Respiratory System Flashcards
Why do large organisms need transport systems?
SA:VOL ratio is too small to transport substances by diffusion because the distance is too large
What are the adaptations of exchange surfaces?
Thin exchange surfaces for short diffusion pathway
large SA:VOL ratio
Maintain steep concentration gradient
what are the adaptations of the lungs?
Large surface area - large amounts of alveoli
Good blood supply - maintains high concentration gradient
Short diffusion distance - alveoli and capillary are 1 cell thick
moist surface - gases dissolve and facilitate diffusion
Explain the structure of the respiratory system?
Air is inhaled by mouth/nose and travels down the trachea
trachea branches into 2 smaller tubes called bronchi
brochi are divided into bronchioles which sends air to alveoli where it is exchanged into the blood
Lungs surrounded by pleural membrane
ribcage surrounded by intercostal muscles protects organs
What are goblet cells?
secrete mucus to trap dust and microorganisms to prevent infection
What are elastic fibres?
in lungs
Fibres that stretch and recoil when inhaling and exhaling
what is smooth muscle?
In the lungs
control the diameter of airway by contracting or relaxing
what is cartilage?
in the lungs
C shaped rings
provide strength and support
prevents airway from collapsing
Describe inhalation
Diaphragm moves down and flattens
internal intercostal muscles contract and external relax
ribcage moves upwards and out
increased volume of thorax, decreased pressure so air enters lungs
Describe exhalation
Diaphragm moves upwards
internal intercostal muscles relax and external contract
ribcage moves upwards and out
decreased volume of thorax, increased pressure so air pushed out lungs
what is a spirometer?
Equipment used to investigate volume of air someone can breathe
Consists of chamber filled with oxygen that moves up or down when people breathe
a pen draws a spirometer trace
What is tidal volume?
the volume of air in each breath
what is vital capacity?
the maximum volume of air that a person can exhale form their lungs after a maximum inhalation
what is breathing rate?
the number of breathes per minute
what is oxygen consumption?
the volume of oxygen used by the body
Why does the volume of the chamber decrease?
Spirometer contains soda lime which absorbs CO2 breathed out.
Oxygen in the chamber would be consumed by the person
Describe the structure of the gill
Each gill made of several gill filaments stacked on top of each other
Gill filaments covered in lamellae - increases surface area
Gill filaments have thin cell walls - short diffusion path
What is a counter current system?
Blood in the capillaries flow in opposite direction to the water
Maintain oxygen concentration gradient
How are fish gills ventilated?
When fish opens it mouth, the buccal cavity lowers, increasing mouths volume
pressure decreases, causing water to enter mouth into buccal cavity
fish closes mouth, buccal cavity moves up, volume reduces
pressure increases forcing water through the gill filaments
water moves over gill filaments and increases pressure, operculum is forced open and water leaves
Describe ventilation in insects
Air enter through pores called spiracles
Air moves down the trachea, which branches into tracheoles
walls of tracheoles are thin - short diffusion path
Rhythmic abdominal movements push air into and out of the spiracles - maintain steep concentration gradient
