chest wall and the anatomy of ventilation

Question 1

how many joints does ribs articulate with vertebrae and what are these joints called

Answer 1

• articulates at 2 distinct joints
• known as costal joint
• for typical ribs head of the rib articulates with the inferior costal facet of the numerically corresponding vertebrae as well as the superior costal facet of the superior vertebrae. Also a joint between the rib and the transverse costal facet (costotransverse joint)
• for atypical ribs the head of the rib only articulates with the numerically corresponding vertebrae not also with the one above it

Question 2

what does auscultation asses

Answer 2

• air flow in lungs

Question 3

what is the aim of percussion of the thorax

Answer 3

• to detect sounds in lungs and ether the lungs are filled e.g. with air, fluid solid
• air (resonant sound)
• fluid (dull sound)
• solid (flat sound)

Question 4

how is the thoracic cavity divided

Answer 4

• pleural cavity- contais left and right lung
• mediastinum- contains the heart, trachea, oesophagus, blood vessels, nerves and is found between the two pleural cavities

Question 5

what is the anatomy of the pleural cavity and the two layers plus what is the role of the pleural cavity

Answer 5

• parietal pleura lines the thoracic wall
• visceral pleura lines the lungs
• pleural cavity found between the two layers filled with fluid
• acts as a lubricant and provided surface tension which prevents lungs rom collapsing

Question 6

how is the lungs positioned in thorax

Answer 6

• posteriorly exceeds just above the clavicle and goes all the way down to 10th rib, pleura can reach 12th rib
• anteriorly goes down to 6th ribcage and pleura to 7th

Question 7

what muscle is the diaphragm made of and what nerves stimulate the diaphragm

Answer 7

• skeletal striated muscle
• innervated by phrenic nerve either via the somatic nervous system or autonomic nervous system

Question 8

what are the three openings of the diaphragm

Answer 8

• caval opening within the central tendon which the inferior vena cava and branches of phrenic nerves pass
• oesophagus opening (through muscular part) which the oesophagus passes, left and right vagus nerves and lymphatic vessels
• aortic opening through tendinous arch which the aorta, azygos vein and thoracic duct pass

Question 9

where does the intercostal muscles occupy and the three layers of the intercostal muscles

Answer 9

• occupy the intercostal spaces
• three layers which include the external intercostal, inner intercostal and innermost intercostal
• innervated by intercostal nerves
• blood supply is intercostal veins and intercostal arteries

Question 10

what is the artery supply of the intercostal muscles and where do the intercostal arteries arise from

Answer 10

• posterior and anterior intercostal arteries
• anterior intercostal arteries arises from internal thoracic artery which arises from subclavian arteries
• posterior intercostal arteries arise from either the supreme intercostal arteries or the thoracic aorta

Question 11

what is the venous system of the intercostals and what veins do they drain into

Answer 11

• posterior and anterior intercostal veins
• anterior intercostal veins drain into internal thoracic vein
• posterior intercostal veins drain into azygos system which eventually drains into superior vena cava

Question 12

what does herpes zoster infect

Answer 12

• reactivation known as shingle
• found in spinal ganglion
• affect a single dermatome

Question 13

what lymph nodes does the lymphatics of the chest wall and parts of the mediastinum drain into

Answer 13

• paravertebral nodes
• parasternal nodes
• paramammary nodes
• these than drain into either the right lymphatic duct or thoracic duct

Question 14

where does the thoracic duct/ right lymphatic duct drain lymph into the venous system

Answer 14

• junction between internal jugular and subclavian vein

Question 15

where is the veins, arteries and nerves in the intercostal muscles

Answer 15

• in the costal groove
• order VAN (top to bottom)
• between internal intercostal muscle and inner most intercostal muscle

Question 16

what muscles are used for forced inhalation

Answer 16

• as well as the contraction of diaphragm and external intercostal muscles during forced inhalation accessory muscles such as the pectorals and sternocleidomastoid muscles contract

Question 17

what muscles contract during forced exhalation

Answer 17

• abdominal wall muscles
• internal intercostal muscles

Question 18

what are the anatomical structures of the breast

Answer 18

• outer surface consists of the nipple and areola (pigmented area surrounding the nipple)
• subcutaneous tissue found just under the skin which is made of connective tissue (superficial fascia), fat and blood vessels
• mammary glands
• lactiferous ducts and sinus
• stroma- more connective tissue which is more deeper than subcutaneous tissue and surrounds the mammary glands
• pectoral fasica
• pectorals major
• clavipectoral fasica
• pectorals minor
  -retromamary space (space between pectoral fascia and deep layer of superficial fascia)

Question 19

how is the mammary glands divided in breast

Answer 19

• divided into lobes, which divide into lobules
• alveoli found at end of lobules
• alveoli site where milk is produced
• lactiferous ducts drain milk from alveoli to nipple
• lactiferous sinus stores the milk/ acts as a reserve just before it enters/leaves the nipple

Question 20

where is the rib in terms of rib level

Answer 20

• between 3rd and 7th rib
• nipple aligned with 4th rib
  -anchored by suspensory ligaments

Question 21

where does 75% of lymph in the breast drain into

Answer 21

axillary lymph nodes via the anterior pectoral lymph node

Question 22

where do majority of cancers develop

Answer 22

upper outer quadrant due to large amount of glandular tissue

Question 23

how does cancer in breast spread

Answer 23

• along lymph passages
• typical spread is superior and laterally to axillary lymph passages via anterior pectoral lymph nodes