Lecture 31 - Thorax, Mediastinum, And Body Flashcards
What is the ventral body cavity made up of?
Body cavity -> Ventral (Front) = * thoracic (holds heart and lungs), *Abs = hold stomach, * Pelvic (hold urinary and reproductive system)
Dorsal (Back) = *cranial (brain) & Vertebral ( Spin/ spinal cord
What are the membranes in the ventral body, its function and show an example?
- The viscera membranes is a lining around body cavities that protects damage form organs. It consist of :
- Parietal layer (hollow layer) = the outer layer
- Visceral layer = inner lining and directly covers the surface for individual organs
Think of a fist inside a balloon:
- The parietal lining = The outside of the balloon
- The Serous fluid = the air inside
- The Visceral lining = the skin of the fist
- The fist = the heart
What is the serous membrane and where is it located?
The serous membrane is based on where its at
- Pluera = lungs
- Pericardium = heart
- Peritoneum = anything in the stomach
What is the thorax and what is it made up of?
The thorax is chest area and it is made up of these:
- a wall
- 2 pleural cavities = lungs
- lungs = inside pleural cavity
- mediastinum = separates lungs from each other and found medially
What is the function of the thorax?
- Houses and protects
- heart, lungs, and great vessels - Place for structure passing from the neck to the stomach
- Helps in breathing - 2 lungs
- Support for upper limbs = upper body attached to axial skeleton form sternoclavicular joint
What are the muscles of the thorax?
From inner to outer =
- Innermost intercostal
Internal intercostal
External intercostal
- The inner ones help with exhaling by compressing the ribs
- The external helps with inhaling by spreading the ribs out
What are the differences in muscle striations of the intercostal muscle?
The inner ones have the same = point diagonally to the right
The external points diagonally to the left
What does the diaphragm consist of ?
- The diaphragm is a tunnel that runs from the neck to the stomach
- It consist of 3 openings =
1. Inferior vena cava (biggest vein / goes up form stomach to heart)
2. Esophogus
3. Aorta
What is the difference between artery and veins and what is the aortic hiatus?
- Arteries carry blood away from the heart
- Veins carry blood to the heart
- The aortic hiatus runs from the heart tot he lower limbs and stomach
What are the different arteries of the thoracic wall IMPORTANT , what are the veins, and what does intercostal region mean?
There are 4 different arteries
- Internal. Thoracic artery =
- Branches off subclavian artery
- towards the middle and runs down / parallel to sternum - Anterior intercostal artery =
- in front of and in between spaces of ribs - Musculophrenic artery =
- comes off of internal thoracic artery (at the bottom) and located in the costal region - Posterior intercostal artery =
- comes off of the aorta from the back
- the veins have the same names as these arteries, but with them being called veins
- intercostal region means the spaces between ribs
Discuss the venous drainage of the thorax
Most of the thorax drains in this order
- Thoracic veins -> azygos vein -> superior vena cava -> heart
- The azygos veins drains into a bigger vein = superior vena cava
Think of this order =
Small rivers -> big rivers - > to ocean (the heart)
Discuss the venous drainage of the thorax again:
The thoracic veins drain into the azygos vein which then runs up to the superior vena cava and then the heart
What is the mediastinum and what does consist of?
- The mediastinum is the space between the lungs and the heart - it seperates the right and left lung
- It divides into SM = great vessels (which carry blood to and form the heart), AM = thymus gland, MM = heart, and PM
- It extends from the sternum, to vertebrae and Superior thoracic aperture to diaphragm
