anatomy exam 2

superior thoracic Aperture (thoracic inlet)

• bounded anteriorly by the sternal manubrium and costal cartilages of 1st ribs, T1 posteriorly, and the 1st ribs laterally

• transmits trachea, esophagus, aortic arch and branches, superior vena cava and several nerves and blood vessels to and from neck

inferior thoracic aperture (thoracic outlet)

• bounded anteriorly by the xiphisternal joint and costal margins (7-10), T12 posteriorly, and 12th ribs laterally

• contains diaphragm and transmits esophagus, aorta and inferior vena cava, nerves and blood vessels to and from abdomen

sternal angle (angle of Louis)

• formed by articulation of manubrium with body of sternum

• at level of 2nd costal cartilage

• opposite the intervertebral disc btwn T4 and T5

• used to identify the 2nd rib and base of heart

transthoracic plane

RATPLAT

R: rib 2

A: aorta arch start and end

T: trachea (bifurcating)

P: pulmonary artery (bifurcating)

LA: ligamentum arteriosum

L: left recurrent laryngeal nerve

A: azygous vein

T: thoracic duct (part of lymphatic system)

sternum

manubrium:

• suprasternal notch (juglar notch)

• sternal angle (angle of Louis)

• clavicular notch

Body:

• costal (hyaline) cartilage

• intercostal space

Xiphoid process

• xiphisternal joint

ribs

3 types of ribs

1. true ribs (1-7): direct attach to the body of the sternum

2. false (8-12)

3. floating (11-12)

• ribs 1, 10, 11, 12 articulate with 1 vertebra

• all other ribs articulate with 2 vertebrae

breast anatomy

• adipose tissue

• mammary glands

• lactiferous ducts

• suspensory ligaments

• nipple

• areola

• retromammary space

tail of spence

• extension of breast tisse into the axilla, in upper outer quadrant

• can detect cancer cells in this area through lymph node

• upper outer: axillary tail, majority of cancers

respiration musculature

1. external intercostals

• fibers run inferomedially

• TP to mammary line

2. internal intercostals

• fibers run superomedially

• sternum to scapular line

3. innermost intercostals

• fibers run superomedially

• mammary line to scapular line

neurovascular bundle

V: intercostal VEIN

A: intercostal ARTERY

N: intercostal NERVE

4 parts of parietal pleura

1. costal

2. mediastinal

3. diaphragmatic

4. cervical (pleural or ‘cupula’)

right lung

• 3 lobes

• 2 fissures

  • oblique

  • horizontal

left lung

• 2 lobes

• 1 fissure

  • oblique

right lung impressions

• azygous vein

• SVC

• IVC

• esophagus

• liver

left lung impressions

• aorta (arch and descending)

• left subclavian artery

• stomach and spleen

mediastinum

central compartment of thoracic cavity: space btwn the 2 pleural sacs

contains:

• heart

• great blood vessels:

  • aorta

  • SVC

  • pulmonary trunk & veins

• azygous system of veins

• trachea

• esophagus

• thymus gland

• thoracic duct & lymph nodes

• vagus & phrenic nerves

• sympathetic trunks

boundaries & divisions

• anterior: sternum

• posterior: thoracic vertebrae (T1-T12)

• lateral: pleural cavities (lungs)

• superior: thoracic inlet (superior thoracic aperture)

• inferior: diaphragm

• superior mediastinum: above the level of T4-T5 (sternal angle)

  • contains thymus, aortic arch, brachiocephalic veins, SVC, trachea, esophagus, vagus & phrenic nerves, thoracic duct

• inferior mediastinum: below T4-T5 to diaphragm, divided into 3 parts

1. anterior: small, btwn sternum & pericardium, contains thymus (in children)

2. middle: contains heart, pericardium & roots of great vessels

3. posterior: btwn pericardium & vertebral bodies, contains descending aorta, esophagus, thoracic duct, & azygous system

thoracic aorta

• continuation of the arch of aorta

• begins at inferior border of T4 and descends left of T5-t12

• passes through the aortic hiatus at T12

• branches: bronchial (1 right, 2 left), esophageal, pericardial, mediastinal

• gives posterior intercostal arteries (9 pairs, 3rd-11th spaces), subcostal, and superior phrenic branches

azygos venous system

• azygos vein ascends on the right from T12 to T4

• connects the superior and inferior venae cavae

• drains posterior thoracic and abdominal walls

• hemiazygous ascends on the left from T12 to T9 and joins azygos near T9

• accessory hemiazygos descends from T5 to T8 and joins azygos at T7/T8

trachea

• trachea: fibrocartilaginous tube with C-shaped rings; lies anterior to esophagus

• trachea extends from C6 to T4 and bifurcates at the carina near the sternal angle (T4-T5)

esophagus

• esophagus extends from C6 to T9 in the thorax and passes through the esophageal hiatus at T10

