lesson 11 Flashcards
(80 cards)
1
Q
What type of tissue is blood?
A
A special type of connective tissue
2
Q
What are the main components of blood?
A
- Fluid matrix (plasma)
- Formed elements (cells and cell fragments)
- Fibrous component (fibrin during clotting)
3
Q
What happens during blood clotting?
A
Fibrinogen is converted to fibrin
4
Q
What is plasma?
A
The straw-colored, transparent fluid matrix of blood
5
Q
What is serum?
A
The remaining blood fluid after fibrinogen is removed as fibrin
6
Q
What percentage of blood is plasma?
A
Species-dependent, but generally 35-50%
7
Q
What is plasma composed of?
A
- 90% water
- 10% dissolved substances (proteins, inorganic ions, hormones, pigments, vitamins, dissolved gases)
8
Q
What are the three main formed elements of blood?
A
- Erythrocytes (Red Blood Cells - RBCs)
- Leukocytes (White Blood Cells - WBCs)
- Platelets (Thrombocytes)
9
Q
What are the two categories of leukocytes?
A
- Agranulocytes
- Granulocytes
10
Q
Which cells are agranulocytes?
A
- Lymphocytes
- Monocytes
11
Q
Which cells are granulocytes?
A
- Neutrophils (heterophils in some species)
- Eosinophils
- Basophils
12
Q
How do platelets differ in mammals and birds?
A
- In mammals, platelets are cell fragments
- In birds, thrombocytes are whole cells
13
Q
Which is the most numerous blood cell?
A
Erythrocytes (RBCs)
14
Q
What is the shape of erythrocytes?
A
Biconcave disk
15
Q
Are mammalian RBCs nucleated?
A
No, they are non-nucleated
16
Q
How do RBCs appear under common staining techniques like Wright’s or Giemsa’s?
A
They stain pink
17
Q
What is rouleaux formation?
A
A phenomenon where RBCs stack like coins when blood is stagnant (not circulating)
18
Q
What happens to RBCs in an isotonic solution?
A
They remain unchanged
19
Q
What happens to RBCs in a hypotonic solution?
A
- They swell and assume a spherical shape
- If swelling is excessive, the plasma membrane bursts, releasing hemoglobin (hemolysis)
- Cell remnants leave a ‘shadow’ or ‘ghost’
20
Q
What happens to RBCs in a hypertonic solution?
A
They shrink irregularly (crenation)
21
Q
What is the primary function of erythrocytes?
A
Transport oxygen to body tissues via hemoglobin
22
Q
What is oxyhemoglobin?
A
Hemoglobin combined with oxygen
23
Q
What features of erythrocytes make them efficient gas transporters?
A
- Biconcave shape (20-30% greater surface area than a sphere)
- Lack of nucleus (more space for hemoglobin)
- Resilient, elastic structure (prevents injury and allows passage through capillaries)
24
Q
What proteins make RBCs tough and flexible?
A
- Spectrin
- Actin (form a network beneath the membrane)
25
What gives cheeks and lips a pink or red appearance?
Oxyhemoglobin in capillaries
26
What color is reduced hemoglobin?
Blue instead of red
27
What are Howell-Jolly bodies?
Non-refractile nuclear remnants found in some feline and equine RBCs
28
What are the two major types of leukocytes?
**Agranulocytes** (lack specific granules in the cytoplasm, rounded cells with rounded nuclei) and **Granulocytes** (contain specific granules in the cytoplasm, have lobed or segmented nuclei)
29
Which leukocyte is the second most common after neutrophils?
Lymphocytes
30
What percentage of normal leukocyte count do lymphocytes comprise?
20-30%
31
What are the three sizes of lymphocytes?
Small, medium, and large
32
What are the characteristics of lymphocytes?
* High nuclear/cytoplasmic ratio
* round slightly basophilic nucleus
* small lymphocytes are the most common in circulating blood
* medium lymphocytes resemble monocytes
* large lymphocytes are mostly found in extravascular lymphatic tissue
33
What are the two immunological classifications of lymphocytes?
B-Lymphocytes (B cells) and T-Lymphocytes (T cells)
34
What is the function of B cells?
Production of antibodies (immunoglobulins) in response to antigens
35
What type of immunity do B cells provide?
Humoral (blood-borne) immunity
36
Where are B cells found?
1. Bone marrow
1. Bursa of Fabricius (in birds)
1. germinal centers of lymphatic nodules
1. splenic nodules
37
What is the function of T cells?
Cell-mediated immunity (CMI)
38
What do T cells differentiate into after antigenic stimulation?
1. Cytotoxic T cells
1. T helper cells
1. T suppressor cells
1. memory cells
1. lymphokine-producing cells
39
What are lymphokines?
