LEC 2 Exam.txt

• This is Starling’s Law of Capillaries:
  1. At the arterial end of the capillary, the hydrostatic forces are very high, which will tend to force fluids into surrounding tissues. Note: hydrostatic forces are outward (from the capillary) directing.
  3. Also at this end, the oncotic and osmotic forces are low compared to the hydrostatic forces, so the hydrostatic forces will dominate. Note: oncotic and osmotic forces are inward (to the capillary) directing.
  5. At the venule end of the capillary, the hydrostatic forces are weak, which will NOT force fluids into surrounding tissues.
  7. While at this end, the oncotic and osmotic forces are very high compared to the hydrostatic forces, so the oncotic/osmotic forces will dominate.
• About 90% of the fluid forced out beginning at the arterial end will be recovered prior to the venule end.

Titi seemed to differentiate osmotic from oncotic by way of saying that osmotic is a “salt” or Sodium thing whereas oncotic is a “protein” thing.

Wiki says: “Oncotic pressure, or colloid osmotic pressure, is a form of osmotic pressure exerted by proteins in blood plasma that usually tends to pull water into the circulatory system.”

The book states on page 683: “Osmotic pressure generated by blood colloids (such as plasma proteins).”

25% - right, and 75% - left

• • Collect interstitial fluid to maintain balance.
  • Filtering of interstitial fluid through lymphoid tissue containing lymphocytes and “other defensive cells” to promote immunity.

• • Are found almost everywhere that blood capillaries are found.
  • They are more permeable than blood capillaries.
  • Blind-ended microscopic
  • Originating in the villi of the small intestine are called lacteals.
  • Single layer of flattened endothelial cells

• • Unlike the arterial system, they get bigger instead of smaller!!!
  • The entire system provides for (fluid balance) and filtering and monitoring of fluids for antigens via the T & B cells within the lymph nodes and tissues.

• 1. The pressure gradient created via respiration.
  3. The milking effect created by skeletal muscle contractions.
  5. The very great number of one-way semilunar valves within the lymph system.

• • Each lymph node has many afferent vessels feeding it, but only 1 or 2 efferent vessels emptying it via the hilum.
  • The afferent deliver unfiltered lymph.
  • The efferent vessels deliver filtered lymph.

• 1. Palatine are the largest and most often infected.
  3. Lingual is located at the base of the root of the tongue.
  5. pharyngeal is at the top of the Nasopharynx and is often called the adenoids
• The function of the tonsils is to guard against bacterial invasion of the nasal and oral cavities. Their “strategy” is to invite & engulf bacteria into crypts to be destroyed by T lymphocytes.

• • Spleen
  • Lymph Nodes
  • Thymus
  • Tonsils

• • Cancer of the lymph tissue.
  • Hodgkin
  • non-Hodgkin

• • Is a swelling in an area of the body due to an “ineffective” lymph system.
  • It can be caused by surgical removal of lymph nodes and vessels as with a mastectomy causing lymphedema of the arm. In these cases the lymph system almost always grows back.
  • The second cause of lymphedema is seen more in tropical areas and is caused by a lymph infection of the parasitic worm – filarial. It can lead to elephantiasis.

• These are “born with” and they are not species specific.
  1. Physical barrier – skin & mucus
  3. Phagocytes – Neutrophils and Monocytes
  5. Immunological Surveillance
  7. Interferon - produced only be infected cells, which are not “saved”, in an effort to save nearby cells.
  9. Compliment
  11. Inflammatory response
  13. Fever

• 1. Neutrophils - 60-70% of WBC
  3. Monocytes - 3-8% of WBC
  5. Eosinophils - 2-4% of WBC

• • Cell-mediated: T-Cells react to abnormal (e.g. cancerous) and pathogens. Activated T-Cells do NOT respond to antigens. They work to destroy from within the cell.
  • Humoral (fluid): B-Cells produce antibodies that attach to antigens (proteins on the surface of the specific cell or virus) for action by T-Cells. They cannot cross the cell boundary.

• Inherited or innate immunity are those mechanisms that you are born with ready to act. Shades of gray: 1) being born with antibodies from mom’s placenta does NOT count as inherited; 2) neither does the trillions of naïve T & B-cells count as inherited, because although you are born with them and they are “ready-to-go”, they do need to be activated by some outside influence.
• • Natural-Active - Acquired immunity by having the disease.
  • Natural-Passive - Antibodies cross the placenta or are received in mother’s milk.
  • Artificial-Active - Weakened or dead antigens given via “vaccination”.
  • Artificial-Passive - Antibody given by injection.

Active immunity lasts longer than passive immunity.

