Lecture 11, 12 And 13 Flashcards
Define hypoxia
Low levels of oxygen
Define normoxia
Normal levels of oxygen
Define hyperoxia
High levels of oxygen
Define anoxia
No oxygen
What does respiration refer to?
The sum of the processes that accomplished the movement of oxygen from the environment to the cell and the removal of carbon dioxide
What are the two components to respiration?
Internal or cellular respiration ‘true respiration’
External respiration or respiratory has exchange
What is air composed of?
79% nitrogen and 21% oxygen
What is the air pressure at sea level?
101 kpa
Give some diffusion enhancements
. High diffusion coefficients (high permeability)
. A low diffusion distance (thin epithelial- making the barrier thin)
. Large SA
. Vascularisation or bathed in coelomic fluids
. Converting the gas into a non-diffusible for-uses special respiratory proteins e.g. haemoglobin
(So no longer has a partial pressure so you have increased that partial pressure difference)
What is the trouble with external gills or external evaginations?
They need to be supported
What are the two main contributions of bulk transport?
. By passes diffusion
. Enhances gas gradient by moving fluids with different gas contents
Give an example of an aquatic animal that has a tidal ventilation respiratory system
Sea cucumbers
What is ram ventilation?
When the fish simply opens its mouth and the water flows over (doesn’t pump)
What kind of ventilation do lamprey use?
When feeding uses tidal ventilation
When free swimming between hosts water flows into mouth and out of gills
What is increased SA related to?
The activity of the animal
Respiration surface must be kept moist. So what must animals do?
. Remain in moist areas
. Have covered or fully internal structures (doesn’t have to be kept moist)
How have lung fish developed a way to extract oxygen from air?
Gulp it- expands its buckle cavity and air is drawn in (oxygen levels can drop in water suddenly)
What how frogs breath? What is a problem with this method?
The buccopharyngeal cavity is contracted this focuses air into the lungs. The problem is that the frog can only breath when its mouth and nose are closed which is a problem when eating
How do reptiles breath?
Air is sucked into the lungs by the phagocytic cavity, this sets up a negative pressure and air is moved in. (They can breath and eat at the same time)
Describe what happens in inhalation
. Diaphragm contracts . Thoracic cavity expands . Intrapleural pressure becomes negative . Lungs expand . Air enters
Describe what happens in exhalation
. Diaphragm relaxes . Thoracic cavity contracts . Intrapleural pressure becomes less negative . Lung contract . Gases in lung expelled
Why are elephants about to swim?
Because they have layers of connective tissue that hold the lung together. They have connective tissue that are able to move against each other as well. So, they are able to expand their lungs without damaging them
What is pneumatization?
Air sacs penetrate viscera and many bones
Which animals are examples of open systems?
Arthropods, molluscs, crustaceans
What animals show closed systems?
Oligochaete and Annelida, octopus and squid
Describe a vertebrate muscular heart
. Pumps the blood around the body
. Consists of multiple chambers
. Thin auricle or atria
. Thick ventricle
What is the systemic circulation system?
To and from the body tissues
Ideally high flow rates
And therefore high pressure
What is the pulmonary circulation system?
To and from the lungs
Ideally high flow rates
Has to be low pressure
Describe a fish heart
Tube-like
Associated valves
4- chambers
What are the 4 chambers of a fish heart called?
Sinus venomous
Atrium
Ventricle
Conus arteriosus
Describe the sinus venosus chamber of a fish heart
Thin walled venous chamber
Receives blood from: duct of Cuvier, coronary veins, hepatic veins
Describe the atrium chamber of a fish heart
Large and thin walled
1st chamber: initial acceleration of blood flow
Describe the ventricle chamber of a fish heart
2nd gambler: main propulsive force for cardiac flow.
Pumps into conus artriosus- continuous with aorta.
Chambers separated by values
Describe the conus arteeiosus chamber of a fish heart
Short in body fish and amphibians
Not found in adult amniotes
Capacitance vessel: smooths flow of blood to gills.
Very elastic- smooths changes in pressure when heart beats and increases pressure
