Exam 4 Notes: Set 1
Exam 4 Notes: Set 1 Bio 1144
Popular in Biology II
Popular in Biology
This 5 page Class Notes was uploaded by Murry on Thursday March 31, 2016. The Class Notes belongs to Bio 1144 at Mississippi State University taught by Thomas Holder in Spring 2015. Since its upload, it has received 47 views. For similar materials see Biology II in Biology at Mississippi State University.
Reviews for Exam 4 Notes: Set 1
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 03/31/16
Exam 4 Notes: Set 1 The Respiratory System • Gas Exchange o Oxygen into the body and carbon dioxide out of the body o All cells need oxygen o Carbon dioxide produced by the cells treated as waste and released through the body o Capillaries are the site of gas exchange; site must meet certain criteria: § Thin, moist surface (epithelium tissue) § Lots of capillary beds § Barrier-forming concentration gradient (plasma membranes of epithelial tissue) o Gills – fish and some amphibians (aquatic organisms) use these for gas exchange § Air about 21% oxygen § Water is less than 1% oxygen concentration of air § More creatures use gills rather than lungs; therefore aquatic animals require much less oxygen § Must have very efficient system for obtaining oxygen § In water, exchange is more difficult because of low oxygen concentration § Gills are most efficient design for water breathers § Typical Gill Design: • Fish have 5 pairs of gills • Amphibians have 3 pairs of gills • Blood carrying carbon dioxide enters gills at back end of gill region • Water carrying oxygen enters at front of gill region • Countercurrent Exchange Mechanism – blood and oxygen flowing in different directions in a gill design; helps maintain rate of gas • Oxygen diffuses from water into blood as long as there is a concentration gradient (high to low); continues to diffuse as long as there is a gradient until equilibrium is reached • Oxygen from water diffuses into deoxygenated blood in entire length of gill region • Highest oxygen concentration is when water enters the mouth; lowest oxygen concentration is water leaving the gills • Fish must open mouth and possibly swim (expend energy) to gain oxygen • Energetically efficient; highly efficient in water o Cutaneous Respiration – gas exchange through the skin § Highly efficient; no energy expended § Still requires gradient and everything required for proper gas exchange site § Some fish and many amphibians exchange gas this way; mammal and bird skin too thick and covered in hair/feathers o Buccopharyngeal Respiration – ventilation (mouth breathing) § Lining of mouth cavity is thin, moist epithelium § Some amphibians require 90% oxygen from cutaneous respiration and other 10% through this form of respiration o Lung Respiration – gas exchange occurs in lungs § Most efficient for land animals § Some fish and amphibians have simple sacs that function as lungs (8 species of lung fishes) § Reptiles and birds have larger sacs and more lobes to provide for more exchange area § Mammals have largest lungs with more lobes – a “vascularized sponge” • With each inhalation/exhalation cycle, only about 1/6 of air is replenished § Birds require more oxygen than mammals and take up around 25% of air • Pathway of Airflow o Most pathways are lined with epithelium that is mucus secreting; this warms up and moistens the air that passes through o Cilia – act as filters in nasal cavity; filters out particles from getting into body with air intake o Some of the pathway is lined with cartilage rings o External nares (Nostrils): § Nasal cavity – contains cilia and mucus which warms and moistens inhaled air § Internal nares – 2 openings in the back of the nasal cavity where nasal cavity and mouth cavity connect § Connected by pharynx; respiratory and digestive systems cross paths (can lead to choking) § Glottis – opening to respiratory tube called § Epiglottis – flap to prevent things from entering glottis § Larynx – voice box § Trachea – windpipe; the largest section of the respiratory pathway tube § 2 Bronchi – 2 lungs (bronchus = singular lung) • Fork at trachea • Right bronchus is a wider, straighter tube • Left bronchus is slightly curved because it has to go around the heart § Bronchioles – smallest tubes in respiratory pathway branching off of bronchi • Inside the lungs • Empty into an air pocket called an alveolus § Alveoli – air pockets that are endings of respiratory tube; site of gas exchange • Contain thousands of capillary beds • Lined with simple epithelial tissue • Inhaled air is high in oxygen and low in carbon