Warm up: p. 187 Draw & label lungs and alveoli HW 1: Ch 9 Guided Reading HW 2: Watch Crash Course – Respiratory systems, part 1 and 2. WRITE 5 FACTS ABOUT EACH Text corrections: deadline this fri, mar 2nd MONDAY Warm up: p. 187 Draw & label lungs and alveoli Test Return – Watch: Circulation and Contractions Finish and turn in: Blood Cell Packets Watch: Respiratory System Bozeman Science Let’s check: Our measurements: veins & arteries Step 1) Measure distance using the small epu’s (eyepiece units) Step 2) Multiply times 250μ (low power) or 100μ(med) Measure the thickness of an artery wall = ________μ Measure the thickness of an artery = ___________ μ

Gas exchange in alveoli Understanding COPD Smoking is Bad for You HW 1: Ch 9 Guided Reading HW 2: Watch Crash Course – Respiratory systems, part 1 and 2. WRITE 5 FACTS ABOUT EACH Text corrections: deadline this fri, mar 2nd WEDNESDAY Warm up: PowerPoint Notes Watch: Gas exchange in alveoli Understanding COPD Smoking is Bad for You What Happens When You Quit Smoking

Lab Practical: 9.1 Lung tissue microscopy Ch Review: Quiz Tuesday HW 1: Ch 9 Guided Reading HW 2: Watch Crash Course – Respiratory systems, part 1 and 2. WRITE 5 FACTS ABOUT EACH Text corrections: deadline this fri, mar 2nd FRIDAY Warm up: Lab Practical: 9.1 Lung tissue microscopy Ch Review: Quiz Tuesday

TEST REVIEW Ch. 8 Mammal Circulatory System

The external and internal structure of the mammal heart and the path blood takes from the vena cava to the aorta through the body and back to the heart, including the names of the various types of vessels and their pressure difference The heart has several coronary arteries on its surface to supply oxygen and nutrients to the heart Internally, the heart has 4 muscular chambers. Blood returns to the heart from the body through the vena cava and empties into the right atrium. The atrium contracts sending blood through the AV valves into the right ventricle. From there it travels through the semi-lunar valves and out of the pulmonary artery to the lungs Returning from the lungs the blood enters the heart through the left atrium AV valve left ventricle semilunar valve and out of the aorta to carry oxygenated blood to the body The pathway of blood transport includes oxygenated blood traveling through arteries, arterioles, capillary beds. Venules and veins then carry deoxygenated back to the heart. The highest pressure is in the aorta as it leaves the left ventricle. It steadily decreases as it travels through the body and returns.

Ventricles are much larger and thicker than atria. The differences in the thickness of the walls of the different heart chambers and how differences in pressure affect the opening and closing of each of the 4 heart valves. Ventricles are much larger and thicker than atria. Atria are thin because they have a very short distance to pump blood The left ventricle is the largest and thickest as it has to pump blood to the entire body. The right ventricle is much smaller than the left as it only has to pump blood to the lungs. As blood enters the right atrium, it flows into the right ventricle forcing open the AV valve. As the atrium contracts, atrial systole, its pressure rises and blood is forced in to fill the remaining space in the ventricle. The pressure of the full ventricle causes the AV valve to close.

Cont’d The contraction of the ventricle, ventricular systole, occurs which increases the pressure in the ventricle, forcing open the semi-lunar valve so blood then exits the ventricle. When either the atria or ventricles are relaxing, diastole is occuring.

The path of electrical impulses and how each one coordinates the contraction of the heart from start to finish.  Include the names of the 3 tissues where each impulse originates. Impulses which cause the heart to beat originate in the SAN – synoatrial node – in the right atrium The impulse travels to the AVN – atrioventricular node causing the atrium to contract. It continues down the septum (through the Bundle of His) until it reaches the Purkyne Fibers which spread the impulse up from the base of the heart to the ventricles, causing them to contract. The heart is myogenic – meaning it will beat on its own with any nerve impulses from the brain.

Chapter 9: Gas Exchange

Gas exchange Human gas exchange system links the circulatory system with the atmosphere Clean and warm entering air Maximize surface area for diffusion of oxygen and carbon dioxide Minimize distance for diffusion Maintain adequate gradients for diffusion

What is Human Respiration? The human respiratory system allows us to obtain oxygen and eliminate carbon dioxide. Breathing consists of 2 phases: Inspiration- the process of taking in air Expiration- the process of blowing out air

Cellular Respiration requires O2 O2 is needed to convert glucose into cellular energy (ATP) in all body cells Carbon dioxide (CO2) is produced as a waste product The body’s cells die if either the respiratory or cardiovascular system fails = NO ATP!

