Ch.10: Blood Flashcards
1
Q
Blood transports everything that must be carried from one place to another, such as:
A
- Nutrients
- Wastes
- Hormones
- Body heat
2
Q
Blood is the only fluid _____, a type of _____, in the human body
A
- Tissue
* Connective tissue
3
Q
What are the components of blood?
A
- Formed elements (living cells)
* Plasma (nonliving fluid matrix)
4
Q
When blood is separated:
A
• Erythrocytes sink to the bottom (45 percent of blood, a percentage known as the hematocrit)
• Buffy coat contains leukocytes and platelets (less than 1 percent of blood)
*Buffy coat is a thin, whitish layer between the erythrocytes and plasma
• Plasma rises to the top (55 percent of blood)
5
Q
What are the characteristics of blood?
A
• Sticky, opaque fluid • Heavier and thicker than water • Color range *Oxygen-rich blood is scarlet red *Oxygen-poor blood is dull red or purple • Metallic, salty taste • Blood p H is slightly alkaline, between 7.35 and 7.45 • Blood temperature is slightly higher than body temperature, at 38°Celsius or 100.4°F
6
Q
What is the volume of blood in the body?
A
- About 5–6 liters, or about 6 quarts, of blood are found in a healthy adult
- Blood makes up 8 percent of body weight
7
Q
Plasma is __ water.
A
90%
8
Q
Plasma includes many dissolved substances, such as:
A
- Nutrients
- Salts (electrolytes)
- Respiratory gases
- Hormones
- Plasma proteins
- Waste products
9
Q
What are plasma proteins?
A
• Most abundant solutes in plasma • Most are made by the liver • Include: *Albumin *Clotting proteins *Antibodies
10
Q
What is albumin?
A
An important blood buffer and contributes to osmotic pressure
11
Q
What are clotting proteins?
A
Help to stem blood loss when a blood vessel is injured
12
Q
What are antibodies?
A
Help protect the body from pathogens
13
Q
Blood _____ varies as cells exchange substances with the blood.
A
- Composition
- Liver makes more proteins when levels drop
- Respiratory and urinary systems restore blood p H to normal when blood becomes too acidic or alkaline
14
Q
Plasma helps distribute body _____.
A
Heat
15
Q
What are erythrocytes and what are their function?
A
• Red blood cells (RBCs) • Main function is to carry oxygen • RBCs differ from other blood cells: *Anucleate (no nucleus) *Contain few organelles; lack mitochondria *Essentially bags of hemoglobin (Hb) *Shaped like biconcave discs • Normal count is 5 million RBCs per cubic millimeter (mm3) of blood
16
Q
What are leukocytes and what are their function?
A
- White blood cells (WBCs)
- Crucial in body’s defense against disease
- Complete cells, with nucleus and organelles
- Able to move into and out of blood vessels (diapedesis)
- Respond to chemicals released by damaged tissues (known as positive chemotaxis)
- Move by amoeboid motion
- 4,800 to 10,800 W B Cs per mm3 of blood
17
Q
What are platelets?
A
- Fragments of megakaryocytes (multinucleate cells)
- Needed for the clotting process
- Normal platelet count is 300,000 platelets per mm3 of blood
18
Q
Hemoglobin is an _____ protein.
A
- Iron-bearing
- Binds oxygen
- Each hemoglobin molecule can bind 4 oxygen molecules
- Each erythrocyte has 250 million hemoglobin molecules
- Normal blood contains 12–18 grams of hemoglobin per 100 milliliters (m l) of blood
19
Q
Concept Link 1
A
Recall that hemoglobin is an example of a globular protein (look back at Figure 2.19b, p.50). Globular, or functional, proteins have tertiary structure, meaning that they are folded into a very specific shape. In this case, the folded structure of hemoglobin allows it to perform the specific function of binding and carrying oxygen. The structure of globular proteins is also very vulnerable to p H changes and can be denatured (unfolded) by a p H that is too low (acidic); denatured hemoglobin is unable to bind oxygen.
20
Q
What is the result of homeostatic imbalance of RBCs?
A
- Anemia
* Sickle cell anemia (SCA)
21
Q
What is anemia?
A
- A decrease in the oxygen-carrying ability of the blood due to:
- Lower-than-normal number of RBCs
- Abnormal or deficient hemoglobin content in the RBCs
22
Q
Sickle cell anemia (SCA) results from _____.
A
Abnormally shaped hemoglobin
23
Q
What is polycythemia?
A
Disorder resulting from excessive or abnormal increase of R B Cs due to:
• Bone marrow cancer (polycythemia vera)
• Life at higher altitudes (secondary polycythemia)
24
Q
Increase in RBCs slows _____ and increases _____.
