thoracic cavities
includes left and right pulmonardy cavities and a central mediastinum, boundaries are superior thoracic aperture (composed of T1, 1st set of ribs and superior boarder of manubrium), inferior thoracic aperture (bounded diaphragm), and thoracic walls)
mediastinum
compartment between the two pulmonary caveties, border between superior and posterior and anterior mediastinum is between T4 and 5 to the sternal angle
superior mediastinum
Thymus, R&L brachiocephalic v, superior vena cava, arch of aorta and br, trachea, esophagus, phrenic nerves, vagus n, L recurrent br of L vagus n, thoracic duct, other n vessels and lymphatics
anterior mediastinum
Thymus, lymph nodes, sternopericardial ligaments
posterior mediastinum
Esophagus, trachea, thoracic aorta, azygous v, thoracic duct and nodes, sympathetic trunk, thoracic lymph nodes
middle mediastinum
within the pericardium, includes heart, origins of great vessels, nerves and smaller vessels
lines of parietal pleural reflection
relatively abrupt lines where parietal pleura changes directions as it passes from one wall of pleural cavity to another, include costodiaphragmatic, costomediastinal, and costovertebral
recesses of parietal pleural
the pulmonary cavities present when the partial pleuras are in contact with each other during experation, includes costodiaphragmatic and costomediastinal.
pulmonary ligament
where theparietal pleurasurrounding the root of the lung extends downwards from the hilum in a fold, holds lung in place
lung conduction system
goes from trachea to right (shorter and wider) and left main bronchi (positioned more laterally), to lobar bronchi (two for each main bronchi) to segmental bronchi (several for each lobar bronchi), to bronchopulmonary segments (the largest subdivisions of a lobe)
lingula of left lung
a projection of the upper lobe of the left lung that serves asa homologue for middle lobe of right lung
pneumothorax
Entry of sufficient air into the pleural cavity can cause the lung to collapse. Decrease in surface tension between parietal and visceral pleura. Elastic recoil of lung
orificies of right atrium
atrioventricular, coronary sinus, inferior and superior vena cava
crista terminalis
a vertical wall, internally seperates the smooth and rough parts of the atrial wall
septum (fossa ovalis)
a thumbprint- size depression on the interatrial septum, a remnent of the oval foramen of the fetus
pectinati muscle
rough muscular anterior wall of right atrium
orficies of left atrium
atrioventricular and pulmonary veins
foramen ovale
In fetus allows blood to enter left atrium from right atrium
right A-V valve
also called tricupsid, composed of cusps, chordae tendinae, and papillary muscles
cordae tendinae of tricupsid
attach the free edges and ventricular surface of the three cusps, much like the cords attaching to a parachute
cusps of tricupsid
include anterior, posterior, and septal, they attach to the fibrous ring around the orffice
papillary muscles of tricupsid valve
attach the cordae tendinae to the ventricular wall, they contract before contraction of the right ventricle, tightening the tendinous cords and drawing the cusps together
conus arteriosus
smooth, funnel shaped outflow track out of the right ventricle, leading to pulmonary valve
orfices of right ventricle
atrioventricular and pulmonary trunk
pulmonary valve
three cusps valve including right, left, and anterior, when its closed looks like a mercides benz logo
trabecula carnae
rounded or irregular muscular columns which project from the inner surface of therightandleftventriclesof the heart
septomarginal trabecula
a curved muscular bundle that traverses the right ventriclar chamber from the inferior part of the IVS to the base of the anterior papillary muscle, carries part of the right branch of the av bundle , this shortcut provides cordinated contraction of the anterior papillary muscles
aortic valve
semilunar valve, it is located posterior to the left side of the sternum at the level of the 3rd intercostal, also has three cusps
orifices of left ventricle
includes aortic and atrioventricular
atrioventricular valve of left ventricle
also called mitral valve, har two cusps including anterior and posterior, each recieves cordae tendinae from more than one papillary muscles, located at the level of the 4th costal ridge
interventricular septum
seperates the two ventricles
right auricle
conical muscular pouch that projects from the right atrium creating room in atrium as it overlaps the ascending aorta
left auricle
tubular muscular pouch that projects from superior left atruim where the atrium overlaps with the pulmonary arteries, represents the primordal atrium
coronary sulcus
grooves that seperates the atria from the two ventricles, anteriorly contains left and right coronary a and corresponding circumflex a, and part of great cardiac v, posterialy, contains circumflex a, coronary sinus until it drains into rt atruim at midline, and great cardiac v and small cardiac v
