Pleural Cavity, Mediastinum, Trachea, Lungs, Diaphragm

Question 1

______ is the removal of pleural fluid. What is the clinical relevance of this?

Answer 1

• Thoracocentesis
• A needle is inserted into the costodiaphragmatic recess at the 7th or 8th intercostal space and ventral to the costochondral junction

Question 2

______ is an invasive procedure that involves using a needle and catheter to remove fluid (called a pericardial effusion) from the sac around the heart (the pericardium).

Answer 2

Pericardiocentesis

Question 3

The _____ ______ is the oval opening into the cranial part of the thoracic cavity. What are its boundaries?

Answer 3

-Thoracic Inlet
-Bilaterally: The first pair of ribs
Dorsally: The first thoracic vertebra
Ventrally: The manubrim of the sternum

Question 4

What organs traverse the aperture of the thoracic inlet?

Answer 4

1. Trachea
2. Espohagus
3. Vagosympathetic nerve trunks
4. Recurrent laryngeal nerves
5. Phrenic nerves
6. First two thoracic spinal nerves
7. Several vessels

Question 5

The walls of the ____ ____ are formed by the muscles, bones, and ligaments of the thoracic wall. It is bounded by the subserous ______ _____.

Answer 5

• Thoracic cavity

- Endothoracic fascia

Question 6

What is endothoracic fascia?

Answer 6

Areolar tissue that attaches the muscles, ligaments, and bones to the underlying costal and diaphragmatic pleurae

Question 7

____ are serous membranes that line the wall of the thorax and cover the lungs. They form right and left sacs that enclose the ____ ____.

Answer 7

• Pleura

- Pleural cavities

Question 8

What are the two kinds of pleura?

Answer 8

1. Parietal

2. Pulmonary (visceral)

Question 9

____ pleura for the walls of pleural cavities. What are the three parts?

Answer 9

• Parietal
  1. Costal
  2. Mediastinal
  3. Diaphragmatic

Question 10

The _____ pleurae is the cranial extent of the parietal pleura in the pleural cavity extending through the thoracic inlet. Which side is bigger?

Answer 10

• Cupula

- Left

Question 11

What is the clinical relevance of the cupula pleurae?

Answer 11

It can be mistakenly opened during caudal neck surgery or neck injury causing pneumothorax, which is air in the pleural cavity

Question 12

The visceral portion of the pleura is called the ____ pleura. What does it adhere to?

Answer 12

• Pulmonary

- Adheres tightly to the surface of the lungs and follows all of their irregularity

Question 13

What are pleural recesses and why do they occur?

Answer 13

• They are spaces where regions of parietal pleura are directly applied to each other
• This occurs because the parietal pleura forming the pleural sac is larger than the space the lungs occupy, or the pulmonary pleura

Question 14

What are the two pleural recesses?

Answer 14

1. Costodiaphragmatic

2. Costomediastinal

Question 15

The _____ is the space between the right and left pleural sacs.

Answer 15

Mediastinum

Question 16

What organs are enclosed in the mediastinum?

Answer 16

1. Thymus
2. Heart
3. Aorta
4. Trachea
5. Esophagus
6. Vagus nerves
7. Other nerves and vessels

Question 17

The mediastinum is divided into three parts by the heart. What are they?

Answer 17

1. Cranial mediastinum
2. Middle mediastinum (occupied by the heart)
3. Caudal mediastinum

Question 18

The roots of the lungs divide the mediastinum into two parts. What are they?

Answer 18

1. Dorsal mediastinum

2. Ventral mediastinum

Question 19

What is unique about the mediastinal pleura in the dog, horse, and sheep? What is the clinical relevance of this?

Answer 19

-The mediastinal pleura has fenestrations or perforations. Because of these holes, if pneumothorax occurs, it is most often bilateral.

Question 20

What are the two parts of the respiratory tract? What is in each part?

Answer 20

1. Upper respiratory: Respiratory structures between the nares and lungs including the nasal cavity, pharynx, larynx, and trachea
2. Lower respiratory: Lungs

Question 21

What is the main function of the upper respiratory tract, and what are its other functions?

Answer 21

• Main: conducting air to and from the lungs

- Other: modification of inspired air, thermoregulation, defense against harmful substances, olfaction

Question 22

What is the main function of the lower respiratory tract? Where does this function occur?

Answer 22

• Main function: Gas exchange- exchange of oxygen from the atmosphere with carbon dioxide from the blood
• Occurs in respiratory bronchioles, alveolar ducts, and alveoli

Question 23

What are the two parts of the trachea? Where does the trachea start and end?

Answer 23

1. Cervical part- starts from the cricoid cartilage of the larynx
2. Thoracic part- ends at the bronchi

Question 24

The trachea enters the thoracic cavity to the ____ of the esophagus, then turns ____ to the esophagus. It ends at the ____ of the ____.

