This talks about the the function of the bronchioles and the disorders of the function of the bronchioles so in this presentation I will talk about the importance and why it is important

1. BEAUTY NDHLOVU
BSC NURSING STUDENTS
UNZA

3.  At the end of this lecture/discussion, students
should be able to demonstrate their basic
knowledge of the applied anatomy and
physiology of the Bronchioles and the lungs
and be able to apply the knowledge to
condition of the respiratory system.

4. At the end of the lecture/discussion students should be
able to:
1. Define the bronchioles and the lungs
2. Describe the functions of the bronchioles and lungs
3. Explain the mechanism of respiration and discuss
lung volumes and capacities

5.  Respiration is the process of gaseous exchange
between the environment and an organism.
The trachea, bronchus, bronchioles, lungs and
diaphragm are the primary structures of the
lower respiratory tract involved in respiration.

6.  BRONCHIOLES: These are the smaller
branches of the bronchial airways in the lower
respiratory tract which controls air entry.
 LUNGS: The lungs are soft, spongy, cone-
shaped organs in the thoracic cavity on either
side of the heart and great vessels responsible
for blood oxygenation.

7. The two primary bronchi are formed when the
trachea divides at about the level of the 5th
thoracic vertebra. The right bronchus is wider,
short and more vertical than the left bronchus
and is more likely to become obstructed by any
inhaled foreign body.

8.  After entering the right lung it divides into
three branches one into each lobe, each then
divides into smaller tubes called bronchioles.
The left bronchus it is narrower and longer
than the right bronchus. After entering the left
lung it divides into two branches one to each
lobe.

9. Functions
 Control of air entry- this is done by the contraction
and relaxation of involuntary muscles in their walls.
 The medium bronchus has the highest airway
resistance.

12.  ASTHMA results when you have
bronchospams of these muscles hence causing
narrowing of the lumen of the bronchi.
 BRONCHITIS is the inflammation of the
bronchi.
 BRONCHIECTASIS occurs when one has a
permanent dilatation of the bronchi and
bronchioles due to infections.

13.  The lungs are soft, spongy, cone-shaped organs in the
thoracic cavity on either side of the heart and great
vessels.
 The lungs are divided into lobes; the left lung has two
lobes while the right lung has three lobes.

15. Breathing or ventilation is the movement of air from
outside the body into the body.
Expansion of the chest during inspiration occurs as a
result of muscular activity, partly by voluntary and
partly by involuntary

16. 1. INTERCOSTAL MUSCLES
During difficult or deep breathing they are
assisted by muscles of the neck, shoulders and
abdomen.
 There are 11 pairs of intercostal muscles that
occupy the spaces between the 12 pairs of ribs.
They are arranged in two layers, the external
and internal intercostal muscles.

17. I. THE EXTERNAL INTERCOSTAL
MUSCLE FIBRES
These extend downwards and forwards from the
lower border of the rib above to the upper
border of the rib below.

18. II. THE INTERNAL INTERCOSTAL
MUSCLE FIBRES
 These extend downwards and backwards from
the lower border of the rib above to the upper
border of the rib below, crossing the external
intercostal muscle fibres at right angles
 The first rib is fixed.
 Therefore, when the intercostal muscles
contract they pull all the other ribs towards the
first rib.

19.  Because of the shape and size of the ribs they
move outwards when pulled upwards,
enlarging the thoracic cavity.
 The intercostal muscles are stimulated to
contract by the intercostal nerves.

21. The diaphragm is a dome-shaped muscular
structure separating the thoracic and abdominal
cavities.
It forms the floor of the thoracic cavity and the
roof of the abdominal cavity and consists of a
central tendon from which muscle fibres radiate
to be attached to the lower ribs and sternum and
to the vertebral column.

22.  When the muscle of the diaphragm is relaxed,
the central tendon is at the level of the 8th
thoracic vertebra.
 When it contracts, its muscle fibres shorten
and the central tendon is pulled downwards to
the level of the 9th thoracic vertebra, enlarging
the thoracic cavity in length.

23.  This decreases pressure in the thoracic cavity
and increases it in the abdominal and pelvic
cavities.
 The diaphragm is supplied by the Phrenic
nerves.
 The intercostal muscles and the diaphragm
contract simultaneously, enlarging the thoracic
cavity in all directions, that is from back to
front, side to side and top to bottom

25.  The average respiratory rate is 12 to 15 breaths
per minute in an adult. Each breath consists of
three phases (cycle of breathing);
 (i)Inspiration, (ii) expiration and (iii) pause

27.  1. INSPIRATION: Atmospheric pressure due
to the weight of air is the force that moves air
into the lung When the capacity of the thoracic
cavity is increased by simultaneous
contraction of the intercostal muscles and the
diaphragm, the parietal pleural moves with the
walls of the thorax and the diaphragm.
 This reduces the pressure in the pleural cavity
to a level considerably lower than atmospheric
pressure.