• esophageal constrictions: arch of aorta, left primary bronchus, and esophageal hiatus

thoracic duct

• major lymphatic trunk; ascends btwn the thoracic aorta and azygos vein from T5-T12

• in the superior medastinum it lies on the left side of the esophagus, deep to the arch of aorta

• receives lymph from both lower extermities, lower abdomen, left thorax, left head/neck, and left upper limb

• drains into the left brachiocephalic vein

• begins inferiorly as the cisterna chyli anterior to T12

phrenic nerve

• arise from C3-C5

• provide the sole motor supply to the diaphragm and about 1/3 of its sensory supply

• right phrenic descends along the right brachiocephalic vein and SVC

• left phrenic descends btwn the left subclavian and left common carotid arteries and crosses the arch of the aorta

heart

• located in the middle mediastinum, btwn lungs

• enclosed by pericardium: fibrous (outer) & serous (inner) layers

• serous pericardium has parietal and visceral layers (epicardium)

• located obliquely in the middle mediastinum

• roughly spans from the 2nd-5th intercostal spcaes

• 2/3 of heart lies left of midline

• base (posterior surface): faces posteriorly toward vertebral column (mainly left atrium)

• apex: points left & downward to 5th intercostal space, midclavicular line (formed by left ventricle)

• resting on: the diaphragm, with pericardium fused

• superior border: from 2nd to 3rd costal cartilages, formed by both the atria & great vessels

• right border: from 3rd to 6th costal cartilages, mainly right atrium

• inferior border: from right border to apex, mostly right ventricle & a little of left ventricle

• left border: from apex up to 2nd costal cartilage, mostly left ventricle & part of left atrium

layers of heart wall

• epicardium: outer layer (visceral pericardium)

• myocardium: thick muscular layer for contraction

• endocardium: smooth inner lining of chambers

cardiac surfaces & grooves

• sternocostal (anterior) surface:

  • mostly right ventricle

  • lies just behind the sternum & costal cartilages

• diaphragmatic (inferior) surface:

  • formed by both ventricles, mainly left ventricle

  • rests on diaphragm

• pulmonary (left) surface:

  • formed by mainly left ventricle, which makes the cardiac impression on the left lung

• base (posterior) surface):

  • formed mainly by left atrium (receives pulmonary veins)

  • faces posteriorly toward vertebral column coronary sulcus (atrioventricular groove):

    • separates atria from ventricles

    • contains right coronary artery, circumflex artery, and coronary sinus

  • anterior interventricular sulcus:

    • btwn right and left ventricles on anterior surface

    • contains anterior interventricular artery (LAD) and great cardiac vein

  • posterior interventricular sulcus:

    • on the diaphragmatic surface

    • contains posterior interventricular artery & middle cardiac vein

cardiac veins

• venous drainage of heart:

  • deoxygenated blood from myocardium returns via cardiac veins, all emptying into the coronary sinus → right atrium

• main cardiac veins:

  • great cardiac vein: runs with LAD artery in the anterior interventricular sulcus

  • middle cardiac vein: runs with posterior interventricular artery

  • small cardiac vein: runs along right margin of heart with marginal artery

  • anterior cardiac veins: drain directly into right atrium (not through coronary sinus)

right atrium

• receives venous blood from SVC, IVC, and coronary sinus

• divided internally by crista terminalis into:

  • smooth posterior wall (sinus venarum)

  • rough anterior wall (pectinate muscles)

• fossa ovalis: remnant of fetal foramen ovale on interatrial septum

• right auricle: muscular pouch extending from atrium

right ventricle

• forms most the anterior surface of the heart

• internal structures:

  • trabeculae carneae: muscular ridges on inner wall

  • papillary muscles: anchor chordae tendineae, which attach to valve cusps

  • tricuspid valve: btwn RA and RV

  • moderator band (septomarginal trabecula): carries conduction fibers from septum to anterior papillary muscle

  • conus arteriosus (infundibulum): smooth outflow region leading to pulmonary trunk

left atrium

• receives 4 pulmonary veins (2 from each lung)

• mostly smooth-walled; small pectinate muscles only in auricle

• sends blood through mitral valve to left ventricle

left ventricle

• thickest myocardium (3x right ventricle)

• contains trabeculae carneae, papillary muscles, and chordae tendineae similar to RV

• aortic vestibule: smooth outflow tract to aortic valve

• opens into ascending aorta via the aortic semilunar valve

• forms apex of the heart

blood flow

body → SVC/IVC → RA → tricuspid valve → RV → pulmonary semilunar valve → pulmonary trunk → lungs → pulmonary veins → LA → mitral valve → LV → aortic semilunar valve → aorta → body

blood flow

• right heart → pumps DEOXYGENATED blood to lungs (pulmonary circuit)

