Lecture 5 - Intro to Resp System

Question 1

What are the 5 main functions of the respiratory system?

Answer 1

1. gas exchange - delivery of oxygen for distribution to tissues
2. vocalisation
3. olfaction
4. temperature control
5. acid-base regulation

Question 2

give a BRIEF overview of respiration

Answer 2

ventilation - movement of O2 to and remove CO2 from lung
exchange - of O2 between alveolar and blood
Transport - of O2 and CO2 between lungs and tissues
exchange - of O2 and CO2 between blood and cells

Question 3

what anatomical features are in the upper respiratory tract?

Answer 3

nose - incl. external nose, nasal vestibule, paired nasal cavities, paranasal sinuses
nasopharynx
larynx
proximal trachea

Question 4

what anatomical features are within the lower respiratory tract?

Answer 4

trachea
bronchi
lungs

Question 5

describe the nose (in one sentence)

Answer 5

bony case with movable cartilaginous projections rostally

Question 6

describe the features of external nose

Answer 6

has specialised nasal integument, surrounding paired nostrils
nasal plate in carnivores and small ruminants
nasolabial plate in ox
rostral plate in pigs
philtre - sagittal groove in rostral nasal integument
nasal plate is kept moist in some species, ox and pig have underlying glands, dog has overflow from nasal cavity

Question 7

describe the nasal vestibule

Answer 7

• passage from nostril to wider nasal can

- mucocutaneous junction = site of the opening of lateral nasal gland ducts - and nasolarimal duct in horse

Question 8

how is the nasal vestibule divided in horses?

Answer 8

divided dorsally = nasal diverticulum

ventrally = true nostril leading to nasal cavity

Question 9

what is the function of the nasal cavity

Answer 9

to conduct air from the nostrils to the nasopharynx

Question 10

what are the anatomical boarders of the nasal cavity?

Answer 10

divided in middle by nasal septum
ventrally (floor) bound by hard palate - seperates from oral cavity
caudally limited by ethmoid bone
bone casing extend rostrally into cartilage
divided into small passages = conchae
communicate with nasopharynx through choana

Question 11

What gland duct opens within the nasal vestibule?

Answer 11

Lateral nasal glands (in carnivores) 
Nasolacrimal duct (in horse)

Question 12

What seperates the nasal cavity into small passages in which air flow through?

Answer 12

Chonchae - turbinate bones

Question 13

What hole communicates the nasal cavity with the nasopharynx?

Answer 13

Choana

Question 14

What are the nasal cartilages and what are their functions?

Answer 14

Septal cartilage - rostral part
Sevredal paired cartilages

Function = form framework of mobile part of nose

Question 15

What muscles move the nasal cartilages and what nerves innervate the nasal cartilages?

Answer 15

Levator nasolabialis and caninus

Innervated by CNVII - facial

Question 16

Describe what the chonchae are and what are there function within the nasal cavity?

Answer 16

Scrolls of bone, covered in mucosa
Function = increase SA for heat exchange, filtration and humidification of air.
Special function = olfaction

Question 17

What are the three conchae and what are their shapes?

Answer 17

Dorsal - single elongated scroll
Ventral - double scroll in most species, single in horse, complex filling of ventral part of nasal cavity in dogs
Ethmoidal - numerous fine bony scrolls attached to ethmoid bone, lateral and dorsal walls

Question 18

What is the special function of the ethmoidal bones?

Answer 18

Support olfactory mucosa

Question 19

Describe the lateral nasal gland

Answer 19

Only in carnivores
Serous gland between mucosa and maxillary bone in lateral wall
OPENS in lateral wall of nasal vestibule
Secretions wet external nose

Question 20

Describe the nasolacrimal duct

Answer 20

Drains tears from medial canthus of the eye
Runs within lateral wall of nasal cavity
Distal opening in nasal vestibule: at mucocutaenous junction in horse, ventral to alar fold in dog

Question 21

Describe the functions of the paranasal sinuses

Answer 21

Diverticula of nasal cavity into skull bones
Develop after birth
Lined with normal nasal epithelium
Frontal and maxillary present in all species

Functions= lighten skull, allow bony development for muscle attachment, thermal and mechanical protection of soft tissue
Resonance of voice

Question 22

What are the frontal sinuses?

Answer 22

Drain into ethmoid region except in horse

Extend into cornual process in ruminants

Question 23

What are the maxillary sinuses?

Answer 23

Communicate with nasal cavity through narrow nasomaxillary opening except in dog and cat - they have maxillary recess
House roots of upper check teeth

Question 24

Describe the frontal and maxillary paranasal sinus within the horse

Answer 24

Maxillary - rostral and caudal divisions
Partly filled by unerupted cheek teeth
Frontal - extend into dorsal concha, drains into caudal maxillary sinus

Drainage of ALL sinuses into nasal cavity through narrow common nasomaxillary opening

Question 25

What is the clinical importance of the paranasal sinus?

Answer 25

May need to gain access for surgical drainage or tooth removal
Important landmarks: nasolacrimal duct running from medial canthus of eye to nasoincisive notch = avoid

Question 26

What is the area of access bounded by when trying to access the paranasal sinuses within the horse?

Answer 26

Line between infraorbital foramen and medial canthus of eye
Facial Crest
Line between infraorbital foreamen and rostral boarder of facial crest
Vertical line through medial canthus of eye

Question 27

What are differences of the nose in birds?

Answer 27

Nostril located in upper beak
Cere = keratinised tissue at base of upper beak, can be used to sex budgies
No soft palate - no nasopharynx
Nasal gland located in lateral wall of nasal cavity, secretes sodium in marine birds