Trachea, bronchi, bronchioles Leading from the throat to the lungs is the trachea, and at the base are two bronchi (singular: bronchus) which then subdivide several times into even smaller bronchioles

Human Respiratory System Figure 10.1

Organs in the Respiratory System STRUCTURE FUNCTION nose / nasal cavity  warms, moistens, & filters air as it is inhaled pharynx (throat)  passageway for air, leads to trachea larynx  the voice box, where vocal chords are located trachea (windpipe)  Cartilage keeps the windpipe "open” trachea is lined with fine hairs called cilia which filters air before it reaches the lungs bronchi  two branches at the end of the trachea, each leads to a lung bronchioles  a network of smaller branches leading from the bronchi into the lung tissue & ultimately to air sacs alveoli  the tiny sacs in the lung where gases are exchanged

Trachea, bronchi, bronchioles Cartilage in the trachea and bronchi keep airways open and air resistance low, and prevents them from collapsing or bursting as air pressure changes during breathing Trachea: regular C-shaped cartilage rings Bronchi: irregular blocks of cartilage

Bronchioles Surrounded by smooth muscle which contract/relax to adjust diameter of airways Relax= greater diameter, more air Possible because there is no cartilage

Warming and cleaning the air As air flows through nose and trachea, it is warmed and moistened by evaporation from the lining to protect lungs from drying out (desiccation) Small hairs inside nose and mucosal membranes trap suspended particles (dust, pollen, bacteria, viruses)

Structures of Thoracic Cavity Cartilage rings support pressure from breathing & maintain open pathways of trachea and bronchi Pleural membranes(2) –fluid filled to reduce friction from movement Smooth muscle that relaxes and contracts (absence of cartilage) Figure 10.3

Learn this: it’s on p. 188 in your book!

Bronchial tree (Bronchi) Right main bronchus Each bronchus runs into a lung, behind pulmonary vessels - pulmonary artery/vein from heart

smaller tubes, tubes smaller than 1 mm called bronchioles Bronchi divide into smaller tubes, tubes smaller than 1 mm called bronchioles Brochioles: tissue changes as becomes smaller Cartilage disappears No mucus or cilia in tissue cells Smooth muscle - relaxation (“bronchodilation”) and contraction (“bronchoconstriction”)

Bronchial “tree” and associated Pulmonary arteries

Alveoli End-point of respiratory tree Structures that contain air-exchange chambers are called alveoli Respiratory bronchioles lead into alveolar ducts: walls consist of alveoli Ducts lead into terminal clusters called alveolar sacs – microscopic chambers There are 3 million alveoli!

Alveoli Terminal end of bronchioles. Have very thin lining of epithelial tissues (single cell thick) and are surrounded by capillaries carrying deoxygenated blood Thinness of barriers ensures fast diffusion Walls contains elastic fibers which can stretch and recoil during breathing

Alveoli Oxygen moves into bloods via partial pressure differences between alveoli (high) and capillaries (low) Carbon dioxide moves from high in capillaries to low in alveoli Blood is constantly moving so pressure gradient is maintained

Microscopic detail of alveoli Single layer thick- diffusion surrounded by fine elastic fibers Alveolar macrophages – free floating “dust cells”

Macrophages Phagocytic white blood cells patrol the surfaces of the airways scavenging small particles like bacteria and fine dust

Trachea and Bronchi lined with Respiratory Mucosa Ciliated epithelium Scattered goblet cells – produce mucin (mucus) and watery fluid Macrophages - digestive enzymes, e.g. lysozyme Together all these produce a quart/day Dead junk is swallowed

Mucus In trachea and bronchi, goblet cells of the ciliated epithelium produce mucus, a slimy solution of mucin, which is composed of glycoproteins with many carbohydrate chains that make them sticky

Mucus, continued Also made by mucous glands beneath the epithelium Some chemical pollutants, like sulfur dioxide and nitrogen dioxide, can dissolve into mucus and irritate the airways

Gas Exchange Between the Blood and Alveoli Figure 10.8A

Smoking Considered disease by Word Health Organization Cigarettes popularized WWI Widespread by both men and women (including children)

Tobacco smoke ~4000 chemicals in cigarette smoke, many toxic Smoke composed of 2 parts: Mainstream smoke: from filter/mouth end Sidestream smoke: from burning tip ~85% released smoke/cigarette

Sidestream smoke Many toxic ingredients are in a higher concentration than in mainstream Tar(carcinogenic), carbon monoxide, nicotine People in the vicinity of sidestream smoke are exposed to toxins, breathing in these toxins is called passive smoking (secondhand smoke)

Tar Mixture of compounds that settles on the linings of airways in the lungs and stimulates a series of changes that may lead to obstructive lung disease and cancer

Smoking and Human Health Threats: Tar and carcinogens Carbon monoxide nicotine Passive smoking (2nd hand smoke)- breathing someone else’s smoke Atmospheric pollution and industrial emissions – lead to respiratory diseases

Chronic (long term) obstructive pulmonary diseases (COPD) Asthma Chronic bronchitis Emphysema