Presumably because any “active” process results in your own body creating millions of its own clones, that is you’ve created a much larger quantity of antibodies or antibody producing cells, whereas any passive process gives you a limited amount of antibodies and NO means to replicate them.

• • Natural Killer (NK) cells comprise 15% of the lymphocyte population, but are neither T or B cells. They are innate defense, that is non-specific, and will kill many types of cancer and virus infected cells.
  • Helper T cells (The “CD4” subset of T-Cells) stimulate the response of T and B-Cells.
  • Cytokines secreted by Cytotoxic (CD8) T-Cells (effector, not memory) they are signaling molecules that further facilitate physical and chemical attack by promoting B-Cell division, plasma cell maturation, and antibody production.
  • Suppressor T-Cells moderate immune response.
  • Note: The CD4 & CD8 subset of T-Cells are important in the diagnosis of AIDS.

In the “T-dependent” areas of the Lymph Nodes and the Spleen. The book in figure 21-25 also says the liver.

• • Proteins of the family immunoglobulins (Ig) produced by plasma cells a.k.a. B-Cells

• • 2 heavy & constant polypeptide chains (the base) bound with 2 disulfide bonds to 2 sets of chains forming a Y, with constant sections close to the bonds and variable sections further out. In addition the outer chains are “light”, while the inner chains are “heavy”.
  • I am MAD at GE for not hiring me.
  • IgM First released during immunization. Elevated levels indicate INFECTION.
  • IgA Fights local infection; major antibody present in mucus, saliva, and tears.
  • IgD Don’t know…
  • IgG Found in Blood, Lymph, Cerebrospinal fluid (CSF): Toxin neutralization; Opsonization; Compliment, Immobilization of bacteria.
  • IgE Allergic reactions and parasitic worm infections

“Complement” enzymes marking microbes for destruction by phagocytic cells.

Name for as group of about 20 inactive enzymes in the plasma or on cell surfaces. They have names like C1, C4b, and C5a. Compliment molecules are activated in a cascade of chemical reactions that are triggered by both innate and adaptive mechanisms. Ultimately this cascade causes the lysis of the cells that initiated the response.

• 1. Specificity - T & B respond to molecular structure of antigen.
  3. Versatility - An “army” of cell clones with millions of different receptors.
  5. Memory - Faster, stronger response in subsequent exposures.
  7. Tolerance - 1) Never attack SELF; 2) Tolerance is a property of immunity that has FAILED during an autoimmune disease.

• • This is NOT the same as an immunodeficiency disease.
  • In the case of an autoimmune disease, the immune system is not compromised, but it is misdirected and recognizes SELF as an enemy.

The clonal selection theory for antigen destruction, first proposed by Sir MacFarlane Burnet in 1959 has two tenets. First: the body contains an enormous number of diverse clonal cells, each committed by certain of its genes to create a specific antibody. We know these as both T and B-Cell lymphocytes. Second, antigens entering the body will contact the specific naïve T or B-Cell and connect via their epitope. This will trigger a massive replication of this T/B-cell into effector and memory T/B-Cells.

Specific portion of an antigen that elicits an immune reaction.

• • Oxygen intake
  • Carbon dioxide expulsion
  • Vocalization
  • Body pH homeostasis
  • Removal & destruction of airborne pathogens & toxins

The renal system moderates via bicarbonates

• • Nasopharynx
  • Oropharynx
  • Laryngopharynx
  • Larynx

• • Trachea
  • Bronchi (Bronchus - singular)
  • Bronchioles - down to lumen < 1 mm - sometimes called terminal bronchioles, or the last bronchioles that serve solely to conduct air.

• • Transport of air
  • Filtering of
  • Humidifying of
  • Warming of

• • All "respiratory" zones contain alveoli.
  • Respiratory bronchioles have thin gas-exchanging walls, which
  • transition into alveolar ducts, which
  • end in one or more alveolar sacs, the walls of which consist of
  • numerous alveoli grouped together

Gas exchange ONLY.

• • Lined with ciliated pseudostratified epithelium with a dense uderlying vasculature of blood vessels to warm air and goblet (mucus producing) cells.
  • Filter & trap inspired particulate matter
  • Helps humidify air
  • Sweep mucus to pharynx where it is swallowed

• • Pseudostratified columnar epithelium
  • Goblet cells - mucus

• • Right lung has 3 lobes - superior, middle, and inferior - with transverse and oblique fissures separating them.
  • Left lung has only 2 lobes because of the room taken up by the heart - superior and inferior - with only an oblique fissure separating them.
  • Thin double layer of pleural membranous covering.
  • Visceral pleura with connective tissues anchoring it to the lungs.
  • Parietal pleura is anchored to the thoracic walls and the diaphragm.
  • There is a small amount of serous fluid in between for friction abatement.
  • The pressure here is less than that of the lungs.

