The document summarizes the structure and function of the respiratory system, specifically the pharynx and larynx. It describes the pharynx as having 3 parts - the nasopharynx, oropharynx, and laryngopharynx. It then discusses the structures of the larynx including the thyroid and cricoid cartilages. The larynx contains vocal cords that open for breathing and close to vibrate, producing different pitch sounds important for speech. The epiglottis prevents food from entering the larynx. Overall, the pharynx and larynx work together to warm, humidify, and filter air as well as enable speech.

1. Presented By:
Abdul Sitar

2. Contents
 Introduction of Respiratory system
 Structure of Pharynx
 Function of Pharynx
 Structure of Larynx
 Function of Larynx
 Reference

3. Respiratory System
 The exchange of gases between the atmosphere
blood and cell is called Respiration .
 Respiratory system provide the route by which the
supply of oxygen or atmosphreric air enter the body
and it provides the route of exhalation for carbon-
dioxide cardiovascular system , blood contaning gases
between lung and body cell.

4. Structure of pharynx
 It is a passage way about 12 – 14 cm long
 It extend form posterior nares,and runs behind the
mouth
 The larynx to the level of six thoracic vertebrae
 Where it becomes the oesophagus
 It is divided into 3 parts

5. Part of Pharynx
 Nasopharynx
 Oropharynx
 Laryngopharynx

6. Nasopharynx
 Nasal part of the pharynx lies behind the nose above
the level of the soft palate
 There are five openings in its wall
 Two internal nares , two opening that lead into the
auditory tube, and one opening into oropharynx
 Posterior wall also contains pharyngeal tonsil

7. Oropharynx
 It is the oral part of the pharynx,
 That is lies behind the mouth .
 It is extending from below the level of soft plate
 The level of upper part of the body of there cervical
vertebra.

8. Laryngopharynx
 It is the laryngeal part of the pharynx
 It extends from orophrynx above & continues as the
oesophagus below with the larynx lined anteriorly
 It is also both respiratory and diagestive in function
 It is lined by non keratinised stratified, squamous
epithelium

9. Function of pharynx
 It is the passage way for air and food
 warming and humidifying
 hearing – The auditory tube,extending from the
nasopharynx to each middle ear

10. Larynx or voice box links the laryngopharynx and the
trachea
Larynx is composed of several irregularly shaped cartilages
attached to each other by ligaments and membrane
The main cartilages are
(1) one thyroid cartilage
(2) one cricoid cartilage
(3) one epiglottis
(4) paired arytenoids cuneiform and corniculate

11. Thyroid cartilage
 It is made up of hyaline cartilage lies in front of the
neck
 Its anterior wall projects into soft tissue in front of
thyroid forming Adam’s apple
 Ligament that connects thyroid cartilage to Hyoid
bone is called thyrohyoid membrane
 Upper part of the cartilage is lined with stratified
squamous epithelium,lower part is lined with ciliated
columnar epithelium

12. Cricoid cartilage
 It is a ring of hyaline cartilage that forms the inferior
wall of larynx
 Attached to first ring of cartilage of trachea by the
cricotracheal ligament or membrane
 Thyroid cartilage is connected to cricoid cartilage by
the cricothyroid membrane or ligament
 This cartilage is lined with ciliated columnar
epithelium.

13. Arytenoids cartilage
 These are triangular pieces of mostly hyaline cartilage
and located at the posterior, superior boarder of
cricoid cartilage
 They gives attachment to the vocal cords to the
muscles and are lined with ciliated columnar
epithelium

14. Epiglottis
 It is a large leaf shaped piece of elastic cartilage that is
covered with epithelium
 It is composed of elastic cartilage and almost anteriorly
covered by taste buds mucosa
 It extends from the posterior aspects of tongue to it
anchoring point or anterior limb of thyroid cartilage
 Glottis consist of pair of folds of mucous membrane
the vocal cord in larynx and space between them is
called rima glottidis.

15. Interior of Larynx
 Vocal cords are two pale folds of mucus membrane
 When the muscles controlling the vocal cords are
relaxed, the vocal cords open and passage way for air
coming up through larynx is clear
 Vocal cords are said to be abducted(open) low pitch
sound produced
 When the muscle controlling vocal cords contract,
vocal cords are stretched to this extend and are
vibrated by air passing through lungs (high pitch
sound produced)muscles are abducted (close)

16. Function of Larynx
 Production of sound
 Speech
 Humidifying
 Filtering, warming
 Passage way for air

17. Reference
 Ross and Wilson principles of anatomy and physiology
edition 10 page No 238-244.

18. Thank you