MIKE RES Flashcards
(147 cards)
1
Q
List of hyoid bones
A
Thyrohyoid bone Keratohyoid bone Epihyoid bone Stylohyoid bone Tympanohyoid cartilage Basihyoid bone
2
Q
Hierarchy of words for larynx area
A
Cricoid Thyroid Arytenoid Hyoid Epiglottis
Cats Tripped At Happy Easter
3
Q
List the four main cartilages
A
Epiglottis
Thyroid
Cricoid
Arytenoid
4
Q
List the four main processes of the Arytenoid cartilage
A
Cuneiform proces
Corniculate process
Muscular process
Vocal Process
5
Q
List the three articulations of the thyroid cartilage and explain movement
A
Cricothyroid
Cricoarytenoid
Thyrohyoid
6
Q
List the 4 main ligaments of the larynx
A
Vestibular ligament
Vocal ligament
Cricothyroid ligament
Cricotracheal ligament
7
Q
Name the 3 folds and ventricle of the larynx
A
Aryepiglottic fold
Vestibular fold
Lat.ventricle
vocal fold
8
Q
List the 4 sections of the larynx
A
Aditus laryngis
Vestibule
Rima glottidis
Infraglottic cavity
9
Q
List the three extrinsic muscles and what the overall fx is
A
Overall fx = deglutition
Thyrohyoid m
Hypoepiglottic m
Geniohyoid m
10
Q
List the five intrinsic muscles
A
Adductors (close glottis) Cricothyroid Lateral cricoartenoid Transverse arytenoid Thyroarytenoid
Abductors (open glottis)
- Dorsal cricoarytenoid
11
Q
Cricothyroid m
A
Intrinsic adductor
Ori- lat cricoid
Ins- lat thyroid
Fx- tenses vocal fold preventing abduction
12
Q
Lateral cricoartenoid m
A
Intrinsic adductor
Ori- lat ros cricoid
Ins- muscular process arytenoid
Fx- ventral edge arytenoid = adduct vocal cords
13
Q
Transverse arytehoid m
A
Intrinsic adductor
Ori + ins = strap over dorsally, arytenoid mus process to bus process
Fx= close/fine tunes
14
Q
Thyroarytenoid m
A
Intrinsic adductor
Dog/horse = divided into ventricular (ros) and vocalis (caud)
Ori = epiglottis + thyroid (midline)
15
Q
Dorsal cricoarytenoid m
A
Intrinsic abductors
Ori - on cricoid
Ins - muscular process of arytenoid
16
Q
Which cranial nerve does innervation of the larynx come from and the two main branches
A
Vagus n. —> cranial laryngeal n and caudal laryngeal n (arises from recurrent laryngeal n).
17
Q
Recurrent laryngeal pathway, left vs right
A
L = around the aortic arch, goes up ventral groove between trachea and oesophagus
R = around R subclavian a. Continues up the dorsalateral trachea
18
Q
Roaring in horses
A
Left recurrent laryngeal hemiplegia
dorsal cricoarytenoid m. (Only abductor)
Surgery correction
19
Q
Caudal laryngeal n. Fx
A
Motor innervation for all intrinsic mm except cricothyroid Lateral cricoartenoid m Transverse arytenoid m Thyroarytenoid m Dorsal cricoarytenoid m
20
Q
Cranial laryngeal n. Fx
And branches
A
Internal Cranial Laryngeal n
sensory to mucosa
External canal laryngeal n
- motor to cricothyroid
21
Q
Microanatomy of trachea
A
Mucosa ( epi= pseudostratified columnar ciliated + goblet cells) (lamina propria = loose, vascular connective tissue) (mucosa cilia elevator)
Submucosa (seromucous tracheal glands)
Musculo - cartilaginous
Adventitia
22
Q
Two sectioning of larynx
A
Cervical
oesophagus Dorsal to trachea rostral 2/3 then on left side caudal 1/3
Thoracic
- Dorsal to cranial vena cava
- bifurcates dorsal to base heart level 4th - 6th intercostal space
23
Q
Tracheal stx 3 parts
A
C shaped hyaline cartilage Open dorsal Annular ligaments (fibre-elastic) Trachealis m Dorsal aspect in gap of rings Smooth m Carnivores = external, herbivores = opposite Shaped different
24
Q
Pleura Stx
A
Serous membrane
simple squamous
Thin lamina propria
Serous fluid/ exudate (fluid leaks out of blood vessels) = lubrication
25
Formation of the pleura including “pulmonary visceral pleura”
As lung grows out from principle bronchi it pulls pulmonary visceral pleura with it
26
List the three layers of the pleura
Pulmonary visceral pleura
Parietal pleura
Pleural space
27
Importance and fx of pleura cavity
Fx - make lungs + pulmonary visceral pleura stick
Achieved =
1. Slight vacuum in pleural space
2. Innate surface tension of fluid
28
Mediastinum definition
Contains everything in the thoracic cavity except
| lungs, caudal vena cava, right phenric artery
29
Cranial mediastinum
```
Pre cardiac
Tracheal
Oesophagus
Blood vessels
Sympathetic trunk
Vagus
Recurrent laryngeal
Phenric
```
30
Middle mediastinum
```
Cardiac region
heart ❤️ (pericardium)
Descending aorta
Oesophagus
Bifurcation of tracheal
Vagus n.
