Respiratory System Flashcards
Development
Cranial portion of foregut (together with dig. System)
What is the foregut?
Runs from pharynx/esophagus to duodenum
Buccopharyngeal membrane
Rostral portion, dev. Of mouth
How does the lateral walls of foregut develop?
Branchial cleft
Pharyngeal bursa
Visceral arches
Branchial cleft
From external surface/ectoderm
Gives rise to external ear
Pharyngeal bursa
Endoderm/internal layer 4 pairs 1- auditory tube, middle ear, guttural pouches 2- palatine tonsil 3- parathyroid gland and thymus 4- parathyroid gland
Visceral arches
Mesoderm/middle layer
Muscle, bone, cartilage= larynx, trachea, hyoid
Floor of primitive foregut
Phase 3 Tongue (endoderm+mesoderm) Thyroid glands (endoderm)
Invagination of respiratory tube
Phase 4
Tracheoesophageal septum formation (separates trachea+esophagus to ventral-dorsal)
Tracheal pulmonary buds (immature form of lungs)
Formation of bronchus and lower resp. tract
Congenital disorders
Pharyngeal reg: tyroglossal cysts
Laryngotracheal reg: tracheal hypoplasia, tracheoesophageal fistula
Lung reg: pulmonary hypoplasia, lobar hypotrophy of foal
Cysts
Upper respiratory tract
Gaseous exchange
Olfactory/smell
Nostrils
External nasal openings
Bony/cartilaginous
Nasal cartilages
Cartilage of nasal septum
Dorsal lateral nasal cartilage=roof
Ventral lateral cartilage= floor
Alar cartilage= in equine, allows nostrils to expand
Philthrum
Groove from upper lip to nose tip
“Subnasal groove”
Rostral bone
In pigs only
Nasal conchae/turbines
Thin sheets of cartilage or bone surrounded by nasal mucosa
Dorsal
Ventral
Ethmoidal- most caudal, ethmoidal bone separates brain from nasal cavity
Nasal meatuses
"Compartments" Ventral-olfactory Medial- sinusal Ventral- respiratory All communicates by common nasal meatus
Paranasal sinuses
Maxillary
Frontal
Ethmoidal
Sphenoidal
Sinus
Air filled cavities
Decreases head weight
Protection
Heating air
Vomeronasal organ
Btw hard palate and nasal septum, communicating oral+nasal cavity (not equine)
Detects pheromones
Accessory olfactory system
Larynx
Cartilagenous tube Btw pharynx and trachea Phonation organ Protects respiratory system Ventral to esophagus
Epiglottis
Most cranial
Thyroid
Biggest one
Ventral/lateral
Makes the floor and lateral walls of larynx
Articulates with hyoid
Cricoid
Caudal
Ring-shaped
Joins trachea caudally, thyroid cranially, arythenoids dorsally
Arythenoids
Small
Joins dorsally to epiglottis and thyroid
Interarythenoid cartilage
Vocal chords attach to muscular process and vocal process
Cuneiform process
On epiglottis
Corniculate process
On arythenoids
Ligaments of larynx
Cricothyroid- ventrally btw cricoid and thyroid
Cricoarythenoid- dorsally btw cricoid and arythenoid
Folds of larynx
Vestibular folds in carnivore+eq, cranial
Vocal folds- vocal chords caudally
Muscles of larynx
Cricothyroid- btw cricoid and thyroid, latitudinal
Dorsal cricoarythenoid- btw cricoid and arythenoids, dorsally longitudinal
Transverse arythenoid- btw arythenoids dorsally
Ventricular muscle- cranial
Vocal muscle- dorsal to ventricular M
Dilating muscles of larynx
Dorsal cricoarythenoid
Closing muscles of larynx
Lateral cricoarythenoid
Transverse arythenoid
Narrowing muscles of larynx
Ventricular
Cricothyroid
Extrinsic muscles of larynx
Fixes larynx
Moves it cranial or caudal
Intrinsic muscles of larynx
Most internal
Very short
Expand or contract
Vestibule
First cranial part of laryngeal cavity
Glottis
Intermediate part, narrower
Infraglottic cavity
Most caudal part
Laryngeal cavity
Prevents foreign bodies into resp. System
Phonation
Allows breathing
Trachea
Cartilagenous tube
From larynx to lungs (cricoid to base of heart level)
Cervical al thoracic portion
Carina
Bifurcation of trachea
Divides into left and right main bronchus
Pigs and ruminant have extra right tracheal bronchus
Trachea innervation
Vagosympathetic trunk
Jugular vein
Common carotid artery
Composition of trachea
Cartilagenous incomplete rings Annular ligaments between Tracheal muscle joins ring dorsally Equine- large egg shaped Dog- tracheal muscle above, egg shaped Pig- very round Ox- egg shaped (standing) with pointy cartilage ends
Pleura
Thin serous membrane covering lungs
Parietal pleura
Covers thoracic cavity, except lungs
Pulmonary ligaments
Costal
Diaphragmatic
Mediastenic
Visceral pleura
Covers directly lungs
Pleural cavity
Btw pulmonary/visceral pleura and parietal pleura
Pulmonary ligament
Caudally/ventrally to diaphragm fixing lungs to diaphragm
Recesses
Space/cavity
Costodiaphragmatic- dorsal btw costal pleura and diaphragmatic pleura
Costomediastenic- ventrally
Dorsal surface of lungs
Convex
Borders will “fall down”
Diaphragmatic surface of lungs
Caudal
Mediastenal surface of lungs
Medial surface
Pulmonary hilus/hilum
Costal surface of lungs
Dorsal
In contact with lungs
Fixation of lungs
Cranially by trachea
Dorsally by pulmonary ligament
Bronchial tre
Main/principal bronchus Lobar bronchi Segmental bronchi Bronchioli (less than 1mm, no cartilage rings) Respiratory bronchioles
Right side lung lobulation
Cranial lung lobe
Middle lung lobe
Caudal lung lobe
Accessory lung lobe
Left side lung lobulation
Cranial lung lobe
Caudal lung lobe
General about lung lobulation
Cranial lung lobe can be divided into cranial/caudal portion
All species have accessory lobe
Ruminants most lobulated (2 portions of cranial, both sides)
Equines have least lobulated (no middle lobe)
Functional circulatory system
Pulmonary arteries+veins
R ventricle to pulmonary artery
Nutritive circulatory system
Thoracic aorta (bronchial arteries), bronchial veins (azygous veins)
Lymphatic circulatory system
Mediastenic (above aorta),
tracheobronchial (carina level)
Nervous system
Vagus N (10) Sympathetic trunk
Thymus
Lymphatic organ next to heart
Diaphragm
Main inspiratory muscle
Separates thoracic cavity and abdominal cavity
Lumbar area to ziphoid process of sternum, oblique
Derived from mesoderm
Diaphragmatic hernia
Defect allowing abdominal organs into thoracic cavity
Hiatal hernia
Esophageal hiatus fails to close
Central tendinous portion
Caudal vena cava hiatus- most ventral, canal foramen
Muscular ring of diaphragm
3 surfaces
Costal, sternal, lumbar
Causes of diaphragm
Left+right
Attaches to lumbar surface
Right crus
Esophageal hiatus
Bigger/larger
Vagal trunks
Left crus
Aortic hiatus
Aorta+azygous vein
Thoracic duct
