through the body by rhythmic contractions.
• These contractions occur because of changes in abdominal and thoracic pressure during breathing and also because of skeletal muscle contractions

Question 34

A nurse is caring for a client with an injury.
The blood along the wound has already
clotted. The nurse explains to the client the
importance of clotting.

a. Why is the clotting of blood important?

Answer 34

Clotting of blood protects the body from losing vital plasma fluid and blood cells by sealing off broken blood vessels. Without this action, individuals would not survive even minor cuts and wounds.

Question 35

How does the process of the clotting of
blood work?

Answer 35

• When tissue is injured, platelets break down and cause the release of thromboplastin, which interacts with certain protein factors and calcium ions to form prothrombin activator.
• This activator reacts with additional calcium ions to convert the plasma protein prothrombin to thrombin.
• Thrombin then converts the soluble plasma protein fibrinogen into insoluble threads of fibrin.
• The threads of fibrin form a net to entrap red blood cells and platelets to form a clot, which acts like a plug in a hole and tends to draw injured edges together.