Cross Sectional Anatomy Flashcards
Meninges
- connective tissue membrane
- covers brain and spinal column
- inner layer—pia mater
- mid layer—arachnoid mater
- outer layer—dura mater
Function of Digestive System
- converts food into nutrients that are absorbed and used throughout the body
- gets rid of what it doesn’t need
Function of Cardiovascular System
- delivers oxygen and nutrients to cells
- removes carbon dioxide from cells
- delivers nutrients (sugars, fats, vitamins, minerals, proteins) to body cells
- removes waste products to bring to the liver, kidneys, or lungs for elimination
Function of Respiratory System
-absorbs oxygen into blood and gets rid of carbon dioxide
Function of the Skeletal System
- structure
- protection
- shape
- movement
- blood cell production: bone marrow produces red blood cells, which carry oxygen to tissues
What are the 2 parts of the skeletal system?
- axial (head, neck, torso)
- appendicular (arms, legs)
How many bones are in the human body?
206
What system do the Respiratory System and Cardiovascular System make?
Cardiopulmonary System
What are the bumps on bones for?
insertion or attachment
3 Types of Muscles in the Muscular System
- skeletal: help you move, voluntary
- cardiac: around heart, involuntary
- smooth: involuntary (ex. respiratory, digestive tract)
Function of the Muscular System
- voluntary and reflexive movement
- skeletal stability and organ protection
- internal organ function (ex. smooth muscle in bladder allows urine to be expelled)
- regulates body temperature
- circulates blood and other substances throughout the body
How many muscles are in the human body?
650
Function of Nervous System
- communication
1) sensory input
2) integrates info
3) output (responds)—activates effector organ
Function of Excretory/Urinary System
- excretes waste
- maintains pH
Function of Reproductive System
- female: releases egg, nourishes egg
- male: delivers sperm
Function of Lymphatic System
- network of tissues and organs that help get rid of toxins/waste
- 3 Primary Functions:
1) transport lymph throughout the body
2) returns excess interstitial fluid to blood
3) absorbs fats and vitamins from the digestive system
Function of Integumentary System
- protection
- first line of defense
Function of Endocrine System
- produces hormones
- chemical messenger
- controls functions of body
Linea Terminalis
- invisible line from the sacral promontory to symphysis pubis
- division between abdominal and pelvic cavities
Connective Membranes
- meninges
- synovial
Epithelial Membranes
- cutaneous
- mucous
- serous
Hiatus is a…
hole or opening
How many major organ systems are there?
11
What are the boundaries of the Abdominal Cavity?
- superiorly: diaphragm
- inferiorly: linea terminalus
- anteriorly: umbilicus, skin, muscles
- posteriorly: muscles, vertebrae
- laterally: skin, muscles
What lumbar level is transpyloric?
mid L1
What lumbar level is subcostal?
mid L3
What lumbar level is transumbilical?
between L3 and L4
What lumbar level is interiliac?
lower L4
What lumbar level is transtubular?
mid L5
Xiphoid Process
bone on bottom of sternum
What are the 2 types of membranes in body cavities?
1) connective
2) epithelial
Parietal Serosa
lines cavity wall
Visceral Serosa
covers organs
Cavity Membranes
-thin sheets of tissue that line cavities and organs
External Oblique Muscle
- outermost layer
- originates from ribs
- extends downward and medially
- inserts on the anterior side of the rectus abdominus, aponeurosis, iliac crest and pubic tubercle
Internal Oblique Muscle
- middle layer
- originates from the iliac crest to the inferior borders of the ribs and the aponeurosis on the lateral portion of rectus abdominus muscle
- extends upward and medially
- perpendicular to the external oblique muscle
Transverse Abdominus Muscle
- inner most of the flat abdominal muscles
- originates from: costal margin, lumbar fascia, anterior 2/3 of iliac crest and lateral half of the ingual ligament
- inserts on the aponeurosis of the posterior rectus sheath
- fibers are transverse
Aponeurosis
- layers of flat broad tendons
- ventral abdominal region has one of the thickest aponeuroses (also seen in the dorsal lumbar region, palmar and plantar regions)
- joins muscles and body parts the muscle acts on
Rectus Abdominus Muscle
- anteriorly on each side of the linea alba
- long and vertical
- extends from xiphoid process to symphysis pubis
- enclosed in a sheath of the aponeuroses of the 3 lateral muscles
Psoas Major Muscle
- origin: vertebral bodies, intervertebral discs and transverse process of T12-L5