SEM image of alveoli normal emphysema

Chronic bronchitis - Tar stimulates goblet cells Destroys cilia; bacteria & viruses collect Smoker’s cough; pneumonia

Emphysema Inflammation of constantly infected lung causes phagocytes (white blood cells) to leave blood and line airways Release elastase which destroys elastin walls of alveoli (can’t stretch/recoil) Air is trapped, alveoli can burst Reduces surface area for gas exchange – less O2 in blood Wheezing, breathlessness, Heart enlargement

Emphysema Elastin is responsible for recoil of alveoli when we exhale Without elastin, alveoli walls do not stretch and recoil. As a result, the bronchioles collapse during exhalation, trapping air in the alveoli, which often burst

Emphysema Large space appear where alveoli burst, which reduces surface for gas exchange Capillaries also decrease in #, so less oxygen gets to blood This condition is called emphysema

Emphysema Loss of elastin makes if difficult to move air out of lungs ‘dead’ air remains in lungs permanently People with emphysema do not oxygenate their blood well and have a rapid breathing rate

Emphysema As disease progresses, blood vessels in lungs become more resistant to blood flow This causes the right side of the heart to enlarge

Emphysema As lung function deteriorates, wheezing and breathlessness become worse Can cause permanent bed rest Many people with chronic emphysema need a continuous supply of oxygen to stay alive

Collapsed Lung

Lung cancer Tar in tobacco smoke contains several carcinogens React with DNA in epithelial cells to produce mutations Mutations lead to overproductions of cells (tumor)

Lung cancer Cancer spread through bronchial epithelium and enters lymphatic tissues Cells may breakaway (metastasis) and form secondary tumors Takes 20-30 yrs to develop. Most tumor growth occurs before any symptoms are present Most common symptom coughing up blood as result of tissue damage

Smoker’s lung

Malfunctions & Diseases of the Respiratory System asthma severe allergic reaction characterized by the constriction of bronchioles  bronchitis inflammation of the lining of the bronchioles emphysema condition in which the alveoli deteriorate, causing the lungs to lose their elasticity (macrophages attack and destroy elastin) pneumonia condition in which the alveoli become filled with fluid, preventing the exchange of gases lung cancer irregular & uncontrolled growth of tumors in the lung tissue

Lung Capacity Figure 10.10A

Gas exchange Need oxygen for respiration Multicellular organisms have gas exchange surface where external oxygen can diffuse into body, and carbon dioxide can diffuse out In humans: alveoli (found in lungs, total surface area over 70m sq)

Lungs Found in thoracic (chest) cavity surrounded by pleural membranes, which enclose an airtight pleural space (aka pleural cavity) pleural space contains small amount of fluid to reduce friction during ventilation

Chapter 9 Smoking

Lung diseases Major cause of death and illness worldwide Air pollution, smoking, allergic reactions Small particle not filtered out by mucus/macrophages settle in lungs and make lungs susceptible to airborne infections, as well as asthma

Lung disease Each lung disease characterized by: Signs: visible manifestation of a disease that are detected upon examination (ex: high temp) Symptoms: senses expression of disease (ex: nausea, headache)

Chronic Obstructive Pulmonary Diseases (COPD) Umbrella term for long term (chronic) lung disorders Asthma, chronic bronchitis, emphysema Linked to smoking and air pollution

Chronic bronchitis Tar in cigarette smoke stimulates goblet cells and mucous glands to enlarge and secrete more mucus causing it to accumulate in bronchioles Also inhibits cleaning action of ciliated epithelium lining airways by destroying them or inhibiting their function

Chronic bronchitis Mucus in bronchioles collect dirt, bacteria, and viruses which stimulates ‘smoker’s cough’ in an attempt to move mucus up airways Over time, damaged epithelium is replaced by scar tissue, and smooth muscle around bronchioles becomes enlarged, causing airways to narrow

Chronic bronchitis Infections (like pneumonia) easily develop in accumulated mucus Infection inflames lungs, which become further narrowed This long-term damage and obstruction of the airways is called chronic bronchitis Sufferers have severe cough, and produce large amount of phlegm (mucus, bacteria, WBC mix)

Emphysema Inflammation of constantly infected lungs cause phagocytes to leave the blood and line the airways To reach lining of lungs, phagocytes must release elastase, an enzyme that destroys elastin in the walls of the alveoli to make a pathway for phagocytes to remove bacteria

copd Chronic bronchitis and emphysema often occur together in chronic smokers Chronic bronchitis can be reversible, but emphysema is not Over 60 million people worldwide affected by COPD WHO predicts COPD to be third leading cause of death worldwide by 2030

Lung cancer Tumors located by: Bronchoscopy- endoscope view of bronchi Chest x-ray CT scan By the time most lung cancers are discovered, they are well advanced (stage III-IV) and treatment involves surgery, radiotherapy, and chemotherapy Stage IIIA survival rate: 14% Stage IIIB survival rate: 5% Stage IV survival rate: less than 1%