Blood, Lymph and Immunity Flashcards
1
Q
What is the direction of lymph flow?
A
- afferent lymphatics
- subcapsular sinus
- efferent lymphatics
2
Q
What cells are found in lymph nodes?
A
- lymphocytes
- phagocytes
3
Q
What are the tissues of the macrophage and mononuclear cells phagocytic “system”?
A
- lymph nodes
- tissue macrophages
- hepatic endothelium
- splenic endothelium
- bone marrow sinusoids
- mucosa-associated lymphatic tissue (MALT)
- gut-associated lymphatic tissue (GALT)
- tonsils (pharynx)
- Peyer’s patches
- lymphatic drainage
- thoracic duct
- fluid returns back to the general circulation
- drains lymph and chyle back to near the cranial vena cava
4
Q
What are the palpable lymph nodes?
A
palpable lymph nodes – parotid (dog), mandibular, superficial cervical, axillary, superficial inguinal, popliteal
5
Q
What is the spleen?
A
- a reservoir for red blood cells
- a sight of immune surveillance (especially phagocytosis) and removal of aged or damaged RBCs
6
Q
What is the thymus?
A
- disappears (atrophies) in the adult after puberty
- cortex – site of T lymphocyte production, which go out and populate lymphoid tissues and structures
7
Q
What is the 3 functions of blood?
A
- transport of gases, nutrients, metabolic waste products, cells and hormones
- regulation of body temperature and acid:base balance (pH)
- immunological defense
8
Q
Describe blood volume among species…
A
- n liters as % of body weight (kilograms) – important to consider to recognize in cases of fluid loss and circulation for pharmacology 2.2 lbs = 1 kg
- human – 7% of body weight
- dog – 7.2%
- cow – 7.7%
- sheep – 8%
- horse – 9.7%
9
Q
What are the components of blood?
A
- fluid = plasma
- constant exchange of inorganic salts with extracellular fluid space
- contains 3 types of proteins (“plasma proteins”) – the plasma proteins contribute to the colloidal osmotic pressure within the vascular system
- albumins – most abundant – transport of insoluble substances such as fatty acids
- globulins – alpha, beta, gamma
- transport proteins
- gamma = immunoglobulins
- fibrinogen – blood clotting
10
Q
What is plasma?
A
serum and clotting factors
11
Q
What is serum?
A
fluid component after clot is formed
12
Q
Describe red blood cells…
A
- red blood cells make up 99.9% of blood’s formed elements
- function: the transport of respiratory gasses (O2 and CO2)
- live about 120 days
- low RBC count = anemia
- increased RBC count = polycythemia
13
Q
Describe white blood cells…
A
- white blood cells – leukocytes
- immunologic functions
- remove and defend against pathogens
- remove abnormal cells
- observe on peripheral blood smears
- granulocytes or PMNs (polymorphonuclear leukocytes)
- neutrophil
- eosinophil
- basophil
- mononuclear cells
- monocytes
- lymphocytes
14
Q
What is a neutrophil?
A
- description
- granules contain lysosomal enzymes and bacterial compounds (hydrogen peroxide and superoxide)
- very dense, segmented nucleus that forms 2-5 lobes –> also called PMNs
- function: 1st line of defense (quick response)
- phagocytosis of small pathogenic microorganisms
- hydrogen peroxide kills bacteria
- life space : hours - 3 days
15
Q
What is a eosinophil?
A
- description
- large granules stain red with eosin
- a bilobed nucleus
- functions
- attack objects (bacteria, protozoa, or cellular debris) by phagocytosis and exocytosis of toxic compound (nitric oxide and cytotoxic enzymes)
- defend against large multicellular parasites
- release anti-inflammatory substances in allergic reactions
- life span: 10 - 12 days
16
Q
What is a basophil?
A
- description
- rare and smaller
- dense granules stain deep purple or blue with basic dye
- nucleus generally can not be seen
- functions
- enhance inflammatory response by:
- release histamine
- dilates blood vessels
- release heparin
- prevents blood clotting
- tissue mast cells release same compounds, but they are distinct populations with separate origins
- release histamine
- enhance inflammatory response by:
- life span: hours - 3 days
17
Q
What is a monocyte?
A
- description
- largest (twice the diameter of a RBC)
- spherical
- nucleus is large and tends to be oval or kidney bean shaped
- functions
- enter peripheral tissues to become a tissue macrophage – major and aggressive phagocytes
- release chemicals to attract and stimulate other phagocytic cells
- secrete substances that lure fibroblasts into the region to produce scar tissue
- life span: months
18
Q
What is a lymphocyte?
A
- description
- slightly larger than RBC
- round and large nucleus, often look like nuclei without cytoplasm
- migrate in and out of blood
- mostly in connective tissues and lymphatic organs
- type and functions
- T cells: cell-mediated immunity: provide “killer” cells to directly attack foreign invaders
- B cells: humoral immunity: production and distribution of antibodies
- NK cells: immune surveillance: the detection and subsequent destruction of abnormal tissue cells
- life span: days to years
19
Q
What is differential blood count?
