Respiration

1
Respiration

• Respiration
• Physiological process by which oxygen moves into
  an animals internal environment and carbon
  dioxide moves out
• Aerobic respiration
• Cellular process, produces ATP
• Oxygen is used
• Carbon dioxide is produced

2
Respiratory System

• Works with the circulatory system to deliver
  oxygen and remove carbon dioxide
• Also helps regulate acid-base balance

3
Pressure Gradients

• Concentration gradients for gases
• Gases diffuse down their pressure gradients
• Gases enter and leave the body by diffusing down
  pressure gradients across respiratory membranes

4
Factors In Gas Exchange

• Surface-to-volume ratio
• Small, flat animals
• Ventilation
• Adaptations enhance exchange rate
• Respiratory pigments
• Hemoglobin and myoglobin

5
Surface-to-Volume Ratio

• As animal size increases, surface-to-volume ratio
  decreases
• Small, flat animals can use the body surface as
  their respiratory surface
• Larger animals have special structures to
  increase respiratory surface, such as gills or
  lungs

6
The main function of the respiratory system is
_____.

1. gas exchange
2. breathing
3. energy production
4. transportation of oxygen to tissues

7
Respiratory Surfaces

• In flat animals

CO2
O2
8
Respiration

• Respiration
• Physiological process by which oxygen moves into
  an animals internal environment and carbon
  dioxide moves out
• Aerobic respiration
• Cellular process, produces ATP
• Oxygen is used
• Carbon dioxide is produced

9
Respiratory System

• Works with the circulatory system to deliver
  oxygen and remove carbon dioxide
• Also helps regulate acid-base balance

10
Pressure Gradients

• Concentration gradients for gases
• Gases diffuse down their pressure gradients
• Gases enter and leave the body by diffusing down
  pressure gradients across respiratory membranes

11
Factors In Gas Exchange

• Surface-to-volume ratio
• Small, flat animals
• Ventilation
• Adaptations enhance exchange rate
• Respiratory pigments
• Hemoglobin and myoglobin

12
Surface-to-Volume Ratio

• As animal size increases, surface-to-volume ratio
  decreases
• Small, flat animals can use the body surface as
  their respiratory surface
• Larger animals have special structures to
  increase respiratory surface, such as gills or
  lungs

13
The main function of the respiratory system is
_____.

1. gas exchange
2. breathing
3. energy production
4. transportation of oxygen to tissues

14
Respiratory Surfaces

• In flat animals

CO2
O2
15
In the respiratory cycle, the main muscles used
are the _____.

1. intercostal and diaphragm
2. pharynx and larynx
3. bronchiole and alveoli
4. oral and pleural

16
Fish Gills

• Usually internal
• Water is drawn in through mouth and passed over
  gills

water flows in through mouth
FISH GILL
water flows over gills, then out
17
lid open
mouth closed
mouth open
FISH GILL
water flows over gills, then out.
lid closed
water flows into mouth
a
b
c
respiratory surface
gill arch
gill filament
direction of water flow
direction of blood flow
d
e
oxygen-poor blood from deep in body
oxygenated blood back toward body
Fig. 22-18, p.372
18
Countercurrent Flow

• Blood flows in the opposite direction of water
  flow over the filaments
• Enhances movement of oxygen from water to blood

respiratory surface
direction of water flow
direction of blood flow
oxygen-poor blood from deep in body
oxygenated blood back toward body
19
Vertebrate Lungs

• Originated in some fishes as outpouching from gut
  wall
• Allow gas exchange in air and in oxygen-poor
  aquatic habitats

salamander
reptile
20
Avian Respiration

• Lungs are inelastic and connect to a series of
  air sacs
• Air is drawn continually though each lung

air sacs
air sacs
lungs
air sacs
21
Mammals
Mammal Human adapted to dry habitats
Fig. 22-20c, p.373
22
Lungs are the only respiratory organs in all of
the following animals, except _____.

