M3 chapter 7 Exchange surfaces and breathing Flashcards
in what type of cell is the SA:V smaller?
in larger cells
what is the trachea surrounded by?
16-20 rings of hyaline (c-shaped) cartilage which provide support to prevent it collapsing
what else supports the trachea?
Ligaments connect the rings. a smooth muscle known as the trachealis muscle bridges the gap between the ends of the incomplete rings and runs along the back wall of the trachea.
what is the trachea lined with?
lined by ciliated pseudostratified columnar epithelium
what do goblet cells do?
release and create a mucus between the CPCE, which helps trap microorganisms
how does the trachea trap and destroy pathogens?
mucus traps the pathogens and the cilia beat the mucus up in to the oesophagus to go to the stomach to be destroyed
where are the brochi?
trachea branches into left and right bronchi at the 4th thoracic vertebra
what happens after the trachea branches into left and right bronchi?
the primary bronchi enters the lungs at a point called the hilum and branch into secondary bronchi as they get narrower, which then branch into tertiary bronchi
what happens to the tertiary bronchi as they get narrower?
they become bronchioles which rely in elastic fibres that are attached to the surrounding lung tissue , as they get smaller they become terminal bronchioles which become respiratory bronchioles.
what do respiratory bronchioles do?
these deliver air to the alveoli for gas exchange
why is there an indentation on the left lung?
the heart sits just under the left lung creating an indentation called the cardiac notch
what type of epithelium do the bronchioles have?
start having simple ciliated columnar epithelium, this then changes to simple cuboid epithelium
what adaptation do the alveoli have to them to help diffusion?
they have a moist lining inside them called a surfactant which keeps the alveoli inflated and allows gases to dissolve in.
what are the lungs enclosed in?
a pleural sac which contains pleural fluid to allows inner and outer walls to slide over each other without causing friction during breathing
what is ventilation?
the movement of air into and out of the lungs to supply oxygen to the body and remove carbon dioxide.
where is the diaphragm and what is it controlled by?
muscle which sits near the bottom of the chest and is controlled by the phrenic nerve where it is under autonomic control
what are the 3 openings in the diaphragm?
caval opening (vena cava)
aorta
oesophagus
describe the process of inhalation?
the external intercostal muscles contract whereas the internal ones relax, as a result cause the ribs to raise upwards. The diaphragm contracts and flattens. This causes the volume inside the thoracic cavity to increase, this lowers the pressure. The difference between the pressure inside the lungs and atmospheric pressure creates a gradient, causing the air to enter the lungs
what are the intercostal muscles?
muscles that lie between the ribs
what do internal intercostal muscles do?
when relaxed they move the ribs downwards
what do external intercostal muscles do?
when contracted they move the ribs upwards
what do exchange
areas need to make them efficient?
large surface area
thin to ensure that the distance that needs to be crossed is short.
a good blood supply/ventilation to
maintain a steep gradient, for example that of the alveoli.
what do the ribs do?
protects the lungs by surrounding them
what is a spirometer?
measuring the volume of air inspired and expired by the lungs.
what is tidal volume?
volume of air that is moved in and out of the lungs with each resting breath
what is vital capacity?
the volume of air that can be breathed in when the strongest exhalation is followed by the deepest intake
what is inspiratory reserve volume?
maximum volume that can be breathed in
what is expiratory reserve volume?
maximum amount of air that you can force out of your lungs
what is residual volume?
volume of air that is left in lungs when you have exhaled as hard as possible, this can’t be measured directly
what type of circulatory system to fish have?
single closed system
where does the deoxygenated blood go in a fish?
from the heart to the gills, where the blood picks up oxygen from the water as there is a concentration gradient`
what is the operculum?
bony flap that covers the gills
what are the lamellae?
they branch of the gill arch, they are used to increase surface area
what does the gill arch contain?
contains blood vessels
what are secondary lamellae?
where the primary lamellae folds on its surface to create a greater surface area
what type of flow system occurs in the fish circulatory system?
counter current flow
what is counter current flow?
fluids flow in the opposite direction to each other. diffusion can take place more efficiently as there is always a concentration gradient maintained
what has a higher concentration in the water compared to the lamellae?
oxygen
therefore a concentration gradient is always maintained
what is the buccal cavity of a fish?
the mouth
what is the buccal-opercular pump?
changes in the volume of the buccal cavity acts as a pump to keep oxygen flowing over the gills
how does the buccal opercular cavity work?
floor of mouth moves downwards, increasing the volume of the BO cavity. this decreases pressure of the BO cavity. water flows into the cavity. the mouth closes creating force pushing water toward the gills due to an increase in pressure. this moves the operculum outwards moving water over the gills
what sort of circulatory system do insects have?
open
what bathes insects cells?
haemolymph which acts as blood and tissue fluid
what is a spiracle?
a respiratory opening in the exoskeleton of the thorax and abdomen
how do insects breathe
air enters through spiracles which is connected to the tracheae which is supported by chitin. these divide into tracheoles which are filled with fluid which transports the air for diffusion into the cells
how is the tracheal system ventilated in insects?
tracheoles surrounding flight muscles are squeezed when muscles contract and expand when muscles relax.
