The Thorax Flashcards
Why can you use S/C infusion to correct dehydration?
Because the skin is loosely attached, it’s suitable for large volume of fluid
Position of the shoulder joint
Lies opposite of the ventral end of the 1st rib
What is the site for bone marrow biopsies?
The sternum, long bones and iliac crest
What is the common site for surgically entering the thoracic cavity?
The left 4th intercostal space
Pneumothorax
Capula pleurae injured at the base of the neck and causes lung collapse
Line of pleural reflection
The junction between costal and diaphragmatic pleurae
From 8th-9th costochondral junction to last rib
Thoracocentesis of the dog
Aspiration of fluid from pleural cavity
7th or 8th intercostal space (costodiaphragmatic recess)
What space is for the cat for thoracocentesis?
8th intercostal space
Clinical significance of the lung projection on the lateral thoracic wall?
A triangular field for auscultation or percussion
Triangular field of lung projection
- Cranial: 5th rib
- Dorsal: lateral margin of the back muscles
- Basal/ caudoventral: costocondral junction of the 6th rib to the 11th rib
Diaphragmatic hernia
Common due to trauma of traffic accidents
Chylothorax
Due to rupture of the thoracic duct
Extra fluid in the pleural space will affect the ability of a lung to fill with air
_______% of the air flow is attributed to the diaphragm
70%
What is normal respiration always accompanied by?
Contraction of the diaphragm
What are the 2 parts of the respiratory system?
Non-collapsible tubes for air conduction
Lungs for gas exchange
What does the tubes system do?
Expels the CO2 upon expiration and collects oxygen upon inspiration
How is the respiratory system divided?
Upper respiratory system: cranial to the thoracic inlet
Lower respiratory system: caudal to the thoracic inlet
What are the body parts of the upper respiratory system?
Nose
Nasal Cavities
Nasopharynx
Common pharynx
larynx
Trachea
Nasal Cavities
Bony folds covered with mucous membranes (conchae) that cause turbulence in the inspired air
Significance of the nasal cavities?
So the air will contact its mucous membranes that filter and regulate its hydration and temperature
Panting
Mouth breathing
Helps cool the body
Also done when suffering from a disease
How do the nasal cavities connect to the nasopharynx?
The internal nares (choanae)
What is the function of the larynx?
Acts as the chief organ of phonation and serves as the gateway to the trachea
What is the trachea made of?
35 incomplete rings of hyaline cartilage
When does the trachea contract?
In response to vagal nerve fibers within the recurrent laryngeal nerves
What is the inner aspect of the tracheal rings lined with?
Ciliated pseudostratified columnar and goblet cells
How is the thoracic inlet bounded?
Dorsally: first thoracic vertebra
Ventrally: manubrium
Collaterally: the first ribs
What body parts does the lower respiratory system have?
Trachea
Bronchi
Lungs
How is each lung separated from each other?
The mediastinum
What are the two branches of the bronchi?
Left and right principal bronchi
How does the left principal bronchi divide?
Cranial and caudal lobar bronchi
How does the right principal bronchus divide?
Cranial, middle, caudal and accessory
Bronchioles
Airways 1 diameter or less
Each ones supplies a lobule of lung
Glandular and non-cartilaginous
Alveoli in walls
Aveoli
Smallest collective unit of lung tissue
Where does gas exchange occur?
Respiratory bronchioles
Alveolar ducts
Alveolar sac
Alveoli
What do the left and right pulmonary arteries do?
Feed the lungs with unoxygenated blood being sent there for gas exchange
What does the pulmonary veins do at the level of the capillary network?
Return the oxygen rich blood, draining via large branches into the left atrium
Position of lobar pulmonary arteries and veins in relation to the lobar bronchi
Cranial or or lateral (arteries)
Ventral and medial (veins)
When are the pulmonary arteries and veins individually located, dissected, ligated and severed?
During pulmonary lobectomy
How is nutrients supplied to the lung?