Phrenic n.
```
31
Caudal mediastinum
Post-cardiac
plica venae cava (Caudal vena cava, R phenric n.)
Mediastinal recess (accessory lobe-horses)
Pulmonary ‘ligament’ (pleural fold)
32
Costo-diaphragmatic recess
no lung
33
3 surfaces of the lung
Costal
Mediastinal
Diaphragmatic
34
3 borders of the lung
Dorsal
Ventral (with cardiac notch)
Basal
35
List lung lobes L and R
```
L = Cranial (cranial + caudal)
R = Cranial, intermediate, caudal, accessory
```
36
Tracheal bronchus
Extra tracheal bronchus (pigs + ruminants) on the right
Horse called the primary bronchus
37
Cardiac notch
The heart pokes out
38
Hilus explained an list the things coming out
```
Anchors lungs to trachea and heart
Contains
principal bronchus
Pulmonary vessels
Bronchial vessels
Lymphatic vessels and nodes
Nerves
```
39
The two divisions of internal structure and the parts in it
```
Conducting = branching bronchi
Respiratory = respiratory bronchioles down
```
40
1 bronchi principal
1.Mucosa
longitudinal fold, epi = pseudo, lamina propria = loose connective (lymphocytes, capillary)
2. Smooth muscle = (circular to spiral)
3. Submucosa = (sero-mucous bronchial glands, elastic fibres BV)
4. Fibroelastic/cartilage (cartilage plates —> less continuous, them trachea)
41
2 secondary bronchus
```
ciliated epithelium
bronchial glands
elastic fibres
smooth muscle (circular)
cartilage
```
42
3 secondary bronchus
smooth muscle is spiral, bronchial glands and cartilage
43
Bronchioles
But muscle v important in controlling resistance to air flow and distribution of air to alveoli
- Bronchioles small but many of them = largest cross-sectional area of airway
have smooth muscle (spiral) and mucous around
44
Terminal bronchioles
Usually Respiratory bronchioles
2 from each term. Bronchioles
Occasional alveoli
CLUB CELLS
45
Explain the levels of the trachea
46
Club cells
(Formerly ‘Clara cells’)
Replace goblet cells of respiratory bronchioles and onwards
Secrete = “lipoprotein surfactant”
47
List the alveoli cells
Pneumocyte
Endothelial cell
Capillary
Alveolar space
48
Explain Blood-gas barrier
Type 1 epithelial cells
Basement membrane
Endothelial cells of capillaries
49
Explain the 3 factors which the lung has to combat and the 3 adaptions they have
Alveoli = delicate
Exposed to air
Smooth muscles = control rate
So air is humidified, warmed and filtered
50
Superficial lymphatics
Lx = sub-pleural connective tissue
51
Deep lymphatics
```
Lx follows bronchial tree
Follows bronchial tree
Tracheal-bronchial
Pulmonary
Mediastinal
Lymph nodes
```
52
Innervation of lungs
```
Vagus (parasympathetic)
-broncho-constriction
Sympathetic
-broncho-dilation
-vasoconstriction bronchial aa
```
53
Explain the two divisions of the blood system
```
Functional
Oxygenation
Relatively simple
Pulmonary arteries and veins
Provide nutrition to alveoli (O2)
```
Nutritional
Supply (pleura, stroma
54
List the phases of embryology larynx, trachea and lungs
```
Starts at pharyngeal region
laryngotracheal groove in floor foregut
Pseudo glandular
Canaliculi
- Repiratory bronchioles, air sacs, blood supply
Terminal sac
- epithelium differentiates type I and II
Alveolar stage
- alveoli
```
55
Explain the pump mechanism
Lung have elasticity which helps with contraction
| Inspiration (expansion) based on thoracic wall and diaphragm
56
Thoracic cavity bounded by
```
first 2 ribs cranially
Thoracic vertebrae dorsally
Sternum ventrally
Ribs laterally
Diaphragm caudally
IMPORTANT = a sealed cavity by costal and diaphragmatic pleura
```
57
Thoracic cage
Ribs, vertebrae and sternum
58
Thoracic inlet
```
Cranial end of thoracic cage
Bound by
1st vertebrae
1st pair of ribs laterally
Manubrium sterni ventrally
```
59
Thoracic outlet
Caudal extreme
Last thoracic vertebrae
Last pair of ribs + costal arch
Diploid cartilage
60
Movement of thorax during respiration, the two joints
Costo-vertebral joints
| Sternal ribs have costa-sternal joints
61
Costs-vertebral joints, the two parts
1. Articulation of the head
