Thorax: Mediastinum & Heart Flashcards
Where is the anterior mediastinum?
Extends from behind sternum to the pericardium
WHat is located in the anteiror mediastinum?
- Fat
- Lymph nodes
- Thymus (central)
- Located in the anterior/superior mediastinum, anteior to pericaridal sac, all the way up to thyroid glad.
- **Lymphoid organ **
- Growns until puberty then gradually diminished in size become mostly replaced by fat over time .
- Requires good **blood supply. **
Thymus Gland
From above the first rib, down to the sternal angel and T4 above the periocardial sac
Superior Mediastinum
What are the contents of the superior mediastinum?
Retrosternally
- Thymus
- Great veins; brachiocephalic vein & SVC
What are the contents of the superior mediastinum?
**Intermediatly **
- Aortic arch & great branches
- Nerves (vagus, phrenic, sympathetic branches)
What are the contents of the superior mediastinum?
Pre-vertebrally
- Trachea
- Esophagus
- Left reccurent laryngeal nerves
- Thoracic Duct
- Lymphnodes
Some thing is lodged in the trachea in the thoracic level of T2, peircing anteriorly, what will it puncture?
How about a posterior puncture?
Right or left common carotid arterys anteiror
The esophagus posteior
The conduit, lots running up and down.
RUns posterior.
T5- T12
Posterior Mediastinum
Content of the posterior mediastinum?
- Thoracic Descending aorta
- Thoracic Duct
- Primary Bronchi
- Azygous system
- Esophagus
- ANS/Spalachic nevers
- Vagus nerve (sympathetic in posteriro)
Located in the posterior mediastinum, prevertebrally.
Esophagus
WHat are the 3 retrosternal (most superficial layer) great veins of the mediastinum?
- Left brachiocephalic
- RIght brachiocephalic
- Superior Vena cava
Venous RETURN to heart
Formed by the union of the right and left brachiocephalic veins
Superior Vena Cava
Formed by union of left internal jugular and subclavian veins
Left Brachiocephalic Vein
Arm head vein
Formed by union of right internal jugular and subclavian veins
Right Brachiocephalic Vein
Arm head vein
2nd layer, behind venous system, takes oxygenated blood out of LV and to the rest of the body
Aorta; aortic arch,
Anterior= ascending
Posterior= descending
Arterial branch coming off the ascending aorta, to the right side.
Unpaired.
Brachiocephalic Artery (trunk) SINGULAR
Higher into the neck, thr brachiocephalic trunk splits into 1. and 2. ?
- Right subclavian artery
- RIght common carotid artery
2 arterys coming directly off of the aortic arch and going to the left side?
- Left common carotid
- Left Subclavian artery
Thick fiborous connecting running out from the aortic arch and attaching down to the left pulmonary trunk.
Important landmark
Ligamentum Arteriosum
Where in the aortic arch connections is most suseptible to anuresyms?
The transtion from the aortic arch to the left subclavian artery.
The ____ nerve brancnes out once it reaches the aortic arch, and one of its branches loops under the aorta and up becoming what nerve?
Left Vagus nerve -> loops under and up to become the **reccurent laryngeal nerve **
Location T4-T12 All posterior innercostal arterys come off this. Peirces the diaphram at the T12 at what? What name after?
Thoracic Aorta (descending aorta) ; aortic hiatus -> Abdominal aorta
venous drainage of the thoracic cavity, highly variable system.
Azygous System of Veins
Vein on the right side the returns blood to the heart via the SVC.
Recieves blood from posteiror innercostal veins, hemi, acs. hemi.
Comes up and over the lung and into the SVC
Azygous Vein
2 Veins on the **left side **the returns blood to the azygous vein.
- Hemiazygous Vein
- Acessory Hemiazyous vein
The left inferior intercostal veins return blood where?
Hemiazygous Vein
The left superior intercostal veins return blood where?
Acessory hemiazygous vein
If im at T3/T4 and I perforate the esophagus on the lateral right side what structure will also be cut?
Azygous vein!
Lymph vessel returning lymp to the blood.
L2-3 all the way up to dump into venous angel (left jugular trunk & left subclavian vein )
Runs up spinal collum.
Thoracic Duct
Attached to L2-L3, hold the lymphatic fluid coming from the digestive system. Travles upward through thoracic duct!
Cisterna Chyli
What veins recieve lymph fluid from the thoraci duct?
Venous Angle
Left jugular vein & Left subclavian vein
Originates from the base of the skull and travles down
On the left side:
* runs down the side common carotid and subclavian, goes over the arch of the aorta , branches out (reccurent larygeal nerve) and then continues down along the esophagus, forming a plexus, and once it goes through the esophageal hiatus, it becomes the anterior vagal trunk.
