Chapter 19 Respiratory and Cardiovascular Systems PDF

10/22/20 Chapter 19 Respiratory and Cardiovascular Systems The Human Body Cavity • In humans, the body cavity is divided by the diaphragm into two parts: - Abdominal cavity: contain the digestive organs (e.g., liver, stomach and intestines) - Thoracic cavity: contains the heart and lungs -...

10/22/20 Chapter 19 Respiratory and Cardiovascular Systems The Human Body Cavity • In humans, the body cavity is divided by the diaphragm into two parts: - Abdominal cavity: contain the digestive organs (e.g., liver, stomach and intestines) - Thoracic cavity: contains the heart and lungs - Heart: belongs to the cardiovascular system Lungs: belong to the respiratory system - 1 10/22/20 Human Respiratory System Nasal cavity Nose Larynx Mouth Upper respiratory tract Trachea Bronchi Bronchioles Lower respiratory tract Lungs Diaphragm Figure 17.1 Upper Respiratory Tract: Nasal cavity à Pharynx à Larynx à Trachea Common cold: a viral infectious disease of the upper respiratory system – The most frequent infectious disease in humans - There is no cure for the common cold, but symptoms usually resolve in 7 to 10 days Symptoms: cough, sore throat, runny nose, and fever 2 10/22/20 Lower Respiratory Tract: Tracheaà Bronchi à Bronchioles à Lungs The right lung is divided into 3 lobes The left lung is divided into 2 lobes Right lung Left lung – The left lung is smaller to make room for the heart The bronchi branch into thousands of bronchioles – passageways for air The tubes end in air sacs called alveoli – functional units of the lungs 3 10/22/20 Bronchitis: an inflammation of the bronchial tubes Symptoms: cough, mucus, fever, shortness of breath, increasing the risk of asthma Pneumonia: an inflammation affecting the alveoli Symptoms: fever, chest pain, bloody sputum, lack of air space 4 10/22/20 Breathing • Muscles near the lungs help expand and contract the lungs to allow breathing - Diaphragm: a thin dome-shaped skeletal muscle that separates the thoracic and abdominal cavities - Abdominal muscles - Intercostal muscles located between the ribs - Muscles in the neck and collarbone area (a) Inhalation (b) Exhalation Air flows in Air flows out Chest cavity expands Chest cavity contract Diaphragm Diaphragm contracts, and flattens Volume of Chest Diaphragm relaxes, and returns to dome shape Pressure of Chest Figure 17.2 5 10/22/20 Human Cardiovascular System • The cardiovascular system consists: - Circulating fluid (blood) - Vascular system (arteries, veins and capillaries) - Capillaries Heart Vein Artery Pump (heart) Figure 17.14 6 10/22/20 The Human Blood • 5 L /adult human • Consist of solid (cellular) and liquid components: - Liquid portion: plasma - Cellular portion: red blood cells, white blood cells, platelets Figure 17.10 • Cellular components of blood are produced by stem cells in the bone marrow - Red blood cells: carry oxygen by hemoglobin - White blood cells: components of immune system; several varieties - Platelets: produce blood clots; prevent blood loss Blood stem cell Blood stem cell Plateletproducing cell Red Platelets blood cells White blood cells Figure 17.11 7 10/22/20 Blood Vessels • Arteries – thick, elastic wall; small lumen; carry blood away from heart • Veins – thin walls; large lumen; contain valve; carry blood to heart • Capillaries – single layer, porous wall; where exchange occurs From body The Human Heart To body Semilunar valves To lungs Right atrium Left atrium Left ventricle AV valve Right ventricle From lungs • Consist of four chambers: - Atrium (left, right): - Ventricle (left, right): pumping chambers • Contain valves: AV valve AV (atrium-ventricle) valve - Semi-lunar valve - Figure 17.13 8 10/22/20 Gas exchange occurs by simple diffusion between the alveoli and the capillaries 1 2 Oxygenated blood from the lungs travels to the left atrium of the heart. Contraction of the left ventricle forces blood into body arteries at high pressure. 4 Blood flows through the arteries and arterioles into capillaries. 6 Oxygen in 1 Contraction of the heart muscle forces blood into the left ventricle. 3 5 Carbon dioxide out Gas exchange in lungs 3 Gas and material exchange occurs in body capillaries. Capillaries empty into the venues, which carry blood to the veins and eventually to the right atrium. 7 Blood is forced into the right ventricle by contraction of the right atrium. 8 Contraction of the right ventricle sends blood into vessels in the lungs. 2 7 8 Gas exchange in capillary beds throughout body tissues 6 Carbon dioxide in 5 4 Figure 17.17 Oxygen out Gas exchange occurs by simple diffusion between the alveoli and the capillaries Each alveolus is surrounded by a net of capillaries O2: alveoli à capillaries CO2: capillaries à alveoli 9 10/22/20 Carbon Monoxide Poisoning: red blood cells pick up carbon monoxide quicker than they pick up oxygen Sources: automobile exhaust fumes, fires burning with poor ventilation, and smoking tobacco 10