2 convex facets articulate 2 adjacent vertebral bodies
Rotatory or trochoid joint
Ligament of the head + inter capital ligament
2. Articulation of tubercle
tubercle projects caudally at junction of neck and body
Tubercle art
62
Costa-sternal joints
synovial joints
Costal cartilage inter-sternebral cartilages (equivalent to intervertebral disc)
Joint capsule thin except dorsal and ventral, joint is strengthened by “stero-costal radiate ligaments”
63
Costo-chondral joints
fibrous joints between rib and costal cartilage
| Periosteum and perichondrim merge
64
Motion of the rib movement
- Mainly rotation around head-tubercle axis
| - greater movement in caudal ribs than cranial
65
Intercostal muscles
External
Run up/forwards, drawing ribs cranially and laterally for inspiration
Internal
Muscle fibres run down/forwards
“Action controversial, possible involved in inspiration”
66
List 9 muscles that may assist with breathing
```
Scalenus
Latissimus dorsi
Longissimus thoracic
Iliocostalsis
Rectus thoracis
Transverse thoracis
Serratus dorsalis
Serratus cranialis
Serratus caudal
```
67
Thoracic wall blood vessels dorsal branch
This branch is divided into
spinal branch - spinal cord and its coverings
Dorsal cutaneous branch to dorsal skin
68
Thoracic wall blood vessels ventral branch
Runs down medial surface medial surface of internal intercostal muscles, immediately caudal to ribs
Gives off multiple branches of lat. cutaneous branches
69
Explain the anastomoses of dorsal intercostal artery
It anastomoses with the dorsal intercostal arteries
70
Thoracic wall nerves
Run with the blood vessels
71
Diaphragm attachements
```
Dorsal = near thoracolumbar junction
Laterally = roughly along line of last rib
Ventrally = near xiphisternum
```
72
Diaphragm structure
```
Tendinous centre surrounded by muscular periphery which radiate from centre
Has three parts
Lumbar
Costal
Sternal
```
73
Explain the lumbar part of the diaphragm
Lumbar part is wider, has two muscular crura attached to lumbar vertebral bodies
Right crus is larger than left (right extends past midlineover to left side)
74
Explain the costal part of the diaphragm
Attachment from 8-last rib
| This part periphery interdigitates with transverse abdominal muscle
75
Explain the sternal part of the diaphragm
Attachment arises from dorsal surface of sternum just cranial to diploid cartilage
76
Where is the only place where pleura and peritoneum come together
Lumbocostal arch = between crura and attachment to last rib, passing over the posts muscles without attachment.
77
List the three hiatus in the diaphragm
1. `Aortic
most dorsal
Contains (aorta, right azygos vein and cisterna chyli)
2. Oesophageal hiatus
located at the junction of right and tendinous centre
Contains (oesophagus, vagus nerve trunk and oesophageal vessels
3. Caval foramen
an opening in tendinous centre on the right side
Caudal vena cava
78
Diaphragm blood supply
```
Musculophrenic artery
supplies muscular periphery
A terminating branch of internal thoracic artery
Cranial phrenic artes
supplies crura
Arises from thoracic aorta at aortic hiatus
Phrenic-abdominal artery
arising from abdominal aorta
Also applies diaphragm
```
79
Phrenic nerves description
Motor and sensory to diaphragm
Arises from ventral branches of cervical nerves (5-7)
Untie just cranial to thoracic inlet to form left and right phrenic nerves
pass medial to subclavian arteries
At level of 1st rib L and R communicates with cervical-thoracic (stellate ganglion), via a communicating branch
80
`Phrenic nerves L vs R
Left stays in mediastinum and runs across surface of the heart
Right phrenic nerves leaves mediating to run with caudal vena cava in the plica vena cave
81
Phrenic nerve termination
Many branches on surface of diaphragm
82
Explain innervation of periphery of diaphragm
Also receives sensory fibres form last several intercostal nerve
83
Step of mechanics of breathing which decreases pressure
Volume change by ribs swinging forward with increases value laterally.
