Difference between revisions of "Respiration in Non-Homeotherms - Anatomy & Physiology"

Revision as of 11:13, 15 August 2008

()Map CARDIORESPIRATORY SYSTEM (Map)

Introduction

Fish

Fish live in a relatively dense and viscous fluid, which has little oxygen carrying capacity. In order to gain sufficient gaseous exchange for survival, fish have developed a highly efficient system which has a large surface area, and utilises energy - the gills.

Gills

Gills are in the walls of both sides of the pharynx and are composed of filaments which increase the surface area. When a fish breaths, it takes in water into the mouth, which is then forced out through the gills.

A Countercurrent Exchange system is in place within the gills to make gaseous exchange more efficient.

Amphibia

In amphibian species, the skin forms the major, and sometimes only respiratory organ.

The skin of amphibia is:

Thin
Poorly keratinised
Highly vascularised
Moist to promote diffusion of gases

Aquatic amphibians may also have internal gills and Pharyngeal Slits.

Most Amphibia also have lungs for breathing. This contains interconnecting septa which divide the lumen into Faveoli, compartments which open into a central chamber within each lung.

Reptiles

Reptiles have a fundamentally different respiratory system to that of mammals, in that they lack a bronchial tree.

Route of Air in the Reptiliant Respiratory System:

Air enters via nares
Nasal Cavity
Choana
Glottis (base of tongue)
Trachea
Bronchi
Lungs

The lungs are paired, with respiration only occuring in the cranial region.

The Respiratory surface is composed of Faveoli, honeycomb shaped structures which line the walls.

Lizards

No diaphragm
Simple, saclike, paired lungs
Cranial part of lung is site of respiratory function
Caudal part of lung forms air reservoir
Ventilation occurs via expansion and contraction of the ribs

Snakes

Larynx projects medially from the floor of the mouth and is fused with the first few cartilage rings of the trachea. This forms a rigid Glottis.
Tongue is fixed at the rostral point of the oral cavity.
Generally only the right lung is present. The lung of snakes is very fragile.
Inspiration is an active process, made possible by expansion of the ribs. It occurs approx once every 30seconds in large, healthy snakes. Expiration is a passive prcoess.

Chelonians

Have paired lungs in the Dorsal Cavity. Intestines etc lie in the Ventral Cavity. These are separated by a diaphragmatic septum which has no muscular part.
Lungs are ventilated by leg movement in terrestrial animals.

