Popular in Human Physiology
verified elite notetaker
Popular in Department
This 3 page Class Notes was uploaded by Alesa Taylor on Friday April 8, 2016. The Class Notes belongs to 3014 at Mississippi State University taught by James Stewart in Spring 2016. Since its upload, it has received 22 views.
Reviews for Chapter 13
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 04/08/16
Chapter 17 Respiration is the entire sequence of events that results in the exchange of oxygen and carbon dioxide between the external environment and the mitochondria Mitochondrial respiration: O2 to produce ATP through cellular respiration and CO2 is produced as waste External respiration: also called ventilation – gas exchange occurs at the respiratory surface (lungs) Internal respiration: diffusion of gas into the tissues o Gas molecules move down their concentration gradients from the outside of the body to the inside (O2), from tissues into cells to mitochondria and in the opposite direction for (CO2) Unicellular and small multicellular living in aquatic environment are very small, with thin membranes o Use diffusion gradient to drive gas exchange directly with the environment Larger organisms, diffusion alone is too slow to maintain the rates of gas exchange needed to support metabolic requirements using bulk flow and diffusion and needs a respiratory system Ideal gas law: P = nRT / V o P = Total pressure o V = Volume of chamber o n = number of moles of gas molecules o R = gas constant o T = temperature in kelvin This states that the total pressure exerted by a gas is related to the number of moles of the gas and the volume of the chamber o Higher temperatures make molecules move faster Partial pressure- Air is a mixture of gases, (N=78%, O=21%, Argon=.9%, CO2=.03%) and a variety of trace gases. Dalton’s law of partial pressure states that in a gas mixture each gas exerts its own partial pressure. The sum of these partial pressures in a mixture yields the total pressure of the gas mixture in a chamber. Partial pressure is proportional to the number of gas molecules Respiration strategies- 1. Circulating the external medium through the body 2. Diffusion of gases across the body surface and circulatory transport 3. Cutaneous respiration 4. Diffusion of gases across a specialized respiratory surface and circulatory transport 4a. Gills-outpocketings (evaginations) of the body surface where gas exchange occurs in water 4b. Lungs- infoldings (invaginations) of the body surface forming internal body cavity that contains the external medium Ventilation- Active movement of the respiratory medium across the respiratory surface Non-directional - medium flows passed respiratory surface in unpredictable pattern – such as animals that wave gills Tidal - medium moving in and out of respiratory chamber in a back and forth movement Unidirectional - enters chamber at one point and exits at another point– flows in one direction. The circulatory system allows oxygen from the respiratory surface to be transported across long distances by bulk flow. The movement of blood through the respiratory surface can also affect exchange efficiency o With unidirectional ventilation, we observe flow blood in one of three ways relative to the flow of the medium (air): Co-current/Concurrent Countercurrent- Blood and medium flow in opposite directions. Blood leaving the gas exchange surface can approach that of the inhaled medium; as blood flows through the gas exchanger it becomes progressively more oxygenated, whereas the medium becomes progressively deoxygenated as it travels in the opposite direction; Partial pressure gradient favors diffusion of oxygen into the blood; most efficient Crosscurrent- Blood flows at an angle to the flow of medium. After they exit the gas exchange surface, capillaries coalesce into an efferent blood vessel. The partial pressure of O2 of the efferent vessel is higher than would be seen with concurrent flow but lower than that with countercurrent. First capillary has fully oxygenated medium, but subsequent ones encounter increasing levels of depletion. o Animals can respond to changes in their environmental O2 or metabolic demands o Alter rate or pattern of ventilation o Cannot change type of ventilation; cannot change anatomy Two major animal lineages have colonized terrestrial habitats o Vertebrates Amphibians Reptiles Birds Mammals o Arthropods Crustaceans Chelicerates (scorpions, spiders, etc.) Insects The major function of the respiratory system is to supply body with oxygen and dispose of carbon dioxide o Respiration- collective definition o Internal respiration: gas exchange at systemic capillaries o Cellular respiration: oxygen used by cell to convert glucose to ATP and Carbon dioxide is waste Conducting zone (1-7): Respiratory pathways that carry air to sites of gas exchange: nose, nasal cavities, paranasal sinuses, pharynx, larynx, trachea, bronchi Respiratory zone (8-9): Site of gas exchange: lungs, alveoli The nose is and airway for respiration, moistens and warms air, filters air of foreign particles, resonating chamber for speech, houses olfactory/smell receptors Mucosal linings- olfactory mucosa near roof of cavity; houses receptors Respiratory mucosa traps fine particles; ciliated cells move debris to pharynx where swallowed Nasal conchae- functions to cause turbulent air flow (heat) and increases mucosal surface area Paranasal sinuses- open into nasal cavity; functions to process air as nasal cavity Passageway that connects mouth and nasal cavity (superior) to larynx and esophagus (inferior) Nasopharynx- Serves only as air passageway Uvula- “little grape” closes off nasopharynx preventing food from entering nasal cavity Oropharynx- Posterior to mouth Laryngopharynx- Continuous with esophagus and larynx to conduct food and air. Larynx- attaches to hyoid bone, opens into laryngopharynx, continuous with trachea Laryngeal cartilages-Epiglottis “Upon the tongue”- guardian of airways, attaches to posterior aspect of tongue and internally to thyroid cartilage Trachea- Location: Descends from larynx, through neck into mediastinum and divides mid-thorax into primary bronchi. Structure: contains 16-20 C- shaped rings joined by fibroelastic connective fiber o Trachealis muscle- decreases the trachea diameter during swallowing, sneezing and coughing. o Carina “keel” marks the point where trachea branches to primary bronchi
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'