1. Respiration

2. 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

3. Atmospheric Pressure
Pressure exerted by the weight of the air on objects on Earth’s surface
At sea level = 760 mm Hg

4. Gas Exchange Respiration
Pharynx (Throat)
Epiglottis
Larynx (Voice Box)
Trachea (Windpipe)
Pleural Membrane
Bronchiole
Alveoli
Intercostal Muscle
Diaphragm

5. Human Respiratory System

6. RESPIRATION
The two systems that supply oxygen and eliminate carbon dioxide are the
Cardiovascular System
Respiratory System
Failure of either of the two systems:
disrupts homeostasis
promotes cell death
from oxygen starvation and waste product overflow

7. Respiration Exchange of gases between atmosphere, blood and cells
Three types
Pulmonary ventilation
Inflow and outflow of air between atmosphere and lungs
External (pulmonary) Respiration
Exchange of gases between lungs and blood
Internal Respiration
Exchange of gases between blood and cells

8. Upper Respiratory Tract
Nose – Openings – internal nares
Nasal cavity divided by the nasal septum
Functions of the Nose
Interior structures warm, moisten and filters air
Receives olfactory stimuli
Provides a resonating chamber for speech sounds

9. Air Passage Air passes through nasal convolutions
Mucous membrane lines the cavity and shelves
traps particles
More surface area for
warming (from capillary beds)
filtering
moistening air

10. Pharynx Composed of skeletal muscle lined with mucous membrane
Passageway for air and food
Resonating chamber for speech sounds

11. Larynx Voice Box connects pharynx with trachea Thyroid
forms front wall (triangular)
Adam’s apple
Epiglottis – (epi-above; glottis-tongue)
leaf shaped covered by epithelium on top of larynx
Stem attached to thyroid cartilage
“leaf” free – trap door

12. Trachea Wall is lined with mucous membrane and supported by cartilage
Pseudo stratified ciliated columnar epithelium makes up the inside of the trachea
Goblet cells
Mucous
Traps inhaled particles
Ciliated columnar cells
Cilia
Provide cleansing action to remove mucus with particles

13. Lungs Pleural membrane
double layer that encloses and protects each lung
Parietal pleura membrane
outer layer is attached to the wall of the thoracic cavity and diaphragm
Visceral pleura
covers the lungs themselves
Pleural cavity
space between the two membranes
contains fluid to reduce friction 13

14. Bronchi The trachea divides into a right and left primary bronchus
The right is more vertical, shorter and wider than left
more objects lodge here
Structured like the trachea
Incomplete rings of cartilage
Lined with pseudo stratified ciliated epithelium

15. Secondary Bronchi One leads to each lobe of the lungs
Right lung=3 lobes
Left lung= 2 lobes
Secondary bronchi break down to tertiary bronchi bronchioles terminal bronchioles

16. Alveolus Alveolus cup-shaped projection lined with epithelium
Alveolar sacs
two or more alveoli that share a common opening
Gas exchange takes place here at the alveoli
Arteriole and venule surround alveolus to form a capillary network
Lungs contain 300 million alveoli
large surface area

19. Oxygen Transport
Most oxygen is carried bound to hemoglobin in red blood cells
Hemoglobin has a great affinity for oxygen when it is at high partial pressure
in pulmonary capillaries
Lower affinity for oxygen in tissues, where partial pressure is low

20. Bicarbonate Formation
+ H+
CO2 + H2O
H2CO3
carbonic acid
HCO3–
bicarbonate
Most carbon dioxide is transported as bicarbonate
Some binds to hemoglobin
Small amount dissolves in blood

21. 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
12 – 20 adults
15 – 30 children
25 – 50 infants

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

23. Normal Passive Exhalation
Muscles of inhalation relax
Thoracic cavity recoils
Lung volume decreases
Air flows down pressure gradient and out of lungs

24. Active Exhalation
Muscles in the abdomen and the internal intercostal muscles contract
This decreases thoracic cavity volume more than passive exhalation
A greater volume of air must flow out to equalize intrapulmonary pressure with atmospheric pressure

25. Respiratory Volumes Tidal volume Normal quiet breathing 500 ml
Inspiratory reserve volume
Forced inhalation
3100 ml
Expiratory reserve volume
Forced exhalation
1200 ml
Residual volume
Air left in lungs after expiratory volume

26. Respiratory Volumes inspiratory reserve volume tidal volume
vital capacity
total lung capacity
expiratory
reserve volume
residual volume

27. Control of Breathing Medulla oblongata sets main rhythm
centers in pons fine-tune it
Magnitude of breathing depends on concentration of oxygen and H+
Brain detects H+
increases breathing
Carotid bodies and aortic bodies detect drop in oxygen, increase breathing

28. pneumotaxic center
apneustic center
medullary respiratory center

29. food, water intake
oxygen intake
DIGESTIVE
SYSTEM
RESPIRATORY
SYSTEM
elimination
of carbon
dioxide
nutrients,
water,
salts
oxygen
carbon
dioxide
CIRCULATORY
SYSTEM
URINARY
SYSTEM
water,
solutes
elimination
of food
residues
rapid transport
to and from all
living cells
elimination of
excess water,
salts, wastes

30. Carbon Monoxide (CO) Colorless, odorless gas
Competes with oxygen for binding sites in hemoglobin
Binding capacity is at least 200 times greater than oxygen’s
Exposure impairs oxygen delivery

31. Impacts, Issues Video
Up In Smoke

32. smoking In the US, about 3,000 teenagers take up smoking every day
Just one cigarette immobilizes cilia that line airways of the lungs for hours, preventing them from sweeping away airborne pathogens and pollutants

33. smoking Filmy gunk from pathogens promotes: asthma attacks bronchitis
colds
Nicotine:
constricts blood vessels
raises blood pressure
makes blood stickier and clots more likely
Costs of smoking:
clogged arteries
heart attacks
strokes
lung cancer