Astral ribs swing downwards which increases volume ventrally
Diaphragm contracts = caudal volume increases
84
Explain the negative pressure in the inter-pleural region normally
Inter pleural is always slightly negative
85
Explain tracheal collapse, difference between cough on expiration and inspiration
Common signalment = older small and toy breeds
Goose-honk cough
Cough on
Inspiration = collapse in cervical trachea
Expiration = collapse in thoracic trachea
86
Anatomical dead space
Air in tract which does not undergo gaseous exchange
- trade off = narrow airways which reduce dead space but increase resistance with narrow lumen
87
What happens at birth
```
Born, lungs filled with fluid
Remove as much fluid asap
Exaggerated respiratory movements open alveolar sacs
A quick transition to air-filled lungs
Need to make sure surfactant produced
```
88
Nose components
External nose
Nasal cavities
Paranasal sinuses
89
Bones of the nose
Nose and nasal cavity is supported by none and cartilage lined by mucous membrane
90
Supporting bones of the nose
Nasal, maxillary, incisive, frontal, lacrimal, zygomatic, ethmoid
91
Floor of the nasal cavity
Roof of oral caivty, formed by the bones
Incisive
Maxillary palatine process
Palatine
92
External nose
Species specific
Morphology= lateral nasal cartilages + type of skin round nose
Nose is supported by dorsal and ventral lateral nasal carriages
Sometimes an accessory cartilage present
93
Lateral nasal carriages
Are extensions of cartilaginous nasal septum
94
Dog, cat and goat nasal cartilage
Cartilages are complete laterally
Thick hairless skin (plenum nasale)
confined to area around nostrils
Well defined philtrum
95
Pig nose cartilage
Complete laterally
-extra medial supported by rostral bone
Plenum rostral is continuous with upper lip
Small philtrum
96
Ox external nose cartilage
Complete laterally
Plenum nasolabialis continuous with upper lip
No philtrum
97
Horse eternal nose cartilage
Lateral cartilages are small
Extra alar cartilages
supports dorsal, medial + ventral carriages
No cartilage support laterally allowing for great distension fo nostrils ( as obligate breathers)
Normal hairy skin around nostrils
Blind ending diverticulum
98
Gland present and not present in planum based on species
Present in ruminants and pigs
Absent in carnivores but lateral nasal glands, glands in septic and lachrymal glands have same fx in providing moisture for nose
99
Nasal septum role
Divides nasal cavity into left and right halves
100
Nasal septum consists of
1. Perpendicular plate (caudally) (continuous with cribriform plate
2. Cartilaginous nasal septum
101
Nasal conchae
Thin complies, bony scrolls projecting from lateral wall
There sections
dorsal (slightly curled)
Ventral (tightly folded series of scrolls)
102
Mucosal folds
```
Straight fold
rostral extension of dorsal conchae
Alar fold
-rostal extension of ventral conchae
- alar fold appears bulbous particular in dog (diverting air to increase evaporation)
```
103
Ethmoidal conchae (ethmoturbinates)
are series of folding plates (not scrolls)
Caudal part of nasal cavity
Associated with ethmoid bone
Cranial border = frontal sinus
104
What are the three meatuses
Dorsal and ventral conchae divide the cavity into 3 spaces called meatuses
Dorsal
Middle
Ventral
105
List four structures associated with nasal
Incisive duct
Vomero-nasal organ
Lateral nasal gland
Naso-lacrimal
106
Explain the incisive ducts
Aka naso-palatine
Paired ducts
Connect oral and nasal cavities
Nasal opening is in the ventral meatus at the level of canine tooth
Oral opening is on the incisive papillae just caudal to upper incisors
107
Explain horse incisive ducts
Duct does not open into oral cavity (ends blindly)
108
Explain the vomer-nasal organ
Aka organ of Jacobson
paired blind sacs that run caudal from incisive ducts and end at the level between 2nd and 4th cheek teeth
Supported by cartilage
Fx
epithelium of ducts has both respiratory and olfactory mucosa
Detect pheromones & ‘flehmen’ response
Associated with the relationship between taste and smell
109
Explain lateral nasal gland
produces serous fluid, is microscopic
Present in all species except ox
Near nasomaxillary opening, duct opens into middle meatus near end of straight fold
Fx
moistens inhaled air, may aid comer-nasal organ
