Chapter 7 (Mammalian Gas Exchange) Flashcards
Definition of a tissue?
Group of similar cells working together which are specialised to carry out a specific function
Eg, xylem tissue, phloem tissue, ciliated epithelium
Definition of an organ
A group of different tissues working together which are specialised to carry out specific functions.
Eg, lungs, leaves
Definition of an organ system?
Collection of organs working together with a specific function
Eg, circulatory system- heart, blood vessels, blood
Gas exchange system.
What makes up the gas exchange system?
Lungs, trachea, bronchi, bronchioles, larynx, mouth, diaphragm.
Function of GES?
- Diffusion of respiratory gases, CO2 + O2 into blood stream
- Rate of diffusion determines by many factors: SA:V incr., diffusion rate incr.
Why would diffusion rate be too slow in multicellular organisms?
NOT FINISHED!!!!
Large diffusion distance between cells and outside environment
Definition of tidal volume?
Volume of air that moves in and out of the lungs during a normal breath ~0.5dm3
Definition of Vital capacity?
Maximum volume of air that can be inhaled or exhaled.
Definition of residual volume?
Volume of air that remains in the lungs after a forced exhalation (important as it prevents the lungs collapsing and alveoli sticking together)
Definition of breathing rate?
Number of breaths taken in a given time period (usually one minute)
Definition of pulmonary ventilation?
Movement of fresh air into lungs and removal of stale air out of lungs over a minute.
PV( dm3min-1) = Tidal volume x breathing rate
Consists of inspiration and expiration
To maintain diffusion gradient.
Definition of FEV1
Forced expiratory volume in one second - Volume of air forcibly exhaled in first second of forced exhalation
Definition of PEFR
Peak expiratory flow rate
Maximum rate of forced exhalation through mouth
Normal values of PEFR?
PEFR measurements used to diagnose pulmonary disorders,
eg, asthma, COPD
For asthmatic person - a lot lower than healthy person.
PEFR increases with age - maximum value at age 30-35.
PEFR measurements then fall from age of 35 as person ages to 85.
Definition of respiratory arrest?
Occurs when person stops breathing Causes: Obstruction in airway blocking trachea or bronchi Drug overdose - depresses nervous system and breathing system so they stop Asthma attack Severe pneumonia severe shock heart attack
EAR information?
Expired air resuscitation
- Call for help (wear gloves and mask)
- Roll person onto back. remove obstruction visible in mouth, use sweeping motion of finger.
- If unresponsive, open air ways - Hold head back by pressing on forehead and lifting chin. Move tongue from back of throat.
- Check for breathing - chest movement and sounds.
- Pinch nostrils closed and make seal around mouth with your mouth.
- Blow gently into mouth and watch chest rise. Repeat when chest falls. If no, try again + recheck airways.
- After 2 breaths check pulse. If pulse, continue
- If no pulse, carry out CPR.