interventricular sulcus
groove that seperates the two ventricles, anterior one lies on left side of sternocostal surface and contains anterior interventricular a and great cardiac vein, posterior one lies midline on diaphragmatic surfuce and contains posterior interventricular a and middle cardiac vein
layers of the pericardium
the tough external layer is the fibrous pericardium and is continuous with central tenden of diaphragm, the internal glistening serous membrane is the parietal layer of serous pericdium, this layer is also reflected onto the heart at the great vessels to form the visceral layer of serous pericardium
transverse pericardial sinus
a transversly running passage within the pericardial cavity between where the aorta and pulmonary trunk leaves the heart and where the svc, ivc and pulmonary veins enter the heart
oblique pericardial sinus
a wide pocket like recess in the pericardial cavity posterior to the base (posterior aspect) of the heart, formed by the left atrium
esophagus
fibromuscular tube that extends from the pharynx to the stomach, enters superior mediastinum between trachea and vertebral column, initialy inclines to the left but is then pushed back medially by arch of the aorta, it again inclines to the left when it passes through the diaphragm via the esophageal hiatus
thoracic duct
largest lymphatics channel, conveys lymph from all of body except right upper limb, thorax, head and neck and empties into venous system near the union of left internal jugular and subclavian veins (left venous angle), the origin of the brachicephalic v, lies between axygos vein and descending aorta
thymus
a primary lymphoid organ, in the inferior part of neck and anterior part of superior mediastinum
abdominal quadrants
created by median plane and transumbilical plane
right upper quadrant
includes right lobe of liver, gallbladder, pylorus of stomach, parts 1-3 of duodenum, head of pancreas, right suprarenal gland, right kidney, right colic (hepatic) flexure, superior part ascending colon, right half of transverse colon
left upper quadrant
includes left lobe of liver, spleen, stomach, jejunum, proximal half of ileum, body and tail of pancreas, left kidney, left suprarenal gland, left colic (splenic) flexure, left half of transverse colon, superior part of descending colon
right lower quadrant
cecum, appendix, most of ileum, inferior part of ascending colon, right ovary, right uterine tube, abdominal part of right ureter, abdominal part of right spermatic tube, uterus (if enlarged), urinary bladder (if full)
left lower quadrant
sigmoid colon, inferior part of descending colon, left ovary, left unterine tube, abdominal part of left ureter tube, abdominal part of left spermatic cord, uterus (if enlarged), and urinary bladder (if very full)
anterolateral abdominal wall layers of fascia
from superficial to deep: skin, camper fascia (fatty layer), scarpa fascia (deep membranous), investing fascia between muscle layers, transversalis fascia, extraperitoneal fat, parietal peritoneum
median umbilical fold
fold in parietal peritoneum covering ureachus, which is a fetal vestage that connected developing bladder to umbilical cord
medial umbilical fold
fold in parietal peritoneum covering obliterated umbilical cord, which brought blood to heart in fetus
lateral umbilical fold
fold in parietal peritoneum covering inferior epigastric
rectus sheath
contains rectus abdominis muscle, pyramidalis muscle, inferior and superior epigastric artery and vein, thoracoabdominal nerves (T7-12), and lymphatics
rectus sheath superior to arcuate line
superior to deep: aponeurosis of external oblique, laminae of aponeurosis of internal oblique with rectus abdominis in between, aponeurosis of transversus, transversalis fascia
rectus sheath inferior to arcuate line
superior to deep: aponeurosis of external oblique, laminae of aponeurosis of internal oblique, aponeurosis of transversus, rectus abdominis, transversalis fascia
inguinal ligament
passage way from abdominal to genital region, carries spermatic cordformed by free inferior border of the external oblique aponeurosis (inguinal ligament), from deep inguinal ring to superficial inguinal ring
deep inguinal ring
opening in transversalia fascia, lies just lateral to lateral umbilical folds
superficial inguinal ring
opening in the external oblique fascia
inguinal triangle
medial border= lateral margin of rectus sheath, superolateral border=inferior epigastric vessels, inferior border= inguinal ligament, is a weakening in abdominal wall where hernias can protrude
lateral boundaries of inguinal canal
enters through transversalis fascia, transversus abdominis, internal oblique and lateral crus of external oblique is anterior
medial boundaries of inguinal canal
exists through external oblique between pubic tubericle and pubic crest and only external oblique fascia is anterior, posterior wall is conjoined ligament.
