Unit L The Respiratory System Bozeman Respiratory System

Unit L: The Respiratory System

Bozeman: Respiratory System Intro

Surviving Thin Air The high mountains of the Himalayas have claimed the lives of even the world’s top mountain climbers The air at the height of the world’s highest peak, Mt. Everest is so low in oxygen that most people would pass out instantly if exposed to it

Surviving Thin Air Twice a year, flocks of geese migrate over the Himalayas They are able to fly at such a high altitude because of the efficiency of their lungs These birds have blood with hemoglobin with a very high affinity for oxygen This adaptation allows them to carry large amounts of oxygen to their tissues to exchange with carbon dioxide

Standards I can outline the 4 major aspects of the process respiration. I can describe structure and function of the airway. I can describe structure and function of alveoli. I can describe the processes of inhalation and exhalation. I can outline the nervous control of breathing.

So what is Respiration? The process of gas exchange, often called respiration is the interchange of O 2 and CO 2 between an organism and its environment

Crash Course – Respiration Part 1

Mechanisms of Gas Exchange There are three sequences of gas exchange; how respiration occurs 1. Breathing 2. Transport of gases by the circulatory system 3. Exchange of gases with body cells

The Four major aspects of respiration 1. Breathing (inhaling and exhaling) 2. External respiration (gas exchange at the lungs) 3. Internal respiration (gas exchange at the tissues) 4. Cellular respiration (making ATP in cells)

Animals exchange O 2 and CO 2 across moist body surfaces Animals have a respiratory surface which is often moist. This moist layer allows O 2 and CO 2 to diffuse easily and quickly into the circulatory system Some animals, like the earthworm, use their entire skin as a gasexchange organ In most animals specialized body parts provide large respiratory surfaces for gas exchange

Gills are adapted for gas exchange in aquatic environments In a fish, gas exchange is enhanced by ventilation and the countercurrent flow of water and blood

The tracheal system of insects provides direct exchange between the air and body cells Land animals exchange gases by breathing air Tracheal systems in insects Transport O 2 directly to body cells through a network of finely branched tubes

Terrestrial vertebrates have lungs In mammals, air inhaled through the nostrils, nasal cavity, passes through the pharynx and larynx into the trachea, bronchi, and bronchioles

Terrestrial vertebrates have lungs The bronchioles end in clusters of tiny sacs called alveoli and this is where gas exchange occurs

Connection: Smoking is a deadly assaults on our respiratory system Mucus and cilia in the respiratory passages Protect the lungs Can be destroyed by smoking A single drag on a cigarette exposes a person to over 4000 chemicals, 50 of which are known carcinogens. People die 1314 years younger. Smoking can also cause emphysema; alveoli loose their elasticity and deteriorate reducing lung capacity

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Breathing ventilates the lungs Breathing: is the alternation of inhalation and exhalation The contraction of rib muscles and the diaphragm Expands the chest cavity and reduces air pressure in the alveoli (negative pressure breathing) Vital capacity is the maximum volume of air we can inhale and exhale but our lungs still hold a residual volume

Breathing ventilates the lungs Air flows in one direction; through the more efficient lungs of birds

Breathing is automatically controlled We can control some of our breathing but we have automatic control centers that ensure coordination between the circulatory system and the respiratory system. In your brain, there areas called Pons Medulla Oblongata The Medulla control center signal the diaphragm and rib muscles to contract The pons smooths out the basic rhythm of breathing set by the medulla

p. H and CO 2 levels The medulla control center monitors the CO 2 levels in the blood and regulates breathing rate in response. The way it regulates the CO 2 levels is by monitoring p. H levels When CO 2 increases in your blood and Cerebral-spinal Fluid, p. H drops slightly This is because the CO 2 goes into the blood and reacts with water to produce carbonic acid This results in your medulla control center sending a signal to increase respiration and eliminate more CO 2

p. H and buffers – Negative Feedback Loop

Secondary control over breathing in the Aorta! There are sensors in your aorta and carotid artery that monitor concentrations of O 2 and CO 2 that send messages to nerves which relay the information to the medulla. This may result in conditions of low oxygen, like high elevation. Hyperventilation – suspends breathing because too much CO 2 has been removed from the blood.

Blood transports respiratory gases Transport The of gases in the body heart pumps oxygen-poor blood to the lungs Where it picks up O 2 and drops off CO 2 Then the heart pumps the oxygen-rich blood to body cells Gas Where it drops off O 2 and picks up CO 2 transport and exchange in the body Gases diffuse down partial-pressure gradients in the lungs and the tissues

Hemoglobin carries O 2 and helps transport CO 2 and buffer the blood Hemoglobin in red blood cells Consists of four polypeptides chains of two types Attached to each polypeptide is a chemical group called heme (green) at which the center is a iron group (black) Every hemoglobin carry up to four O 2 molecules Transports oxygen, helps buffer the blood and carries some CO 2 The partial pressure of oxygen in the tissue reflects how much oxygen the cells are using

Crash Course: Respiration Part 2

Hemoglobin carries O 2 and helps transport CO 2 and buffer the blood Most CO 2 enters the red blood cells, where some combines with hemoglobin. The rest reacts with water molecules forming carbonic acid Red blood cells contain an enzyme that accelerates this reaction to break them apart into hydrogen ion and a bicarbonate ions Hemoglobin will then bind the H+ ion, minimizing the change in blood p. H CO 2 is transported as bicarbonate ions in the plasma, where they are carried to the lungs This process is reversed in the lungs so the CO 2 diffuses from the alveoli to the exhaled air

Words to know! Oxyhemoglobin: O 2 attached to hemoglobin (HBO 2) Carbaminohemoglobin – CO 2 attached to hemoglobin (HBCO 2) Reduced hemoglobin – once oxygen is released into tissues from hemoglobin (HHB) Bicarbonate ions – is alkaline and helps buffering p. H Carbonic anhydrase – enzyme that balances the p. H of blood by converting CO 2 and H 20 into bicarbonate ions and hydrogen ions

Respiration Comparison Internal Respiration External Respiration

Connection - The human fetus exchanges gases with the mother’s bloodstream A human fetus exchanges gases with maternal blood in the placenta Fetal hemoglobin has a higher affinity for oxygen transfer from maternal blood At birth, increasing CO 2 in the fetal blood Stimulates the breathing control centers to initiate breathing because the baby’s lungs are filled with amniotic fluid.