7
differentiate between lymph, lymphatic vessel, lymphatic tissues, lymphatic organs
Lymph
• Fluid, similar to plasma, very little protein – essentially extracellular
fluid → called lymph when it enters lymphatic capillary/vessel
• Chemical composition varies in different places (in intestines (more
creamy from fat absorption), after lymph nodes (more lymph cells))
Lymphatic vessels
• Transport the lymph; mechanisms of flow similar to venous return
Lymphatic tissues
• Composed of aggregates of lymphocytes and macrophages that
populate many organs in the body
Lymphatic organs ▪Defense cells are especially concentrated in these
organs
• Separated from surrounding organs by connective tissue capsules
describe the 3 lines of defense
1. Skin and mucous membranes
2. Innate defense mechanisms
• Leukocytes and macrophages, antimicrobial proteins, natural killer
cells, inflammation, and fever
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
3. Adaptive immunity
• Defeats a pathogen and leaves the body with a “memory” of it so it
can defeat it faster in the future
innate= 1+2/ adaptive =3
describe the 3 stages in humoral immunity
Recognition
● Recognition in humoral immunity
○ Immunocompetent B cell has thousands of surface
receptors for one antigen
○ Activation begins when an antigen binds to several of
these receptors, links them together, and is taken into
the cell by receptor-mediated endocytosis
■ Small molecules are not antigenic because they cannot link multiple
receptors together (haptens)
○ B cell processes (digests) the antigen
■ Links some of the epitopes to its MHC-II proteins
○ Displays these on the cell surface
Attack and Memory
● Attack in humoral immunity
○ Antibodies bind to antigen, render it harmless, “tag it”
for destruction
● Memory in humoral immunity
○ Some B cells differentiate into memory cells
describe boyles law
the pressure of a gas increases as its volume decreases, assuming constant mass & temp
p1v1=p2v2
what is hemoglobin? what is it purpose? describes its saturation to molecule ratio.
Hemoglobin
• Four protein (globin) portions
• Each has a heme group, binds one O2 to an iron atom
• Oxyhemoglobin (HbO2)—O2 bound to hemoglobin
• Deoxyhemoglobin (HHb)—hemoglobin with no O2,
Hb serves as a buffer for H+
One hemoglobin can carry up to 4 O2
100% saturation Hb with 4 O2
molecules per Hb
50% saturation Hb with 2 O2
molecules per Hb
describe the immunity fxn of the lymphatic system
Excess filtered fluid picks up foreign cells and chemicals from the tissues
• Fluid passes through lymph nodes where immune cells stand guard against
foreign matter
• Activates a protective immune response if needed
describe all the protective cells
Neutrophils
• Can kill using phagocytosis and
digestion
• Can kill by producing a cloud of
bactericidal chemicals
• Lysosomes degranulate—discharge
enzymes into tissue fluid causing a
respiratory burst
• Creates a killing zone around
neutrophil, destroying several bacteria
- Includes H2O2, HClO, O2-
Eosinophils
• Found especially in mucous membranes
• Guard against parasites, allergens
(allergy-causing agents), and other
pathogens
• Kill tapeworms and roundworms by
producing superoxide, hydrogen peroxide,
and toxic proteins
• Promote action of basophils and mast cells
• Phagocytize antigen–antibody complexes
• Limit action of histamine and other
inflammatory chemicals
Basophils
• Secrete chemicals that aid mobility and action of other
leukocytes
• Leukotrienes: activate and attract neutrophils and
eosinophils
• Histamine: a vasodilator, which increases blood flow
• Speeds delivery of leukocytes to the area
• Heparin: inhibits clot formation that would impede
leukocyte mobility
Mast cells also secrete these substances
• Type of connective tissue cell very similar to basophils
leukocytes
• Leukotrienes: activate and attract neutrophils and
eosinophils
• Histamine: a vasodilator, which increases blood flow
• Speeds delivery of leukocytes to the area
• Heparin: inhibits clot formation that would impede
leukocyte mobility
Mast cells also secrete these substances
• Type of connective tissue cell very similar to basophils
Lymphocytes
• Three basic categories: T, B, and NK cells
• Circulating blood contains
• 80% T cells
• 15% B cells
• 5% NK cells
• Many diverse functions
• NK cells are part of innate immunity, all others are part of adaptive
immunity; helper T cells function in both
Monocytes and Macrophages
Monocytes—emigrate from the blood into connective tissues
and transform into macrophages
Macrophage system—all the body’s avidly phagocytic cells,
except leukocytes
• Wandering macrophages: actively seek pathogens
• Widely distributed in loose connective tissue
• Fixed macrophages: phagocytize only
pathogens that come to them
• Microglia—in central nervous system
• Alveolar macrophages—in lungs
• Stellate macrophages—in liver
what antibodies are involved in the primary & secondary humoral response
primary-