In dogs = moistens nose and aids thermoregulation
110
Explain naso-lacrimal duct
runs from medial cantos of eye into nasal cavity
Opens into floor of nostril at the junction of skin and mucosa
Pigs (often dogs) have a second opening on lateral surface near the end of the ventral conchae)
drains eye to prevent weeping
Aids in moistening nose and nasal cavity
Often blocked in brachiocephalic breeds
111
Microanatomy of nasal cavity
There are two regions
Respiratory
Olfactory
112
Location of respiratory mucosa
paranasal sinuses
Part of dorsal and all ventral conchae
Lateral, dorsal, ventral nasal wall and part of the septum
113
Explain the respiratory mucosa histology layers
Epi- pseudostratified columnar, ciliated w goblet cells (same as trachea and bronchi)
Paranasal sinuses are more cuboidal to squamous epithelium with fevered glands and goblet cells
Laminar propria and submucosa
loose connective tissue, blends w periosteum or perichondrium
Contains simple branched tubuloacinar mixed nasal glands (less in sinuses)
Deeper layers contain erectile venous plexuses with smooth muscle sphincters
114
Olfactory mucosa Lx
```
Lines these structures
Ethmoturbinates
Parts of the dorsal conchae
Part of the nasal septum
vomeronasal organ
```
115
Olfactory mucosa 3 cell types of the epithelium
Sensory (olfactory) cells
bipolar neurons
Extend through entire height of epithelium
Long non-motile cilia
2. Sustentacular (supporting cells)
slender cells, many microvilli (no cilia)
3. Basal cells
- rough spherical, nuclei close to basement membrane
116
Olfactory mucosa laminar propria and submucosa
contains Bowman’s glands (mainly serous)
Moistens surface so odiferous molecules can dissolve
Flush surface of epithelium to remove odiferous substances
Deep layers contain deep erectile venous peruses and bundles of non-myelinated olfactory nerve fibres (film olfactorum)
117
Three functions of the nasal cavity
```
Olfaction
macrosmatic = good animal smell
Microsmatic = poor sense of smell (humans)
Anosmia = no smell sense
2. Filtration of inspired air
dust and bacteria are trapped in mucous layer
Removed by ciliary action
3. Warming and humidifying air
maintain a layer of moisture in alveoli
Humidified air assist with olfaction
Warm air holds more moisture
Warming air= thermoregulation
```
118
Explain paranasal sinuses generally
are diverticulum of the nasal cavity that extend into surrounding bones
Continuous with naso cavity
Lined by mucoperiosteum
Originate in embryo continues to enlarge after birth as skull matures
119
List 6 possible fx of paranasal sinuses
```
Lighten skull
Thermally insulate
Protect eyes, nasal passages and cranial cavity
Absorb shock to head
Impart resonance to voice
Increase area of olfactory membrane
```
120
Give general description of maxillary sinus
```
Largest, communicates with middle meatus via has-maxillary opening
Species variation
hard palate - palatine sinus
Sphenoid bone - sphenoid sinus
Medial aspect of orbit - lacrimal sinus
Nasal conchae - conchal sinus
```
121
Frontal sinus
Opens into ethmoidal meatus of nasal cavity
| - except in horse - opens into caudal maxillary sinus
122
Ethmoidal meatus
Narrow cavity located obliquely below the superior concha
123
List the four pairs of horse paranasal sinuses
Maxillary
Frontal (or conch-frontal)
Sphenopalatine
Ethmoidal
124
Explain paranasal maxillary sinuses
incomplete bony septum divides rostral and caudal parts
Drains -= middle meatus via nasomaxillary opening
Longitudinal plate of infraorbital canal divides it into lateral and medial
Important communication with cheek teeth
125
Explain paranasal frontal
-with dorsal conchal diverticula
drains = caudal maxillary sinus via frontomaxillary opening (not directly into nasal cavity)
Many incomplete bony septa in frontal sinus
126
Ox paranasal sinuses
```
6 pairs of sinuses
Maxillary sinus with with diverticula
palatine
Lacrimal
Sphenoid
Conchal
```
Frontal sinuses
completely surround cranial cavity
Involves frontal, parietal, interparietal, part of temporal, occipital bones
Corneal diverticulum in adults (deworming adult cattle exposes mucoperiosteum of frontal sinus)
127
Explain pig paranasal sinuses
```
5 Pairs of paranasal sinuses
Maxillary sinus with 3 diverticula
Lacrimal
Sphenoid
Conchal
Frontal sinus
involves frontal and parietal bones
