Learning Objectives

Explain, with the use of diagrams, the process of Explain, with the use of diagrams, the process of breathingbreathing

Examine Respiratory Tissue slides under the Examine Respiratory Tissue slides under the microscope and Identify tissue types within themmicroscope and Identify tissue types within them

Mechanism of breathing …

Movement of the ribcage and diaphragm ventilate the Movement of the ribcage and diaphragm ventilate the lungs.lungs.

This is important:This is important: Inspiration (inhalation) brings fresh supplies of OInspiration (inhalation) brings fresh supplies of O22 to to

maintain the Omaintain the O22 concentration gradient. concentration gradient.

Expiration (exhalation) removes waste air with its cargo Expiration (exhalation) removes waste air with its cargo of COof CO22 to maintain the CO to maintain the CO22 gradient. gradient.

Movement of respiratory gases is by diffusion so it is Movement of respiratory gases is by diffusion so it is driven by concentration differences.driven by concentration differences.

Inspiration External intercostal External intercostal

muscles contract, pulling muscles contract, pulling the ribcage upwards and the ribcage upwards and outwards.outwards.

Diaphragm contracts, Diaphragm contracts, pulling it from a domed to pulling it from a domed to a flattened shape.a flattened shape.

Combined effect is:Combined effect is: volume of the thorax and volume of the thorax and

lungs increaselungs increase pressure is reducedpressure is reduced air enters, goes down the air enters, goes down the

pressure gradient.pressure gradient.

Expiration - relaxed External intercostal External intercostal

muscles relax and the muscles relax and the ribcage falls under its own ribcage falls under its own weight.weight.

Diaphragm relaxes and Diaphragm relaxes and gut pressure pushes it gut pressure pushes it back into its domed shape.back into its domed shape.

Elastic recoil of lung Elastic recoil of lung tissue.tissue.

Combined effect is:Combined effect is: volume of the thorax and volume of the thorax and

lungs decreaselungs decrease pressure is increasedpressure is increased air is forced out.air is forced out.

Expiration - forced Internal intercostal Internal intercostal

muscles contract, pulling muscles contract, pulling the ribcage down and in.the ribcage down and in.

Abdominal muscle Abdominal muscle contracts pushing the contracts pushing the diaphragm upwards.diaphragm upwards.

Combined effect is:Combined effect is: volume of the thorax and volume of the thorax and

lungs decreaselungs decrease pressure is increasedpressure is increased air is forced out.air is forced out.

Exercise, singing, playing Exercise, singing, playing a wind instrument.a wind instrument.

To Do:

Draw diagrams to explain the process of Draw diagrams to explain the process of breathing.breathing.

Help yourself to a Microscope and examine slide Help yourself to a Microscope and examine slide of lung tissue under high magnification – What of lung tissue under high magnification – What tissues do you expect to see? Can you identify tissues do you expect to see? Can you identify some of these tissues?some of these tissues?

bronchiole and alveolar tissue bronchiole and alveolar tissue

Lumen Lumen or airwayor airway

Epithelium – ciliated Epithelium – ciliated in bronchiole but not in bronchiole but not respiratory respiratory bronchiolebronchiole

Smooth muscleSmooth muscle

Alveolar spaceAlveolar space

Capillary – blood vessels Capillary – blood vessels have been injected with have been injected with dyedye

Alveolar wall cell Alveolar wall cell (nucleus purplish (nucleus purplish stainstain))

TracheaTrachea

Blood vessel with Blood vessel with numerous blood cells numerous blood cells clearly visibleclearly visible

CiliaCilia

Goblet Goblet cellcell

Cartilage – Cartilage – chondrocytes clearly chondrocytes clearly visiblevisible

Ciliated Ciliated epitheliumepithelium

Smooth muscleSmooth muscle

Elastic tissueElastic tissue

PREP

The content of today’s lesson (found on page 46 The content of today’s lesson (found on page 46 – 49) to be written up, in the format of your – 49) to be written up, in the format of your choice, in your Prep Bookschoice, in your Prep Books

To be completed and checked by next lesson To be completed and checked by next lesson (Monday)(Monday)