Trắc nghiệm, bài giảng pptx các môn chuyên ngành Y dược hay nhất có tại “tài liệu ngành Y dược hay nhất”; https://123doc.net/users/home/user_home.php?use_id=7046916. Slide môn anh văn chuyên ngành y ppt dành cho sinh viên chuyên ngành Y dược. Trong bộ sưu tập có trắc nghiệm kèm đáp án chi tiết các môn, giúp sinh viên tự ôn tập và học tập tốt bộ môn anh văn chuyên ngành y bậc cao đẳng đại học ngành Y dược và các ngành khác
FUNCTION OF THE RESPIRATORY SYSTEM Respiratory function -Supply tissues with oxygen -Dispose of CO2 Voice production Smell … PROCESSES OF RESPIRATION Pulmonary ventilation: air moves into and out of the lungs External respiration: gas exchange in the lungs Transportation: accompanied by the cardiovascular system Internal respiration: gas exchange in tissues THE CONDUCTING ZONE The nose a) Air passage b) Moistens and warms entering air c) Clean inspired air d) Others: • Reclaim heat • Resonating chamber • Smell Moistens and warms entering air Respiratory mucosa -> mucous glands -> watery mucus -> moistened fluid Rich plexus of capillaries & thin walled veins: warms the air CLEAN INSPIRED AIR Nasal hair • Anterior nasal passage • Filtered dust, large practicles Mucus • Lysozymes: anti-bacterial enzymes • Defensisns: Natural antibiotic • Sticky fluids: Physically trap dust, debris… Current of Cilia • Movements of ciliated cells -> move the sheet of mucous toward the throat -> swallow and digest Mucosa • Sensory nerve endings -> sneeze reflex The pharynx - Tonsils The Larynx Trachea -> Bronchial tree Same functions and functionrelated structures as the nose Waldeyer's tonsillar ring Have you ever wondered how oxygen gets from the air into our blood? Do you know how carbon dioxide gets out of our blood and enters our lungs? GAS EXCHANGE IN THE LUNGS • In the lungs, oxygen and carbon dioxide (a waste product of body processes) are exchanged in the tiny air sacs (alveoli) at the end of the bronchial tubes The alveoli are surrounded by capillaries When a person inhales, oxygen moves from the alveoli to the surrounding capillaries and into the bloodstream At the same time, carbon dioxide moves from the bloodstream to the capillaries and into the alveoli The carbon dioxide is removed from the lungs when a person exhales Gases are exchanged between the alveolar air and the blood by diffusion, the movement of molecules from an area of higher concentration to an area of lower concentration, where concentration refers to how much of one substance is present in a mixture of substances The rate of diffusion is influenced by a variety of factors, including atmospheric pressure and the magnitude of the concentration gradient of the diffusing substance In the lung: • à PO2 in the alveolar air is higher than blood • à O2 diffuse rapidly from alveolus • à to blood plasma In the peripheral tissues: • à PO2 is lower than blood • à O2 diffuses out from blood • à to tissues In the lungs • à PCO2 is lower than in the blood • à CO2 diffuses out • à into alveoli Blood carries CO2 in 3 forms: dissolved gas (8%) HCO3-ion in the plasma (73%) carbamino haemoglobin in the red blood cells (19%) A large amount of CO2 combines with H2O in the red blood cells (RBC) to form carbonic acid (H2CO3) then ionizes to form H++ HCO3HCO3- from the red blood cell: diffuse out into the plasma loss of negatively charge HCO3- from the red blood cell balanced by the inward diffusion of -ve chloride ions (Cl-) = chloride shift • O2 = transported by the haemoglobin molecule in the red blood cells • Each haemoglobin molecule à carries 4 mol of O2 Each polypeptide chain contains: 2 subunits of alpha polypeptides chains and 2 subunits of beta polypeptides chains • When one mol of O2 binds to one of the haem group in the haemoglobin à produces a conformational change in that subunit à transmitted to the other subunits à facilitate O2 binding to the rest of the polypeptide à concerted conformational change of the subunits à increases affinity of haemoglobin for O2 à resulting in sigmoid shape for the O2 dissociation curve of the haemoglobin The cooperative effect is reversible à when one subunit of oxyhaemoglobin unloads its O2, à other three quickly follow suit à conformational change à lowers its affinity for O2 The O2 dissociation curve shows: - when haemoglobin is exposed to a gradual increase of PO2, - it absorbs O2 rapidly at first - but more slowly as the PO2 continues to rise The % of O2 saturation of haemoglobin = 95% - when blood flows through the lungs (PO2 = 105 mmHg) The % of O2 saturation of haemoglobin = 70% - when blood flows through a moderately active/resting muscle (PO2=40 mmHg) As the blood from the lungs reaches the muscle at rest: - 25% of the O2 carried in the heamoglobin is unloaded to the surrounding tissues - for cellular respiration - 70% of the oxygen is still retained by the haemoglobin REGULATION OF RESPIRATION • Breathing is controlled by the central neuronal network to meet the metabolic demands of the body • A collection of funtionally similar neurons that help to regulate the respiratory movement are present in the medulla region of the brain They are called the Respiratory center • Dorsal respiratory group (medulla) – mainly causes inspiration • Ventral respiratory group (mesulla) – causes either expiration or inspiration • Pneumotaxic center ( upper pons) inhibits apneustic center & inhibits inspiration, helps control the rate and pattern of breathing • Apneustic center (lower pons ) – to promote inspiration ... mol of? ?O2 binds to one of the? ?haem group in the haemoglobin à produces a conformational change in that subunit à transmitted to the other subunits à facilitate O2 binding to the rest of the polypeptide... moves from the alveoli to the surrounding capillaries and into the bloodstream At the same time, carbon dioxide moves from the bloodstream to the capillaries and into the alveoli The carbon dioxide... to how much of one substance is present in a mixture of substances The rate of diffusion is influenced by a variety of factors, including atmospheric pressure and the magnitude of the concentration