A
- Blood flow
* Blood viscosity
25
What is leukocytosis?
* WBC count above 11,000 cells per mm3 of blood
| * Generally indicates an infection
26
What is leukopenia?
* Abnormally low WBC count
| * Commonly caused by certain drugs, such as corticosteroids and anticancer agents
27
What is leukemia?
* Bone marrow becomes cancerous
| * Numerous immature WBC are produced
28
What are the types of leukocytes?
* Granulocytes
| * Agranulocytes
29
What are agranulocytes?
• Type of leukocyte
• Lack visible cytoplasmic granules
• Nuclei are spherical, oval, or kidney-shaped
Include lymphocytes and monocytes
30
What are granulocytes?
* Type of leukocyte
* Granules in their cytoplasm can be stained
* Possess lobed nuclei
* Include neutrophils, eosinophils, and basophils
31
List of the WBCs, from most to least abundant:
* Neutrophils (never)
* Lymphocytes (let)
* Monocytes (monkeys)
* Eosinophils (eat)
* Basophils (bananas)
32
What are neutrophils?
* A type of granulocyte
* Most numerous WBC
* Multilobed nucleus
* Cytoplasm stains pink and contains fine granules
* Function as phagocytes at active sites of infection
* Numbers increase during infection
* 3,000–7,000 neutrophils per mm3 of blood (40-70% of WBCs)
33
What are eosinophils?
* A type of granulocyte
* Nucleus stains blue-red
* Brick-red cytoplasmic granules
* Function is to kill parasitic worms and play a role in allergy attacks
* 100–400 eosinophils per mm3 of blood (1-4 percent of WBCs)
34
What are basophils?
* A type of granulocyte
* Rarest of the W B Cs
* Large histamine-containing granules that stain dark blue
* Contain heparin (anticoagulant)
* 20–50 basophils per mm3 of blood (0-1 percent of WBCs)
35
What are lymphocytes?
* A type of agranulocyte
* Large, dark purple nucleus
* Slightly larger than RBCs
* Reside in lymphatic tissues
* Play a role in immune response
* 1,500–3,000 lymphocytes per mm3 of blood (20-45 percent of WBCs)
36
What are monocytes?
• A type of agranulocyte
• Largest of the white blood cells
• Distinctive U- or kidney-shaped nucleus
• Function as macrophages when they migrate into tissues
Important in fighting chronic infection
• 100–700 monocytes per mm3 of blood (4-8 percent of WBCs)
37
What is hematopoiesis?
The process of blood cell formation
38
Hematopoiesis occurs in:
Red bone marrow (myeloid tissue)
39
All blood cells are derived from a:
Common stem cell (hemocytoblast)
40
Hemocytoblasts form what two types of descendants?
* Lymphoid stem cell, which produces lymphocytes
| * Myeloid stem cell, which can produce all other formed elements
41
Since RBCs are anucleate, they are unable to _____, _____, or _____.
* Divide
* Grow
* Synthesize proteins
42
RBCs wear out in:
100 to 120 days
43
When worn out, RBCs are eliminated by _____ in the _____ or _____.
* Phagocytes
* Spleen
* Liver
44
Lost RBCs are replaced by division of _____ in the _____.
* Hemocytoblasts
| * Red bone marrow
45
Rate of R B C production is controlled by a hormone called:
Erythropoietin
46
_____ produce most erythropoietin as a response to reduced _____ levels in the blood
* Kidneys
| * Oxygen
47
Homeostasis is maintained by _____ from blood _____ levels.
* Negative feedback
| * Oxygen
48
Concept Link 2
Recall the concept of negative feedback control (see Chapter 1, p. 19). In this case, erythropoietin is released in response to a low blood oxygen level, which stimulates the bone marrow to produce more red blood cells. With their numbers increased, the red cells carry more oxygen, increasing the blood oxygen level and reducing the initial stimulus.
49
W B C and platelet production is controlled by:
Hormones
50
Colony stimulating factors (CSFs) and interleukins prompt _____ to generate _____.
* Bone marrow
| * Leukocytes
51
Thrombopoietin stimulates production of _____ from _____.
* Platelets
| * Megakaryocytes
52
What is hemostasis?
The process of stopping the bleeding that results from a break in a blood vessel
53
Hemostasis involves what three phases?
1. Vascular spasms
2. Platelet plug formation
3. Coagulation (blood clotting)
54
What is step 1 of hemostasis?
* Vascular spasms
* Immediate response to blood vessel injury
* Vasoconstriction causes blood vessel to spasm
* Spasms narrow the blood vessel, decreasing blood loss
55
What is step 2 of hemostasis?
* Platelet plug formation
* Collagen fibers are exposed by a break in a blood vessel
* Platelets become “sticky” and cling to fibers
* Anchored platelets release chemicals to attract more platelets
* Platelets pile up to form a platelet plug (white thrombus)
56
What is step 3 of hemostasis?
