Gaseous Exchange Flashcards
What is gaseous exchange?
When CO2 moves from the blood into the alveolus and O2 moves from the alveolus into the blood
What is the chemical and word equation for gaseous exchange?
Glucose + Oxygen —-> Carbon dioxide + Water + Energy
C6H12O6 + 602 —–> 6CO2 + 6H2O + 38ATP
Explain respiration completely
- When energy s released from food
- Occurs in the mtochondria
O2 and CO2 are needed
CO2 is gotten rid of and O2 is obtained through gaseous exchange
What is breathing?
Air moving into and out of the lungs ( inhaling and exhaling)
What are the requirements for an efficient gaseous exchange system?
- Large SA
- Moist exchange surface
- Thin exchange surface
- Good transport system
- Good ventilation
- Protection of the gaseous exchange system
Explain the importance of each requirements of GE
1) Allows for max exchange of gases
2) The gases dissolve in the moisture before they diffuse
3) Gases move across rapidly
4) Oxygen is transported away rapidly so that the diffusion gradient between the blood and the alveolus remains steep for efficient diffusion of gases
5) Fresh air with a high concentr. of O2 is continually drawn into the lungs and air with a high concentr. of CO2 is continually expelled from the lungs
6) Lungs = delicate therefore must be protected so that no damage occurs. If damaged = gaseous exchange wont be efficient
Explain how each requirement for gaseous exchange is achieved.
1) Many alveoli incr the SA for GE
2) Fluid found on the inner surface of the alveoli
3) The alveoli have a single layer of endothelium and capillaries have a single layer of endothelium
4) Rich capillary system surrounds each alveolus
5) The lungs ; diaphragm and intercostal muscles create a system which draws air in and out of the lungs
6) Protected by the rib cage; intercostal muscles; diaphragm; spinal column and the 2 pleura
What parts make up the air passages?
Nasal cavities; Pharnyx; Trachea; Bronchi
What do the nostrils lead to?
What do the hairs do?
What is the nasal cavity lined with?
What is the goblet cells involved in?
What do the cilia do?
1) 2 nasal cavities, separated by the septum
2) Trap dust and impurities in the air being inhaled
3) Ciliated columnar epithelium which have goblet cells
4) Mucus - moistens the air and traps impurities
5) Beat to move mucus and impurities backwards into the pharynx where its swallowed
** epithelium has many blood capillaries beneath it which warm the inhaled air
What is the purpose of the pharynx?
What is at its entrance?
1) Common passage for food and air - Lower end splits into oesophagus and trachea
2) Covered by epiglottis which prevents food and liquid from entering the trachea
What is the upper part of the trachea known as?
How is the trachea kept open?
What is it lined with?
1) The larynx/ voice box
2) C - Shaped cartilage rings so air can move through unimpeded
3) Ciliated epithelium
What does the trachea divide into?
How are they kept open?
What do they do?
1) The bronchi
2) O - Shaped cartilage rings
3) Enter lungs and divide into smaller and smaller tubules which end in air sacs ( called alveoli)
Explain / Describe the lungs fully
- Left lung = 2 lobes - Right lung = 3 lobes
- Each lung =covered by 2 membranes called plueral
- Pulmonary vein leaves lungs
- Pulmonary artery enters lungs and divides into many capillaries which surround the alveoli
Small tubules and alveoli form cone shaped organs
What are the alveoli?
A pouch like sac formed by a single layer of squamous epithelium / endothelium
Explain the ribs and intercostal muscles completely
- 12 pairs of ribs surround and protect spongy lungs
- Join thoracic vertebrae @ back & attach onto sternum in front with costal cartilage
- 2 sets of intercostal muscles ( internal; external) = found between ribs; create breathing movements
- Pleural membranes = surround lungs; separated by thin layer of fluid ( reduces friction between lungs and ribs during breathing movements)