• left heart → pumps OXYGENATED blood to body (systemic circuit)

• valves ensure one-way flow btwn chambers and vessels

fetal circulation

• ductus venosus:

  • connects umbilical vein → IVS

  • allows oxygenated blood from placenta to bypass the fetal liver

• foramen ovale:

  • shunts blood from RA → LA, bypassing pulmonary circuit

• ductus arteriosus:

  • connects pulmonary trunk → descending aorta

  • diverts most blood awat from the nonfunctional fetal lungs

• umbilical arteries (2):

  • carry deoxygenated blood from fetus → placenta

• after birth:

  • foramen ovale → fossa ovalis

  • ductus arteriosus → ligamentum arteriosum

  • umbilical vein → ligamentum teres hepatis

  • ductus venous → ligamentum venosum

ausculation points

A: aortic valve- 2nd intercostal space, right sternal border

P: pulmonary valve- 2nd left intercostal space, left sternal border

E: Erb’s Point- 3rd left intercostal space

T: tricuspid valve: 4th left intercostal space, left lower sternal border

M: mitral valve: 5th intercostal space, midclavicular line (apex)

peritoneum- visceral layer

• greater omentum

• lesser omentum

peritoneum- parietal layer

• mesentery

• mesocolon

greater omentum

• greater curvature of stomach

• connects with transverse colon, spleen, and diaphragm

lesser omentum

• lesser curvature of stomach

• connects to stomach and duodenum of liver

retroperitoneal structures (SADPUCKER)

S: suprarenal glands

A: abdominal aorta/IVC

D: duodenum (2nd & 3rd segment)

P: pancreas (except tail)

U: ureters

C: colon (descending and ascending)

K: kidneys

E: esophagus

R: rectum

peritoneal ligaments- off liver

double layer of peritoneum

connects organ to organ or ro abdominal wall

off liver

• falciform ligament: liver to anterior abdominal wall

• hepatogastric ligament: membranous part of lesser omentum

• hepatoduodenal ligament: free edge of lesser omentum, contains portal triad

• hepatorenal ligament: connects liver to area around kidneys

peritoneal ligaments- off stomach

continuous attachment to greater curvature, paer of greater omentum

off stomach

• gastrophrenic ligament: to inferior diaphragm

• gastrosplenic ligament: cover hilum of spleen

• gastrocolic ligament: to transverse colon

subdivisions of peritoneal cavity

• greater sac: larger main compartment

• omental bursa (lesser sac): sac-like cavity posterior to stomach, lesser omentum, and related structures

  • allows smooth movement of stomach against posterior structures

• omental foramen:

  • also called epiploic foramen or foramen of Winslow

  • opening between greater and lesser sacs

  • boundaries

    • anterior: hepatoduodenal ligament

    • posterior: IVC and right crus of diaphragm

    • superior: liver

    • inferior: superior duodenum

digestive organs

• functions: ingestion, secretion, propulsion, and mixing, digestion, absorption, defecation

• digestion can be mechanical or chemical

• organs are found in head & neck, thoracic cavity, abdominal cavity, and pelvic cavity

GI Tract vs Accessory Organs

• alimentary tract = gastro-intestinal (GI) tract

• muscular tube from mouth to anus about 20-30 ft long

• true GI organs form the actual tube food passes through

• accessory organs either do not touch foos or are unnecessary for digestion, but help by secretions or mechanical action

embryonic regions & vascular supply (CSI)

all 3 regions drain venous blood into the hepatic portal vein (liver)

1. foregut:

• supplied by branches of celiac trunk

• forms esophagus, stomach, part od duodenum, liver, gallbladder, and upper pancreas

2. midgut

• supplied by branches of the superior mesenteric artery

• forms duodenum to proximal 2/3 transverse colon, including lower pancreas

3. hindgut

• supplied by branches of inferior mesenteric artery

• forms distal 1/3 transverse colon to superior rectum

borygmus

gurgling stomach sounds

celiac trunk

3 major branches

1. L gastric a.

2. splenic a.