- pass along the iliac crest of the pelvis
- inserts on the lesser trochanter of femur
- long and thick
- in transverse, they appear as large muscular masses adjacent to the lumbar vertebral bodies
- circular muscle
Quadratus Lumborum (QL) Muscle
- thick muscular sheath
- origin: iliac crest and transverse process of L1-L4
- ascends to insert on inferior border of 12th rib
- in transverse, appears lateral and posterior to psoas major muscle
- flat muscle
Serous Membranes
- lines cavities that are closed to exterior (pleural, pericardial, peritoneal)
- occur in pairs
- secretes a fluid that lubricates the surface of membranes, reducing friction
- double lined (everything is expanding and contracting)
Peritoneum
-the serous membrane in the abdominal cavity
Epithelial Membranes
- moist membranes
- line all body cavities that are open to the exterior (respiratory, digestive, urinary, reproductive)
Synovial
-membrane that lines joint cavities
Epithelial means…
skin
Synovial means…
joints
Cutaneous means…
skin
Visceral means…
organ
Parts of Digestive System (aka GI/Gastrointestinal Tract)
- extends from mouth to anus
- liver
- gall bladder
- pancreas
Parts of Cardiovascular System
- heart
- arteries
- veins
- capillaries
- blood (45% blood cells, 55% plasma)
- red blood cells
- white blood cells
- plasma
Parts of Respiratory System
- nose
- mouth
- pharynx
- larynx
- trachea
- bronchi and bronchioles
- alveoli
- lungs
Parts of Nervous System
- brain
- spinal cord
- nerves
- sensory organs
Parts of Excretory/Urinary System
- kidneys
- ureters
- urinary bladder
- urethra
Parts of Reproductive System
- ovaries and testes (gonads)
- uterus (female)
- penis (male)
Parts of Lymphatic System
- thymus
- spleen
- tonsils
- adenoids
- appendix
- lymph nodes
- lymph fluid
- lymph vessels
Parts of Integumentary System
- skin
- hair
- nails
- eyelashes
- eyebrows
Parts of Endocrine System
- pituitary
- pineal
- thyroid
- parathyroid
- adrenal glands
- hypothalamus
- pancreas
- ovaries
- testicles
Abdominal Cavity
- stomach
- intestines
- gall bladder
- liver
- kidneys
- pancreas
- spleen
- ureters
Pelvic Cavity
- reproductive organs
- urinary bladder
- lowest part of large intestine
What are the 2 major categories of glands in the body?
1) exocrine
2) endocrine
Endocrine Glands
- part of Endocrine System
- secrete their products (hormones) directly into the blood (rather than through a duct)
Exocrine Glands
-glands that produce and secrete substances onto an epithelial surface or into a lumen by way of a duct
Examples of Endocrine Glands
- pineal gland
- pituitary gland
- hypothalamus gland
- thyroid gland
- parathyroid glands
- adrenal glands
- pancreas
- ovaries (female)
- testes (male)
Examples of Exocrine Glands
- sweat glands
- salivary glands
- mammary glands
- ceruminous glands
- lacrimal glands
- sebaceous glands
- mucous glands
Osseous means…
bone
Pleural Cavity
fluid filled space between the lungs
Mediastinum Cavity
- division of the thoracic cavity
- between the lungs
Pericardial Cavity
cavity within the mediastinum
Is the aorta intraperitoneal or retroperitoneal?
retroperitoneal
What is the function of the aorta?
-supplies body structures with oxygen rich blood
Where does the abdominal portion of the aorta begin?
-2.5cm above the transpyloric line at the aortic hiatus (T12) in the diaphragm
Where does the aorta run?
-vertically along midline, slightly left lateral and anterior to spinal column
What are the aortic subdivisions?
- ascending aorta
- aortic arch
- descending aorta (thoracic and abdominal)
What are the branches of the abdominal aorta?
- celiac trunk (left gastric artery, common hepatic artery, splenic artery)
- superior mesenteric artery (SMA)
- Lt and Rt Suprarenal Arteries (same level as SMA)
- Lt and Rt Renal Arteries
- Lt and Rt Gonadal Arteries
- Lumbar Arteries (L3/L4)
- Inferior Mesenteric Artery (IMA)
- Branches into Lt and Rt Common Iliac Arteries (CIA)
- Median Sacral Artery
What do the paired and unpaired visceral branches of the aorta supply?
-supply the viscera (organs) of the abdominal cavity
Unpaired Visceral Branches
- celiac trunk
- superior mesenteric artery
- inferior mesenteric artery
Paired Visceral Branches
- suprarenal arteries
- renal arteries
- gonadal arteries
What do the unpaired and paired parietal branches supply in the aorta?
-supply the abdominal wall
Celiac Trunk
- anterior branch of abdominal aorta
- 1st unpaired visceral branch
- L1 level
- lies superior to and within a few centimetres of the SMA
- superior to the level of the pancreas
- also known as celiac axis
What are the major branches of the celiac trunk?
