Respiratory Sys Objectives

What is the function of the respiratory system

What is the function of the respiratory system

To deliver O2 to the blood and take CO2 away from the blood

Describe and identify two levels of gas exchange

Internal respiration (cellular respiration) and external respiration (exchange of O2/CO2 between body and atmosphere)

4 Processes involved in external respiration

1. Pulmonary Ventilation (movement of air in and out of lungs)

2. Exchange of O2/CO2 between blood and lungs

3. Transportation of O2/CO2 between lungs and tissues by blood

4. Exchange of O2/CO2 between blood and tissues by diffusion

6 Other functions of the respiratory system

1. Balance PH of blood (CO2 in carbonic acid)

2. Vocalization

3. Defense against pathogens (mucosal elevator)

4. Respiratory pump (venous return of blood to heart)

5. Activate plasma proteins

How many lobes make up each lung

Left lung has two lobes and the right lung has three lobes

Structures and functions of the upper airway

Air passages in head and neck that create path for airflow.

1. O2 enters nasal/oral cavity

2. O2 travels to pharynx

3. diverges with food

4. O2 enters larynx

Two zones of the respiratory tract

1. Conduction zone creates path for airflow into respritory zone

2. Respiratory zone is where O2/CO2 move in and out of blood

What is the importance of goblet and ciliated cells

Goblet cells secrete mucus to trap pathogens

Ciliated cells move in whiplike fashion to push mucus up and out of lungs

Smoking’s effect on ciliated cells and mucosal elevator

Smoking paralyzes ciliated cells so the mucosal elevator cant function

Structures of the respiratory zone

Respiratory Bronchioles and Alveoli

Function of respiratory bronchioles

lead to alveoli

How do gas molecules pass into blood

O2 diffuses from high to low concentration across one layer of type 1 cells, through respiratory membrane, into capillary

6 components of the chest wall

1. 12 pairs of ribs

2. sternum (breast Bone)

3. thoracic vertebrae

4. Intercostal muscles (external and internal)

5. Diaphragm

6. Pleura - layer of epithelial cells that surround the lungs

What is pneumothorax and its cause

Presence of air/gas in pleural space (between lungs and pleura) caused by air leaking from lungs, caused by traumatic injury

Pressure gradient during inspiration

Palv < Patm

Pressure gradient during expiration

Palv > Patm

Alveolar Pressure

Palv (pressure of air inside alveoli)

Atmospheric Pressure

Patm (pressure of the air outside the body)

Intrapleural pressure

Pip (Pressure between lungs and pleura)

Transpulmonary pressure

difference between Pip and Palv

Muscles involved inspiration (inhalation)

1. external intercostals

2. diaphragm

Muscles involved in expiration (exhale)

1. During quiet expiration the muscles relax

2. during active breathing, contract abdominal and internal intercostal muscles

two factors that affect pulmonary ventilation

1. Lung compliance

2. airway resistance

Define low lung compliance

how easy the lungs expand, tuberculosis creates scar tissue that affects compliance

Asthma

Spastic contraction of smooth muscle in bronchiole walls

Allergies

Histamine causes bronchi to contract and produce more mucus

Diffusion across alveoli and blood

down the concentration gradient (high to low concentration)

3 factors that rate of diffusion depends on

1. rate of diffusion increases as concentration increases

2. rate of diffusion increases as surface area increases

3. rate of diffusion increases as permeability of the membrane increases

Partial Pressure

determined by fractional concentration on gas and total atmospheric pressure

Concentration of O2 in air

21%

Concentration of N2 in air

79%

Patm

760mm/hg

2 factors that determine solubility of gas in liquid

1. solubility of the gas (co2 is more soluble than o2)

2. increase in partial pressure = increase in solubility of gas

What are the bends

when a SCUBA diver surfaces too quickly and the nitrogen bubbles form because of the rapid decrease in pressure

Pulmonary edema

Accumulation of excess fluid in the alveoli, between type I cells

Why is alveolar press’ different than atmospheric press’

1. o2 immediately diffuses from alveoli into bloodstream

2. Atmospheric air mixes with remaining co2 in lungs

3. Inspired air mixes with water vapor in lungs

Why does partial pressure vary depending on the location on respiring tissue

it depends on how much the tissue is working

3 factors that determine alveolar Po2 and Co2

1. Po2 and Pco2 of atmosphere

2. volume of air reaching alveoli /minute

3. rate of metabolism of respiring tissue

hyperpnea

rate of alveolar ventilation increase as needs for o2 increase

Hypoventilation

if Po2 fails to increase with need

Hyperventilation

happens if Pco2 gets to low

Inspiratory Reserve volume

Max volume of air inspired after quiet inspiration (3000ml)

Expiratory Reserve Volume

max volume of air expired after quiet expiration (1000ml)

Tidal Volume

Volume of air inspired/expired in quiet breath (500ml)

Residual Volume

Volume of air in lungs after max expiration (1200ml)

Inspiratory capacity

max volume of air that can be inspired after quiet expiration

Vt + IRV

Vital Capacity

Max volume of air that can be expired after max inspiration

Vt + IRV + ERV

Total Lung Capacity

max volume of air lungs can hold

Vt + IRV + ERV + RV