On the right side:
* Crosses of over right subclavian artery after it has branches of the brachiocephalic trunk, nerve branches and it then loops down under sub. artery and up into larynx (reccurent larygneal nerve) and continues down along the esophagus, forming a plexus, and once it goes through the esophageal hiatus, it becomes the posterior vagal trunk.
Vagus Nerve (10)
Path of the left Vagus Nerve
On the left side:
* runs down the side common carotid and left subclavian, goes over the arch of the aorta , branches out down and under the arch of the aorta and back up (reccurent larygeal nerve) and then also continues down to the esophageal hiatus as anterior vagal trunk .
Path of right vagus nerve
On the right side:
* Crosses over right subclavian artery after it has branched off the brachiocephalic trunk, nerve branches and it then loops down under right subclavian artery and up into larynx (reccurent larygneal nerve) and also continues down to enter abdomen through the esophageal hiatus as posterior caval trunk
From a lateral view
Where does the right phrenic nerve go?
Pass on top of pericardium TIGHTLY. Outside of fibrous layer. Provides **sensory to fiboruus pericaridum. **
RUns lateral to the vertebral to bodies, most posterior in throrax. T1-L2.
Splanchi nerves come off and run down into the abdomen.
Sympathetic Chain
Unique nerves that carry pre-ganglionic GVE (motor) signals to the abdominal viscera. And** GVA (sensory) **
Splanchnic nerves
Posterior to the trachea, descending.
Traverses both superior and posterior mediastinum
Esophagus
What 3 structures compress the esophagus as it descends?
- Aortic Arch
- Left Main bronchus
- DIaphram
An aortic arch aneurysm (ballon out of vessle) can push posteriorly and constrict what?
Compress the esophagus!
An impingment on the left bronchus can causes what?
Compression of the esophagus!
Stenosis of the esophagyeal hiatus can causes what?
Impingment of the esophagus
The right and left vagus nerve run down the side of the esophagus, and start to form a mesh called:
spreading over the top of the esophagus and then when they get to the stomach they from _____
Esophagyeal plexus
Trunks
Runs posterior mediastinum but anterior to the esophagus, C6- T4/5, bifrucates into R/L main bronchus.
Trachea
Describe the structure of the trachea
C shaded cartilage rings, posterior wall facing the esophagus is smooth muscle. Allows for esophagus to push into the trachea.
Wider, Comes out of trachea much more vertically.
RIght Main Bronchus
narrower and takes more horizontal path
Left main bronchus
If we accidentally inhale some thing, what bronchus is the item more likely to go into left or right?
Right broncus! More vertical and wider!
Main bronchus divide into ____ which supply each lobe with air.
Lobar bronchi; secondary
Lobar (secondary) bronchi divides into what?
which supply bronchopulmonary segment (very sepcific)
Segmental bronchis (tertiary) which supply
Tiny arterys and veins that go to the bronchi
Bronchial artery and veins
Go **INTO the lungs **through the hilum with deoxygenated blood from the **heart from the right ventricle **
Trunk bifrucates ~T4/T5
Right and left.
Pulmonary Artery
Leave the lungs through the hilum with oxygenated blood and go to the heart, entering via the left atrium
Right and left 2 on each side.
Pulmonary Veins
Posterior to ascending aorita, SVC and upper right pulmonary vein
Anterior to right main bronchus
2.
Right Pulmonary Arterys
Anterior to the descending aorta, and left main bronchus.
1
Left Pulmonary Artery
2 on each side, both come into the left atrium carrying oxygenated blood from the lungs.
Superior & inferior
Pulmonary Veins
Bronchi and pulmonary arteries pair and branch in unison. Pulmonary veins arise from pulmonary capillaries and drain toward and then
course within the septa between adjacent segments.
Pulmonary vasculature
Fibroserous sac enclosing heart and roots of great vessels
Pericardium
Serous pericardium the is directly over the heart; epicardium.
Visceral pericardium
Middle layer, next to pericardium
Parietal Layer;
Fiborous layer of the pericardium, outer most.
FIborous pericardium
2 functions of the pericardium?
- Lubricated container for the heart
- Restricts movement of the heart
WHere is the pericardium attached?
- Anteriorly to the **sternum **via sternopericardial liagments
- Attached inferiorly to the central tendon of the diaprham
What innervates the pericardium?
The phrenic nerve that passes by very closely on the left and right. Supplies somatic sensation (pain)
Provide blood supply to the fiborous pericardium
Pericardiacophrenic vessels
Where does the heart sit?
- Behind the sternum
- Base is posterior
- Right side 3-6th costal cartilages
- Left side 2nd-
- Apex at mid clavicular line at 5th innercostal space (L) anterior
Path of deoxygenaated blood via pulmonary arterys to lung
Pulmonary Circuit
Path of Oxygenated blood via the pulmonary veins to the heart and then out to the rest of the body.