- left gastric artery (LGA)
- splenic artery (SA)
- common hepatic artery (CHA)
Left Gastric Artery
- branch of the celiac trunk
- courses superior and left lateral
- supplies the lesser curvature of stomach
- joins with right gastric artery
- not readily visualized
Left Splenic Artery
- branch of the celiac trunk, travelling left towards the splenic hilum
- supplies the spleen, pancreas, stomach and greater omentum
- forms the superior border of the pancreas
- easily visualized (very tortuous due to it’s relationship with the pancreas)
Common Hepatic Artery
- celiac trunk branch
- courses horizontally to the right
- branches into gastroduodenal artery, proper hepatic artery and right gastric artery
Gastroduodenal Artery (GDA)
- courses inferiorly
- landmark: head of pancreas
- supplies the greater curvature of the stomach and anastomoses with the splenic artery
Proper Hepatic Artery
- courses superiorly
- supplies the liver by branching into the right and left hepatic arteries
Right Gastric Artery
- supplies medial aspect of the stomach
- anastamoses with left gastric artery
Superior Mesenteric Artery
-anterior
-lower level of L1
-just below transpyloric line
inferior to the celiac axis
-courses anteroinferiorly
-proximal portion is readily seen as a landmark
-branches supply: small intestine, cecum, ascending colon and transverse colon
-other branches supply: pancreatic head and duodenal area
Renal Arteries
- paired visceral branches off lateral aspect of aorta
- located a few centimetres inferior to the origin of SMA at upper L2 level
- courses horizontally to each kidney
- RRA runs posterior to IVC
Gonadal Arteries
- paired visceral branches just inferior to the renal vessels (lower level of L2)
- descend along the psoas muscles, over the external iliac vessels
- not readily visualized
Lumbar Arteries
- 4
- arise from posterolateral surface of the aorta along the upper four lumbar vertebrae
- supply the posterolateral abdominal wall
Median Sacral Artery
- unpaired
- arises from posterior surface of aorta
- proximal to bifurcation
- supplies posterior abdominal wall
Aortic Bifurcation
- L4
- bifurcates into Lt and Rt common iliac arteries
- at L5 and S1 they divide further into internal and external iliac arteries
Internal Iliac Artery
-supplies the wall and the viscera of the pelvis, perineum, and gluteal region
External Iliac Artery
- continuous with the femoral artery
- supplies the lower limbs
Common Iliac Veins
- external and internal iliac veins join to form a common iliac vein anterior to the sacroiliac joint
- drain the regions supplied by the iliac arteries
- Rt and Lt common iliac veins pass obliquely upward from the SI joint to the 5th lumbar vertebrae where they form the IVC
Lumbar Veins
-4 to 5 pairs of vessels that collect blood from the muscles and skin of the posterior abdominal wall
Gonadal Veins
- testicular veins ascend through spermatic cord, into abdomen
- ovarian veins originate in the ovary
- ascends retroperitoneally into the abdomen
- Rt opens directs into IVC
- Lt drains into the left renal vein
Renal Veins
- L2
- around same level as renal arteries
- anterior to renal arteries
- superior to gonadal veins
- LRV: drains left kidney, receives the left suprarenal vein and left gonadal vein before emptying into the IVC, LRV passes anteriorly to aorta just inferior to the origin of SMA
- RRA: drains right kidney, slightly inferior to the LRV because the right kidney is lower than the left
- RRV is shorter and narrower than LRV
- passes posteriorly to the 2nd part of duodenum
Why is the RRV narrower than the LLV?
-the LRV has the suprarenal and gonadal veins emptying into it
Suprarenal Veins
- Rt is shorter than Lt
- Rt empties directly into IVC
- Lt empties into Lt renal vein
Hepatic Veins
- drain blood from the liver
- the central veins of liver lobules collect blood from the interlobular venous sinusoids
- central veins merge to form right, middle and left hepatic veins
- exit from the posterior surface of the liver and empty directly into the IVC
Hepatic Portal System
- drains all of the nutrient rich blood from the stomach, intestines, pancreas and spleen
- delivers it to the liver to be processed via the portal vein
- all blood from the digestive system must pass through the liver before entering into the IVC
What does the SMV drain?
- small intestine
- cecum
- ascending colon
- transverse colon
What does the IMV drain?
- descending colon
- sigmoid colon
- rectum
- empties into the splenic vein posterior to pancreatic body
What does the SV drain?
- spleen
- pancreas
What vein does the IMA drain into?
-splenic vein
What 2 veins join to form the Portal Confluence?
