Anatomy Flashcards
What is the origin and attachment of the mesentery?
Duodenal flexture L2 to R sacroiliac joint
Outline the blood supply to the pancreas and venous drainage
Arterial supply:
- Gastroduodenal artery gives of the R gastroomental and pancreatoduodenal arteries: supply the anterior and posterior head of the pacreas
- Splenic artery branches supply the head neck and tail
Venous drainage:
- Splenic vein drains into portal vein
- Pancreaticoduodenal dains into SMV and sometimes into portal vein
- inferior pancreaticoduodenal drains into SMV
Outline why the liver is a common site for pancreatic cancer metastasis
Venous drainage from the pancreas goes to portal vein
Outline the surfaces of the spleen
Diaphragmatic surface Gastic impression renal impression colic impression pancreatic impression
Describe the structures forming the lesser omentum
Double layer of peritoneum formed by the hepatogastric ligament and the hepatoduodenal ligament
What structures are contained within the portal triad?
portal vein, hepatic artery proper and common bile duct
What is the arterial supply of the gall bladder and where does this artery usually arise from?
Cystic artery, typically arising from the R branch of the proper hepatic a
Which structures form the hepatic vein?
Splenic vein, inferior mesenteric vein and the superior mesenteric vein join to form the portal vein, the L gastric vein and oesophageal vein also drain into the portal vein
Which ligament is the portal triad located in?
Hepatoduodenal
Outline the lobes of the liver, what is the significance of the quadrate lobe
Right and Left lobes, caudate superior btw R and L lobes, quadrate inferior between groove for ligamentum teres and the fossa for the gall bladder. Quadrate lobe recieves blood supply from both sides of the liver
What proportion of blood do the hepatic artery and portal vein bring in to the liver respectively
Hepatic artery brings 30% of total blood - 50% of which is oxygenated
Portal vein brings in 70% of total blood - 50% of which is oxygenated
What is Meckels diverticulum?
Congenital abnormality resulting in a full diverticulum (of 2 or more types of mucosal layers) occuring the the distal ileum. It is an embryological remnant.
Describe the arterial supply of the small intestine
SMA: gives off inferior pancreatic duodenal, illeal and jejunal arteries
Describe the difference between the meso appendix and the veriform appendix
Mesoappendix: the peritoneum suspending the appendix from the ileum
Veriform Appendix: blind muscular diverticulum containing lymphoid tissue
Where is McBurneys Point?
One third of the distance between the anterior superior iliac spine and the umbilicus. Roughly corresponds to most common site of appendix
What are the names of the three tenia coli? And which tenia coli is most likely to be affected by diverticulum
Tenia Coli Libra (free), omental, mesenteric
Mesenteric tenia coli most likely to be affected by diverticulum as it is the site of greatest weakness
Why is the descending colon the most likely place for diverticulum to occur?
Site of highest pressure and lowest motility in the large intestine
What forms the longitudinal muscles of the rectum?
the meeting of the tenia coli
What forms the longitudinal muscles of the rectum?