IgM peak around 10-12 days
IgG peak around 15-17 days
secondary
IgM- slight peak around 5-7days
IgG big peak around 5-7 day
describe charles law
Volume of a gas is directly proportional to its absolute
temperature
• Affects expansion of lungs
-On a cool day, 16°C (60°F) air will increase its temperature by 21°C
(39°F) during inspiration
• Inhaled air is warmed to 37°C (98.6°F) by the time it reaches the
alveoli
• Inhaled volume of 500 mL will expand to 536 mL and this thermal
expansion will contribute to the inflation of the lungs
what are the 3 ways that carbon dioxide can be transported
Carbon dioxide is transported in the blood in three forms:
• Gas dissolved in plasma (5% of CO2)
• Carbonic acid (90% of CO2)
• Carbamino compounds, mostly carbaminohemoglobin, HbCO2
(5% of CO2)
describe all the lymphatic cells and their fxns
Neutrophils—antibacterial
Natural killer (NK) cells—large lymphocytes that attack and destroy bacteria, transplanted tissue, host cells infected with
viruses or that have turned cancerous
T lymphocytes (T cells)—mature in thymus
B lymphocytes (B cells)—activation causes proliferation and differentiation into plasma cells that produce antibodies
Dendritic cells
• Branched, mobile APCs found in epidermis, mucous membranes, and lymphatic organs
• Alert immune system to pathogens that have breached the body surface
Reticular cells
• Branched stationary cells that contribute to the stroma of a lymphatic organ
Macrophages- Phagocytize debris, bacteria, dead neutrophils, foreign matter
describe the course of a fever
1. infection & pyrogen secretion
2. hypothalamic thermostat is reset to higher set point
3. onset- body temp rises
4. stadium- body temp oscillates around new set point
5. infection ends, set point returns to normal
6. defeverance- body temp returns to normal
compare the conducting and respiratory zones
Conducting zone of respiratory system
• Includes those passages that serve only for airflow
• No gas exchange
• Nostrils through major bronchioles
Respiratory zone of the respiratory system
• Consists of alveoli and other gas exchange regions
compare bronchodilation & bronchoconstriction
Two factors influence airway resistance: bronchiole diameter
and pulmonary compliance
Bronchodilation (increase in diameter)
• Epinephrine and sympathetic stimulation
• Increase airflow
Bronchoconstriction (decrease in diameter)
• Histamine, parasympathetic nerves, cold air, and chemical
irritants
• Decrease airflow
• Suffocation can occur from extreme bronchoconstriction brought
about by anaphylactic shock and asthma
normal levels of pH, PCO2, PO2 and how are they regualted?
Rate and depth of breathing adjust to maintain arterial blood
levels of:
• pH 7.35 to 7.45
• PCO2 40 mm Hg
• PO2 95 mm Hg
Brainstem respiratory centers receive input from central and peripheral chemoreceptors that monitor composition of CSF
and blood
Most potent stimulus for breathing is pH, followed by CO2,
and least significant is O2
differentiate between primary & secondary lymphatic organs
primary-
Red bone marrow is involved in hematopoiesis (blood formation) and immunity
Thymus—member of the endocrine, lymphatic, and immune systems
• Houses developing lymphocytes
• Secretes hormones regulating their activity
• Bilobed organ located in superior mediastinum between sternum and
aortic arch
• Degeneration
(involution) with age
secondary-
Lymph nodes—most numerous lymphatic
organs
• About 450 in typical young adult
• Serve two functions
• Cleanse the lymph
• Act as a site of T and B cell activation
Elongated, bean-shaped structure with
hilum
Enclosed with fibrous capsule with
trabeculae that divide interior into
compartments
• Stroma of reticular fibers and reticular
cells
tonsils
spleen- the body’s largest lymphatic organ
Parenchyma exhibits two types of tissue
• Red pulp: sinuses filled with erythrocytes
• White pulp: lymphocytes, macrophages surrounding small
branches of splenic artery
LO 2° Lymphatic Organs
compare cellular & humoral immunity
Cellular (cell-mediated) immunity
• Lymphocytes directly attack and destroy foreign cells or diseased host
cells
• Rids the body of pathogens that reside inside human cells, where they are
inaccessible to antibodies
• Kills cells that harbor them
Humoral (antibody-mediated) immunity
• Mediated by antibodies that do not directly destroy a pathogen but tag it for
destruction
• Many antibodies are dissolved in body fluids (“humors”)
• Effective against extracellular viruses, bacteria, yeasts, protozoans, and
molecular (noncellular) disease agents such as toxins, venoms, and
allergens
describe the cells of the alveolus
Squamous (type I) alveolar cells – cover
95% of alveolar surface area
Great (type II) alveolar cells; secrete
surfactant; cover 5% of alveolar surface
area
Alveolar macrophages (dust cells) most
numerous cells in lungs
describe pulmonary compliance. what does surfactant have to do w it? what is surfactant?