- splenic vein
- superior mesenteric vein
Serous Membranes
- lines cavities that are closed to the exterior (pleural, pericardial, peritoneal)
- occur in pairs
- secrete a serous fluid that lubricates the surfaces of membranes, reducing friction
What is the peritoneum?
- thin serous membrane that forms lining of the abdominal and pelvic cavities
- covers most intra abdominal organs
- provides a pathway for blood vessels and lymph
- secretes a serous fluid that separates the 2 linings, where they come together and allows the organs to move around in the abdominal cavity with less friction
Visceral Peritoneum
-covers organs
Parietal Peritoneum
-lines cavity (forms a closed sac)
What is the difference between the peritoneal cavity in males and females?
- males it is closed
- females it is open through uterine tubes, uterus and vagina
What are the 3 layers of the peritoneum?
- mesenteries
- omenta
- peritoneal ligaments
Mesentary
- double layer of peritoneum that suspends organs in abdominal cavity
- serves as a conduit for blood vessels, lymphatic vessels and nerves
Omenta
-double layer of peritoneum that is attached to the stomach
What is the greater omentum?
- connects stomach to transverse colon
- folds back up and attaches to the anterior surface of the transverse colon
What is the lesser omentum?
- connects stomach to liver
- forms hepatogastric and hepatoduodenal ligaments
- connects the greater sac via the ‘Foreman of Winslow’
What is the function of the greater omentum?
1) fat deposition
- fat storage area
2) immune contribution
- phagocytosis
3) infection/wound isolation
- may physically limit the spread of infection
- can wrap around areas of infection/trauma
What is the space behind the lesser omentum and stomach?
- omental bursa (aka lesser sac)
- the remainder is termed the greater sac
What does the passageway between the greater and lesser sacs allow for?
-passage of vessels and nerves
Epiploic Foreman (Foreman of Winslow)
‘epiploic’- associated with omentum
‘omentum’- fold of peritoneum that attaches the stomach to something else
The greater sac is also called the…
abdominopelvic cavity
The lesser sac is also called the…
omental bursa
What are the 3 ligaments of the greater omentum?
- gastrophrenic ligament
- gastrosplenic ligament
- gastrocolic ligamaent
Gastrophrenic Ligament
-connects greater curvature of stomach to the diaphragm
Gastrosplenic Ligament
-connects greater curvature of stomach to the spleen
Gastrocolic Ligament
- connects greater curvature of stomach to the first part of the duodenum and the transverse colon
- forms a fatty apron that lies over the intestines
What ligaments make up the lesser omentum?
- hepatogastric ligament
- hepatodudodenal ligament
Hepatogastric Ligament
-connects lesser curvature of stomach to the liver
Hepatoduodenal Ligament
-connects lesser curvature of stomach to the duodenum
Falciform Ligament
- divides liver into Lt and Rt lobes
- attaches anterosuperior surface of the liver to the anterior abdominal wall and diaphragm
Ligamentum Teres (round ligament)
- remnant of left umbilical vein
- originates from free edge of falciform ligament and extends to umbilicus
Coronary Ligament
- attaches liver to inferior surface of diaphragm
- has 2 layers of peritoneum that are separated by the bare area
Lt and Rt triangular Ligaments
-where the layers of coronary ligament meet to the Lt and Rt
What are intraperitoneal structures?
- completely surrounded by visceral peritoneum
- attach to the abdominal cavity by the mesentery
What are the intraperitoneal structures?
- stomach
- first part of duodenum
- majority of intestines
- ovaries
- gallbladder
- spleen
- liver (except bare area)
What are introperitoneal structures?
-structures in the abdominal cavity, but not the peritoneal cavity
What are the retroperitoneal structures?
- adrenal glands
- aorta
- IVC
- transverse and descending duodenum
- pancreas
- ureters
- ascending and descending colon
- kidneys
- esophagus
- rectum
What are the borders of the liver?
- superior, anterior and a portion of posterior: diaphragm
- posterior: lumbar region and muscular abdominal wall
Bare Area (liver)
- direct contact with diaphragm
- not covered by peritoneum
Subphrenic Recess
-peritoneal space that separates the inferior portion of the liver from the diaphragm
What is the inferior margin of the liver?
-border between diaphragm and visceral surface
Subhepatic Space
-inferior to anterior visceral surface of the liver
Hepatorenal Recess (Morrison’s Pouch)
-space between the liver and right kidney
According to Couinaud, in the centre of each liver segment there is a…
- portal vein
- hepatic artery
- bile duct
According to Couinaud, in the periphery of each segment there is…
-vascular outflow through hepatic veins
What divides the liver into superior and inferior segments?
portal veins
What divides the Rt lobe of the liver into anterior and posterior sections?
right hepatic vein
What divides the Lt lobe into medial and lateral sections?
left hepatic artery
What do the hepatic veins do?
drain blood to IVC
Which part of the liver does the RHV drain?
right anterior and posterior
Which part of the liver does the MHV drain?
