The Respiratory SystemHailee and Jordan

Key Terms

Alveolus Bronchial tree Bronchopulmonary segment External respiration Internal respiration Respiratory membrane Surfactant Ventilation

Terms Defined

Alveolus a small cavity, pit, or hollow, in particular

Bronchial tree the branching system of bronchi and bronchioles conducting air from the windpipe into the lungs

Bronchopulmonary segment A subdivision of one lobe of a lung based on the connection to the segmental bronchus

Ex: the right upper lobe has apical, anterior, and posterior segments External respiration

exchange of gases between the external environment and a distributing system of the animal body or between the alveoli of the lungs and the blood

Terms Defined Cont.

Internal respiration the exchange of gases between the cells of the body and the blood by way of the fluid bathing

the cells Respiratory membrane

includes the alveolar epithelial cells as well as the pulmonary capillary endothelial cells Surfactant

a substance that tends to reduce the surface tension of a liquid in which it is dissolved Ventilation

the process of exchange of air between the lungs and the ambient air

Vocabulary

Alveoli Bicarbonate ions Diaphragm External respiration Oxyhemoglobin Pleura Stretch receptors Surfactant Tidal volume Trachea

Voab Defined

Alveoli Tiny air sacs in the lungs

Bicarbonate ions Form in which most carbon dioxide is transported

Diaphragm Primary muscle inspiration

External respiration Exchange of gases between air and blood

Vocab Defined Cont.

Oxyhemoglobin Form in which most oxygen is transported

Pleura Serous membrane around the lungs

Stretch receptors Initiate the Hering-Breuer reflex

Surfactant Reduces surface tension inside alveoli

Vocab Defined Cont.

Tidal volume Air exchanged in normal quiet breathing

Trachea Supported by C-shaped hyaline cartilage

Functions and Overview of Respiration

Respiration is the sequence of events that results in the exchange of oxygen and carbon dioxide between the atmosphere and the body cells

Every 3 to 5 seconds nerve impulses stimulate the breathing processes, or ventilation The entire process of respiration includes ventilation, external respiration, transport of

gases, internal respiration, and cellular respiration

Ventilation

Ventilation (breathing) is the movement of air through the conducting passages between the atmosphere and the lungs

Air moves through the passages because of pressure gradients that are produced by contraction of the diaphragm and thoracic muscles

Gas Laws and Respiration

The diffusion of gases from the alveoli to the blood (external respiration) and from the blood to the tissues (internal respiration) depends on two fundamental properties of gases which are known as Daltons law of pressures and Henry’s law

Dalton’s law of pressures Total pressure is exerted by a mixture of gases is equal to the sum Pgas1 + Pgas2 + Pgas3 + Pgas4 = Ptotal

P= Pressure Henry’s law

When a mixture of gases is in contact with a liquid, each gas dissolves in the liquid in proportion to its own solubility and partial pressure

Transport of Gases

The blood transports the respiratory gases, oxygen and carbon dioxide, between the lungs and tissue cells

Approximately 3% of the oxygen is transported as a dissolved gas in the plasma. The remaining percent is carried by hemoglobin molecules

Regulation of Respiration

The basic breathing rate is established by the respiratory center in the brain stem but environmental conditions and emotions include variations in the rate

The respiratory center includes groups of neurons in the medulla oblongata and pons Although the respiratory center establishes the basic rhythm of breathing, it’s

influenced by factors that cause variations in the rate and depth of breathing

Recall

Definitions1. Tiny air sacs in the lungs2. Exchange of gases between air and blood3. Reduces surface tension inside alveoli4. Supported by C-shaped hyaline cartilage5. Serous membrane around the lungs6. Primary muscle inspiration 7. Air exchanged in normal quiet breathing8. Form in which most oxygen is transported9. Form in which most carbon dioxide is

transported10.Initiate the Hering-Breuer reflex

TermsA. AlveoliB. Bicarbonate ionsC. Diaphragm D. External respirationE. OxyhemoglobinF. PleuraG. Stretch receptorsH. SurfactantI. Tidal volumeJ. Trachea

Recall Answers

Definitions1. Tiny air sacs in the lungs2. Exchange of gases between air and blood3. Reduces surface tension inside alveoli4. Supported by C-shaped hyaline cartilage5. Serous membrane around the lungs6. Primary muscle inspiration 7. Air exchanged in normal quiet breathing8. Form in which most oxygen is transported9. Form in which most carbon dioxide is

transported10.Initiate the Hering-Breuer reflex

TermsA. AlveoliB. Bicarbonate ionsC. Diaphragm D. External respirationE. OxyhemoglobinF. PleuraG. Stretch receptorsH. SurfactantI. Tidal volumeJ. Trachea