Answer 24

• Right
• Ventral
• Base

Question 25

Describe the structure of the trachea.

Answer 25

- Tracheal cartilage made of hyaline cartilage composed of 35 incomplete rings - Tracheal muscle made of smooth muscle that connects the tracheal cartilage dorsally - Annular ligaments of the trachea made of fibroelastic tissue that connects consecutive tracheal rings

Question 26

At what vertebra does tracheal bifurcation occur? What does it bifurcate into? Is it dorsal or ventral to the base of the heart?

Answer 26

- T4 to T5 - Left and right primary bronchi - Dorsal

Question 27

The _____ ____ is the crest inside the bifurcation of the trachea.

Answer 27

Tracheal carina

Question 28

The lungs serve a _____ function in the mechanical act of breathing or respiration. What does this mean?

Answer 28

- Passive | - It expands according to the volume of the thoracic cavity

Question 29

Each lung contains a concave ____ that lies adjacent to the diaphragm and an ____ that lies in the thoracic inlet.

Answer 29

- Base | - Apex

Question 30

What are the four surfaces of the lungs and where are they located?

Answer 30

1. Costal- lateral, against the ribs 2. mediastinal- face the opposite lung 3. Diaphragmatic- Against the diaphragm 4. Interlobar- Contact adjacent lobes of the same lung

Question 31

What are the lobes and parts of the lobes of the left lung?

Answer 31

1. Cranial lobe - cranial part - caudal part 2. Caudal lobe

Question 32

What are the lobes of the right lung?

Answer 32

1. Cranial lobe 2. Middle lobe 3. Caudal lobe 4. Accessory lobe

Question 33

From the right and left sides, how can you see the accessory lobe of the right lung?

Answer 33

- Left side: Seen through the caudal mediastinum | - Right side: Seen through the plica venae cavae

Question 34

The _____ ____ ___ is a fold of pleura from the right caudal mediastinum that surrounds the caudal vena cava.

Answer 34

Plica venae cavae

Question 35

The ____ lobe of the right lung passes dorsal to the caudal vena cava.

Answer 35

accessory

Question 36

What is the cardiac notch, where is it located, and what is its clinical relevance?

Answer 36

- It is a tissue between the cranial and middle lobes of the right lung, located at the 4th and 5th intercostal spaces. - It exposes the right ventricle of the heart so that a cardia puncture can be performed here

Question 37

True or False: Both the left and right lungs have a cardiac notch, but it is not obvious on the left lung.

Answer 37

True

Question 38

What is the duel blood supply of the lungs and what are their functions?

Answer 38

- Pulmonary vessels that function as the lungs and perform gas exchange - Bronchial vessels that supply nutrients for the lungs by providing a regular systemic blood supply to the lower respiratory tract

Question 39

Pulmonary vessels transport ____ blood to the lungs and return ____ blood from the lungs.

Answer 39

- Deoxygenated | - Oxygenated

Question 40

What is the path of blood flow through pulmonary vessels?

Answer 40

``` Deoxygenated blood in the right ventricle: 1. pulmonary trunk 2. Left and right pulmonary arteries 3. Pulmonary veins Left atrium ```

Question 41

What is the path of blood flow through the bronchial vessels to supply the lungs with blood?

Answer 41

Left ventricle--> aorta--> 1. Right 5th or 6th intercostal artery 2. Bronchoesophageal arteries 3. Bronchial arteries

Question 42

The _____ of the lung are the area where vessels and bronchi enter the lungs.

Answer 42

Hilus

Question 43

The ____ of the lung is the aggregation of structures which enter the lungs.

Answer 43

Root

Question 44

The ______ is a musculotendious plate between the thoracic and abdominal cavities. What are its functions and how is it innervated?

Answer 44

- Diaphragm - Functions: aids in respiration, separates the thoracic and abdominal cavities - Nerve supply: Right and left phrenic nerves

Question 45

What are the four parts of the diaphragm?

Answer 45

- Central tendon - Sternal part - Costal part - Lumbar part (Right crus and left crus)

Question 46

There are three openings in the diaphragm that serve as a passage of structures from the thoracic to abdominal cavities. What are they and what passes through each?

Answer 46

1. Aortic hiatus (aorta, azygos vein, thoracic duct) 2. Esophageal hiatus (esophagus and vagal nerve trunks) 3. Foramen vena cava (caudal vena cava)

Question 47

Where can lung auscultation and percussion be performed?

Answer 47

Triangular area of auscultation and percussion - Cranial: triceps and teres major muscliest the 5th rib - Dorsal: Back muscles at ribs 5-11 - Basal Border (caudoventral)- 6th rib at the costochondral junction, to mid 8th rib, to dorsal 11th rib