Systemic Circuit
Outermost simple squamous epithelium + fatty layer of the heart
Epicardium
Cardiac musle cells. Thickest layer.
Myocardium
Areolar connective tisssue + endothelium
Endocardium
Bring in deoxygenated blood from the body, upper half, into the right atrium
& Brings in Deox blood from lower half of body
SVC & IVC
Largest blood vesses, takes oxygenated blood from the left atrium and delivers it to the rest of the body.
Ascending aorta
Takes deoxygenated bood from the heart and delivers it to the lungs for oxygenation
Pulmonary arterys
Recieves DeOX blood from the SVC and IVC & Coronary Sinus (blood OF heart)
Pecitante muscle (rough outer surface)
Closed FOssa ovalis; remanent of embryonic foramen ovale.
Right atrium
Recieves deOX blood from the right atrium via the Triscuspid (RA) valve and then pushes it out the Pulmonary valve to the **pulmonary arteries **and to the lungs
Forms large part of sternocostal surface of the heart
Right Ventricle
Recives **oxygenated blood **from the lungs via the ** 4 pulmonary veins. **
Forms anatomical base of the heart. Little pectinate muscle (very smooth)
Left Atrium
Recieves oxygenated blood from the Left atrium via the Bicsupid (LA) valves, then pushes it out the aortic semi-lunar valve and to the rest of the body.
Powerful expulsion pump; sustains flow of high pressure circulation
Left ventricle
3 leaflets, transfers blood from right atrium to right ventricle
Left of sternum; 5 innercostal space
Chordae tendinae & papillary muscles
Tricuspid/ Right arterioventricular valve
2 leaflets, transfers blood from left atrium to left ventricle
Over apex of the heart; left 5th innercostalspace at midclavicular line
Chordae tendinae & papillary muscles, rough trabeculae carnea.
Bicuspid/ Left arterioventricular valve
Attaches to the pulmonary trunk in the right ventricle
left of the sternum at 2nd innercostal space
Pulmonary Valve
Attaches to the left ventricle to the aorta
Right of the sternum 2nd innercostal space
Aortic Valve
What are the low pressure vessels in the body?
Veins
What are the high pressure vessles in the body?
Arteries
Tendonous like structures that help anchor valves, and muscles that become part of wall of the heart.
Allows Unidirectional flow.
Chordae Tendinae & Papillary Muscles
surrounding atrioventricular, aortic, and pulmonary orifices (can calcify), valves attach to this
Fibrous rings
Inside the right ventricle, part of conducting system runs there.
Septomarginal Trabeculae
Smooth muscle on wall near the pulmonary trunk in the right ventricle.
Infundibulum (Conus arteriosus)
Rough muslces on the wall of the right ventricle
Trabecule Carnea
Explain cardiac muscle orientation and its significance
Both superficial and deep muscles, spiral and overlap and diffrent angles.
Complex wrining motion! Helps blood flow the most efficently for cardiac conducting system
Supply blood to the heart 2 within the aortic sinus.
Right and Left.
Coronary Arterys
Within the aortic sinus, there are 2 ____. The relaxation of the aorta (elastic artery) blood rushes into these. Valves of aorta closed.
Supply blood to the heart!
Coronary Arterys
Crosses btwn the RA and RV and supplys blood to both
Right Coronary Artery
What branch of Right coronary artery?
Helps supply the RA and partially LA. Also works in the conducting system of the heart
Sino-Artitial Nodal Branch
What branch of Right coronary artery?
Goes down the right ventricle, supplys blood to it
Marginal Branch
What branch of Right coronary artery?
Loops back around to the posteior aspect of the heart. Terminal Branch. Supplys RV
Posterior interventricular branch
Which coronary artery supplys blood to the majority of the hearts conducting system?
SA node, Septomarginal ridge, etc
Right Coronary artery
A blockage of the right coronary artery can lead to long lasting effects & impariment to what?
The conducting system of the heart.
Large artery supplying blood for the heart, to the Majority of the LV and LA. Comes from aortic sinus.
Left Coronary Artery
What branch of left coronary artery?
Biggest branch of left coronary artery, runs btwn RV and LV. Supplys majority of blood to LV
Anterior interventricular branch
Blockages to the Anterior interventricular branch of the left coronary artery can result in what?
Cutting off the majority of the blood supply to the LV= widow maker.
Branches of the Anterior interventricular branch of left coronary that spread over LV
Diagonal branches
What branch of left coronary artery?
Loops around the heart posteriorly and supplys posterior and lateral walls of the LV
Circumflex Branch
Branches off the circumflex branch and also supplys posterior of LV
Left Marginal Branch
What Cardiac Vein?
Brings blood back into the right atrium
Coronary Sinus
What cardiac Vein?
Starts anteiror then loops back posterior going into the coronary sinus
Great cardiac vein
What valve? just left of sternum at 5th intercostal space
Tricuspid LA