dioxide • Blood is high in carbon dioxide and low in oxygen • Gases diffuse from high to low concentrations § Exhaled air follows the pathway in reverse (exits out the same tubes in reverse order) § Inhaled air pathway: nasal cavity à internal nares à pharynx à epiglottis à glottis à larynx à trachea à bronchi à bronchioles à alveoli § Exhaled air pathway: alveoli à bronchioles à bronchi à trachea à larynx à glottis à epiglottis à pharynx à internal nares à nasal cavity § Mammal lungs are the largest of all vertebrates. o Diaphragm – important part of respiratory system that makes breathing possible; expands and relaxes to pull air in and out § Not part of any pathway, just an associated organ that controls system § Organ composed of involuntary smooth muscle § Separates thoracic and abdominal cavities § Inhalation – diaphragm contracts and pulls down, expanding chest cavity (rib cage); lugs expands and air is pulled in; passive movement into lungs § Exhalation – diaphragm relaxes and pulls up, chest and rib cage compress; lungs expel air; passive air movement out of lungs The Urinary System • Waste disposal: ions and urinary waste • Ions produced by breakdown of proteins • Filtering or “cleaning” of the blood • Involves minimum water loss à necessary to get rid of wastes • Water is a transport vehicle and necessary for most chemical reactions • Water diffuses across selectively permeable membranes (into different body compartments) through osmosis • Osmosis – diffusion of water from high to low concentrations across selectively permeable membrane • Osmoregulation – the regulation of salt and water balance in bodily fluids, cells, and tissues o Red blood cells in fresh water swell and possibly burst, but osmoregulation causes a redistribution of water through osmosis to prevent that from happening. o Hydrogen molecule secretion maintains pH • Urinary system produces and excretes nitrogen waste that has been filtered out of the blood. • Loss and Gain of Water in Humans: o Gains: § Drinking: 48% § Water in Food: 40% § Metabolic Water: 12% o Losses: § Urine: 60% § Evaporation: 34% § Feces: 6% • Nitrogenous Wastes of Vertebrates o Mostly formed from proteins; some from DNA and RNA o Ammonia – nitrogenous waste that becomes toxic when it is stored in the body; easily released from the body in water; fish release ammonia easily o Urea – primary nitrogenous waste of amphibians and mammals; also toxic if stored; easy to get rid of in minimal amount of water o Uric Acid – primary nitrogenous waste of birds and reptiles; released in a paste- like form; mammals can build up too much nucleic acid which produces uric acid which is stored in joints à causes gout • Organs of the Urinary System o Kidneys – largest organ associated with system; act as filters § Always in pairs in vertebrate animals § Simple structures in fish, not big or elaborate § Mammals, birds, and reptiles have more complex kidney system § The bigger the animal and the more active the animal, the more advanced the kidney needs to be § Metanephric kidneys – most advanced form of kidneys; drained by a ureter, has lots of nephrons, and filter at much higher blood pressures o Ureter – a tube draining the kidneys; carries waste product to urinary bladder o Urinary Bladder – where urine is stored o Urethra – tube that releases urine from the body o Nephron – functional unit of all vertebrate kidneys § Nephron becomes more complex going from fish to mammals § Filters 18 L of blood every day § Around 1 million nephrons per kidney in humans § Composed of: • Renal corpuscle (glomerulus + bowman’s capsule) o Glomerulus – capillary bed that filters/cleans the blood; blood moves at such high pressure that it forces some substances out o Bowman’s Capsule – receives filtrate from glomerulus • Renal Tubule – receives filtrate from Bowman’s Capsule; 4 parts: o Proximal tubule (nearest to Bowman’s Capsule) o Lower Loop o Distal tubule (farthest from Bowman’s Capsule) o Collecting duct § 3 Stages of Cleaning Blood: 1. Filtration – cleaning blood inside glomerulus; high pressure filters things out like water, impurities, glucose, salts, ions, etc. 2. Reabsorption – removing good substances out of the tubule to keep inside the body; reabsorbs about 60% of desirable substances; happens in proximal tubule 3. Secretion – forcing waste ions into the tubule to be excreted; happens in distal tubule § Goal: to remove as much waste as possible, save as many desirable substances as possible, and conserve water.
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'