ENT & HEAD NECK SURGERY

1. Dr.Satish Kumar Ray
Ent Hns 1st year Resident
PoAHS, Pokhara, Kaski

2.  Function of nose and paranasal sinuses
 Measurement of nasal airway
 olfaction

3. 1. Respiratory function
2. olfactory function
 Respiratory functions include
 heat exchange
 Humidification
 filtration
 voice modification
 Nasal resistance

4.  Provides O2 and removes CO2 from body
 Takes place in alveoli
 Role of nose: modify air
ideal for exchange
does not damage the alveoli
 Achieved by:
heat transfer
humidification
filtration

5.  Heat exchange
The temperature of inspired air can range
from −50 to 50 °C
 Filtration
Turbinates pattern of airflow exhale all
inspired air.
Heat & energy inspired airstream
saturation micro-organism & particles
heavier sink into mucosal layer
processed by enzymes & immune cells

6.  Providing a physical buffer against injury to
the face
 Vocal resonance
 Reduction of skull weight
 Humidification
 Heat insulation
 Air conditioning

7. At rest
 Inspiratory flow rate ranges 5-12 L/min
 Pressure change of 50 Pa between the
nostrils and the nasopharynx
During exercise
 Flowrate increases & pressure decreases
 Flowrate increase upto 150l/min

8.  nasal flow is laminar as it enters the nasal
vestibule
 velocity as it passes through the nasal valve
At this point turbulent flow is observed
causes velocity of air to decrease causing
prolonged contact
allowing the nose to perform its vital functions.

9.  physiological activity
 each side of the nose alternates the phases of
congestion and decongestion.
 Vascular activity produces the changes
 Cyclical & occur every 4 to 12 hours
 Changes being constant for each person
 cyclical secretions in the side experiencing
greatest flow

10.  exercise
 pregnancy
 hormones
 infections
 allergy
 fear
 emotions
 sexual activity
Autonomic nervous system regulates many
of the change

11.  Accounts for upto ½ the total airway resistance
Laminar flow,
R = pressure/flow rate
 Achieved through three key components
I. Nasal vestibule
II. Nasal valve
III. inferior turbinates.

12. During inspiration
 can collapse to the negative pressure caused
by inspiration increasing nasal resistance
 A flow of 30 L/min is the limiting rate
 Prevented by ala nasi muscle contraction
changes shape of vestibule reduction
of turbulance without affecting cross section
area
During exercise ala nasi muscle contracts
radius nasal cavity nasal resistance

13. During Expiration
 positive pressure within the vestibule
increases the radius of the nose and in turn
improves nasal airflow

14.  narrowest part of the nasal airway
 approximately 2 cm posterior to the anterior
nares
 cross-sectional area between 55–83 mm2
 produces the most turbulent airflow
 Cottle maneuver is used to assess the
narrowing of the nasal valve area at rest.

16.  can swell and recede affecting dimensions of
the nasal cavity affecting nasal airway
resistance.
 Changes laminar inspired air into turbulent
 1–2 mm causes significant nasal airflow
velocity to 0.42 m/s compared to 0.89 m/s in
the normal healthy nose

17. 2 elements
A. Glycoproteins → produced by mucus glands
B. Water with its proteins & ions
→ serous glands
→ transudation from capillary network
Nasal mucus film → 2 layers
a. Upper viscous layer(gel)
b. Lower watery layer(sol)
Tips of cilia have small hooks which enter the viscous
layer & facilitate its movements

19. Propels mucus backward towards the nasopharynx
Relatively short ≈5μm
Over 200 cilia present on each cell
Absent in pt. with Kartagener’s syndrome

20.  Beat freq (at body temp)=10-20Hz (mean = 14 Hz)
 Rapid propulsive stroke followed by a slow
recovery phase
 Energy from ATP (ATPase of dynein arms)
 Mucous blanket is propelled backwards by
metachronous movement of cilia

21.  Drying
 Temperature
 PH
 Infection
 drugs

22.  Autonomic nervous system
 Influenced by local inflammatory reactions
Sympathetic supply:
 superior sym ganglion
Postganglionic fibers → deep petrosal and vidian
nerves → continue through sphenopalatine
ganglion → nasal cavity
Neurotransmitters:
Noradrenaline: arterial, arteriole & venous
constriction

23. Parasympathetic supply
Superior salivary nucleus (pons)
↓
Intermediate branch of facial nerve
↓
Geniculate ganglion
↓
Continue along GSPN, deep petrosal nerve and nerve of
pterygoid canal
↓
Synapse in sphenopalatine ganglion
Neurotranmitter:
Acetylcholine: vasodilation, ↑ glandular secretion

24.  Prevent noxious substances entering the
lower respiratory tract.
1. Mechanical defence
2. Immunological defence
Mechanical defence
 Removes particles 30 μm or upward
 Vibrissae stop the largest particles.
 Mucociliary flow is main defence mechanism

25. mucociliary transport
 cilia of the respiratory epithelium & mucous
blanket
Viscoelastic properties trap larger particles
 expels filtered particles and debris into the
nasopharynx and oropharynx
 as well as elimination through sneezing and
coughing

26.  able to neutralize antigens by
1. innate mechanisms
2. learned
3. adaptive immunological responses
IgA & IgE are found on the surface
act whenever the mucosa is breached
 Ig A constitutes 70% of the total proteins
in nasal secretions.

