Download GASEOUS EXCHANGE

Oxygen is needed for _______________
Oxygen is needed for cellular respiration.
WHAT IS THE DIFFERENCE BETWEEN
BREATHING AND GASEOUS EXCHANGE?
Discuss with a peer. 1 and half minutes
After respiration the oxygen gas is changed into ______________,
Carbon dioxide
If CO2 accumulate it joins with water forming carbonic acid → change pH → affect
enzymes
REQUIREMENTS FOR AN EFFICIENT GAS
EXCHANGE SYSTEM
See table pg 205
•
Large, moist and thin surface
•
A transport system
•
Ventilating mechanism
•
protection
HOW REQUIREMENTS ARE SATISFIED IN
DIFFERENT ORGANISMS (SEE PG 206-207)
VOLUME TO SURFACE AREA RATIO PG 208
GASEOUS EXCHANGE SYSTEM IN HUMANS
AIR PASSAGE:
Nasal passage (warmed, moistened and cleaned of dust and germs) →
→ pharynx
→ trachea (has c-shaped cartilage to keep it open)
Trachea → 2 bronchi → bronchioles → alveolus
ADAPTATIONS OF AIR PASSAGES SEE TABLE PG 211
THE LUNGS (PG 213)
INTERNAL STRUCTURE OF LUNG
ADAPTATIONS (PG 214)
ACTIVITY 2.4.7 PG 220 NO 1-3
ACTIVITY 2.4.7 PG 220 NO 1-3
1 a) F
b) B
c) A
d) J
e) K
f) C
2 rib cage
Fluid of pleural membrane
3. C- Rib
D- intercostal muscle
G- Trachea
H- Pulmonary artery
I- Pulmonary vein
BREATHING PRAC 2.4.4 PG 215-216
BREATHING SEE TABLE ON PG 217
Inhalation and exhalation difference.
ACT 2.4.5 PG 218
TEST FOR CO2
Clear lime water turned milky in the presence of CO2
MODIFICATION OF BREATHING RATE
Can be modified voluntarily within limits .
Average of 15 breaths per minute.
See flow diagram pg 224- How breathing rate is controlled involuntarily.
*Homeostasis
GASEOUS EXCHANGE AND TRANSPORT
AT LUNGS
O2 moves from lungs to capillaries and CO2 moves from the capillaries to the lung by
DIFFUSION.
OXYGEN TRANSPORT
Oxygen + haemoglobin (RBC) = oxyhaemoglobin
Some also dissolved in plasma.
→ left side of heart → aorta → all cells of the body.
….GASEOUS EXCHANGE AND TRANSPORT
AT THE TISSUES:
O2 moves from the capillaries to the tissues and CO2 from the tissues to the
capillaries by DIFFUSION.
TRANSPORT OF CO2
Mostly: CO2 + H2O (plasma) = carbonic acid → bicarbonate ions
Some dissolves in blood plasma
Some CO2 + haemoglobin = carbhaemoglobin
→ Right of heart → lungs
ACTIVITY 2.4.9 PG 227-228
AVAILABILITY OF O2 AT HIGH ALTITUDES PG 228
Air at high altitudes is less dense and thus has less O 2
People living high altitudes breath more deeply and quickly, they also have more red
blood corpuscles.
ACTIVITY 2.4.10 PG 229-230
DISEASES AND ALLERGIES OF THE GAS
EXCHANGE SYSTEM
Allergen- something which causes an allergic reaction
Disease- normal functioning is disturbed.
SEE TABLE PG 231
ASTHMA
HAY FEVER
LUNG CANCER
TB
BRONCHITIS
EMPHYSEMA
TB (VIDEO + PG 231-234)
CAUSES
SPREAD
SYMPTOMS
TEST
VACCINE
TREATMENT
SMOKING
ARTIFICIAL RESPIRATION