• • Trachea has cartilage rings
  • Bronchus has cartilage plates
  • Bronchioles have NO cartilage.

• • Pseudostratified columnar epithelium
  • Simple columnar epithelium
  • Cuboidal epithelium
  • Simple squamous epithelium

Their numbers decrease

• • Pneumocyte I - Gas-exchange
  • Pneomocyte II - Produce surfactants

• • The surfactant coats the inside surface of each alveolus simple squamous epithelium.
  • The "outside" is basement membrane which is shared "basement membrane" with the capillaries.
  • The surfactant reduces surface tension of fluids. This attraction of water molecules would otherwise cause the alveoli to stick shut as air moves in and out.
  • Also the concentration of surfactant is higher in smaller alveoli, thus opposing the Young-LaPlace law that would have air flow from smaller alveoli to larger ones (instead of out), and because of pressure differential, collapse the smaller alveoli.

Edema and excessive mucus production that causes coughing and difficulty breathing, especially expiration.

Chronic Bronchitis

• • BOOK: A collection of signs or symptoms, usually with a common cause that gives a clear picture of a pathological condition.
  • TITI: varying clinical symptoms, often with many causes.

• • COPD Chronic Obstructive Lung Disease.

• • TITI: Detached membrane (from the larynx?)
  • BOOK: Laryngitis, or inflammation of the mucus linings of the larynx, is characterized by edema of the vocal folds, resulting in hoarseness (dysphonia) or loss of voice. In children younger than 5 years, it may cause difficulty breathing, a condition often called croup.

• • TITI: Losing elasticity of or having fewer alveoli, i.e. "rooms" for gas exchange.
  • BOOK: Abnormal condition characterized by trapping of air in alveoli that causes them to rupture and fuse to other alveoli (thus reducing gas-exchange surface area). It is one of a number of conditions classified as a COPD.
  • When the alveoli stay “open”, it results in a “big chest” - a false look of power.

• • TITI: Cigarette smoker
  • BOOK: 75% of lung cancers are attributable to smoking, and in 40% of the most common form: non-small cell, it has already metastasized. 85% of the cancer in the U.S. is non-small cell.

• • TITI: Sore throat
  • BOOK: Inflammation of the pharynx is often caused by a viral infection. Dysphagia (difficulty swallowing) often accompanies it. Bacterial infection by Streptococcus is termed “strep throat”.

• • TITI: Obstructive disorder caused by spasm of the smooth muscles in the walls of the bronchioles.
  • BOOK: As well as inflammation (edema and excessive mucus production) of the mucus membranes.

• • TITI: Very contagious & caused by Mycobacterium.
  • BOOK: It is a chronic bacillus infection where inflammatory lesions called tubercles form around colonies of TB bacilli producing cough, fatigue, chest pain, weight loss and fever.

Labored breathing

Upper respiratory infection

• • TITI: Lower respiratory track - acute inflammation of tracheobronchial tree with excessive mucus that stagnates air flow.

• • TITI: Intra pleural space is normally at a lower pressure than the alveoli. If pleura is pierced, the elastic tissue in the lungs can deflate.
  • BOOK: Pleural spaces is always at a lower pressure than atmospheric.
  • In addition to the elastic fibers of the lungs that are always attempting to recoil, the surface tension of the fluid lining the alveoli is also trying to "come together", i.e. collapse the alveoli.

Air in the pleural space.

• • TITI: Inflammation of the nasal cavity mucus membrane - a sore nose.
  • Caused by the common cold (rhinoviruses) or flu (influenza viruses).

Chemotaxis, Diapedesis, Increased blood flow, and Increased vascular permeability.

• • Two that affect respiratory rate are CO₂, and pH.
  • Central: medulla oblongata monitors H⁺ in the cerebrospinal fluid. Acidosis (low pH) leads to hyperventilation.
  • Peripheral: Both the aortic arch and the carotid sinuses monitor the partial pressure of CO₂ or PCO₂. In this case an increase of PCO₂ above homeostatic levels is the most powerful stimulus to breath faster.

• • Hering-Breuer is the response to stretching of the lungs beyond a certain point stimulates stretch receptors within them. These receptors then send inhibitory impulses to the inspiratory neuron, relaxation of the inspiratory muscle occurs and expiration follows the Hering-Breuer expiratory reflex.
  • A similar scenario occurs during extreme exhalations.