27.  Rhinomanometry
 acoustic rhinometry
 peak nasal flow
 subjective measurements

28.  functional measure of nasal patency
 provides a measure of nasal resistance to
airflow
 R = δP/V
R = resistance to air flow
δP = trans-nasal pressure, in cm H2O or Pa
V = nasal air flow, in litre/s or cm3/s

30. Techniques:
 Active rhinomanometry: with normal breathing
(anterior and posterior)
 Passive rhinomanometry: generation of nasal
airflow & pressure from ext source eg. Fan or
pump
 Active rhinomanometry
1. Anterior
2. posterior methods

31. A patient performing anterior active rhinomanometry. The tape with the
pressure tube is applied on
the left (untested) nostril, which allows nasopharyngeal pressure detection

33.  nasal patency in health is unstable and may
be even more variable in disease,
 difficult to give any normal range
 Total nasal patency is more stable
 total nasal resistance range: 0.15–0.39 Pa
cm3 s
 maximum in the infant at around 1.2 Pa cm3
s
 declines to the adult value at around 16–18
years of age
 slow decline with increasing age.

34.  Use of acoustic pulse to measure cross sectional
area
 Reflected sound is detected by microphone:
amplified and processed by computer system
 Measure of nasal cross sectional area along the
length of the nasal passage
 Quicker & easier

35. A child performing acoustic rhinometry

37. Average measurements:
Minimum cross sectional area: ≈0.7 cm2 (0.3-1.2
cm2)
With decongestion : ≈0.9 cm2 (0.5-1.3 cm2)
volume of the nasal cavity
 3.71 cm3 (3.58–3.84) in school children aged
9–11 years
 5.44 cm3 (5.21–5.67) in adults, after
decongestion

38. Clinical application
various deviations of nasal structure
 valve stenosis, septal deviation, turbinate
hypertrophy and tumour masses.

39.  peak inspiratory or expiratory airflow through
the nose associated with maximal respiratory
efforts
 measure of nasal conductance
 effort dependent and is less sensitive
 Instruments: Wright,mini-Wright, and Youlten
flow meters
 reliable measurements:standard pulmonary
spirometry equipment

40. A patient performing peak nasal inspiratory flow.

41.  useful for large changes in nasal conductance
 Used after nasal challenge and nasal
decongestion
 Mean PNIF
in adult males was 143 L/min, and 122 L/min
in females.

43.  The ability to detect environmental chemicals is a
primary function of the nose.
information:
 The safety of a substance or environment
 The aesthetic properties
 Basic communication
 flavours of foods & beverages
 aids the process of digestion
livelihood
Loss of smell can also adversely affect nutrition,

44.  The olfactory neuroepithelium exists within a
small region nasal mucosa (said to be ~2
cm2)
 Upper recesses of the nasal chambers lining
the cribriform plate and sectors of the
superior turbinate, middle turbinate, and
septum
 Olfactory cleft harbours the majority of the
olfactory neuroepithelium
 only 10–15% of the air reaches the olfactory
neuroepithelium

45.  The main olfactory system
 The accessory olfactory system
 The trigeminal somatosensory system
 The nervus terminalis or terminal nerve

46. odourants
1. enter the nose during either active (e.g.
sniffing) or passive (e.g., diffusion)
processes
2. Pass through olfactory cleft
3. move to aqueous phase of the olfactory
mucus
 pseudostratified columnar epithelium,
supported by a highly vascularized lamina
propria.

47. I. bipolar sensory receptor neuron
II. supporting or sustentacular cell
III. duct cell of Bowman’s glands
IV. microvillar cell
V. horizontal (dark) basal cells
VI. globose (light) basal cells

48. Organization of the olfactory membrane and olfactory
bulb and connections to the olfactory tract.

49. Approximately 6 million receptor cell axons
coalesce into 30–50 fascicles, termed the
olfactory fila
traverse the cribriform plate and pia matter
synapse with second-order neurons
glomeruli of the olfactory bulb.

50. second-order neurons:mitral and tufted cells
Collaterals synapse within the periglomerular and
external plexiform layers
 brain regions addition to the AON(anterior
olfactory )nucleus
I. Piriform cortex
II. The olfactory tubercle
III. The entorhinal area.
IV. The amygdaloid cortex
V. The corticomedial nuclear group of the
amygdala

51. centrifugal fibre projections from cortex
modify and control olfactory input.
Third-order projections reciprocal fashion
Thalamus,hypothalamus,hippocampus &
orbitofrontal cortex
Areas of the cortex smell perception:pre-
piriform and intermediate piriform cortices

52. signal transduction
 requires a complex cascade of events
 activation of G proteins (Golf) and various
second messenger enzymes

53.  Scott-Brown's Otorhinolaryngology and Head
and Neck Surgery, Eighth Edition
 Cummings otolaryngology head and neck
surgery
 Guyton and hall textbook of medical
physiology