- right anterior
- left medial
Which part of the liver does the LHV drain?
-left medial and lateral
What is the gastrointestinal tract composed of?
- mouth
- pharynx
- esophagus
- stomach
- sm and lg intestines
Esophagus
- cricoid cartilage to stomach
- mostly in thoracic cavity, but partly in abdomen
- anterior to vertebral column and Rt of aorta
At what level does the esophagus move to the left, passing anterior to the aorta, en route to the stomach?
T7
At what level does the esophageal hiatus penetrate the diaphragm?
T10
The right margin of the esophagus is continuous with the ______ ______ ___ ___ ______.
lesser curvature of the stomach
Cardiac Notch
-separates the left margin of esophagus from the fundus of stomach
Where does the esophagus enter the stomach?
the cardiac orifice
What is the EGJ?
-esophageal gastric junction
What is the lower esophageal sphincter?
- located at the cardiac orifice (where the stomach and esophagus meet)
- slows passage of food into the stomach to avoid reflux
What quadrant is the stomach located in?
LUQ
Where is the lesser curvature of the stomach?
directly medial and superior
Where is the greater curvature of the stomach?
directly lateral and inferior
What are the regions of the stomach?
- cardia
- fundus
- body
- pylorus: antrum and canal
What vessels supply the stomach?
- LGA: lesser curvature and part of stomach
- SA: lateral fundus (via short gastric arteries) greater curvature (via Lt gastro-epiploic artery)
- CHA: greater curvature (via Rt gastric and Rt gasto-epiploic arteries)
What are the 4 parts of the duodenum?
1) bulb
2) descending
3) transverse
4) ascending
What surrounds the jejunum and ileum?
-superiorly and laterally by large bowel (colon)
How long is the jejunum and ilium?
5.8m
Where is the jejunum and ileum located?
- central and lower part of abdominal cavity
- extends from duodenaljejunal flexure and terminates at the large bowl in the Rt iliac fossa (ileocecal junction)
Where do most digestive processes take place?
small bowel
The large intestine is also known as the…
- large bowel
- colon
What are the 7 portions of the colon?
- cecum
- ascending colon
- transverse colon
- descending colon
- sigmoid colon
- rectum
- anus
Is the colon intraperitoneal or retroperitoneal?
retroperitoneal
What are the 2 flexures associated with the colon?
1) hepatic/Rt colic
2) splenic/Lt colic
Where is the appendix located?
- RLQ
- 1/3 of the distance between a line drawn from the ASIS and umbilicus (aka McBurney’s point)
Which vessel runs posterior to the pancreas?
-splenic vein
Where is the portosplenic confluence?
-anterior to the uncinate process and posterior to the neck of the pancreas?
Which vessels supply the pancreas and which vessels drain the pancreas?
- supplied by splenic artery
- drained by splenic vein
What are the 2 pancreatic ducts?
1) Duct of Wirsung (aka main pancreatic duct)
2) Duct of Santorini (aka accessory duct)
Duct of Wirsung (main pancreatic duct)
- begins at the tail of pancreas
- empties into the descending duodenum
Duct of Santorini (accessory pancreatic duct)
- branch of the main pancreatic duct
- enters the duodenum superior to the duct of Wirsung
What do the Lt and Rt hepatic ducts do?
-drain Rt and Lt lobes of the liver of bile
What do the Lt and Rt hepatic ducts join to form?
the common hepatic duct
Where are the Lt and Rt hepatic ducts located?
- intrahepatic
- on inferior surface of the liver and exited medially toward the hilum (aka porta hepatis)
What are the 2 billiard ducts?
What do the join to form?
1) common hepatic duct
2) cystic duct
-join to for the CBD (common bile duct)
Where is the CBD (common bile duct) located?
- enters descending duodenum through the Sphincter of Oddi
- runs posterior to the 1st portion of the duodenum and the pancreatic head
Where are the kidneys located?
- lateral to each side of the spine
- along posterior body wall, against psoas muscles
- inferior to the diaphragm
Which kidney is more superior?
left
What protects the kidneys?
- floating ribs
- pararenal fat
- Gerota’s fascia
- perirenal fat
- renal capsule
Hydronephrosis
- kidney slips out of protective layers
- ureters twist and block urine (caused by nephroptosis)
What is the renal hilum and where is it located?
- medial border of kidneys where blood vessels enter and exit
- located at the transpyloric plane
What structures are located at the renal hilum?
- ureter
- renal artery
- renal vein
What do the renal arteries supply and where are they located?