Bronchial arteries from the bronchoesophageal arteries
Bronchial lymph center
Main lymph node center concerned with bronchi and lungs
Tracheobronchial and pulmonary lymph nodes and associated ducts
Lymphatic drainage from the lungs
Filters through pulmonary –> tracheobronchial lymph nodes –> thoracic duct or sternal lymph nodes –> right lymphatic duct
How is motor innervation to the lung?
Autonomic
What do the sympatheitc nerves cause?
Bronchodilation via B2 receptors
What do parasympathetic terminals of the vagus cause?
Bronchodilation via muscarinic cholinergic receptors
What do sensory fibers of the vagus nerve do?
Give stretch receptors in the bronchi and bronchioles to inhibit further inspiration and prevent overstretching of the lung
Coelom
Large cavity within the trunk
Divided into cranial thoracic, caudal abdominal, and pelvic cavities
Normally empty
What is the cranial thoracic cavity of the coelum lined with?
Endothroacic fascia
What is the caudal abdominal and pelvic cavities of the coelom lined with?
Transversalis fascia
Pleura
Thoracic cavity containing different body organs within the bony thorax
Stretch receptors for regulation of respiration
2 pleural cavities
Parietal pleura
Serous layer lining the walls of cavities
Costal (ribs), diaphragmatic (diaphragm) and mediastinal (sternum)
Visceral pleura
Pleura that covers the lungs
Also called pulmonary
Pulmonary ligament
Formed by connecting pleura
In thoracic surgery, this must be cut to reflect the caudal lobe cranially
Where is negative pressure maintained?
Within the thoracic cavity outside the lung
As muscles expand the body thorax, this causes the pressure to drop
Muscles of inspiration
Expanding the thoracic cavity
Diaphragm, external intercostal, scalenus, rectus thoracic, serratus ventralis, serratus dorsalis cranialis
What muscles decrease the thoracic capacity?
Ex. abdominal oblique
In. abdominal oblique
Transversus abdominis
Rectus abdominis
What muscles decrease the thoracic cavity?
Internal intercostal
Rectus abdominis
What are the 3 functions of the respiratory system?
Ventilation (external)
Gas exchange (external)
Oxygen utilization
What are the soft tissues of the thoracic inlet?
Trachea
Great vessels
Nerves
Esophagus
Lymph nodes
What is contained within the bony thorax?
13 thoracic vertebra dorsally
13 pairs of ribs (costal arch)
13th rib (floating rib)
8 sternebrae
What are the functions of the bony thorax?
Protection
RBC production by sternum and ribs
Expiration
Thoracic outlet
Last thoracic vertebra
Last ribs (10-13)
Coastal arch and xiphpoid sternum
Diaphragm separates the thoracic and abdominal cavities
What are the intercostal arteries?
Two sets: dorsal and ventral intercostal arteries (12 on each side)
Where does the dorsal intercostal artery come from?
Aorta
Where does the ventral intercostal artery come from?
Internal thoracic artery
How do the intercostal veins run?
Dorsal to azygous vein
Ventral to the internal thoracic vein
How is the CNS connected to the body?
By peripheral nerves (sensory and motor)
What is a typical spinal nerve composed of?
Dorsal root (sensory)- spinal ganglion, afferent fibers
Ventral root (motor)- efferent and autonomous fibers
What forms the spinal nerve?
Dorsal and ventral root within the vertebral canal
What is the function of the coelom?
Produce adhesions among organs to move freely relative to one another
Pericardium
Pericardial cavity
Within the mediastinum of the thoracic cavity
Visceral pericardium= epicardium
Peritoneum
Abdominal cavity
Clinical consideration of the pleura
Hemothorax
Hydrothorax
Pyothorax
Pneaumothorax
Chylothorax
Clinical consideration of the cardiac notch
Space between the cr, and medial node of the right lung
Where you inject meds during euthanasia
Cardiac puntcure
What is the lung in greek and latin?
Pulmo= greek
pneumon = latin
Pulmonitis and pneumonia
Inflammation of the lung
Internal gas exchange
Exchange of gas between blood and other tissues