3. common hepatic a.

superior mesenteric artery

• inferior pancreaticduodenal artery: feeds under surface of pancreas

• superior mesenetric artery

• jejunum: empty portion of stomach (absorption of nutrients)

• jejunal arteries:

  • loops of these are called arcades

  • anastomic

  • longer vasa recta (straight parts)

• ileum: more arcades, shorter vasa recta

• ileal arteries

• appendicular artery

• ileocolic artery: ileum + colon

• right colic artery: feeds R portion of colon

• middle colic artery: gives blood to transverse colon

inferior mesenteric artery

• left colic artery

• several (flexure/bend) sigmoid artery

• superior rectal artery

hepatic portal vein

• primary formation: superior mesenteric vein + splenic vein

• also receives inferior mesenteric vein, gastric vein, jejunal and ileal intestinal, ileocolic, R colic, middle colic, L colic, sigmoidal, & superior rectal veins

• drains GI tract to liver

• hepatic veins then drain from liver to IVC

portal caval anastomoses

• esophageal: L gastric ←→ esophageal veins of azygous system → esophageal varices

• rectal: superior rectal ←→ middle and inferior rectal veins → rectal varices/ hemorrhoids

• paraumbilical: paraumbilical ←→ superficial epigastric veins → capcut medusae

• retroperitoneal: colic veins ←→ renal, suprarenal, gonadal, and paravertebral veins → ascites

• intrahepatic: L branch of portal vein → patent ductus venosus/ portosystemic shunt

liver

• largest gland, 2nd largest organ

• 4 lobes: right, left, quadrate, caudate

• ligaments: falciform, ligamentum teres hepatis, ligamentum venosum, R and L coronary, R and L triangular

• bare area and IVC on posterior liver

• portal triad travels in lesser omentum

gallbladder

stores bile on posteroinferior surface of liver near quadrate lobe

pancreas

• retroperitoneal gland with endocrine & exocrine function

• parts: head, body, tail

• about 6in long and sits behind stomach

• 2 ducts: main pancreatic duct & accessory pancreatic duct

spleen

• lymphatic organ, not a digestive organ

• highly vascular; recycles blood cells (red pulp) & provides immunity (white pulp)

• 1, 3, 5, 7, 9, 11 rule: 1×3×5 in, 7 oz, deep to ribs 9-11

bile duct system

• R and L hepatic ducts → common hepatic duct

• cystic duct comes from gallbladder

• common hepatic duct + cystic duct → common bile duct

• common bile duct joins main pancreatic duct at hepatopancreatic ampulla & papilla

• also called ampulla of Vater with sphincter of Oddi

pancreatic duct system

• main pancreatic duct = duct of Wirsung

• joins common bile duct at hepatopancreatic ampulla and sphincter of Oddi

• empties into duodenum at major duodenal papilla

• accessory pancreatic duct = duct of Santorini

• empties into duodenum at minor duodenal papilla

4 layers of GI tract

1. mucosa: forms lumen

2. submucosa: vasculature for mucosa

3. muscularis: inner circular + outer longitudinal smooth muscle

4. stomach adds a 3rd oblique layer

5. mouth, pharynx, superior half of esophagus, and external anal sphincter are skeletal muscle

6. serosa= serous membrane from peritoneum; called adventitia in thorax

stomach review

• features: cardia with cardiac sphincter, fundus, greater curvature, lesser curvature, pylorus with pyloric sphincter

• rugae are folds of mucosa

• muscle layers: longitudinal, circular, oblique

small intestines

parts and features

• duodenum: shortest segment; receives stomach contents, common bile duct, and main pancreatic duct

• duodenum subdivisions: superior, descending, inferior, ascending; superior part includes duodenal bulb

• jejunum= middle portion about 2/5 of length

• ileum= final segment, 3/5 of length; ends at ileocecal valve

internal features

• plicae circulares = circular folds

• villi with microvilli increase SA

• villi contain capillaries

• lymph capillaries= lacteals; absorb lipids

jejunum vs. ileum

• jejunum: more plicae circulares & villi, fewer longer arcades & vasa recta, traces of MALT

• ileum: fewer plicae circulares and villi, multiple shorter arcades and vasa recta, Peyer’s patches

large intestine

main parts

• cecum and vermiform appendix

• ascending colon, transverse colon, descending colon, sigmoid colon

• sigmoid colon enters pelvic cavity

• rectum & anus are in pelvic cavity

key features

• ileocecal valve

• tenia coli

• Haustra formed with plicae semilunares

• appendices epiploicae

• hepatic flexure and splenic flexure

• rectal valves, anal canal, internal sphincter, external sphincter

kidney

location

• lateral to vertebral column, deep to 12th rib

• superior level about T11, inferior level about L3, hilum at L1-L2

• R kidney lies lower than L

• primary retroperitoneal structure; overlies transversalis fascia

covering and structure

• fibrous capsule & adipose capsule provide padding and protection

• adipose capsule helps prevent nephroptosis

• hilum is medial indentation for ureter, renal artery, and renal vein

• renal sinus contains fat

• renal pelvis is expanded upper ureter in hilum

• minor calyces drain pyramids; major calyces form renal pelvis

blood supply

• renal artery from abdominal aorta; renal vein to IVC

• arterial sequence:

  • segmental → lobar → interlobar → arcuate → cortical radiate → afferent arteriole → glomerular capillaries → efferent arteriole → peritubular capillaries/ vasa recta