the meeting of the tenia coli
Outline the blood supply of the Large intestine
SMA –> branches to iliocolic (which branches to superior and inferior, inferior branches to colic, appendicular and ileal)
SMA —> right colic (ascending colon)
SMA —> middle transverse colon until distal 1/3
IMA —> Left colic (ascending and descending branches)
IMA —> Sigmoid artery
Outlne the arterial and venous supply of the rectum and outline the significance of the venous supply
Arterial supply:
- Superior rectal artery from IMA
- Middle rectal artery from inferior vesicle arteries (internal iliac)
- Inferior rectal arteries branch from internal iliac
Venous supply:
- Superior rectal veins drain into IMV and portal vein
- Middle and rectal veins drain into the systemic venous system
Clinical significance: portal hypertension —> internal hemorrhoids due to drainage of IMV into portal vein
AND
Suppositories distributed systemically due to uptake of inferior rectal and middle rectal veins
Outline which structures may be palpated in a PR exam in males and females
Males: prostate and seminal vesicles
Females: cervix
Both: sacrum, coccycx and ischial spines and tuberosities
Outline the nervous supply to the anal canal and its clinical significance
- Inferior hypogastric plexus (symp and parasymp) provide visceral innervation to anal canal superior to pectinate line —> SENSITIVE TO STRETCHING
- Inferior rectal nerve (branches of pudendal nerve) provides somatic innervation to the anal canal below the pectinate line —-> SENSITIVE TO PAIN TOUCH AND TEMP
- Clinical significance: external haemorrhoids occur below pectinate line and will therefore be painful as they are innervated somatically. Internal haemorrhoids will not be painful as they are innervated viscerally
Outline the process of defecation
- Faeces moves into rectum - activation of stretch receptors
- Puborectalis and anal sphincters relax –> straightening of anorectal junction
- intra-abdominal and intrarectal pressure increase resulting in evacuation
- puborectalis and external sphincter contract to close anal canal
Which muscle is responsible for depressing the tounge
Hypoglossus (think under tounge)
Which muscle is responsible for pulling the tounge forward
Genioglossus (think: stick your tounge out at geniuses)
What is the motor and sensory innervation of the muscles of the soft palate
Sensory: Glossopharyngeal N
Motor: Vagus N
Which muscle is responsible for elevating and retracting the tounge?
Styloglossus
Outline the sensory and motor innervation of the tounge
Sensory
- Ant 2/3 general: facial; special (taste): lingual
- Post 1/3 glossopharyngeal nerve and vagus
Motor:
- hypoglossal nerve for all except palatoglossus (vagus)
Outline where fractures of the mandible usually occur in adults, how does this differ from children and the elderly?
- Usually occurs at the angle or neck of the mandible and affect the contralateral side due to transmission of force through the bone (angle if mouth open, neck if mouth closed)
- children and elderly less likely to avoid impact and so usually fracture the mental protuberance or the condylar processes
What muscles make up the pelvic floor?
Pubococcygeus, illiococcygeus, ischiococcygeus, puborectalis
What muscles make up the levator ani
pubococcygeus, illiococcygeus and puborectalis
Outline the deep and superficial perineal spaces
- The deep perineal space lies inferior to the fibrous fascia of the pelvic diaphragm and superior to the perineal membrane and contains the external urethral sphincter
- the superficial perineal space lies inferior to the perineal membrane and contains muscles associated with the external genitalia
- the perineal membrane gives a point of attachment for external genitalia
Outline the layers of the perineum and pelvic floor from most superficial to deepest
- superficial perineal space
- perineal membrane
- deep perineal space
- pelvic diaphragm fascia
- pelvic diaphragm: puborectalis, ileococcygeus, ischiococcygeus, pubococcygeus
Outline the arterial supply to the perineum
Internal pudendal artery –> inferior rectal artery and perineal artery
Outline the nervous innervation of the perineum
Innervated by the pudendal nerve S2-4 which branches into:
- Inferior rectal nerve –> motor to external anal sphincter and sensory to skin of anal triangle
- Perineal nerve —> skeletal muscles in the deep and superficial pouch and posterior labial region
Why are some drugs administered sublingually? Outline the pathway sublingual drugs take
Bypass 1st pass metabolism to the liver and therefore are not metabolised before they reach their target. Sublingual vein –> deep lingual vein –> external jugular –> SVC –> heart
Outline the pathways involved in erection and ejaculation
- Erection: Parasympathic stimulation via the pelvic nerve
- Emmision: Sympathetic stimulation via the hypogastric nerve
- Ejaculation: Sympathetic stimulation via the pudendal nerve
What is the contents of the Superior Mediastinum
- Great vessels, trachea, oesophagus, thoracic duct and thymus
In which mediastinal compartment does the heart lie?
The middle compartment of the inferior mediastinum
What is the role of the azygous and hemiazygous system
The azygous system drains the thoracic and anteriolateral abdominal walls
Outline the blood supply and nervous innervation to pericardium, why is this clinically significant?