• • This question is really about muscles used to accomplish each action.
  • Normal Inspiration: Diaphragm alone or in conjunction with the external intercostal muscles. (Intercostals force the rib cage up and out, increasing thoracic volume.
  • Forced Inspiration: Add to above the sternocleidomastoid, pectoralis minor, and serratus anterior, to further raise and expand the rib cage.
  • Normal Expiration: Ordinarily passive, i.e. simply relaxing muscles that have been contracted to inspire.
  • Forced Expiration: Contraction of the abdomen (rectus abdominis, external oblique, internal oblique, and transversus abdominis) and internal intercostals can create a very large pressure gradient.

• • TITI: Trachea is NOT part of the “upper”.
  • Upper: nose, pharynx, and larynx
  • Lower: trachea, bronchus, bronchioles, alveolar ducts ,and alveoli

• • Alveolar sacs
  • Alveolar ducts
  • Respiratory bronchioles (which are different from terminal or solely conducting bronchioles).

Conducting Zone Structures

• • There are 5 sinuses: 2 maxillary, 1 ethmoid, 1 sphenoid, and 1 frontal.
  • Their function is to produce mucus, act as lightening holes in the skull, and as vocal resonance chambers.
  • They are all connected to the nasal pharynx.

• • Pressure and Volume are inversely proportional at a constant Temperature.
  • As the volume of the lungs increase, the pressure decreases creating a pressure gradient with the air outside the body. Since greater pressure fluids flow to lower pressure areas, air flows INTO the lungs.
  • Likewise, as the volume of the lungs decreases, the pressure increases creating a pressure gradient with the air outside the body, resulting in air flows OUT of the lungs.

• • Eupnoea is normal breathing.
  • Dyspnea is a shortness of breath. It is a common symptom of many medical disorders.

• • P_B (Titi: Pat_m) is atmospheric pressure, or 760 mm Hg at sea level.
  • P_A is alveolar pressure. (Titi: P_a) P_v “intrapulmonary pressure”)
  • P_IP is intrapleural pressure.

Alveolar pressure will typically vary from atmospheric pressure (P_B) by 1 to 3 mm Hg

Intrapleural pressure will always be less than atmospheric pressure by 2 to 6 mm Hg. 2 after an exhalation, and 6 during peak inhalation.

• 1. 98.5% of O₂ is transported attached to hemoglobin as Oxyhemoglobin. Each hemoglobin molecule can bind with as many as 4 molecules of oxygen.
  3. 1.5% is simply dissolved in plasma.
  Notes:
  • Heme has a higher affinity (bonding potential) for carbon monoxide than it does for oxygen, so this makes carbon monoxide poisoning easier.
  • The partial pressure of oxygen is high in the lungs.

• 1. Dissolved in plasma: 7-10%
  3. Carbaminohemoglobin: ~20%
  5. Bicarbonate ion: ~70%

• • Alveoli – Capillaries; Pulmonary blood; O₂ IN & CO₂ OUT
  • Capillaries – Tissue; Systemic blood; O₂ IN & CO₂ OUT
  • Partial Pressures & Boyle’s Law always operate High to Low.
• Alveoli: PP O₂ ~ 104 mm Hg
• Pulmonary capillaries: PP O₂ ~ 40 mm Hg

• Arteriole blood PP O₂ ~ 104 mm Hg
• Tissue blood PP O₂ < 40 mm Hg

• Arteriole blood PP CO₂ ~ 40 mm Hg
• Tissue blood PP CO₂ > 45 mm Hg

• • The pneumotaxic center is a network of neurons in the pons. It antagonizes the apneustic center, cyclically inhibiting inspiration. It limits the burst of action potentials in the phrenic nerve, effectively decreasing the tidal volume and regulating the respiratory rate. It's absence will increase in depth of respiration and a decrease in respiratory rate.
  • Medulla Oblongata sets the basic rhythm via the Medullary Rhythmicity Area.
  • This can be over-ridden by the PONS, which in turn can over-ridden by the Cerebral Cortex, where for example, we may consciously “hyperventilate” or breath to sing.
  • There are 3 sets of receptors that influence the autonomic process:
    1. Chemoreceptors, e.g. excess H⁺ ions, or acidosis, will trigger hyperventilation for pH balance. These are in the aortic arch and carotid sinuses, and they send their data to the PONS.
    3. Baroreceptors, e.g. the partial pressure of O₂ or CO₂, are collocated with the chemoreceptors, and they also influence via the PONS.
    5. Stretch receptors in the lungs and thorax signal directly to the medulla oblongata.

2800 to 3000 ml - about 1.5 ml per minute