Animal Anatomy and Physiology - Respiration 2024 PDF

Animal Anatomy and Physiology – Respiration FIS 0374 BIOLOGY 2 2024 Ms Ameertha LEARNING OUTCOMES ❖ Describe the respiratory tract of human and the air pathway into the lungs ❖ Describe the structure and characteristic of hemoglobin ❖ Explain the oxyhemoglobin dissociation curve ❖...

Animal Anatomy and Physiology – Respiration FIS 0374 BIOLOGY 2 2024 Ms Ameertha LEARNING OUTCOMES ❖ Describe the respiratory tract of human and the air pathway into the lungs ❖ Describe the structure and characteristic of hemoglobin ❖ Explain the oxyhemoglobin dissociation curve ❖ Explain oxygen and carbon dioxide transport ❖ Compare inhalation and exhalation Respiratory tract of human A transport system that connects respiratory organs is necessary to perform gaseous exchange with the atmosphere effectively. Nasal Cavity ❖ Air from the environment enters through nose. ❖ Cilia lining the mucous membrane will filter the dust particles and remove them in the form of mucus.  Is mouth a respiratory organ?? Pharynx (throat) ❖ Receives air from the nasal cavity and air, food, and water from the oral cavity. Larynx (voice box) ❖ Protects the lower respiratory tract from aspirating food into the trachea. Trachea (windpipe) ❖ Surrounded by cilia in the inner layers and protective cartilaginous rings. ❖ Lined with mucosa tissue with goblet cells that produce sticky mucus. Lungs ❖ Contains 3 right lobes and 2 left lobes Bronchus and bronchioles ❖ Contains epithelial cells that secrete mucus to trap bacteria and airborne particles. ❖ Cilia will sweep the mucus upwards for removal. Alveoli ❖ Large surface area to allow efficient gas diffusion simultaneously. ❖ Lined with thin and moist squamous epithelium cells. ❖ Surrounded by blood capillaries - Oxygen in alveoli and carbon dioxide in capillaries create a steep concentration gradient to allow gaseous exchange. ❖ Contains soapy surfactants to prevent lungs from collapsing or over inflating. ❖ Phagocytes are present to kill bacteria ❖ Pulmonary surfactant is a complex mixture of phospholipids and proteins that functions to reduce surface tension at the alveolar air interface preventing atelectasis. Collapsed lung Hemoglobin (Hb) ❖ The respiratory pigment in red blood cell that carries oxygen and carbon dioxide. Made of four subunits of conjugated protein. Animation of a typical human red blood cell cycle in the circulatory system. This animation occurs at a faster rate (~20 seconds of the average 60-second cycle) and shows the red blood cell deforming as it enters capillaries, as well as the bars changing color as the cell alternates in states of oxygenation along the circulatory system. https://www.youtube.com/watch?v=K1S7STZ2BrA Oxyhemoglobin dissociation curve ❖ A sigmoid curve that represents the saturation of oxygen in hemoglobin. ❖ O2 Partial pressure = 0 mm Hg - No oxygen bound (0%). - Polypeptide chains of hemoglobin are tightly connected. Oxyhemoglobin dissociation curve ❖ Between 20 - 40 mm Hg - More heme groups are bound to oxygen. - Oxyhemoglobin readily dissociates at body tissues to release oxygen. ❖ 100 mm Hg - Oxygen fully occupies hemoglobin (99%). - At pulmonary capillaries surrounding alveoli. Myoglobin ❖ Hemoglobin (or haemoglobin) and myoglobin are heme proteins that act as oxygen binding proteins. ❖ The main point of difference between the two lies in the fact that hemoglobin is found all over the body and myoglobin is found only in muscle tissues. Oxyhemoglobin dissociation curve ❖ For myoglobin in muscle - Curve is displaced to the left. - Myoglobin picks up oxygen faster at very low partial pressure due to increased affinity for oxygen Transport of Oxygen ❖ Following the concentration gradient of oxygen, oxygen diffuses from the surrounding air > alveoli > blood plasma > erythrocytes > hemoglobin ❖ 95% oxygen is transported in the form of oxyhemoglobin ❖ 5% oxygen is dissolved in blood plasma ❖ Affected by concentration of carbon dioxide, pH, temperature https://www.youtube.com/watch?v=BYGPkRFvzOc  Transport of Carbon dioxide (a) As hydrogen carbonate ions (HCO3-) Hemoglobin Plasma Plasma Cell Alveoli Alveoli Transport of Carbon dioxide - Cl Hb + H+ ⇌ HHb Chloride shift occurs to restore the neutrality Haemoglobinic acid (HHb) of erythrocyte. is formed to control acidity of erythrocyte. Transport of Carbon dioxide a) 70% as hydrogen carbonate ions 1. 𝐻𝐶𝑂3− are transported in blood plasma to reach the lungs 2. The ions enter the erythrocytes and form 𝐻2 𝐶𝑂3 3. Carbonic anhydrase catalyzes the dissociation of 𝐻2 𝐶𝑂3 4. 𝐶𝑂2 is released into blood plasma and alveoli for exhalation  Transport of Carbon dioxide (b) 23% binds to hemoglobin 1. 𝐶𝑂2 from tissues bind with amino group of hemoglobin, forming carbaminohemoglobin 2. Carbaminohemoglobin is transported to lungs 3. 𝐶𝑂2 is released from hemoglobin and diffuses into plasma and alveoli for exhalation (c) 7% dissolves in blood plasma 1. Transport in the form of carbonic acid, once reaches the lung, 𝐶𝑂2 diffuses out to alveoli for exhalation https://www.youtube.com/watch?v=VgpNSdWvrno Controlling breath Inhalation Exhalation Ventral portion of medulla Dorsal and lateral portion Respiratory Centre oblongata of medulla oblongata Diaphragm and Intercostal Contract Relax Muscles Inflate Lungs Deflate Stimulated to promote Not stimulated to promote Stretch Receptors exhalation inhalation Requires ATP Energy Does not involve ATP Thank you!!!