bio262-exam3

After birth and into adulthood the bone marrow is the primary source of hemopoiesis.

Plasma accounts for 55% of the total blood composition. The formed elements include all the cells and cell fragments and account for the remaining 45%.

• The blood plasma is the liquid that contains dissolved substances.
• RBCs, WBCs, & platelets

The contents of the plasma include 91.5% water, 7% proteins, and 1.5% solutes

Most agranular leukocytes live 100-300 days and granular leukocytes about 12 hours to 3 days (in contrast to the 120 days for a RBC).

granular leukocytes - Neutrophils, Eosinophils and Basophils

agranular leukocytes - Lymphocytes and Monocytes

The erythrocytes develop originally from a reticulocyte in the red bone marrow. The entire process is stimulated by the hormone erythropoietin (EPO) that is secreted by the kidneys whenever oxygen levels in the blood go down.

• 1. Oxygen carrying capacity of blood falls (hypoxia)
• 2. Kidneys release erythropoietin (EPO) into the blood
• 3. The EPO travels to the bone marrow to stimulate erythropoiesis (in addition to vitamin B12 and globin)
• 4. Results in increased number of RBC’sIncreased oxygen now carried in the blood.

iron, B12, & globin

• A+, A-
• B+, B-
• AB+, AB-
• O+, O-

An antigen is a cell marker that is found on the surface of the red blood cell. It is a way that a cell is “recognized” or identified as part of the host or “self”.

Antibodies are found in the plasma and will produce an immune response or cause agglutination (clumping) if they come in contact with a foreign antigen.

• 1) Vascular Spasm or vasoconstriction
• 2) Platelet Plug Formation
• 3) Blood clotting or coagulation.

Platelet adhesion

• 1) Platelet adhesion,
• 2) Platelet release action
• 3) Platelet aggregation and formation of the plug

The extrinsic pathway occurs when damaged tissue releases TF (tissue factor). The TF eventually is converted into prothrombinase. It is very rapid in comparison to the intrinsic pathway since it does not require as many steps to form the prothrombinase.

The intrinsic pathway occurs when the endothelial cells become damaged and provide signals to begin releasing prothrombinase from inside the blood vessel. (This is also how blood in a collection tube will clot as well) It takes several minutes or longer than the extrinsic pathway to form the prothrombinase.

insoluble fibrin clot will tighten over time and pull the edges of the damaged vessel together.

• The insoluble fibrin clot will tighten over time and pull the edges of the damaged vessel together. The platelets contain a very high
• concentration of actin and myosin which are stimulated to contract in aggregated platelets

Normally, clots dissolve in a process called fibrinolysis. This occurs when plasminogen is incorporated into a clot. Plasminogen activates into plasmin and once activated Plasmin begins to digest the previously insoluble fibrin threads into soluble fibrin threads.

To keep the clot from spreading, adjacent endothelial cells synthesize also produce two important secretions: Prostacylin (PGI2) and nitric oxide (NO). These substances inhibit platelet adhesion, activation, and aggregation in the area of the endothelium that has not been damaged so that the clot doesn’t abnormally spread to adjacent areas.

• Tissue Plasminogen Activator (TPA) and streptokinase convert plasminogen to plasmin and works to break down the fibrin threads to increase the clot dissolution. They can be injected into circulation or the clot directly but are only effective if done so in a timely manner.
• Wayfarin or Coumadin work by inhibiting the cellular activity of vitamin K which is needed for some of the clotting factors to form.
• Aspirin decreases Thromboxane A2 production.
• Plavix prevents ADP and therefore decreases adhesion of platelets.

Ventilation or breathing is the flow of air in and out of lungs. This is the physical movement of air into and out of the lungs.

• External (pulmonary) respiration is the gas exchange between the alveoli and pulmonary capillaries. This is where the oxygen enters the blood and carbon dioxide leaves the blood.
• Internal (tissue) respiration is the gas exchange between blood in systemic capillaries and tissue cells throughout the body. The oxygen is going to leave the blood here and the carbon dioxide enters the blood.

• Atmospheric Pressure (Patm) is the air outside the body and is about 760 mmHg on average.
• Intrapulmonic Pressure is the pressure inside the lungs or alveoli . It is also called alveolar pressure or Palv. This pressure varies with the respiratory cycles.
• Intrapleural Pressure is the pressure inside the pleural cavity. It is also called intrathoracic pressure.

changes in volume and subsequent changes in pressure that occur as a result of the diaphragm and external intercostals contracting

pressure inside the lungs drops

• diaphragm (mm.?)
• external intercostals
• internal intercostals
• abdominals

active

at rest - passive

• forced exhalation - active
• occurs when speaking loudly in public speaking, playing a wind instrument and singing. Now the internal intercostals and abdominal muscles are employed to further compress the lung volume and increases intrapulmonic pressure to drive the air out with more effort.

A characteristic change in volume which is produced by a change in pressure.

The compliance of lungs, due to the elasticity of the lung tissue and thoracic cage, and the lower surface tension in alveoli keeps them from collapsing and maximizes the surface area available for diffusion.

