Arteries arterioles are more like veins venules thin walled with large lumens o

Arteries arterioles are more like veins venules thin

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Arteries/ arterioles are more like veins/ venules (thin walled, with large lumens) o Arterial resistance and pressure are low (24/8 mm Hg) Blood flow: heart During ventricular systole o Coronary vessels are compressed o Myocardial blood flow ceases
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o Stored myoglobin supplies sufficient oxygen At rest, control is probably myogenic During strenuous exercise o Coronary vessels dilate in response to local accumulation of vasodilators o Blood flow may increase three to four times Alterations in blood pressure Hypotension: low blood pressure o Systolic pressure below 100 mm Hg o Often associated with long life and lack of cardiovascular illness o Below 60 mm Hg High concern Hypertension: high blood pressure o Sustained elevated arterial pressure of 140/90 or higher Chronic Borderline 130/85 May be transient adaptations during fever , physical exertion, and emotional upset Often persistent in obese people Homeostatic imbalance: hypertension Prolonged hypertension is a major cause of heart failure, vascular disease, renal failure, and stroke. o Treating BP o Atherosclerosis o Afterload: increase work load on heart Ventricular hypertrophy Primary or essential hypertension o 1 st problem o 90% of hypertensive conditions o due to several risk factors including heredity, diet, obesity, age, stress, diabetes mellitus, and smoking secondary hypertension is less common o due to identifiable disorders, including kidney disease, atherosclerosis and endocrine disorders such as hyperthyroidism and cushing’s syndrome kidney disease: ability to reduce blood volume result: retain more water o increased blood volume and increased blood pressure o another heart problem started first resistance o arterioles decrease resistance o medication that promotes vasodilation lowers blood pressure blood volume o increase urine output little less water in blood volume decrease blood volume; lowers blood pressure diuretics Chapter 22: The Respiratory System Part A Respiratory system: functional anatomy Some medications combine the two
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major organs (most of parts are conducting zone) o nose, nasal cavity, and paranasal sinuses o pharynx o larynx o trachea o bronchi and their branches o lungs and alveoli conditioned air o warm, filtered, humidify LOOK AT DIAGRAM**** Functional anatomy Respiratory zone: site of gas exchange ( diffusion) o microscopic structures: respiratory bronchioles, alveolar ducts, and alveoli (presence) Conducting zone : conduits to gas exchange sites (nasal, pharynx, larynx, trachea, bronchi, upper/ middle lungs) o Moves air up and down, in and out of lungs and conditions air o Includes all other respiratory structures Respiratory muscles: diaphragm and other muscles that promote ventilation The nose and nasal cavity Functions o Conditioning o Provides an airway for respiration o Moistens and warms the entering air o Filters and cleans inspired air o Serves as a resonating chamber for speech o Houses olfactory receptors The nose Nasal cavity: in and posterior to the external nose o Divided by a midline nasal septum o
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