A
- RBCs outnumber WBCs 1000:1
- differential count: the number of each type of cell in a sample of 100 WBCs
- changes in infections, inflammation, and allergic reactions
20
Q
What are platelets and their other name?
A
thrombocytes
- description
- cell fragments; not complete cells. Megakaryocyte sheds cytoplasm to produce ~4000 platelets in a life time
- cytoplasm contains very small pink staining granules which contain some of the clotting factors
- function
1. release important clotting chemicals
2. temporarily patch damaged vessel walls
3. actively contract tissue after clot formation
- life span: 7 - 12 days
21
Q
What is the organization of the immune system?
A
- nonspecific immunity
- do not distinguish one type of threat from another
- specific immunity
- protect against particular threats
- both nonspecific and specific immune responses are complementary and must function normally
22
Q
What is the physical barrier do?
A
- keep hazardous materials outside the body by
- epithelial covering barrier
- specialized accessory structures and secretions of epithelial cells
- hair
- secretions (sweat, mucus, urine, etc.)
- flush surface
- contain bactericidal chemicals: lysozyme, antibodies
23
Q
What do phagocytes do?
A
- first line of cellular defense
- microphages: neutrophils and eosinophils
- macrophages: fixed macrophages and free macrophages
- attack and remove dangerous microorganisms
- engulf a pathogen
- bind to or remove a pathogen with assistance by other cells
- destroy its target by releasing toxic chemicals
24
Q
What is immunological surveillance?
A
- natural killer (NK) cells recognize and destroy abnormal cells by detecting the antigens on the cell membrane of abnormal cells
25
Q
What are interferons?
A
- small proteins released by activated lymphocytes and macrophages and by tissue cells infected with viruses
- functions
- trigger productions of antiviral proteins in normal cells
- antiviral proteins
- do not kill viruses
- block replication in cell
26
Q
What is the complement system?
A
- 11 complement proteins (C)
- complements, or supplements the action of antibodies
- functions
- destruction of target cell membranes by forming the membrane attack complex (MAC) which creates a pore for cell lysis
27
Q
What is inflammation?
A
- the first step in the healing process, characterized by swelling, redness, warmth, pain, and some loss of function
- histamine: increases capillary permeability; heparin: inhibits clotting
- function:
- temporary repair and barrier against pathogens
- retards spread of pathogens into surrounding areas
- mobilization of local and systemic defenses
28
Q
What does a fever do?
A
- pyrogens
- proteins that can reset body’s thermostat and raise body temperature
- pathogens, bacterial toxins, and antigen-antibody complexes
- within limits, for each 1 C rise in temperature, metabolism rate jumps by 10%
29
Q
What are specific defenses?
A
- specific resistance (immunity)
- responds to specific antigens
- with coordination action of T cells and B cells
30
Q
What are T-cells?
A
- thymus-dependent, 80% of circulating lymphocytes
- 3 main types:
- cytotoxic T cells (killer T cells)
- attack cells physically by releasing perforin
- produce cell-mediated immunity
- Helper T cells
- secrete cytokines to stimulate both T cells and B cells
- most numerous T cells
- suppressor T cells
- inhibit T cell and B cell activities
- cytotoxic T cells (killer T cells)
31
Q
What is cell mediated immunity?
A
involves close physical contact between activated killer T cells and foreign, abnormal or infected cells
32
Q
What are B cells?
A
- responsible for antibody-mediated immunity
- attack antigens by producing specific antibodies
- millions of populations, each with different antibody molecules
33
Q
What is the structure of an antibody?
A
- 2 parallel pairs of polypeptide chains
- 1 pair of heavy chains
- 1 pair of light chains
- each chain contains
- constant segments
- 5 types: IgG, IgE, IgD, IgM, or IgA
- variable segments
- contains antigen binding sites
- determines the specificity of the antibody
- ~ 100 million types of antibodies
- constant segments
34
Q
What is an IgG antibody?
A
- 80% of all antibodies
- mainly in plasma
35
Q
What is an IgE antibody?
A
- attaches to exposed surfaces of basophils and mast cells
- important in allergic response
36
Q
What is an IgD antibody?
A
- on surface of B cells
- involved in B cell activation
37
Q
What is an IgM antibody?
A
- first classes of antibody secreted after an antigen arrives
- effective in forming immune complexes
38
Q
What is an IgA antibody?
A
primarily in glandular secretions: mucus, tears, saliva
39
Q
What is the 7 actions of antibodies?
A
- neutralization of antigen binding sites
- precipitation and agglutination
- formation of immune complex
- activation of complement
- attraction of phagocytes
- opsonization
- increasing phagocyte efficiency
- stimulation of inflammation
- prevention of bacterial and viral adhesion