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-{{OpenPagesTop}}
+{{toplink
+|backcolour = D1EEEE
+|linkpage =Cardiorespiratory System - Anatomy & Physiology
+|linktext =Cardiorespiratory System
+|maplink = Cardiorespiratory (Content Map) - Anatomy & Physiology
+|pagetype =Anatomy
+}}
+<br>
+==Introduction==
 ==Fish==
-Fish live in a relatively dense and viscous fluid, which has little oxygen carrying capacity. In order to gain sufficient [[Gas Exchange - Anatomy & Physiology|gaseous exchange]] for survival, fish have developed a highly efficient system which has a large surface area, and utilises energy - the gills.
+Fish live in a relatively dense and viscous fluid, which has little oxygen carrying capacity. In order to gain sufficient gaseous exchange for survival, fish have developed a highly efficient system which has a large surface area, and utilises energy - the gills.
 ===Gills===
-Gills are in the walls of both sides of the [[Pharynx - Anatomy & Physiology|pharynx]] and are composed of filaments which increase the surface area.
+Gills are in the walls of both sides of the pharynx and are composed of filaments which increase the surface area.
-When a fish breaths, it takes in water into the mouth, which is then forced out through the gills. A '''countercurrent exchange''' system is in place within the gills to make gaseous exchange more efficient.
+When a fish breaths, it takes in water into the mouth, which is then forced out through the gills.
+A '''Countercurrent Exchange''' system is in place within the gills to make gaseous exchange more efficient.
-The gill has several important functions in fish physiology: '''respiration, nitrogenous excretion and fluid balance''' regulation.
+==Amphibia==
-The anatomic structure of the gills helps in its functions by providing a '''large and very thin surface'''. The gill filaments are divided into multiple finger-like projections, the primary lamellae, which in turn are divided into secondary lamellae.
+In amphibian species, the [[Skin - Anatomy & Physiology|skin]] forms the major, and sometimes only respiratory organ.
-There is usually very little mucus on the gill surface.
+The [[Skin - Anatomy & Physiology|skin]] of amphibia is:
+*Thin
+*Poorly keratinised
+*Highly vascularised
+*Moist to promote diffusion of gases
-==Amphibia==
+'''Aquatic''' amphibians may also have ''internal gills'' and '''Pharyngeal Slits'''.
-In amphibian species, the [[Skin - Anatomy & Physiology|skin]] forms the major, and sometimes only respiratory organ. The skin of amphibia is thin, poorly keratinised, highly vascularised and moist to promote diffusion of gases. '''Aquatic''' amphibians may also have ''internal gills'' and '''pharyngeal slits'''. Most amphibia also have lungs for breathing. This contains interconnecting septa which divide the lumen into '''faveoli''', compartments which open into a central chamber within each [[Lungs - Anatomy & Physiology|lung]].
+Most Amphibia also have lungs for breathing. This contains interconnecting septa which divide the lumen into '''Faveoli''', compartments which open into a central chamber within each lung.
 ==Reptiles==
-Reptiles have a fundamentally different respiratory system to that of mammals in that they lack a bronchial tree.
+Reptiles have a fundamentally different respiratory system to that of mammals, in that they lack a bronchial tree.
-The air in the reptilian respiratory system flows through the following passage:
+Route of Air in the Reptiliant Respiratory System:
 #Air enters via nares
 #[[Nasal Cavity - Anatomy & Physiology|Nasal Cavity]]
@@ Line 31: / Line 47: @@
 #Lungs
-The lungs are paired, with respiration only occurring in the cranial region. The respiratory surface is composed of '''faveoli''', honeycomb shaped structures which line the walls. In addition, reptiles have a poorly developed mucocillary escalator, and rely on body positioning to clear mucous from the respiratory system.
+The lungs are paired, with respiration only occuring in the cranial region.
+The Respiratory surface is composed of '''Faveoli''', honeycomb shaped structures which line the walls.
 ===Lizards===
-Lizards have no diaphragm and a simple, sac-like, paired [[Lungs - Anatomy & Physiology|lungs]]. The cranial part of lung is the site of respiratory function. The caudal part of the lung forms an air ''reservoir''. Ventilation occurs via expansion and contraction of the ribs. For more information see [[Lizard and Snake Respiration]] and [[Lizard Respiratory System]].
+*No diaphragm
+*Simple, saclike, paired lungs
+*Cranial part of lung is site of respiratory function
+*Caudal part of lung forms air ''reservoir''
+*Ventilation occurs via expansion and contraction of the ribs
 ===Snakes===
-The larynx projects medially from the floor of the mouth and is fused with the first few cartilage rings of the trachea. This forms a rigid '''glottis''' which is highly  mobile and can be displaced laterally to allow breathing during feeding. The tongue is fixed at the rostral point of the oral cavity. Generally, only the right lung is present, or at least functional - ''colubrids'' have a vestigial left lung. The lung of snakes is very fragile. Inspiration is an active process, made possible by expansion of the ribs. It occurs approx once every 30 seconds in large, healthy snakes. Expiration is a passive process. Snakes have no vocal cords, but are able to make hissing noises by passing air through the glottis. Aquatic snakes have air sacs which serve as a buoyancy aid. For more information see [[Lizard and Snake Respiration]] and [[Snake Respiratory System]].
+*Larynx projects medially from the floor of the mouth and is fused with the first few cartilage rings of the trachea. This forms a rigid '''Glottis'''.
+*Tongue is fixed at the rostral point of the oral cavity.
+*Generally only the right lung is present. The lung of snakes is very fragile.
+*Inspiration is an active process, made possible by expansion of the ribs. It occurs approx once every 30seconds in large, healthy snakes. Expiration is a passive prcoess.
 ===Chelonians===
-Chelonians have adapted a '''dive reflex''' which enables them to respire anaerobically. They have extremely high levels of bicarbonate in their blood which allows them to buffer the lactic acid produced. Chelonians have an extremely short trachea in relation to their size. They have paired lungs in the '''dorsal cavity'''. Intestines etc. lie in the '''ventral cavity'''. These are separated by a diaphragmatic septum which has no muscular part. Chelonians possess large spongy lungs which reduce 80% in size when the head and limbs are retracted inside the shell. The lungs have a single intrapulmonary bronchus which radiates in a network of bronchioles and faveoli. Lungs are ventilated by leg movement in terrestrial animals, and have highly developed trunk muscles to facilitate this. Aquatic species are able to respire due to the hydrostatic pressure of water, which forces air in and out of the lungs. In addition, some soft-shelled chelonians are able to absorb oxygen through their shells and skin when submerged.
+*Have paired lungs in the '''Dorsal Cavity'''. Intestines etc lie in the '''Ventral Cavity'''. These are separated by a diaphragmatic septum which has no muscular part.
+*Lungs are ventilated by leg movement in terrestrial animals.
-{{OpenPages}}
-[[Category:Respiratory System - Anatomy & Physiology]]
-[[Category:A&P Done]]