Save
BIOLOGY
Unit 7 Part 2
Unit 7.7
Save
Share
Learn
Content
Leaderboard
Share
Learn
Created by
Delaney Campos
Visit profile
Cards (19)
Gas
Exchange Surfaces
The events that result in
gas exchange
between the body's
cells
and environment
View source
Respiration
1.
Ventilation
(breathing in and out)
2.
External Respiration
(gas exchange between air and blood in lungs)
3.
Internal Respiration
(gas exchange between blood and tissue fluid)
View source
Organisms
are either small enough to allow gas exchange across their membranes, or have developed specialized tissues to allow
diffusion
of gases
View source
Aquatic
animals
Expend more energy carrying out gas exchange (
25
% for fish,
1-2
% for humans)
Water
is more dense, and a given volume of water only carries a
fraction
of air
View source
Small
aquatic organisms (hydra, planarian)
Have a large surface area compared to body size, so most cells can exchange
gases
directly with
environment
View source
Small
terrestrial invertebrates (earthworm)
Use body surface for
respiration
because
capillaries
come close to the surface
View source
Aquatic invertebrates & vertebrates
Use
gills
to extract
oxygen
from water
Gills are highly
vascularized
Use
countercurrent
exchange (water flows in
opposite
direction of oxygen-depleted blood)
View source
Insects
Have inefficient circulation (hemolymph fluid just contained within the hemocoel cavity)
Overcome inefficiency with tracheal system (trachea -> tubules -> tracheoles -> ~0.1um tubes)
Deliver air directly to
cells
without entering the
blood
Air sacs act like bellows to move
air
into and out from the
trachea
tubes
View source
Terrestrial
vertebrates
Lungs are vascularized outgrowths from the lower pharyngeal region
Lungs can be
subdivided
into smaller passageways and spaces
Human lungs have surface area of ~
70m2
(50x skin surface area)
Air
has a drying effect, so lungs are
moistened
to keep them from drying out
View source
Human Lungs & Respiration
1. Air moves from
nose
-> pharynx -> trachea -> bronchi ->
lungs
2.
Filtered
,
warmed
, and humidified in this process
3. At body temp and saturated with
water
once it reaches
lungs
4.
Larynx
and
trachea
permanently held open by cartilage rings to facilitate air movement
5. When
swallowing
, larynx rises, glottis closed by epiglottis, and soft palate covers
nasal passages
View source
Breathing - Inspiration
1. Creation of
negative
pressure in the lungs
2. Rib cage
elevated
3. Diaphragm
contracts
and lowers
4. Thoracic pressure
decreases
to less than
atmospheric
pressure
5. Atmospheric pressure forces
air
into the lungs
View source
Breathing
- Expiration
1. Creation of
positive
pressure in the lungs
2. Rib cage
lowered
3. Diaphragm
rises
4. Thoracic pressure
increases
to more than
atmospheric
pressure
5. Forces air
out
of the lungs
View source
Ventilation
Terrestrial
vertebrates (except birds) use tidal
ventilation
(air moves in and out same route, new air mixes with used air)
Birds use
one-way
ventilation (fresh air never mixes with used air)
View source
Modifications
of Breathing in Humans
Normally
12-20
ventilations per minute
Controlled by
respiratory
center in
medulla oblongata
Can be influenced by
nervous
or
chemical
input
View source
Gas
Exchange and Transport
Gases diffuse from areas of
higher
to
lower partial pressure
Ventilation causes
alveoli
to have higher oxygen and
lower carbon dioxide partial pressure
than blood in pulmonary capillaries
View source
Transport of Oxygen and Carbon Dioxide
1.
External Respiration
(oxygen combines with hemoglobin in RBCs)
2.
Internal Respiration
(oxyhemoglobin gives up oxygen to tissues, carbon dioxide enters blood and binds to hemoglobin or is transported as
bicarbonate
ion)
View source
Disorders
of the Upper Respiratory Tract
Cold
(mild viral infection)
Strep Throat
(acute pharyngitis caused by Streptococcus pyogenes)
View source
Disorders
of the Lower Respiratory Tract
Choking
Acute
bronchitis
Chronic
bronchitis
Asthma
(airways sensitive to irritants, causing spasms)
View source
Disorders
Affecting the Lungs
Pneumonia
(viral, bacterial, or fungal infection)
Pulmonary tuberculosis
(caused by Mycobacterium tuberculosis)
Pulmonary fibrosis
(fibrous tissue buildup)
Emphysema
(alveoli distended, reduced surface area)
Lung cancer
(begins with thickening and callusing of airway cells)
View source
See similar decks
Unit 1: Cell Biology
GCSE Biology
527 cards
Unit 1: Cell Biology
AQA GCSE Biology
407 cards
Unit 7: Ecology
GCSE Biology
734 cards
Unit 8: Ecology
AP Biology
330 cards
Unit 7: Ecology
AQA GCSE Biology
533 cards
Unit 3: Influences of Beauty and Art
AP Chinese Language and Culture
160 cards
Unit 2: Organisation
GCSE Biology
611 cards
Unit 4: Bioenergetics
GCSE Biology
412 cards
Unit 3: Cellular Energetics
AP Biology
524 cards
Unit 2: Electricity
AQA GCSE Physics
547 cards
Unit 1: Energy
AQA GCSE Physics
476 cards
Unit 2: Electricity
GCSE Physics
729 cards
Unit 17: Addiction
AQA A-Level Psychology
991 cards
Unit 2: Cognition
AP Psychology
517 cards
Unit 3: Globalisation
Edexcel A-Level Geography
140 cards
Unit 7: ArrayList
AP Computer Science A
87 cards
Unit 3: Influences of Beauty and Art
AP Spanish Language and Culture
247 cards
Unit 3: Influences of Beauty and Art
AP French Language and Culture
1128 cards
Unit 6: Waves
AQA GCSE Physics
314 cards
Unit 7: Oscillations
AP Physics 1
443 cards
Unit 8: Research
AP English Language and Composition
232 cards