Respiration: An Introduction PDF

RESPIRATION: AN INTRODUCTION SBI3U(G) Breathing is the act of inhaling and exhaling air – why do we do it? We breathe to bring oxygen into contact with specialized tissue that maximizes the transfer of oxygen into our body. Oxygen is vital for creating the energy your cells need to survive....

RESPIRATION: AN INTRODUCTION SBI3U(G) Breathing is the act of inhaling and exhaling air – why do we do it? We breathe to bring oxygen into contact with specialized tissue that maximizes the transfer of oxygen into our body. Oxygen is vital for creating the energy your cells need to survive. 1) Aerobic Cellular Respiration process of obtaining needed energy from the chemical reaction of glucose and oxygen occurs in the mitochondria C6H12O6 + 6 O2 + 36ADP + 36Pi 🡪 6CO2 + 6 H2O + 36ATP Glucose From lungs Out from Sweat Used for: from food lungs Exhaled Growth Urinated Reproduction Reused Movement 1) Aerobic Cellular Respiration Most energy is ‘lost’ as heat, ~36% is used to make adenosine triphosphate (ATP) Adenine (a nitrogenous base) Phosphate groups 1) Aerobic Cellular Respiration ATP is made using the energy derived from the breakdown of glucose, usually in the presence of oxygen the energy from this reaction drives the phosphorylation of ADP to make ATP phosphorylation dephosphorylation dephosphorylation 2) Gas exchange The exchange of carbon dioxide and oxygen molecules between external (air we breathe) and internal environment (blood in capillaries). In single celled organisms such as an amoeba, or simple multicellular animals such as jellyfish, oxygen diffuses from the environment into the cell(s), and carbon dioxide diffuses out. 2) Gas exchange Complex multicellular organisms require specialized gas exchange tissue to maximize the diffusion of oxygen and carbon dioxide. 2) Gas exchange The path of oxygen: enters lungs 🡪 picked up by RBC and carried throughout the body 🡪 leaves RBCs 🡪 dissolves into interstitial fluid 🡪 diffuses into the cells and used to make ATP by that cell. Carbon dioxide follows the reverse path. 3) Ventilation the movement of air in and out of the lungs Ventilation Smoker Lung Healthy Lung Demo The Human Gas Exchange Structures Nasal Cavity Consists of 3 bony plates, called “conchae” (kong-kee) that are covered by a mucus membrane. Trap debris from air with hair and mucus Moistens and warms air (due to many tiny blood vessels). Pharynx (throat) Common passageway for both food and air. Branches into trachea (air passage) and esophagus (food passage). Air moves towards trachea Epiglottis Flap of tissue that prevents food or liquid from entering trachea. Larynx Contains vocal chords where moving air being breathed in and out create voice sounds (tendon-like tissue). Larynx movement ⚪ http://www.youtube.com/watch?v= Z_ZGqn1tZn8 * Trachea Brings air from larynx to lungs. Consists of about 20 cartilaginous rings that prevents collapse during breathing. Muscle layer allows expansion and contraction. Cilia (hair-like extensions of cells) line the interior of trachea trapping dust and beating it upward toward pharynx (16 times per second) until it is swallowed or coughed up.  Vary from sixteen to twenty in number. Each forms a semicircular ring of hyaline cartilage, which occupies the anterior two-thirds or so of the circumference of the trachea. The posterior one-third of the trachea is completed by fibrous tissue and smooth muscle fibers. Bronchi (singular = bronchus) Delivers air to lung. Supported with cartilage rings Lined with cilia and coated with mucus. Bronchioles Microscopic tubes. No rings of cartilage. Delivers warm moist air to alveoli. Alveoli (singular = alveolus) Microscopic air sacs (Total about 300 million – cover 70-90 m2). Supplied with numerous capillaries Made up of a very thin epithelium layer where O2 diffuses from air into blood and CO2 diffuses from blood into air expired Lungs Right (3 lobes) Left (2 lobes) Very elastic, large, soft, sponge-like Diaphragm Thin dome-shaped sheet of muscle, level with bottom of ribs. Stretches across bottom of thoracic cavity. Can relax or contract to reduce or increase the volume of thoracic cavity. Spasms in this muscle create the hiccups. COUGH: Food, dust etc. can trigger the diaphragm and intercostals to relax and/or contract, forcing air out of your lungs at up to 100 km/h! Pleural membranes Two membranes: 1. Inner (around lungs). 2. Outer (inside thorax attached to ribs). Between these two pleura is a narrow space (pleural cavity) filled with fluid to prevent friction between lungs and ribs. If air enters the space, the membranes separate and collapse. Ribs Bones supporting and protecting the thoracic cavity (lungs and heart) Involved in breathing. External intercostal muscles found in between ribs that pull them up and out when they contract, thus expanding thoracic cavity. 3D Tour of the Lungs 4:47 Homework 1. Complete Human Respiratory Structures Worksheet 2. P 439#1-4 & p 446#3,4