High compliance - high elasticity and low surface tension makes healthy lungs easy to expand and compliant.

decreased compliance - there is stiffness of the lungs

increased compliance - elastic recoil decreases and the lungs become “floppy” and are prone to collapse

• Restrictive Airway Diseases such as pulmonary fibrosis, TB and pneumonia
• drop in surfactant production
• decrease in the size of rib cage as seen in osteoporosis

obstructive airway diseases such as in Asthma, COPD or emphysema

• Tidal volume (TV) is the volume of one resting breath.
• Minute ventilation (MV) is the total volume of air inhaled and exhaled each minute.
• Inspiratory Reserve Volume (IRV) Amount in addition to tidal volume during a forceful or maximal inspiration
• Expiratory Reserve Volume (ERV) Amount in addition to tidal volume during a forceful or maximal exhalation
• Residual Volume (RV) Amount left in lungs between breaths. This averages about 1,000 mL’s in an average person.
• Vital Capacity (VC) = IRV + ERV + TV
• Total Lung Capacity (TLC) = IRV + ERV + TV + RV or (VC + RV)

spirometer

The Respiratory Membrane is the area over which O₂ & CO₂ must diffuse. It consists of the alveolar cells, epithelial basement membrane /capillary basement membrane and the endothelial cells of the capillary.

PO₂ of blood in systemic capillaries is 100mm Hg and PO₂ in tissue cells is 40mm Hg at rest. Therefore, O₂ flows out of capillaries and into the tissues throughout the body. CO₂ flows in the opposite direction from about 46mm Hg to 40mm Hg.

O₂ diffuses from the alveolar air where it’s partial pressure is 105mm Hg to the capillaries where PO₂ is 40mm Hg (high to low) and the CO₂ diffuses in the opposite direction from 46mmHg to 40mmHg

Gas exchange requires not only good ventilation of the alveolus, but also good perfusion of its capillaries. Ventilation–perfusion coupling is the ability to match ventilation and perfusion to each other.

Poor ventilation causes local constriction of the pulmonary arteries, reducing blood flow to that area and redirecting this blood to better-ventilated alveoli. Good ventilation, by contrast, dilates the arteries and increases perfusion so that most blood is directed to regions of the lung where it can pick up the most oxygen

Oxygen is transported by hemoglobin as well as dissolved in the plasma

• Four factors adjust the rate of oxygen unloading to the metabolic rates of different tissues:
• Ambient PO2.
• Temperature.
• The Bohr effect.
• BPG. (bisphosphoglycerate)

When factors such as a change in the partial pressure of oxygen and carbon dioxide occurs, an increase in hydrogen ions or decrease in pH occurs, or temperature increases this will cause more oxygen to be released from the hemoglobin.

• dissolved in the plasma (7%)
• carbaminohemoglobin (23%)
• bicarbonate ion (70%)

Once bicarbonate ions diffuse back out to plasma the – ions out must be balanced by + moving into cells. Chloride ions (-) diffuse back into RBC’s to balance charge.

Result of aerobic respiration.

Carbon monoxide binds to same binding site on hemoglobin as Oxygen.

medulla oblongata

the Medulla controls basic rhythm of breathing or regulates the rate and depth of breathing; the Pons regulates the transition from inhalation to exhalation

both the medulla and pons

pons

• the Hering Breuer Inflation Reflex
• stretch receptors in interstitial tissues when stimulated will trigger a forced exhalation so that the lungs do not stretch “too” much

central chemoreceptors in the medulla oblongata will bypass cortical control and force respiration when CO₂ levels get too high (pH gets too low)

pressure gradient for oxygen is lower, making it more difficult to pull oxygen into the blood. respiration will increase and oxygen saturation will decrease.

carotid bodies, aortic bodies

They respond to changes in H+ ion concentration, carbon dioxide and to a much lesser extent the oxygen level in the blood.

medulla oblongata

They respond to increases in H+ concentration in the brain’s extracellular fluid which can result from changes in blood PCO₂ or systemic changes in pH.

7.35-7.45

• Blood : 7.35 – 7.45
• Urine: 4.5 – 8.0 (more variability since it will depend on dietary intake and metabolic processes)

• alkalosis - pH goes above 7.4
• acidosis - pH goes below 7.4

intracellular buffers in the blood, also from respiratory and renal mechanisms

The respiratory response to altered plasma H ion concentration is very rapid (minutes) and keeps this concentration from changing too much until the more slowly responding kidneys (hours to days) can actually eliminate the imbalance.

in respiratory origin, CO₂ levels in the blood will be consistent with the direction of the imbalance (i.e. high CO₂, low pH)

stimulating/inhibiting ventilation

• vomiting - expels acids from the body (stomach contents)
• diarrhea - expels bases from the body (intestinal contents)

both decrease the body's ability to maintain normal pH ranges

• Radiation is the process by which the surfaces of all objects constantly emit heat in the form of electromagnetic waves.
• Conduction is the loss or gain of heat by transfer of thermal energy during collisions between adjacent molecules.
• Convection is the process whereby conductive heat loss or gain is aided by movement of air or water next to the body.
• Evaporation occurs when water vaporizes from the skin and membranes lining the respiratory tract.

all effect both heat loss & gain except evaporation (loss only)

The body monitors temperature through thermoreceptors.

• moderate hypothermia & heat exhaustion
• body retains thermoregulatory ability through homeostatic mechanisms

• profound hypothermia & heat stroke
• homeostatic mechanisms no longer function and body is unable to effect a temperature change

kg/m²

19-24.9

increased statistical risk for obesity related health concerns including hypertension, heart disease, diabetes, gastrointestinal and reproductive health problems.

can be misleading b/c muscle weighs more than fat, so a very muscular person could have a high BMI

A fever occurs when the hypothalamus resets the body’s thermostat or set point for body temperature.

Shivering occurs to help to increase body temperature to the new set point.

“breaking” a fever attempts to return to the body’s normal set point by sweating to release more heat and lower the temperature.