BIOS 1310 Exam #3

Upper respiratory Tract

Nasal Cavity

Pharynx

Uvula

Larynx

Epiglottis

Nasal Cavity

Superior nasal concha

Middle nasal concha

Inferior nasal concha

Nasal Conchae

directs air into 6 meatuses

splits air stream and makes it swirl

Why?

• warming

• traps particles

• better sense of smell

Pharynx

3 divisions:

• Nasopharynx

• Oropharynx

• Laryngopharynx

Tonsils:

• Pharyngeal

• Palatine

• Lingual

Uvula

Uvula

Produces thin mucus

Lubricates pharynx

• for speech

Larynx

contains vocal cords

vocal cords vibrate—→speech

thyroid cartilage

laryngeal prominence

cricoid cartilage

epiglottis

Epiglottis

elastic cartilage

closes during swallowing

Lower Respiratory Tract

Trachea

lungs

Bronchi

bronchioles

alveoli

Trachea

windpipe

c shaped cartilage

• holds it open

• hyaline cartilage

Lungs

Right: 3 lobes

Left: 2 lobes

• to make room for the heart

Hilum

site of entrance and exit of blood vessels, bronchi, etc.

Bronchial tree

branching system of air tubes

Trachea—→Main bronchi—→Lobar bronchi—→Segmental bronchi—→bronchioles—→terminal bronchioles—→Respiratory bronchioles—→alveolar sacs—→alveolar ducts—→alveoli

Alveoli

site of gas exchange

individual air sacs

Zones

conducting zone

respiratory zone

Conducting Zone

Trachea to the terminal bronchioles

conducts air

no gas exchange

Respiratory Zone

respiratory bronchioles and alveoli

site of gas exchange

Main tissue types in respiratory system

elastic connective tissue

cartilage

smooth muscle

Elastic CT

lots in lungs, bronchi, and bronchioles

elastin fibers

• streches w/ inhalation

• elastic recoil during exhalation

  • return to unstreched

  • expels air

Cartilage

C shaped rings in:

• trachea

• main bronchi

  • holds shape to keep them open

Overlapping plates in:

• all other bronchi

Smooth muscle

controls diameter of airways

within bronchioles

protects lungs and body against inhaled irritants or toxins

Bronchospasm

asthma

allergies

chemical fumes

spasm of smooth muscle (contracts)

excessive muscus secretion

swollen mucous membrane

Type I pneumocytes

squamous alveolar cells

line alveoli

thin—→gas diffusion

most abundant

Type II pneumocytes

great alveolar cells

cuboidal

produce surfactant

Surfactant

substance that reduces the surface tension of the liquid it is dissolved in

in lungs…prevents collapse of alveoli

The Respiratory membrane

very thin

• fast gas diffusion

Squamous alveolar cells

+basement membrane

+capillary endothelial cells

Alveolar macrophages

aka dust cells

phagocytize inhaled debris

• stuff not trapped in mucus

Ventilation

Breathing

Inspiration

breathing in

muscles create slight vaccum inside lungs

• create slight pressure difference between atmospheric and intrapulmonary pressures

expiration

breathing out

increased pressure inside lungs

• rebound of chest wall

• elastic CT

• respiratory muscles

Quiet respiration

involuntary

relaxed

Forced respiration

deep and rapid

involuntary: exercise or coughing

or

Voluntary: yelling

Respiratory muscles

diaphragm = prime mover

any that move

any that increase abdominal pressure

Know this list:

• diaphragm

• transverse abdominis

• Internal/External intercostals

• pectoralis minor

• SCM

Ventilators

External pressure inflates lungs

• also applies to mouth to mouth

endotracheal tube

• connected to air pump

Composition of air

Nitrogen: 78%

Oxygen: 20.9%

Argon gases: 0.90%

Other: 0.17%

CO₂: 0.03%

H₂O: 0.5%

Equilibrium

rate of dissolution = rate of release

gases dissolve in water and then are released

Saturation

max dissolved solute

• max solubility

Affected by:

• temperature

• pressure

Dalton’s Law

for mixture of gases:

total pressure = sum of pressures of individual gases

How is O₂ carried in the blood?

Hemoglobin (Hb)

• 4 hemes

• up to 4 O₂ molecules

O₂ in blood

98.5% bound to hemoglobin

• greatly increase solubility of O₂

1.5% dissolved in plasma

CO₂ in the blood

5% dissolved in plasma

• as CO₂

5% binds to proteins

• carbamino compounds

• carbaminohemoglobin

  • HbCO₂

90% as H₂CO₂ and HCO₃

CO₂ loading

carbonic anhydrase : CO₂ + H₂O ←—→ H₂CO₃

• in RBCs