Blood supply: pericardial arteries from the internal thoracic arteries supply fibrous, coronary supply visceral/epicardium
Innervation: phrenic nerve C3, C4, C5
Clinically significant bc pain during an MI can radiate to the L shoulder due to innervation of the phrenic nerve and corresponding dermatomes
What is JVP a measure of and where is it measured?
Right internal jugular vein, measure of central venous pressure (R atrial pressure)
The R internal vein is used because it connects directly into the R atrium
What does the internal jugular vein drain?
Drains the brain, skull and superficial face and neck
What does the internal jugular vein drain?
Drains the brain, skull and superficial face and neck
Which vertebral bodies does the heart lie in front of?
T5-T8
THINK: opening of the inf vena cava in the diaphragm is T8 therefore heart must lie above it
Where does the apex of the heart usually lie on an Xray image
Anterior 5th intercostal space in the midclavicular line
How is the thoracic index calculated?
What is a normal CT index for an adult and for a child?
Why is the CT index larger in an infant?
CT = (MRD + MLD)/ID
where MLD: midline to right heart border
MLD: midline to L heart border
ID: internal diameter of chest
Adult value: <50%
Baby 0-1yr: 53-58%
1-6 years: 45-49%
Because in babies the heart is in a more transverse position in the chest
Which bronchi are you most likely to get something caught in and why?
-
Outline the innervation of the tounge
Motor: Hypoglossal n. CN XII innervates the deep muscles of the tounge
Sensory:
- Ant 2/3 special sensory (taste): Facial
- Ant 2/3 general sensation: Lingual (V3)
- Post 2/3 general and special: Glossopharyngeal
THINK: “taste –> “7th sense” —> therefore seventh nerve –> facial nerve
Outline the 3 phases of swallowing
Oral: formation of food bolus, sensing of uvula
Pharyngeal: bolus moves back into pharynx, tensing of levator palentine and tensor veli
Oesophageal: primary and secondary peristaltic motions
Why does the LES open before the food bolus is near the LES?
Allows for passage of liquids and solids
What lower limb artery supplies the dorsum of the foot to give the dorsal pedis pulse?
Anterior Tibial artery
What artery supplies the plantar surface of the foot and gives off the posterior tibial pulse? Where is this pulse felt?
Posterior tibial artery, felt posterior to the medial malleolus
What artery gives off the fibular artery?
The posterior tibial artery
What artery gives off the popliteal artery
The common femoral artery
Describe the genicular anatomosis, which arteries contribute to these anastomoses
The Poplitial artery gives off the lateral and medial superior genicular branches and the anterior tibial arteries
Describe the gluteal anatomoses
The medial and lateral circumflex arteries from the deep femoral artery and the inferior gluteal arteries contribute to the hip anatomoses
Where would you find the great saphenous vein
from the medial surface of the dorsal venous network running on the medial side of the leg. Joins the femoral vein just distal to the inguinal ligament. Contains multiple valves
What are the 6 signs of acute ischemia
6 Ps: pain, pallor, pulse-lessness, parethesia, paralysis and poikilothermy
Describe the contents of the femoral triangle including which are most medial and which are most lateral
Femoral v. most medial, femoral a., femoral n most lateral
What are the borders of the femoral triangle?
Inguinal lig roof, sartorius lateral border and adductor longus medially
Where does the femoral artery pass through to become the popliteal artery
Adductor hiatus
In which compartment does the superficial femoral artery run? In which does the deep femoral artery run?
Superficial runs in Anterior compartment. Deep runs in medial compartment
Describe the arterial supply to the foot
Posterior tibeal divides into medial and lateral plantar arteries, the anterior tibial gives off the arcuate artery
A woman has cancerous tissue being removed from the pinned location. Where else would
the surgeon check for cancerous tissue that has physically spread within the same space?
The perinephric space within the renal fascia between both kidneys
Which muscles attach to the perineal body?
Bulbospongiousus, deep and superficial transverse, ext anal sphincter and puborectalis
Outline the innervation of the scrotum
Somatic innervation from the genital branch of the genitofemoral nerve and the ilioinguinal nerve.