• Coagulation
• Injured tissues release tissue factor (TF)
• PF3 (a phospholipid) interacts with TF, blood protein clotting factors, and calcium ions to trigger a clotting cascade
• Prothrombin activator converts prothrombin to thrombin (an enzyme)
• Thrombin joins fibrinogen proteins into hair-like molecules of insoluble fibrin
• Fibrin forms a meshwork (the basis for a clot)
• Within the hour, serum is squeezed from the clot as it retracts
*Serum is plasma minus clotting proteins
57
Blood usually clots within:
3 to 6 minutes
58
The blood clot remains as _____ regenerates
Endothelium
59
The blood clot is broken down after:
Tissue repair
60
Which disorders of hemostasis cause undesirable clotting?
* Thrombus
| * Embolus
61
What is a thrombus?
* A clot in an unbroken blood vessel
| * Can be deadly in areas such as the lungs
62
What is an embolus?
* A thrombus that breaks away and floats freely in the bloodstream
* Can later clog vessels in critical areas such as the brain
63
Which disorders of hemostasis are bleeding disorders?
* Thrombocytopenia
| * Hemophilia
64
What is thrombocytopenia?
* Insufficient number of circulating platelets
* Arises from any condition that suppresses the bone marrow
* Even normal movements can cause bleeding from small blood vessels that require platelets for clotting
* Evidenced petechiae (small purplish blotches on the skin)
65
What is hemophilia?
* Hereditary bleeding disorder
* Normal clotting factors are missing
* Minor tissue damage can cause life-threatening prolonged bleeding
66
Large losses of blood have serious consequences, such as:
* Loss of 15 to 30 percent causes weakness
| * Loss of over 30 percent causes shock, which can be fatal
67
Blood transfusions are given for substantial _____, to treat severe _____, or for _____.
* Blood loss
* Anemia
* Thrombocytopenia
68
Blood contains genetically determined proteins known as:
Antigens
69
What are antigens?
* Substances that the body recognizes as foreign and that the immune system may attack
* Most antigens are foreign proteins
* We tolerate our own “self” antigens
70
Antibodies are the “recognizers” that bind foreign:
Antibens
71
Blood is “typed” by using _____ that will cause blood with certain _____ to clump (agglutination) and lyse
* Antibodies
| * Proteins
72
There are over __ common red blood cell antigens.
30
73
The most vigorous transfusion reactions are caused by _____ and _____ blood group antigens
* ABO
| * Rh
74
What is the ABO blood group?
* Presence of both antigens A and B is called type AB
* Presence of antigen A is called type A
* Presence of antigen B is called type B
* Lack of both antigens A and B is called type O
75
What is the Rh blood group?
* Named for the eight R h antigens (agglutinogen D)
| * Most Americans are Rh+ (Rh-positive), meaning they carry the Rh antigen
76
If an R h−(R h-negative) person receives R h+ blood:
* The immune system becomes sensitized and begins producing antibodies; hemolysis does not occur, because as it takes time to produce antibodies
* Second, and subsequent, transfusions involve antibodies attacking donor’s Rh+ RBCs, and hemolysis occurs (rupture of RBCs)
77
What is an Rh-related problem during pregnancy?
* Danger occurs only when the mother is Rh−, the father is Rh+, and the child inherits the Rh+ factor
* RhoGAM shot can prevent buildup of anti-Rh+ antibodies in mother’s blood
78
The mismatch of an Rh− mother carrying an Rh+ baby can cause problems for the unborn child, such as:
* The first pregnancy usually proceeds without problems; the immune system is sensitized after the first pregnancy
* In a second pregnancy, the mother’s immune system produces antibodies to attack the R h+ blood (hemolytic disease of the newborn)
79
What is cross matching?
Testing for agglutination of donor RBCs by the recipient’s serum, and vice versa
80
What are the sites of fetal blood cell formation?
* The fetal liver and spleen are early sites of blood cell formation
* Bone marrow takes over hematopoiesis by the seventh month
81
Congenital blood defects include various types of _____ and _____.
* Hemolytic anemias
| * Hemophilia
82
Incompatibility between _____ and _____ blood can result in fetal cyanosis, resulting from destruction of fetal blood cells.
* Maternal
| * Fetal
83
_____ hemoglobin differs from _____ produced after birth
* Fetal
| * Hemoglobin
84
Physiologic _____ occurs in infants when the liver cannot rid the body of _____ breakdown products fast enough.
* Jaundice
| * Hemoglobin
85
Leukemias are most common in the _____ and _____.
* Very young
* Very old
* Older adults are also at risk for anemia and clotting disorders
