Topographical Anatomy of Ventral Neck + Thoracic Cavity

Question 1

what is the trachea

Answer 1

flexible/non-collapsible tube

Question 2

where does the trachea extend

Answer 2

cricoid cartilage (laynx) to the lungs (within the thoracic cavity)

Question 3

where does the trachea lie

Answer 3

approx ventral and medial

Question 4

what is the esophagus position relative to trachea

Answer 4

changes –> dorsal then to the left of the trachea at thoracic inlet

Question 5

where does the trachea pass

Answer 5

through the thoracic inlet

splits into left and right principle bronchus above base of heart (~T5)

each bronchus enters the root of each lung

Question 6

what is the wall of the trachea composed of

Answer 6

1. mucosa: resp epithelium and submucosal glands
2. fibro-cartilaginous layer
3. adventitia (neck) or serosa (thorax)

Question 7

what are the functions of hyaline cartilage rings

Answer 7

incomplete –> fail to meet dorsally

space is occupied by tracheal muscle –> allows free ends of cartilage to slightly allow the airways to dilate somewhat, more air into lower resp

Question 8

histology of trachea

Answer 8

Question 9

histology of trachea

Answer 9

Question 10

identify the structures

Answer 10

11. Oesophagus
12. Sternothyrohyoid mm
13. Sternocephalic mm
14. External jugular vein
15. Common carotid artery,

vagosymphathetic trunk

(internal jugular vein) within

Carotid sheath;

Recurrent laryngeal n.- out with sheath

15. Superficial cervical lymph nodes

Question 11

what contains the vagus nerve

Answer 11

carotid sheath –> contains vagus nerve –> moves through into different body cavities innervates intrinsic muscles of larynx sympathetic fibres travels upwards to innervate structures of the head of running alongside –> recurrent

Question 12

what structures are associated with cervical trachea

Answer 12

1. cricothyroid muscles and larynx
2. thyroid + parathyroid glands
3. carotid sheath: common carotid artery, vagosympathetic trunk (internal jugular vein)
4. recurrent laryngeal nerve: lies out with the carotid sheath (independent)

Question 13

what is the blood supply to the trachea

Answer 13

branch of common carotid artery (neck)

broncheoesophageal artery (thorax)

satellite veins

Question 14

what is the nerve supply to the trachea

Answer 14

vagus and recurrent laryngeal nerve

sympathetic trunk and middle cervical ganglion

Question 15

what are the clinical considerations to the trachea

Answer 15

1. tracheal collapse: cervicothoracic region (inherited or acquired degeneration)
2. tracheal diameter smaller in brachiocephalic breeds

Question 16

what are theses structures associated with the trachea

Answer 16

Question 17

what are the structures

Answer 17

Question 18

what are the boundaries of the thoracic cavity

Answer 18

1. cranial: thoracic inlet
2. dorsal: thoracic vertebrae, dorsal parts of the ribs and the longus colli muscle
3. lateral: the ribs, costal cartilages, and intercostal muscles
4. ventral: sternum and transverse thoracis muscle
5. caudal: diaphragm

Question 19

what are the structures 1

Answer 19

1. right auricle
2. right ventricle
3. left ventricle
4. left atrium
5. aorta
6. trachea

Question 20

what are the structures

Answer 20

2. right ventricle
3. left ventricle
4. right atrium
5. pulmonary trunk

Question 21

what are the features of feline thoracic cavity n

Answer 21

narrower rostrally and broader caudally

Question 22

what are the structures shown

Answer 22

Question 23

what is each lung invested in and what else does it cover

Answer 23

serous membrane –> pleura

which also lines the corresponding half of the thoracic cavity

Question 24

where do the pleural membranes sit

Answer 24

the space between the right and left sacs forms the mediastinum

Question 25

what is the membrane the lines the lung directly

Answer 25

visceral or pulmonary pleura

Question 26

what does the parietal pleura line

Answer 26

mediastinum

diaphragm

thoracic wall

Question 27

what is the pleural cavity filled with

Answer 27

pleural fluid

Question 28

what is the mediastinum

Answer 28

midline reflection of each pleural sac –> mediastinum

Question 29

what are the organs and structures that lie within the mediastinum

Answer 29

1. heart (within pericardial sac)
2. trachea
3. esophagus
4. thymus
5. great vessels and nerves (except the caudal vena cava, lies slightly right and travels within own pleural reflection)
6. thoracic duct and lymph nodes

Question 30

what are the organs and structures that lie outwith the mediastinum

Answer 30

1. lungs (within pleural sacs)
2. caudal vena cava (plus right phrenic nerve caudal to the heart) –> visible right lateral view

Question 31

what are these structures and what view is this

Answer 31

dorsal view