Testes innervated by the Lesser and Least splanchnic and lumbar splanchnic (T11-L1) and by pelvic splanchnic S2 S4
Outline the innervation of the Dartos and Cremaster muscle and their roles
Dartos: innervated by the genitofemoral nerve and contracts to wrinkle skin when cold
Cremaster: innervated by the genital branch of genitofemoral muscle and contracts to raise the testes and maintain temperature
Describe the contents of the spermatic cord
Ductus deferens Testicular a A. of ductus def Cremasteric a pampiniform plexus genitofemoral n
Which bronchi are you most likely to get a foreign object stuck in?
the R main bronchus due to its wider and shorter passage and runs more vertically
Where is the SA node located? Where is the AV node located?
Superior aspect of the cristae terminalis
Just above the orifice of the coronary sinus
What is the lingula of the L lobe analogous to?
the middle lobe of the Right lung
How many bronchopulmonary segments are there in each lung
10 in the Right lung: 3 upper, 2 middle, 5 lower
8 in the Left lung: 4 upper 4 lower
Where can pareital pleura refer pain to?
Supplied by the phrenic nerve to C3,4,5 or by intercostal nerves to trunk wall
Describe what happens in choking
Laryngeal muscles contract closing the rima glottidus and obstructivting the trachea, the sensitive laryngeal vestibule may lead to coughing reflex
Which spinal nerves give the femoral nerve?
What are the motor and sensory innervations of the femoral n?
How do you test the motor and sensory components of the femoral n?
Femoral Nerve L2-4
Innervation
Motor: Quadriceps femoris group (RF, VL, VM, VI), pectineus, sartorius, illiacus
Sensory: Anteromedial thigh, knee and leg
Clinical Test
Motor: extension of the knee
Sensory: sensation from the medial thigh, knee and leg
What would be the effects of a femoral nerve lesion? What injuries could result in such a lesion?
Effects of lesion include
- Weakening of hip flexion
- Loss of knee extension
- Knee instability
- Loss of sensation to the anteriomedial thigh knee and leg
Injurys resulting in a femoral n lesion include: Disease in the psoas muscle, or in inguinal canal/femoral triangle, pelvic fracture
Which spinal nerves give the obturator nerve?
What are the motor and sensory innervations of the obturator n?
How do you test the motor and sensory components of the obturator n?
Obturator nerve L2-L4
Innervation:
Motor: Adductor brevis, adductor longus, gracilis, 1/2 adductor magnus
Sensory: small strip on medial thigh
Clinical test
Motor: adduction of the leg
Sensory: sensation from strip of medial thigh
What would be the effects of a obturator nerve lesion? What injuries could result in such a lesion?
Effects
- Weakened hip adduction
- Weakened external rotation
- Loss of sensation in strip of medial thigh
- Instability of pelvis; lateral swing of limb with locomotion
Injury causing lesion
- Pelvic neoplasms
- Total hip replacements
- Pregnancy, childbirth
- Rare
Which spinal nerves give the femoral cutaneous nerve of the thigh?
What are the motor and sensory innervations of the lateral femoral cutaneous nerve of the thigh?
How do you test the motor and sensory components of the lateral femoral cutaneous nerve of the thigh?
What would result from a lesion in this nerve?
L2-3
Motor innervation: none
Sensory innervation: lateral thigh
Clinical test: sensation from the lateral thigh
Lesion: loss of sensation to the lateral thigh. Can result from external compression or increases in intraabdominal/pelvic pressure
Which spinal nerves give the posterior femoral cutaneous nerve of the thigh?
What are the motor and sensory innervations of the lateral femoral cutaneous nerve of the thigh?
How do you test the motor and sensory components of the lateral femoral cutaneous nerve of the thigh?
What would result from a lesion in this nerve?
S1-S3
Innervation
Motor: none
Sensory: sensation to posterior thigh
Clinical test
- Sensation to the posterior thigh
Lesion
- Loss of sensation to the posterior thigh, can result from external compression, or increased intraabdominal or intrapelvic pressure (pregnancy)