Pulmonary compliance
• Ease with which the lungs can expand
• Change in lung volume relative to a given pressure change
• Compliance is reduced by degenerative lung diseases in
which the lungs are stiffened by scar tissue - ↑ resistance
• Compliance is limited by the surface tension of the water
film inside alveoli
• Surfactant secreted by great cells of alveoli disrupts hydrogen
bonds between water molecules and thus reduces the surface
tension. This ↑ compliance = ↓ resistance
• Infant respiratory distress syndrome (IRDS)—premature babies
lacking surfactant are treated with artificial surfactant until they can
make their own
describe hypocapnia & hypercapnia. describe how hyperventilation & hypoventilation play into these conditions.
Hypocapnia
• PCO2 less than 37 mm Hg (normal 37 to 43 mm Hg)
• Most common cause of alkalosis
Hypercapnia
• PCO2 greater than 43 mm Hg
• Most common cause of acidosis
CO2 + H2O ← H2CO3 ← HCO3− + ↓ H+
CO2 + H2O → H2CO3 → HCO3− + H+
Hyperventilation can be a corrective homeostatic response to
acidosis
Hypoventilation can be a corrective homeostatic response to
alkalosis
describe metastasis and how it can effect lymph nodes.
Metastasis—cancerous cells break free from original tumor,
travel to other sites in the body and establish new tumors
• Metastasizing cells easily enter lymphatic vessels
• Tend to lodge in the first lymph node they encounter
• Multiply there and eventually destroy the node
• Swollen, firm, and usually painless
• Tend to spread to the next node downstream
• Treatment of breast cancer is lumpectomy, mastectomy,
along with removal of nearby axillary nodes
describe all the cells involved in cellular immunity
Cytotoxic T (TC) cells: killer T cells (T8, CD8, or CD8+)
• “Effectors” of cellular immunity; carry out attack on enemy cells
Helper T (TH) cells
• Help promote TC cell and B cell action and innate immunity
Regulatory T (TR) cells: T-regs
• Inhibit multiplication and cytokine secretion by other T cells; limit
immune response
• Like TH cells, TR cells can be called T4, CD4, CD4+
Memory T (TM) cells
• Descend from the cytotoxic T cells
• Responsible for memory in cellular immunity
what resp muscles are used in inspiration? expiration?
inspiration- external intercostals & diaphragm
expiration- internal intercostals & diaphragm
Composition of Air
• 78.6% nitrogen
• 20.9% oxygen
• 0.04% carbon dioxide
• 0% to 4% water vapor, depending on temperature and
humidity
• Minor gases argon, neon, helium, methane, and ozone
describe all the types of hypoxia.
Hypoxia
• Deficiency of oxygen or the inability to use oxygen
• A consequence of respiratory diseases
Hypoxemic hypoxia
• State of low arterial PO2
• Usually due to inadequate pulmonary gas exchange
• Many possible causes:
• Oxygen deficiency at high elevations, impaired ventilation:
drowning, aspiration of a foreign body, respiratory arrest,
degenerative lung diseases
Ischemic hypoxia
• Inadequate circulation of blood
• Congestive heart failure
Anemic hypoxia
• Due to inability of the blood to carry adequate oxygen
Histotoxic hypoxia
• Metabolic poisons (for example, cyanide) prevents O2 use
in tissue
Hypoxia is often marked by Cyanosis (blueness of skin)