-supply kidneys with blood
- arise bilaterally from AO, below the SMA
- horizontal orientation
- lie posterior to renal veins
- RRA runs directly posterior to IVC
How much cardiac output passes through the renal arteries to be filtered?
1/3
What do the renal veins drain and where are they located?
-drains blood that has been filtered by the kidneys
- enter IVC horizontally
- LRV passes directly posterior to the SMA and anterior to the AO
Which renal vein is longer?
-left is longer than right
Where are the ureters located?
- originate in renal pelvis
- lie medial to renal hilum
- descend anteriorly along psoas major from the hilum to bladder
- cross anteriorly over the iliac arteries
- insert in bladder on inferior posterolateral aspect
Where are the kidneys in relation to the QL muscle?
anterior
Where are the kidneys in relation to the abdominal wall muscles?
posteromedial
Where are the kidneys in relation to the psoas major muscles?
anterolateral
Where are the kidneys in relation to the diaphragm?
inferior
Where are the adrenal glands located?
- superior and slightly medial to each kidney
- anterior to QL and psoas muscles
What encloses the kidneys and adrenal glands?
Gerota’s fascia
Which vessels supply the suprarenal/adrenal glands and which vessels drain the suprarenal/adrenal glands?
- supply: 3 suprarenal arteries
- drain: Lt drains into LRV and Rt drains directly into IVC
Pelvic Cavity
-basin shaped cavity inferior portion go the abdominal/pelvic cavity
What are the 2 components of the pelvic cavity?
- pelvis major (false pelvis)
- pelvis minor (true pelvis)
Pelvis Major (false pelvis)
- between the iliac fossa superiorly and the pelvic brim inferiorly
- considered part of abdominal cavity
- contains abdominal viscera such as parts of the small intestine and sigmoid colon
Pelvis Minor (true pelvis)
- between pelvic brim superiorly and pelvic diaphragm inferiorly
- enclosed by the sacrum, ischium, pubis, and pelvic portions of the ilium
- contains bladder, rectum, internal reproductive organs, and some intestinal tract if it reaches
Linea Terminalis
- imaginary line that separates the true pelvis and false pelvis
- runs from the sacral promontory to the symphysis pubis
Os Coax (hip bones)
Consists of:
- ilium
- ischium
- pubis
-individual bones at birth that fuse in adults
Osseous Components of Pelvic Cavity
- ilium
- ischium
- pubis
- sacrum
- coccyx
Which bones meets to fuse the acetabulum?
- ilium
- ischium
- pubis
Ilium
- largest hip bone
- superior part has large wing like surface called the ‘ala’
- iliac crest is the superior margin limited anteriorly by the anterior superior iliac spine (ASIS) and posteriorly by the posterior superior iliac spine (PSIS)
- inner aspect of the ala: iliac fossa (origin for iliac muscle)
- articulates posteromedially with the sacrum at the SI joints
Pubic Bones
- bodies meet at midline at the symphysis pubis
- small projection lateral to body is pubic tubercle
- superior pubic ramus extends laterally from pubic tubercle to ilium
- inferior pubic ramus extends inferiorly from body to connect with ischium
What does the superior margin of the pubic ramus form?
- pectineal line
- continuous with the arcuate line (pelvic brim)
Pubic Arch in Males
less than 70 degrees in males
Pubic Arch in Females
greater than 80 degrees in females
Ischium Bone
- inferior portion of os coxae
- ramus of ischium meets ischium of pubis bone: ischiopubic ramus
- posteroinferior border of ischium has a bulky, rough surface called the ischial tuberosity
Ischiopubic Ramus
-ramus of ischium meets ischium of pubis bone
What is the inferior border of the greater sciatic notch?
-ischial spine
What is the superior border of the lesser sciatic notch?
-ischial spine
Sacrum
-5 fused distal segments of the vertebral spine
-posterior midline border of the pelvic cavity
-posterior tilt
-anteriorly concave
-supports pelvic viscera
-weight transfer from
sacrum to hip bones to legs
-articulates the 5th lumbar vertebra superiorly, coccyx inferiorly and the os coxae laterally
Sacral Promontory
-marks the posterior portion of the pelvic inlet/brim
What forms the sacral nerve passage?
-anterior and posterior bilateral columns of sacral foramina
SI Joint
- articular surface on lateral aspect to articulate with iliac bones
- aka iliosacral joint, sacroiliac joint
Coccyx
- aka tailbone
- most inferior portion of spine
- 3 to 5 fused rudimentary vertebrae with no processes or foramina
- offers no support, but provides attachment points for some pelvic floor muscles
Female Pelvis
- bones are lighter, thinner
- false pelvis is shallow
- pelvic cavity is wide and shallow
- pelvic inlet is round/oval
- pelvic outlet is comparatively large
- pubic angle large
- coccyx more flexible, straighter
- ischial tuberosities more everted
Male pelvis
- bones heavier and thicker
- false pelvis is deep
- pelvic cavity is narrow and deep
- pelvic inlet heart shaped and smaller
- pelvic outlet compositely small
- subpubic angle more acute
- coccyx less flexible, more curved
- ischial tuberosities longer, face medially
What is the inferior boundary of the pelvis major?
