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Description
In this programme various respiratory mechanisms are demonstrated as illustrations of the Course Unit text. The programme is in three parts. The speakers are Dr. R.N. Hardy and Dr. P. Nathanielsz, ...Lecturers in Physiology at the University of Cambridge, Dr. R.M. Holmes, Lecturer in Biology at the Open University, Dr. C. Rankin, Lecturer in Zoology at the University College of North Wales Bangor, and Professor G,C. Varley, Professor of Entimology, Hope Department, University Museum, Oxford. Dr. Rankin and Dr. Holmes demonstrate the effect of adrenalin on the "blood circulation through the gills of an eel. The effect of adrenalin on the blood pressure in the ventral and dorsal aorta is investigated in vivo. An isolated gill preparation is used to illustrate the fall in gill resistance resulting from vasodilation of gill capillaries after adrenalin perfusion. In the second part of the programme aspects of the control of respiratory movements in mammals are investigated. Dr. Nathanielsz and Dr. Holmes use a decerebrate rabbit preparation to investigate the Hering-Breuer reflex and Dr. Hardy uses a spirometer to show the effects on Dr Holmes of breathing various mixtures of gasses. Finally, Picfessor Varley commentates the sequence showing various respiratory adaptations by aquatic insects. The main types of respiratory mechanism illustrated are open trachael systems, plastrons and gills.
In this programme various respiratory mechanisms are demonstrated as illustrations of the Course Unit text. The programme is in three parts. The speakers are Dr. R.N. Hardy and Dr. P. Nathanielsz, ...Lecturers in Physiology at the University of Cambridge, Dr. R.M. Holmes, Lecturer in Biology at the Open University, Dr. C. Rankin, Lecturer in Zoology at the University College of North Wales Bangor, and Professor G,C. Varley, Professor of Entimology, Hope Department, University Museum, Oxford. Dr. Rankin and Dr. Holmes demonstrate the effect of adrenalin on the "blood circulation through the gills of an eel. The effect of adrenalin on the blood pressure in the ventral and dorsal aorta is investigated in vivo. An isolated gill preparation is used to illustrate the fall in gill resistance resulting from vasodilation of gill capillaries after adrenalin perfusion. In the second part of the programme aspects of the control of respiratory movements in mammals are investigated. Dr. Nathanielsz and Dr. Holmes use a decerebrate rabbit preparation to investigate the Hering-Breuer reflex and Dr. Hardy uses a spirometer to show the effects on Dr Holmes of breathing various mixtures of gasses. Finally, Picfessor Varley commentates the sequence showing various respiratory adaptations by aquatic insects. The main types of respiratory mechanism illustrated are open trachael systems, plastrons and gills.
| Module code and title: | S22-, Comparative physiology |
|---|---|
| Item code: | S22-; 06; 1972 |
| First transmission date: | 08-04-1972 |
| Published: | 1972 |
| Rights Statement: | Rights owned or controlled by The Open University |
| Restrictions on use: | This material can be used in accordance with The Open University conditions of use. A link to the conditions can be found at the bottom of all OUDA web pages. |
| Duration: | 00:23:23 |
| + Show more... | |
| Producer: | Tony Laryea |
| Contributors: | Richard Holmes; Peter Nathanielsz; J. C. Rankin; George Varley |
| Publisher: | BBC Open University |
| Keyword(s): | Adrenalin; Blood circulation; Eel; Gill resistance; Hering-Breuer reflex; Open trachael systems; Plastrons; Respiratory movements; Spirometer; Vasodilation |
| Footage description: | Shots of an African lungfish in a tank (Protopterus). The fish breathes by pushing its mouth out of the water. Richard Holmes introduces the programme. Shots of an experiment conducted by Cliff Rankin which measures blood pressure in the ventral and dorsal aortas of an eel. He injects 0.1 micrograms of adrenalin washed in 0.5 cm cubed of saline and monitors the change in pressure. The adrenalin appears to cause vasolidation of gill capillaries and reduce gill resistance. Holmes analyses the pen recordings. Richard Holmes performs an experiment on an isolated eel gill to illustrate the fall in gill resistance resulting from vasolidation. Again o.1 micro grams of adrenalin is added. Richard Holmes injects the isolated gill with a dye. The spread of the dye in the blood circulating through the gill filaments is seen through a microscope. Richard Holmes at the Physiological Laboratory, Cambridge introduces Peter Nathanielsz. Peter Nathanielsz explains his apparatus for observing changes in air pressure in the lungs of a decerebrate rabbit while simultaneously recording electrical activity in the muscles of the diaphragm. Richard Holmes uses this preparation and apparatus to investigate the Hering-Breuer reflex. He alters the stretch receptors by blowing into the lungs or sucking air out. Holmes then cuts the vagus nerve and repeats the experiment. The respiratory cycle continues after the vagus nerve is severed. The rabbit's brain is then transected between the pons and medulla. The effect of this on respiration is monitored by a kymograph. Apneustic gasping and a prolonged inspiratory gasp results. An experiment is carried out, using a spirometer, to determine the effect of oxygen and CO level in the blood on respiration. The subject is Richard Holmes who breathes various mixtures of the gases. His reactions are monitored. Richard Hardy conducts the experiment. Richard Holmes introduces Prof. George Varley. George Varley provides the commentary for a film sequence showing respiratory adaptations of various aquatic insects. Shots of: mosquito (culex) larvae; rat tailed maggot (Eristalis); water beetle (Dytiscid) larva & adult; notonecta; corixa; Aphelocherius; Alderfly (sialis) larva; mayfly (Ephemera) nymph; pond olive (Cloeon) nymph; damselfly (Coenagrion) nymph; dragonfly (Aeschna) nymph. |
| Master spool number: | 6LT/70534 |
| Production number: | 00521_2124 |
| Videofinder number: | 3580 |
| Available to public: | no |