1. reptiles
2. birds
3. mammals
4. amphibians

23
In addition to gas exchange, the respiratory
system also _____.

1. helps blood in veins return to the heart
2. helps dispose of excess heat and water
3. helps maintain acid-base balance
4. all of the choices

24
Human Respiratory System
pharynx (throat)
epiglottis
larynx (voice box)
trachea (windpipe)
pleural membrane
Bronchiole
intercostal muscle
Alveoli
diaphragm
25
NASAL CAVITY
ORAL CAVITY (MOUTH)
PHARYNX (THROAT)
EPIGLOTTIS
LARYNX (VOICE BOX)
TRACHEA (WINDPIPE)
PLEURAL MEMBRANE
LUNG (ONE OF A PAIR)
INTERCOSTAL MUSCLES
BRONCHIAL TREE
DIAPHRAGM
Fig. 22-21a, p.374
26
bronchiole
alveolar sac (sectioned)
alveolar duct
alveoli
Fig. 22-21b, p.374
27
alveolar sac
pulmonary capillary
Fig. 22-21c, p.374
28
Speech Production

• Vocal cords stretch across laryngeal opening
  opening between them is glottis
• Position of cords is varied to create different
  sounds

29
vocal cords
glottis (closed)
epiglottis
tongues base
Fig. 22-22a, p.375
30
glottis closed
glottis open
Fig. 22-22b, p.375
31
Breathing

• Moves air into and out of lungs
• Occurs in a cyclic pattern called the respiratory
  cycle
• One respiratory cycle consists of inhalation and
  exhalation

32
Inhalation

• Diaphragm flattens
• External intercostal muscles contract
• Volume of thoracic cavity increases
• Lungs expand
• Air flows down pressure gradient into lungs

33
Normal (Passive) Exhalation

• Muscles of inhalation relax
• Thoracic cavity recoils
• Lung volume decreases
• Air flows down pressure gradient and out of lungs

34
INWARD BULK FLOW OF AIR
OUTWARD BULK FLOW OF AIR
b Inhalation. The diaphragm contracts, moves
down. External intercostal muscles contract and
lift rib cage upward and outward. The lung volume
expands.
c Exhalation. Diaphragm, external intercostal
muscles return to resting positions. Rib cage
moves down. Lungs recoil passively.
Fig. 22-23, p.376
35
Active Exhalation

• Abdominal and internal intercostal muscles
  contract
• Contraction decreases thoracic cavity volume more
  than passive exhalation
• Greater volume of air flows out to equalize
  intrapulmonary pressure with atmospheric pressure

36
In the respiratory cycle, the main muscles used
are the _____.

1. intercostal and diaphragm
2. pharynx and larynx
3. bronchiole and alveoli
4. oral and pleural

37
Cutaway View of Alveolus
red blood cell
air space inside alveolus
(see next slide)
pore for airflow between alveoli
38
Respiratory Membrane

• Area between an alveolus and a pulmonary
  capillary
• Oxygen and carbon dioxide diffuse across easily

alveolar epithelium
capillary endothelium
fused basement membranes of both epithelial tissue
s
39
Oxygen Transport

• Most oxygen is bound to heme groups in hemoglobin
  in red blood cells
• Hemoglobin has higher affinity for oxygen when it
  is at high partial pressure (in pulmonary
  capillaries)
• Lower affinity for oxygen in tissues, where
  partial pressure is low

40
Bicarbonate Formation
CO2 H2O
H2CO3 carbonic acid
HCO3 bicarbonate
H

• Most carbon dioxide is transported as bicarbonate
• Some binds to hemoglobin
• Small amount dissolves in plasma

41
Control of Breathing

• Nervous system controls rhythm and magnitude of
  breathing
• Breathing is adjusted as a result of changes in
• Carbon dioxide levels
• Oxygen levels
• Blood acidity

42
Oxygen that enters the pulmonary capillaries of
the lungs is bound and transported by _____.

1. hemoglobin
2. platelets
3. plasma
4. carbon dioxide

43
Bronchitis

• Irritation of the ciliated epithelium that lines
  bronchiole walls
• Caused by air pollutants, smoking, or allergies
• Excess mucus causes coughing, can harbor bacteria
• Chronic bronchitis scars and constricts airways

44
Emphysema

• Irreversible breakdown of lung tissue
• Lungs become inelastic
• May be caused by a genetic defect
• Most often caused by smoking

45
Emphysema
46
Effects of Smoking

• Shortened life expectancy
• Increased rate of cancers
• Increased rate of heart disease
• Impaired immune function and healing
• Harmful to fetus

47
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48
Smokers increase their risk of _____.

1. heart attack
2. stroke
3. breast cancer
4. all of the choices