Low molecular weight proteins produced primarily by T cells
40
Give examples of lymphokines and their functions.
* Macrophage Aggregating Factor (MAF) → causes macrophages to aggregate
* Mitogenic Factor (MF) → stimulates lymphocytes to divide
* Interferon → prevents virus replication
41
Where are T cells found?
Thymus, paracortical zones of lymphatic nodules, periarteriolar zones of splenic corpuscles
42
Which lymphocyte type is most common in circulation?
T cells
43
What is the lifespan of lymphocytes?
It varies from hours to years
44
Which cells are believed to be long-lived memory cells?
Some B and T cells
45
What percentage of lymphocytes do null lymphocytes comprise?
10-15%
46
What are the two types of null lymphocytes?
Circulating stem cells and Natural Killer (NK) cells
47
What is the function of NK cells?
Cell-mediated cytotoxicity (destroy tumor and virus-infected cells)
48
How do activated NK cells destroy target cells?
They release cytotoxic granules that kill the altered cells
49
Which leukocyte is the largest in the blood?
Monocytes
50
What are the characteristics of monocytes?
Kidney-shaped, bean-shaped, round, or trilobed nucleus; gray cytoplasm
51
What is the function of monocytes?
Phagocytosis (they become macrophages in extravascular spaces)
52
Which granulocyte is the most common in the blood?
Neutrophils
53
How big are neutrophils compared to RBCs?
Twice the size of RBCs
54
What does the nucleus of a neutrophil look like?
Segmented with 3-5 lobes connected by fine nucleoplasm strands
55
What color do neutrophilic granules appear?
Light pink to purple (varies depending on stain used)
56
What is a pseudoeosinophil?
A neutrophil in rabbits and guinea pigs where granules stain with acid dyes
57
Are neutrophilic granules always visible?
No, visibility depends on preparatory techniques
58
What is the primary function of neutrophils?
Phagocytosis of bacteria, particles, and microorganisms
59
When is neutrophil phagocytosis most prominent?
During acute inflammation
60
Which granulocyte is the second most frequently found in the blood?
Eosinophils
61
What is the shape of the eosinophil nucleus?
Bilobed
62
What type of staining do eosinophilic granules exhibit?
Acidophilic (stain with acid dyes)
63
In which species are eosinophil granules especially large?
Equines (horses)
64
What do eosinophilic granules contain?
Lysosomes
65
What are eosinophils associated with?
* Allergic conditions
* Parasitic infections
* Sites of antibody/antigen reactions
66
What happens to eosinophil numbers in response to corticosteroids?
They decrease
67
Which granulocyte is the least numerous?
Basophils
68
How does the size of a basophil compare to a neutrophil?
They are about the same size
69
What are the characteristics of basophilic granules?
* Round, coarse, and variable in size
* Stain darker than the nucleus (may partially obscure it)
* Basophilic and metachromatic
70
What conditions may cause an increase in basophils?
Certain parasitic infections (e.g., heartworm infection)
71
What substances may basophils secrete?
Histamines, Heparin
72
What are the contents of azurophilic granules?
Acid hydrolases
Myeloperoxidase
Lysozyme
Bactericidal permeability-increasing protein
Cathepsin G
Elastase
Non-specific collagenase
73
What are the specific granule contents of neutrophils?
Collagenase
Alkaline phosphatase
Lysozyme
Lactoferrin
Phospholipase A2
Phagocytin
74
What are the specific granule contents of eosinophils?
Histaminase
β-glucuronidase
Acid phosphatase
Major Basic Protein (MBP)
Neurotoxin
Cathepsin
75
What are the specific granule contents of basophils?
Histamine
Heparin
Eosinophil
Chemotactic Factor (ECF)
Neutrophil Chemotactic Factor (NCF)
Peroxidase
76
What are the contents of tertiary granules?
Gelatinase, Cathepsin, Glycoproteins
77
What are platelets?
Small cytoplasmic disks that are fragments of a large cell called the megakaryocyte
78
How do platelets appear under a light microscope?
Membrane-bound, round to oval fragments; Contain a central basophilic region (chromomere); Have a pale homogenous peripheral zone (hyalomere); Lack a nucleus
79
What are the three zones of platelets under an electron microscope?
Peripheral zone → Cell membrane with circularly arranged microfilaments
Sol-gel zone → Pale-staining area with microfilaments & microtubules
Organelle zone → Corresponds to chromomere, contains granules and dense bodies for storage
80
What are the functions of platelets?
Participate in hemostasis (blood clotting)
Contain serotonin, which mediates vasoconstriction
Combine with bacteria and act as opsonins, aiding in phagocytosis
