b8 gas exchange

breathing system

lungs are protected by the ribs and intercostal muscles run in between the ribs (external and internal). the air you breathe in goes through the larynx and down the trachea(hollow tubes with c shaped rings of cartilages that give structure but also movement), splitting into bronchi(bronchus) and then into smaller bronchioles, being absorbed by al

thorax

middle section of your body(lungs and ribs)

ventilation

breathing in(inspiration) and then breathing out(expiration)

inspiration

external intercostal and diaphragm contract causing ribs to move outwards and forwards which increases volume and pulls air in

expiration

internal intercostals muscles contract causing the ribs to move downwards and inwards increasing pressure in thorax which pushes air out

alveoli

in the lungs and are optimized for gas exchange. they have a large surface area, thin surface, good blood supply, good ventilation

how are the breathing systems protected

airways are lined with ciliated cells that are covered in cilia that waft the mucus up the throat to be swallowed, and goblet cells that produce the mucus that the pathogens stick to. on the trachea and bronchi

7 things energy is needed for in the body

muscles to contact, protein synthesis, cell division(mitosis, meiosis), active transport, cell growth, passing impulses along neurons, maintain a constant body temperature

aerobic respiration

series of chemical reactions that happen in cells and use oxygen to break down nutrient molecules to release energy(C6H12O6 → 6CO2 + 6H2O)

anaerobic respiration

reactions in cells that break down nutrient molecules to release energy without using oxygen(glucose → lactic acid). much less efficient than aerobic respiration

oxygen debt

when your body cant supply enough oxygen to your muscles under severe load anaerobic respiration starts happening. this creates debt since the generated lactic acid needs more oxygen to get broken down in the liver. heart rate also stays high to transport the acid from muscles to the liver, where it is broken down through aerobic respiration

respiration in yeast

yeast can also use aerobic respiration but instead of lactic acid carbon dioxide and alcohol are produced(C6H12O6 → 2C5H5OH + 2CO2)

how to measure oxygen uptake in respiring organisms

2 test tubes connected by a scale with water, one with woodlice on wool and soda lime, and one with beads to substitute for the woodlice. you can measure as the woodlice use oxygen to respire and shift the scale with water