Review of Surgical Anatomy Flashcards
Abdominal Cavity Boundaries
Anteriorly = the abdominal wall & musculature
Posteriorly = the vertebral column
Superiorly = the diaphragm
inferiorly = the pelvic cavity
Major Blood Supply to the Abdomenal Cavity from the aorta
Decending Aorta: becomes the Abdominal aorta (passing through the diapgram at the level of T12)
the Abdominal Aorta gives off the following branches in decending order
- suprareanals
- renals
- Celiac Trunk which gives supply to gastric, hepatic and splenic arteries
- superior Mesentertic which gives supply to the upper portion of the GI
- inferior Mesenteric which gives supply to the lower portion of the GI
- lumbar Arteries to the vertebra
- to the common Illiacs which give rise to internal and external illiacs and into the femoral
Layers of the Abdominal Wall
anterior to posterior
Rectus Sheath & Arcuate Line
Skin
Camper’s Fascia (adipose tissue)
Scarpa’s Fascia (well defined line of connective tissue)
Anterior Sheath (of the external obliques)
External Obliques
Internal Obliques
Transverse Abdominis
Rectus Abdomnis (the six pack)
Posterior Sheath
Peritoneum
_________________________________________
The Rectus Sheath: the aponeruoses (coming together) of the fasica from each of the muscular layers
- this sheath (thick, connectice tissue) comes together but spreads to engulf the rectus abdominis
- creating anterior rectus sheath and posterior rectus sheath at the level above the arucate line
Below the Arucuate Line
- the rectus sheath only traverses anterior to the rectus abdominus muscles
- only an anterior rectus sheath, no posterior
Blood Supply to the Anterior Abdominal Wall
Nerve Supply to the Anterior Abdominal Wall
Components Superfiscial to the External Obliques
- the subcu. tissue is supplied by small branches of the femoral artery
Components Deep to the External Obliques
- superior deep epigastric from the internal thoracic
- inferior deep epigastric from the external iliac
___________________________________
Nerve Supply: to the wall comes from intercostal nerves 7-12
- these are often damanged in surgery due to cutting = numb
- grow back 1mm/day
Esophagus
- components
- where is it anatomically
- musculature features
- sphincters
Esophagus
- passing from the pharynx into the stomach through the actions of swallowing and peristalsis
Muscles
- the superior 1/3 is skeletal striated muscle: allowing for voluntary control of swallowing
- the inferior 2/3 are smooth allowing for involuntary peristalsis to propel the bolus
Anatomical Location
- sits behind (posterior) to the trachea, behind the aorta
- travels down behind the left mainstem bronchus
- (so it sits a little to the left and back)
- it passes through the diaphgram at the level of T10 via esophageal hiatus
Sphincters
- upper (UES): sits in a consistent state of contraction to block air from enters & block food from exiting swallowing reflex opens up the UES
- swallowing =triggers peristalsis activity to occur
- lower (LES): sits at the exit of the esophagus into stomach and relaxes for 5-10 seconds when swallowing occurs to allow food to propel into it
- issues with LES = GERD
- schatzki ring: a narrowing of the LES via cartilagous ring = dysphagia
Esophagus
- Nerve Supply
- Blood Supply
- Veins & singnificance with portal HTN
Nerve Supply
- vagus nerve (swallowing/eating is a parasymp.)
Blood Supply
Superior: esophageal branches off the internal thyroid (which comes from the left subclavian)
Inferior: bronchial and esophageal arteries off the thoracic aorta
Veins
- esophageal branches of coronary veins drain to the portal vein
- thus if back up in the portal vein & portal HTN => backflow to the esophageal veins and esophageal varices develop
The Stomach
- Functions
- anatomical parts
Anatomical
- cardia
- Fundus
- Body
- Antrum
- pylorus
- greater and lesser curvatures
Function
- a resovior that allows foor to enter and sit in resorvoir for hours
- food is mised and delivered into the duodenum in small amounts once at tehrigth texture and chemical compoudn
- first stages of protein and early carbohydrate digestion occur here
- some, but not many, nutrients are absorbed here
- functions through its own electical pacemaker in the fundus to coordinate perstalsis
The Stomach
- innervation
- blood supply
Innervation
- vagus nerve
- + its own regualtion of peristalsis
Blood Supply
- the greater curvature: gastro-omental artery (right and left)
- the lesser curature: right and left gastric arteries
Small Intestine: Duodenum
function
location
Duodenum
- the first and shortest segment of teh SI
- connected to the stomach through the pylorus
Function
- chemical digestion of chyme from the GB/liver in prearation to absorb
- absorbs iron here
Issues
- pyloritc stenosis: cant exit stomach
- peptic ulcers
Small Intestines: Jejunum & Illeum
Function
Location
Jejum
Location
- the Ligament of Treitz is the bend of the jejum : connecting the duodenuno-jejunal flexure to connective tissue near the SMA
Function
- microvilli to help absorbtion of nutrients
- smooth muslce for perstalsis
Illeum
- the termianal location of the SI
- B12 and bile salts absorbed here
- longest segemnet of the SI
- cannt absorb B12 = darrhea and deficiency
SI
innervation & blood supply
Innervation
- sympatheic (would slow it down) = splancnic nerves
- parasympathetic = vagus (speed it up)
Blood Supply
- superior mesenteric artery
Large Intestines
- which parts are retro and interaperotineal
- layers of the LI
Parts
- cecum (retro)
- acending colon (retro)
- transverse colon (intraperitoneal)
- decending colon (retro)
- sigmoid colon (intraperitoneal)
- rectum
Layers of the large Intestine
- Mucosa: the innermost layer in direct contact with the bolus
- Submucosa: the plexus is here
- Muscularis Propria: the muscular layer which shortesn
- when the muscularis propria shortens: creates outpunches creating haustra
- serosa : outermost layer
- taenia coli: longitundianl muscle
Large Intestines
- function
- absorbs what
- motlitity
Large Intestine
Function & Absorbtion
- absorb, secrete, motility and digestion
Absorbs
- 90% of water is reabsorbed here and sodium
- fatty acids, amino acids, vit. K & Bile acids absorbed
Secretes
- hydrogen, bicarb, chloride and potassium ions
Motility
- motlity increases with stress, eating, high fiber and exercise
Enteric Nervous System
- coordination of the motility for the LI in differnt ways
- retrograde = annular contractions in the RIGHT COLON to keep the stool in the right side and absorb more
- segmentations; randome uncorridanted contractions to propel feces prox and distal
- mass movement: strong and coordinated to start proximal and propel colonic contents distally
Gastrocolic Reflex: activation of the colonic motor in response to a meal
Large Intestine
innervation
blood supply
Innervation
- superior mesenteric plexus : controls cecum, acending colon, appendiz and transverse colon
- inferior mesenteric plexus: Left colic flexture, controls decenidng, sigmoid, and rectum
Blood Supply = SMA and IMA
superior mesenteric artery gives supply to the Acending and transverse colon
- acending = right colic artey + ileocecal artery
- transverse = middle colic artery + marginal artery
inferior mesenteris artery give supply to the decending and sigmoid colon
- Decending = left colic artery & sigmoid arteris
- sigmoid = sigmoid arteries
Rectum
where and function of defication
Rectum
- between colon and anus
- absent taenia coli
Defication
- feces stretch the rectum - stretch receptors pick up on this => triggerrs rectoanal reflex => relaxation of interal anal sphincter = mucosal sample in the transition zone & defication
