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what are the 3 divisions of pharynx, and where are they located?
- Nasopharynx: lies posterior to the nose
- oropharynx: lies posterior to the mouth
- laryngoparynx: lies posterior to the larynx
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what are the functions of the glottis and epiglottis?
- epiglottis: helps keep food from entering the larynx
- glottis: the opening between the vocal cords within the larynx
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What is the function of the cartilaginous rings in the walls of the trachea and bronchi?
they hold a passageway open and spite of the air pressure changes that occur during breathing. The open portion of the rings is oriented posteriorly against the esophagus, this allows the esophagus to expand slightly as food passes down to the stomach
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What is the function of the bronchial tree?
when the bronchus which is along the branches into forming smaller tubes that are called the bronchial tree the branches break down into smaller tubes and fill out throughout the lung
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how is breathing controlled by the nervous system?
- breeding is controlled by groups of neurons composing of the respiratory center, in the brainstem
- the consistent groups of neurons are located in both the medulla and the pons
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how does gas exchange occur in the lungs and in body tissues?
in the lungs, oxygen diffuses from the air in alveoli into the blood of surrounding capillaries. most of the oxygen enters red blood cells and combines with the heme portions of hemoglobin to form oxyhemoglobin. about 97% of the oxygen is tansposted as oxyhemoglobin. only 3% is dissolved in the plasma.
in body tissuees, oxyhemoglobin releases oxygen, and it diffuses from capillary blood into the tissue cells. actually, only about 25% of the oxygen is released, so oxyhenoglobin is present even in deoxygenated blood.
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what organs compose the urinary system, and what are their functions?
- kidneys, ureters, urinary bladder, and urethra.
- kidneys: maintain the composition and volume of body fluids by removing wastes and excess substances in the formation of urine.
ureters: carry urine from the kidneys to the urinary bladder
urinary bladder: expells from the body through the urethra.
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what is the general function of the urinary system?
to maintain the volume and compostion of body fluids within normal limits
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what are the mechanisms of filtration, tubular reabsorbtion, and tubular secretion?
- tubular reabsorbion and secretion involve both active and passive transpost mechanisms
- active transpost is powered by ATP and uses carrier molecules to reabsorb substandces against a concentration gradient
- passive transport includes difustion, osmosis and electrochemical attraction.
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what hormones help regulate water- electrolyte balence and what are there effects?
aldosterone-adrenal cortex-it stimulates reabsorbtion of NA+ from the filtrate into the blood; stimulates the secretion of K+ from blood into the filtrate
antidiuretic hormone- posterior pituitary- stimulates the reabsorbtion of water from the filtrate into the blood by making the distal tubule and collecting ducts more permeable to water; decreases the volume of urine produced
atrial natriuretic hormone - heart- inhibites reabsorbtion of NA+ and water from distal convoltated tubules and collecting ducts
parathyroid hormone- parathyroid glands- stimulates the reabsorbtion of CA++ from the filtrate into the blood; stimulates the secretion of PO4
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what are the nitrageneous wastes in urine, and how are they formed?
urea- waste product of amino acid metabolism
uric acid- is a waste product of nucleic acid metabolism
creatinine- a waste product of muscle metabolism and specifically breakdown the creatine phosphate
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how is the micrution controlled?
- micrution is to urinate
- the bladder can hold up to 1000ml of urine .....you usually urinate at around 200-400ml of urine....the stretch receptors in the bladder are stimulated and trigger micturition reflex
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