RESPIRATORY SYSTEM. Mrs. Ofelia Solano Saludar Department of Natural Sciences University of St. La Salle Bacolod City. Compare and contrast the advantages/ disadvantages of counter current and concurrent types of ventilation on vertebrate respiration.
Mrs. Ofelia Solano Saludar
Department of Natural Sciences University of St. La Salle Bacolod City
Compare and contrast the advantages/ disadvantages of counter current and concurrent types of ventilation on vertebrate respiration.
Describe the functional anatomy of gills, lungs.
List the requirements that a fish must undergo to become a terrestrial vertebrate.
Discuss how the swim bladder is structurally and functionally related to the lungs.
Discuss the phylogeny and attendant modifications of the respiratory tract of the following groups:
RESPIRATION- the process of obtaining oxygen from the external environment & eliminating CO2.
Respiratory System Principles
External respiration- O2 and CO2 exchanged between the external environment & the body cells by diffusion; takes place via highly vascular membranes with thin, moist epithelia
COUNTERCURRENT BLOOD FLOW IN GILLS
Internal gills – wall of pharynx is pierced by typically 6 gill slits between skeletal gill arches; gill pouch is the passage between external & internal slits; the tissue between gill pouches is the gill bar; bars bear internal gill with filaments.
OTHER FUNCTIONS OF GILLS:
In fishes, the arches are supplied with respiratory branchial muscles & aortic blood vessels
About ½ bony fish have swim bladders; 20 fish genera are air breathers
Respiration- the swim bladder of lungfish has a number subdivisions or septa (to increase surface area); O2 and CO2 is exchanged between the bladder & the blood
Sound production - muscles attached to the swim bladder contract to move air between 'sub-chambers' of the bladder. The resulting vibration creates sound in fish such as croakers, grunters, & midshipman fish.
Hearing- some fresh water teleosts(catfish, goldfish, carp) 'hear' by way of pressure waves transmitted via the swim bladder and small bones called Weberianossicles
In Urodeles, lungs are often of minor importance; respiration is often through external gills and skin
Amphibians force air into their lungs by creating a greater-than-atmospheric pressure (positive pressure) in the air outside their lungs. They do this by filling their buccal cavity with air, closing their mouth and nostrils, and then elevating the floor of their oral cavity. This pushes air into their lungs in the same way that a pressurized tank of air is used to fill balloons. This is called positive pressure breathing; in humans, it would be analogous to forcing air into a victim’s lungs by performing mouth-to-mouth resuscitation.
Lizards, crocodilians, & turtles – highly compartmentalized
Highly vascularized: capillaries are open ended in the walls of parabronchi; form a honeycomb appearance
Air sacs: 2 abdominal; 2 posterior thoracic; 2 anterior thoracic; 2 cervical; 1 interclavicular
Cervical air sac
Interclavicular air sac
Anterior thoracic air sac
Abdominal air sac
Posterior thoracic air sac
Air is exchanged via negative pressure ventilation, with pressures changing due to contraction & relaxation of diaphragm & intercostal muscles
Deep-seas divers: some elephant seals can dive for 1500 m and stay for 2 hours!
Stalk of bifurcated lung outgrowth; supported by cartilaginous rings
Leads to bronchi (forms the bird syrinx at that point)
Usually about as long as a vertebrates neck (except in a few birds such as cranes)
Next topic… Circulatory System