Large (up to 5 cm deep)
Difficult to stem pigs mechanically
```
128
Explain dog paranasal sinuses
Two basic Paris of sinuses
Maxillary
often called maxillary recess as communicates freely with nasal cavity
Carnassial tooth embedded in later wall of sinus
Frontal sinus = small and insignificant
129
Cat paranasal sinus
two basic pairs of sinus, similar to dog
Maxillary
0 can have sphenoid extension
P3 and P4 just under orbit therefore infection here can cause discharge and swelling in the eye
Frontal sinus
- blockage or infection of frontal sinus can be alleviated by flushing ethmoidal meatus via sinus
130
Explain the Nasopharynx
Air reaches here from the choanae(internal nares) to nasopharynx
chonanae are separated by vomer (dorsal to palatine bone)
131
Explain the Eustachian tubes
Nasopharynx is connect to middle ear via the auditory (Eustachian) tubes
supported by a cartilaginous trough open ventrally
Keeps middle ear at ambient pressure
In horse = ventrally to form large paired guttural pouches
132
Explain guttural pouches
paired, ventral invaginations of E tubes
Thin walled
Occupy space between base of cranium, atlas and pharynx
Lined with pseudostratificed columnar epithelium
Goblet cells present (mucous)
Guttural pouches sit over stylohhyoid bone which divides them into a small lateral and large medial portion
133
List blood vessel associated with guttural pouch walls
Blood vessels
external and internal carotid artiery
Maxillary artery and vein
Ventral cerebral and transverse facial veins
134
List nervous structures associated with guttural such walls
```
Facial CNVII
IX
X
XI
XII
cranial cervical ganaglion
```
135
List gland structures associated with guttural such walls
Salivary glands - parotid and submandibular
136
Drainage of guttural pouches
Each pouch communicates w nasopharynx via the silt- like pharyngeal orifice of auditory tube opens into nasopharynx
slit supported by cartilage
Opens durning grazing and swallowing
Fluid can accumulate whne block or excessive secretion
137
Surgical access to guttural pouch
Via Viborg’s triangle
lingo facial vein
Ramus of mandible
Tendon of sternocephalic muscle
138
Guttural pouch possible fx
selective cooling of brain
Blood to brain internal carotid artery
Allow loose attachment to pharynx to increase swallowing efficiency in long necked animals
139
Cardio-respiratory evolution
Major changes in cardiovascular system have accompanied changes in respiratory system
Over time it has become more efficient with 4 chambers and seperate pulmonary and systemic circulation
140
Cardio-respiratory evolution in fish
Gas exchange in gills
Requires flow through mouth and over membranes to allow gas exchange
Fish have 1 capillary bed before return to heart
Mammals have 2 capillary beds before return to heart
141
Cardio-respiratory evolution from fish to land
Lobe-finned fish were first to have both gills and lungs
- lungs evolved from single ventral out-pouching of gut
- then due to stability problems with ventral position in water, the lungs migrated to a dorsal position
142
Swim bladder in fish
In modern boney, ray-finned fish is a homolog of lungs
Some swim bladders retain connection with gut via pneumatic duct (trachea homolog)
Lost in most advanced fish, gas regulated by red body
143
Cardio-respiratory evolution in amphibians
Can respire though any moist well-vascularised mucous membrane (mouth, skin, primitive lung)
144
Cardio-respiratory evolution in amniotes
Amniotes = (reptiles, birds, mammals)
Have a distinct, thorax and neck
lungs further from thorax
Evolution of conducting airway and separation of conducting and respiratory components
145
Cardio-respiratory evolution in birds and mammals
Developed completely separate pulmonary circulation, 4 chamber heart, on functional aortic arch
146
Cardio-respiratory evolution of reptile heart
Septum only partly divides ventricle
| Vasculature still retains several aortic arch derivatives
147
Cardio-respiratory evolution of birds
different but very efficient system of pulmonary ventilation compared with mammals
System of air sacs
A flow through system
No gas exchange in air sacs
Air flows through lungs during both inspiration and expiration
Counter current blood flow system as air flows one way
(Very efficient at extracting O2)
