exchange and transport Flashcards
alveoli
tiny air sacs that serve as the primary gaseous exchange surface
consist of thin epithelial cell layer, collagen and elastic fibres
breathing rate
number of breaths per minute
bronchi
divisions of the trachea that lead into the lungs
small tubes supported by incomplete rings of cartilage
bronchioles
many small division of the bronchi
contain smooth muscle to restrict airflow to the lungs but do not have cartilage
lined with a thin layer of ciliated epithelial cells
cartilage
strong, flexible connective tissue that supports the walls of the trachea and bronchi, preventing collapse
it is found in an incomplete ring shape
ciliated epithelial cells
specialised cells with tiny hair-like cilia found lining the trachea
waft bacteria containing mucus up to back of the throat, where it is swallowed
counter current flow
an adapation for gaseous exchange in bony fish
blood in the gill filaments and water moving over the gills flow in opposite directions
maintains a steep oxygen concentration gradient
elastic fibres
fibres of elastin that allow the alveoli to stretch as air is drawn in and recoil back to normal size, expelling air
also found in the trachea, bronchi and bronchioles
exchange surface
a surface where materials are exchanged from one region to another
an effective exchange surface has a large surface area, thin layers, a good blood supply and ventilation to maintain a steep diffusion gradient
expiration
exhalation
diaphragm relaxes and reverts to a dome
the external intercostal muscles relax, moving ribs down and in
the volume of the thorax decreases and thoracic pressure exceeds air pressure
air moves out of the trachea
gill filaments
main site of gaseous exchange in fish, over which water flows
they are found in large stacks (gill plates)
have gill lamellae - provide a large surface area for exchange
gill lamellae
the fine branches of the gill filaments
are adapted for gaseous exchange by having a large surface area and good blood supply
gill plates
large stacks of gill filaments
gills
organs of gaseous exchange in fish
contained in a gill cavity and are made up of gill lamellae, gill filaments and gill plates
goblet cells
specialised cells that secrete mucus onto the trachea lining
mucus traps harmful substances and microorganisms, preventing their entry into the lungs
inspiration
inhalation
diaphragm contracts and flattens
the external intercostal muscles contract
moving the ribs up and out
volume of the thorax increases
thoracic pressure falls below air pressure
air moves into the trachea
internal intercostal muscle
muscles found between the ribs which are responsible for forced exhalation
mammalian gaseous exchange system
a complex system found in mammals in which oxygen and carbon dioxide gases are exchanged
operculum
a flap that covers the gills of bony fish
it protects the gills and helps to maintain a constant stream of water over them
smooth muscle
an involuntary muscle found in the walls of the trachea and bronchi
it constricts the lumen of the bronchi by contracting, reducing airflow to the lungs
spiracles
small, external openings along the thorax and abdomen of most insects
air enters and air and water leaves the gaseous exchange system
spiracle sphincters open and close the spiracles to control gas exchange
spirometer
a device used to examine patterns of breathing
determine different aspects of lung volume
tidal volume
the volume of air that moves into and out of the lungs during a normal breath
trachea (mammals)
the primary airway which carries air from the nasal cavity down into the chest
a tube supported by incomplete rings of cartilage
tracheae (insects)
large tubes that run from the spiracles, into and along an insect’s body
supported by spirals of chitin
the tracheae divide further into smaller tracheoles
tracheal fluid
a fluid found at the ends of the tracheoles
amount of fluid affects the surface area available for gaseous exchange and water loss
tracheoles
divisions of the tracheae that run throughout the tissues of an insect, forming a complex network
main site of gas exchange
are completely permeable to gases
ventilation
the movement of fresh air into the lungs and stale air out of the lungs via inspiration and expiration
vital capacity
the largest volume of air that can be breathed in following the strongest possible exhalation
affinity
the tendency of one substance to bind with another substance
aorta
the artery that takes oxygenated blood away from the heart to the body
arteriole
a type of blood vessel that connects the arteries and capillaries
the walls contain large amounts of smooth muscle, some elastic fibres and some collagen
artery
type of blood vessel that carries blood away from the heart to the tissues, under high pressure
the walls contain collagen collagen, smooth muscle and elastic fibres
atrial fibrillation
an arrhythmia that involves the rapid contraction of the atria, preventing complete ventricular filling
atrial systole
the stage of the cardiac cycle in which the atria contract, pushing blood into the ventricles
the AV valves are pushed open fully and the atria are emptied of blood
atrioventricular node (AVN)
a group of cells located between the atria that slow down the wave of excitation and pass it between the ventricles, along the bundle of His
atrioventricular (AV) valves
found between the atria and ventricles
prevent the back flow of blood from the ventricles into the atria
two types of AV valves
bicuspid
tricuspid
bicuspid valves
the atrioventricular valves found between the left atrium and left ventricle
blood
the transport medium in the mammalian circulatory system
consists of plasma, red blood cells, white blood cells and platelets
bohr effect
the loss of affinity of haemoglobin for oxygen as the partial pressure of carbon dioxide increases
bradycardia
a slow resting heart rate below 60 bpm
bundle of His
a collection of purkyne fibres which run from the AVN down to the apex of the ventricles