-pelvic brim, linea terminalis
What articulates with the auricular surface of the ilium?
-sacrum
What bones form the os coxa?
- ilium
- ishium
- pubic bones
Where do the 3 bones of the os coxa meet?
-acetabulum
Which pelvic bone is most inferior?
-ischium
Which bone articulates with the sacrum inferiorly?
-coccyx
What is the pelvis minor also referred to as?
-true pelvis
A pelvis with an acute subpubic angle belongs to which gender?
-male
False Pelvis Muscles
- actually abdominal muscles, but extend down into the pelvis
- iliopsoas (psoas major and iliacus)
- rectus abdominus
Iliopsoas Muscle
- psoas major joins the iliac muscle at the iliac crest level
- courses anteriorly along the linea terminalis
- travels over pelvic brim
- inserts onto the lesser trochanter of the femur
Rectus Abdominus Muscle
- most anterior muscle of the pelvic cavity
- bilateral to the line alba
- ascends from pubis to xiphoid process vertically
Which 2 muscles cover the true pelvic wall?
- obturator internus (ant)
- piriformis (post)
Obturator Internus
- fan shaped
- covers anterolateral wall of true pelvis
- originates on inner inferior aspect of the obturator foramen, crosses it and leaves pelvis through the lesser sciatic notch where it makes a sharp turn to insert on the medial surface of the greater trochanter
- rotates the thigh
Piriformis Muscle
- originates on anterior surface of the sacrum
- passes through the greater sciatic notch to insert on the greater trochanter of femur
- rotation and abduction of the thigh
Pelvic Outlet Muscles
- support pelvic viscera
- peritoneum
- pelvic diaphragm (levator ani and coccygeus)
- urogenital diaphragm (transverse perineal and external urethral sphincter)
Muscles of the Peritoneum
- external to the pelvic and urogenital diaphragms
- divided into 2 regions:
- urogenital triangle (bulbospongiosus, ishiocavernosus and transversus perineal)
- anal triangle (sphincter ani muscle)
Pelvic Diaphragm Muscles
- levator ani (pubococcygeous, iliococcygeous)
- coccygeous
- line the floor of the true pelvis
- provide support for pelvic organs
Levator Ani Muscles
- pubococcygeous
- iliococcygenous
- hammock like portion of pelvic floor
- aids in contractions of vagina and rectum
Pubococcygeus Muscles
- most medial and anterior muscle of pelvic diaphragm
- extends from pubic bone to coccyx
Iliococcygeous Muscles
- lie posterolateral to the pubococcygeous
- extend from lateral pubic bone and ischial spine to coccyx
Coccygeous
- most posterior muscle pair of the pelvic diaphragm
- extend from ischial spine to coccyx
The pelvic diaphragm is composed of ___ paired muscles.
3
Deep Transverse Perineal
- aka transverse perinei
- horizontal muscles
- originate on ischial tuberosities and pass medially to insert on central perineal tendon
External Urethral Sphincter
- voluntary (unlike internal urethral sphincter)
- stops urine from exiting the bladder
Perineal Muscles
- most superficial layer
- diamond shaped area between pubic arch anteriorly, coccyx posteriorly, and ischial tuberosities laterally
- divided into urogenital (ant.) region and anal region (post.)
UG Region Muscles
- bulbospongiosus
- ishiocavernosus
- superficial transverse perineal
Anal Region Muscles
-sphincter ani
Superficial Transverse Perineal
- arise on ischial tuberosities and pass medially to insert on central perineal tendon
- divides perineum into UG and anal regions
Ischiocavernosus
-arise on ischial tuberosities, pass forward to insert on pubic arch and crus of penis (males) or clitoris (females)
Bulbospongiosus
- median line of UG region
- female it is separated by the urethra/vagina
- male is unites midline and encircles corpus spongiosum of penis
Sphincter Ani Muscles
-surround anal canal
Extrapelvic Muscles
-seen on pelvic sections, but are technically part of lower extremity
- gluteus maximus
- gluteus medius
- gluteus minimis
Which group of organs are located in the false/greater pelvis?
-gastrointestinal organs
Which groups of organs are located in the true/lesser pelvis?
- urinary organs
- reproductive organs and accessory structures (sex dependant)
Where are the cecum and ascending colon found?