superior and inferior boundaries of inguinal canal
inguinal ligament with lacunar ligament forms floor, before the canal pierces through layer of fascia, what lies anterior is also superior border (eg external oblique forms much of superior border)
development of inguinal canal in males
developing testes are located extraperitoneally in superior lumbar region of posterior abdomen, testes are connected gubernaculum, processus vaginalis transverses the developing inguinal canal to reach developing scrotum carrying with it layers of muscle and fascia from abdominal wall (forming spermatic cord), testes then migrate inferioly in body cavity into inguinal canal then scrotum (day 28) following posterior to processus vaginalis
gubernaculum
fibrous tract that connects testes to anterolateral abdominal wall, this connected site will become deep inguinal ring
process vaginalis
peritoneal diverticulum (a blind pouch that pushes outwards), after birth it degenerates but distal expansion remains as the tunica vaginalis, sometimes it remains in inguinal canal which can predispose ppl to hernias, degrades after birth
tunica vaginalis
a serous sheath that surrounds the testes & epididymis
Cryptorchidism
undescended testes, often self-resolves. Testis usually lodged somewhere along normal course of descent
spermatic cord
contains ductus deferens, testicular a, pampiniform venous plexus leading to testicular vein, ductus deferens a, vestige processus vaginalis, autonomics, genital br of genitofemoral n, lymphatics. Surrounded by (deep to superficial) internal spermatic fascia, cremasteric fascia, cremaster muscle, and external spermatic fascia
development of inguinal canal in females
more narrow than in males b/c smaller structures pass through it during development, round lig of uterus passes through Inguinal Canal. Developing ovaries located extraperitoneally in superior lumbar region of posterior abdomen. The Processus Vaginalis traverses the developing Inguinal Canal to reach the developing labia major, Ovaries + uterus are connected to the anterolateral abdominal wall Gubernaculum. Because ovaries are connected to the uterus via ovarian ligaments, ovaries do not migrate into inguinal canal. Postnatally, the Superior Gubernaculum becomes Ovarian Lig (b/w ovaries and uterus) and the Inferior Gubernaculum becomes the Round Lig of Uterus, which is connected to the labia majora. Round ligament of uterus traverses inguinal canal, attaches to subcutaneous tissues of labia majora.
stages of hernias
- Wall weakness 2. Reducible bulge- protruding viscera and parietal peritoneum 3. Incarceration 4. Strangulation - necrosis
indirect inguinal hernia
more common, origin is lateral to lateral umbilical cord, travels within spermatic cord and can descend into testes
direct inguinal hernia
origin is medial to lateral umbilical cord, usually inguinal triangle directly through abdominal wall, does not enter spermatic cord, and can descend into testes
femoral hernia
origin is femoral ring, can exit saphenous opening