CH22 General Terms

Exam 3 Review: Chapter 22: General Terms

respiration - (A) The general term for the set of physiological mechanism used to carry oxygen from the atmospheric air to the mitochondria of every cell in the body; this involves bulk transport (ventilation, circulation) and diffusion (in alveoli, across the alveolar membrane into the erythrocytes and from the capillary beds through the interstitial fluid and into the cell cytoplasm and ultimately to the mitochondria); it is generally divided into three stages: (1) ventilation - the process of inhaling and exhaling, i.e., breathing; (2) external respiration - the diffusion of gases between the alveolar air and the blood; and (3) internal respiration - the diffusion of gases between the blood and the cells. (B) The oxidative process occurring within living cells by which the chemical energy of organic molecules is released in a series of metabolic steps, some occurring in the cytoplasm and some within the mitochondria, involving the consumption of oxygen and the liberation of carbon dioxide and water. aka - aerobic respiration

pulmonary ventilation - The process of exchange of air between the lungs and the atmosphere; it is sometimes divided into two components: (1) pulmonary ventilation - the total exchange of air, usually measured in liters/minute, and (2) alveolar ventilation - the effective ventilation of the alveoli in which gas exchange with the blood actually takes place; the movement of air is accomplished by the muscles of respiration under the autonomic control of the respiratory center in the medulla.

external respiration = alveolar gas exchange = pulmonary gas exchange - The interchange by diffusion (through the alveolar walls) along concentration gradients of oxygen and carbon dioxide between the alveolar air and the blood (plasma and suspended erythrocytes).

internal respiration = tissue gas exchange - The interchange by diffusion along concentration gradients of oxygen and carbon dioxide between the cells of the body and the interstitial fluid surrounding them, which in one sense is a process of nutrition.

cellular respiration - The oxidative process occurring within living cells by which the chemical energy of organic molecules is released in a series of metabolic steps with the production of ATP, some occurring in the cytoplasm and some within the mitochondria, involving the consumption of oxygen and the liberation of carbon dioxide and water; it is generally divided into two stages: (1) anaerobic glycolysis in the cytoplasm followed by (2) the citric acid cycle and oxidative phosphorylation at the electron transport chain in the mitochondria. aka - aerobic respiration

bulk flow - The movement of volumes of water and the solutes (unrestricted by size or charge) dissolved in that water under the influence of hydrostatic or osmotic pressures between cells in the tissues; the movement occurs rapidly through intercellular clefts (not across or through cell membranes); it is the major means of transport across capillary walls.

diffusion - The spontaneous intermingling of molecules or the particles of two or more substances as a result of random thermal motion within a solution (gas or liquid); it is the major means of transport for uncharged molecules across or through cell membranes; it is a form of passive transport which does not require additional ATP expenditure; the rate is dependent on the concentration gradient and the surface area available. aka - simple diffusion, free diffusion

upper respiratory system = conducting portion - The system of airways for ventilating the lungs, consisting of the nasal and oral cavities, the pharynx, the larynx, and the trachea which divides into a series of ever-smaller branches (about 23 anatomical divisions are recognized): the main bronchi, lobar bronchi, segmental bronchi, and so on, to the smallest bronchioles which do not have alveoli, the terminal bronchioles; all these branches have smooth muscle in their walls and are lined with bronchial epithelium, either pseudostratified columnar, columnar, or cuboidal; although the base airway diameter decreases with branching, the overall or total cross-sectional diameter increases tremendously so that peripheral resistance to air flow decreases as the air moves closer to the alveoli; the volume of the air in this system of airways is not available for actual gas exchange, so it has been referred to as the anatomic dead space (normally that is ~0.15 L, i.e., ~30% of a tidal volume).

lower respiratory system = respiratory portion - That portion of lung tissue where external respiration, actual gas exchange, takes place; all included structures have alveoli present in them; the structures involved include 2-5 "generations" or anatomical divisions lined by cuboidal epithelium with smooth muscle in their walls termed respiratory bronchioles, though minimal gas exchange occurs through their walls, then the final branches from the respiratory bronchioles, which have no muscle in their walls, and are lined by a squamous epithelium, the alveolar ducts, and, finally, the alveolar sacs and individual alveoli, which are lined by alveolar type I and type II squamous cells

List:

8. The anatomical and physiological defenses the body uses to provide clean "sterile" air to the respiratory membranes of the lungs.

           (1) the conducting portion of the airways are lined with mucous membranes:
                    (a) mucous traps dust particles and microbes
                    (b) mucous contains lysozyme and other non-specific resistance factors
                    (c) mucous contains IgA class antibodies for immune resistance
                    (d) much of the mucous lining is ciliated (trachea to smaller bronchioles) and ciliary motion sweeps trapped dust particles and microbes upward (the "mucociliary elevator") to be swallowed and sterilized in the acid bath of the stomach
                    (e) beneath the mucous membranes lining the conducting portion of airways are collections of lymphatic tissue, e.g., the tonsils, to provide immune defensive cells to prevent infection

(2) the respiratory portion of the airways where gas exchange occurs are patrolled by alveolar macrophages = "dust cells" which will phagocytize and attempt to destroy any dust particles or microbes which reach this location

Sketch and label:

2. A frontal section of the thorax illustrating the organs, membranes, and (cavities) spaces involved in ventilation.

The Frontal Section is on the right. To answer the question you need only name the lungs, diaphragm and intercostal muscles, parietal and visceral pleural membranes and the pleural cavities. See below. The more complete diagram of body cavities is provided at the bottom as a reminder of the larger relationships.