RESPIRATION

ACTIVITY 1Write down as many terms as you can that are used to describe the respiratory system

•Bullet point your answers

The air continues into many branching airways known as the bronchial tree

The trachea and bronchi have supporting cartilage to keep the airways open

Bronchiole walls contain more smooth muscle.

The airways from the nasal cavity through the terminal bronchioles are called the conducting zone

The air is moistened, warmed and filtered as it flows through these passageways

The air then reaches the respiratory zone

The respiratory zone

Terminal bronchi

Alveoli

The respiratory zone contains alveoli, tiny thin walled sacs where gas exchanges occurs.

Lets now look at the actual site of diffusion, the respiratory membrane

ACTIVITY 2Complete the following worksheets:

1. WS.12. Worksheet 5.13. Worksheet 5.2

ACTIVITY 3Highlight the key words within the following text on IS 1

MECHANICS OF RESPIRATION DURING EXERCISE

• What muscles are involved?• Inspiration – SCOM

(sternocleidomastoid), scalenes & pectoralis minor• Expiration – internal intercostals

& rectus abdominals / obliques

Sternocleidomastoid (SCOM)

Scalenes

ABDOMINALS

ACTIVITY 4Highlight the key words on IS 2

Respiratory system – 3 main processes

• Pulmonary respiration– The breathing of air into and out of the lungs

• External respiration– Exchange of O2 and CO2 between the lungs and

the blood

• Internal respiration– Exchange of O2 and CO2 between the blood and

muscle tissues

RESPIRATORY VOLUMES AT REST

• Tidal volume (TV)– Amount of air inhaled and exhaled with each

breath (approx 500ml)

• Frequency (F) – Rate of breathing

• Minute Ventilation (VE)– VE = TV X f

• Residual volume (RV)– Volume of air remaining in the lungs (1200ml)

RESPIRATORY VOLUMES AT REST (Cont’d)

• Inspiratory reserve volume (IRV)The additional air that can be inhaled after a normal tidal breath in. The maximum volume of air that can be inspired in addition to the tidal volume.

• Expiratory reserve volume (ERV)The amount of additional air that can be pushed out after the end expiratory level of normal breathing

*see IS 3

LUNG CAPACITIES• Inspiratory capacity = IRV + TV• Expiratory capacity = ERV + TV• Vital capacity –Maximal volume of air that can be

expired after maximal inspiration• Total lung capacity–Maximal volume of air contained in the

lungs after a maximal inspiration–TLC = TV + IRV + ERV + RV

Control of breathing• Respiratory Control Centre (RCC)

regulates breathing.• Located in the medulla oblongata• Respiratory muscles – involuntary

neural control• RCC – 2 areas–Inspiratory centre–Expiratory centre

Important terminology1. Chemoreceptors from within the

carotid arteries send information to the inspiratory centre on chemical changes

2. Proprioceptors – muscle movements3. Thermoreceptors – blood

temperature4. Baroreceptors – stretch receptors

NEURAL CONTROL DURING EXERCISE

• Associated muscles (inspiratory centre):– Sternocleidomastoid– Scalenes–Pectoralis minor

• Associated muscles (expiratory centre):– Internal intercostals–Rectus abdominus–Obliques

This is summarised on IS 4

Complete WS2