28.  The visceral pleura follow the parietal pleura,
pulling the lung with it. This expands the lungs
and the pressure within the alveoli and in the
air passages falls, drawing air into the lungs in
an attempt to equalize the atmospheric and
alveolar air pressure.

29.  The process of inspiration is active, as it needs energy
for muscles contraction. The negative pressure
created in the thoracic cavity aids venous return to
the heart and is known as the respiratory pump.
 At rest, inspiration lasts about 2 seconds.

30. 2. EXPIRATION
 Relation of the intercostal muscles and the
diaphragm results in downward and inward
movement of the rib cage and elastic recoil of
the lungs.
 When this occur the pressure inside the lungs
exceeds that in the atmosphere and so air is
expelled from the respiratory tract. The lungs
still contain some air, and are prevented from
complete collapse by the intact pleura.


31.  Unlike the inspiration this process is passive as it
does not require the expenditure of energy.
 At rest expiration lasts about 3 seconds, and after
expiration there is a phase before the next cycle
begins.

32.  In normal quiet respiration there are about 15
complete respiratory cycles per minute.
Different intensities in breathing move
different volumes of air in and out of the
lungs. The lungs and the air passage are never
empty and ,

33. as the exchange of gases takes place only across
the walls of the alveolar ducts and alveoli, the
remaining capacity of the respiratory passages is
called the anatomical dead space (about
150ml).There are four lung volumes;

34. There are four lung volumes:
 The tidal volume
 The inspiratory reserve volume
 The expiratory reserve volume
 The residual volume
1. TIDAL VOLUME
This is the volume of air inspired or expired
with each normal breath; it amounts to about
500 milliliters in the adult male.

35. 2. INSPIRATORY RESERVE VOLUME
This is the extra volume of air that can be inspired over
and above the normal tidal volume when the person
inspires with full force. It is usually equal to about
3000 milliliters

36. 3. EXPIRATORY RESERVE VOLUME
This is the maximum extra volume of air that
can be expired by forceful expiration after the
end of a normal tidal expiration; this normally
amounts to about 1100 milliliters.
4. RESIDUAL VOLUME
 This is the volume of air remaining in the
lungs after the most forceful expiration; this
volume averages about 1200ml

37. There are three lung capacities:
 The inspiratory capacity
 The functional residual capacity
 The vital capacity
1. INSPIRATORY CAPACITY
This is equals to the tidal volume plus the
inspiratory reserve volume. This is the amount of
air (about 3500 ml) a person can breathe in,
beginning at the normal expiratory level and
distending the lungs to the maximum amount.

38. 2. FUNCTIONAL RESIDUAL CAPACITY
This is equals to the expiratory reserve
volume plus the residual volume. This is the
amount of air that remains in the lungs at the
end of normal expiration about 2300
milliliters).
3. VITAL CAPACITY
This is equals the inspiratory reserve volume
plus the tidal volume plus the expiratory reserve

39. volume. This is the maximum amount of air a person
can expel from the lungs after first filling the lungs to
their maximum extent and then.(4600)
THE COMPOSITION OF INSPIRED AND
EXPIRED AIR
Inspired % Expired %
Oxygen 21 16
Carbon dioxide 0.04 4
Nitrogen and rare gases 78 78
Water vapour Variable Saturated

40.  Drugs, e.g. sedatives, alcohol the respirations are low.
 Sleep – normal range
 Temperature influences breathing. In fever,
respiration is increased due to increased metabolic
rate, while in hypothermia it is depressed, as is
metabolism. Temporary changes in respiration occur
in swallowing, sneezing and coughing

41.  In our lecture today we have talked about the
applied anatomy and physiology of the
respiratory system and said breathing is
important as it helps the body to take in our of
oxygen needed for the normal functioning of
the body; we also discussed the functions of
the bronchioles and lungs. We went further to
discuss the breathing mechanism, lung
volumes and capacity

42.  EVALUATION
 What are the functions of the bronchioles and lungs.
 Describe the mechanism of respiration

43. David S, Jackie B and Ricki L. (2003), Hole’s
Essentials of Human Anatomy and Physiology,
International edition, McGraw-Hill Higher Education,
New York, USA.
Dee Unglaub. S, William C.O, Claire W. G, Andrew.
C. S and Bruce R. J. (2004), Human physiology an
integrated approach, 3rd edition, Pearson Education
Inc, San Francisco, Canada

44. Microsoft ® Encarta ® 2009. © 1993-2008
Microsoft Corporation.
Roger Watson (2005), Anatomy and
Physiology for Nurses, 20th edition, Elsevier,
Oxford, UK