What is the difference between external respiration and internal respiration

1
What is the difference between external
respiration and internal respiration?
2
Respiration

• Refers to 2 integrated processes
• external respiration
• Includes processes involved in exchanging O2 and
  CO2
• Hypoxia
• internal respiration
• Involves the uptake of O2 and production of CO2
  within individual cells

3
Steps of External Respiration

• Pulmonary ventilation
• Gas diffusion
• Storage and transport of gases
• Exchange of O2 and CO2

4
What physical principles govern the movement of
air into the lungs?
5
Pulmonary Ventilation

• Physical movement of air in and out of
  respiratory tract
• Provides alveolar ventilation
• Air flows from area of higher pressure to area of
  lower pressure
• atmospheric pressure
• intrapulmonary pressure
• Intrapleural pressure

6
Gas Pressure and Volume
Figure 2313
7
Boyles Law

• Defines the relationship between gas pressure and
  volume
• P 1/V
• pressure is inversely proportional to volume,
  thus, increase volume, decrease pressure

8
Mechanisms of Pulmonary Ventilation
Figure 2314
9

• Respiratory Cycle consists of
• an inspiration (inhalation)- always active
• an expiration (exhalation)- active or passive
• Involves changes in lung volume
• Plural fluid acts as a seal bonding lungs to
  inner wall of chest and superior surface of
  diaphragm

10
Pressure and Volume Changes with Inhalation and
Exhalation
Figure 2315
11
What are the origins and actions of the
respiratory muscles responsible for respiratory
movements?
12
The Respiratory Muscles

• Inhalation - active
• diaphragm
• external intracostal muscles
• accessory respiratory muscles
• Exhalation - passive or active
• abdominal muscles
• internal intracostal muscles and transverse
  thoracis

13
The Respiratory Muscles
Figure 2316c, d
14

• Elastic Rebound
• inhalation muscles relax
• elastic components of muscles and lungs recoil
• returns lungs and alveoli to original position

15

• Lung Compliance
• indicator of expandability
• Low compliance requires greater force
• Factors That Affect Compliance
• Connective-tissue structure of the lungs
• Level of surfactant production
• Mobility of the thoracic cage

16
Respiratory Rates and Volumes

• Respiratory system adapts to changing oxygen
  demands by varying
• Tidal Volume
• Respiratory Rate

17

• Respiratory Minute Volume
• Amount of air moved per minute
• calculated by
• respiratory rate ? tidal volume

18
Respiratory Volumes and Capacities
Figure 2317
19
Pulmonary Volumes

• Expiratory reserve volume (ERV)
• Inspiratory reserve volume (IRV)
• Residual volume

20
Respiratory Capacities

• Inspiratory capacity
• 2. Vital capacity
• Total lung capacity

21
What physical principles govern the diffusion of
gases into and out of the blood?
22
Gas Pressure

• Atmospheric pressure (760 mm Hg)
• produced by air molecules bumping into each other
• Partial Pressure
• pressure contributed by each gas in the
  atmosphere
• Each gas contributes to the total pressure
• in proportion to its number of molecules
  (Daltons law)

23
Composition of Air

• Nitrogen (N2) about 78.6
• Oxygen (O2) about 20.9
• Water vapor (H2O) about 0.5
• Carbon dioxide (CO2) about 0.04

24
Henrys Law

• When gas under pressure comes in contact with
  liquid
• gas dissolves in liquid until equilibrium is
  reached
• At a given temperature
• each gas will dissolve in the liquid in
  proportion to it's partial pressure

25
Henrys Law
Figure 2318
26

• The actual amount of a gas in solution depends on
  the solubility of that gas in that particular
  liquid
• Movement of O2 and CO2 between alveoli and blood
  depends on partial pressure differences

27

• Efficiency of gas diffusion at respiratory
  membrane is due to
• Differences in partial pressure of O2 and CO2
• Small distance for gas exchange
• O2 and CO2 diffuse easily across surfactant layer
• Huge surface area for exchange in alveoli

28
How is oxygen picked up, transported, and
released in the blood?
29
Gas Pickup and Delivery

• Blood plasma cant transport enough O2 or CO2 to
  meet physiological needs
• Red Blood Cells (RBCs)
• Transport O2 to, and CO2 from, peripheral tissues

30
What is the structure and function of hemoglobin?
31
Oxygen Transport

• O2 binds to iron ions in hemoglobin (Hb)
  molecules
• Each RBC has about 280 million Hb molecules
• Hb changes shape each time a molecule of O2 is
  bound
• Carbon Monoxide binds strongly to Hb
• Bohr effect

32
How is carbon dioxide transported in the blood?
33
CO2 in the Blood Stream

• May be
• converted to carbonic acid
• dissociates into H and bicarbonate (HCO3)
• bound to protein portion of hemoglobin
• dissolved in plasma

34
What factors influence the respiration rate? How
are reflex respiratory activity and the brain
centers involved in the control of respiration?
35

• A basic pace of respiration is established
  between respiratory centers in the pons and
  medulla oblongata, and modified in response to
  input from
• chemoreceptors
• baroreceptors
• stretch receptors

36

• Respiratory Reflexes
• Changes in patterns of respiration induced by
  sensory input
• Chemoreceptors
• Baroreceptors
• Stretch receptors

37

• In general, CO2 levels, rather than O2 levels,
  are primary drivers of respiratory activity
• Respiratory activity can be interrupted by
  protective reflexes and adjusted by the conscious
  control of respiratory muscles

38
Protective Reflexes

• Triggered by receptors in epithelium of
  respiratory tract when lungs are exposed to
• toxic vapors
• chemicals irritants
• mechanical stimulation
• Cause sneezing, coughing, and laryngeal spasm