-Rt side of greater pelvis
Where is the descending colon located?
-becomes continuous with sigmoid colon at pelvic brim
What does the sigmoid colon join with?
- rectum at level of mid sacrum
- becomes fixed to posterior pelvic wall
Where is the rectum located?
-follows curvature of sacrum/coccyx onto the pelvic floor where it penetrates the levator ani muscle and becomes the anal canal
Rectouterine Pouch
- peritoneum that extends from the surface of the rectum to the uterus
- female
Vesicouterine pouch
- peritoneum that extends over the uterus anteriorly to the bladder
- female
Rectovesicle
- peritoneum that extends from the upper anterior portion of rectum to the bladder
- male
Where are the ureters located?
- upper half is in abdomen
- cross over pelvic brim anterior to the internal iliac artery origin
- follow course of internal iliac arteries then turn medially at the level of ischial spine to enter urinary bladder on its posteroinferior surface
Where is the urinary bladder located?
-true pelvis
Where is the bladder in females?
- rests on pelvic floor
- posterior to symphysis pubis
Where is the bladder in males?
-superior to prostate gland, which is on pelvic floor
Which way does the urethra project?
- inferiorly from bladder to exterior
- through the prostate gland in males
Female Urethra
- 4cm long muscular tube
- extends from internal urethral orifice to external urethral orifice
- external urethral orifice opens into vestibule just anterior to vagina
Male Urethra
- approx 5 times the length of female urethra
- extends from the internal urethral orifice at the tip of the glans penis
- 3 regions
What are the 3 regions of the male urethra?
- prostatic urethra–prox
- membranous urethra–mid
- penile (spongy) urethra–distal
Prostatic Urethra
- passes through prostate gland
- ejaculatory ducts from prostate gland open into this part
- most proximal portion
Membranous Urethra
- shortest/narrowest portion
- passes through urogenital diaphragm to enter penis
- medial portion
Penile (spongy) Urethra
- longest part
- extends full length of the corpus spongiosum of the penis
- ducts of the bulbourethral glands open into the proximal region of the spongy urethra
- most distal portion
Trigone
- area of bladder forced between the openings for 2 ureters and one opening for the internal urethral orifice
- most sensitive to pain
Female Reproductive Organs
- ovaries
- uterine tubes
- uterus
- vagina
Peritoneal Ligaments
-double folds of peritoneum that hold the reproductive organs in place
Broad Ligament of Uterus
- large fold of peritoneum that covers uterus, uterine tubes, and ovaries
- divides pelvic cavity into anterior (bladder) and posterior (rectum)
Round Ligaments (x2)
- extend from the uterine horns to the anterior pelvic wall
- pass through the inguinal canal and attach to subcutaneous tissue of labia major
Uterosacral Ligaments (2x)
-connects uterus to sacrum
Lateral Cervical (Cardinal) Ligaments
- extend from lateral walls of cervix to the pelvic floor
- stabilize the cervix
What are the 3 peritoneal ligaments that hold the ovaries?
- mesovarium
- ovarian ligament
- suspensory ligament
Mesovarium
-attaches ovary to posterior layer of broad ligament
Ovarian Ligament
- cord like thickening in the broad ligament
- attaches ovary to the lateral wall of uterus
Suspensory Ligament
- extension of broad ligament
- carries ovarian vessels and attaches ovary to lateral pelvic wall
Ovary
- small, solid, oval structure
- 3cm long
- contains 250 000 primary oocytes at birth
Ovarian Fossa
shallow depression in lateral wall of pelvis on either side of uterus
Uterine Tubes
- slender tubes about 10cm long
- located in upper border of broad ligament
- extend from upper lateral angle of the uterus to the ovarian region
- lumen is continuous with the uterine cavity
Infundibulum
-funnel shaped distal portion of uterine tube which is edged with finger like extensions called ‘fimbriae’
Are ovaries and uterine tubes connected?
NO
Uterus
- hollow, pear shaped, muscular organ
- functions to receive embryo and sustain it’s life during development
- located in anterior portion of pelvic cavity, superior to vagina
- usually tilted forward relative to the vagina and bends over superior surface of urinary bladder (anteverted and anteflexed)
- can be retroverted as well
What are the 3 layers of the uterus?
1) endometrium-inner layer
2) myometrium- middle muscular layer
3) perimetrium- serous peritoneum, continuous with broad ligament (outer layer)
How is the uterus divided?
- body
- horn
- cervix
- external os
Uterus Body
- upper 2/3rds (bulges superiorly to fundus)
- uterine tubes enter uterus at it’s broadest part, between the fundus and the body
Uterus Horn
-area where the uterine tube and uterus connect
Cervix
-lower 1/3rd of uterus that expands inferiorly into the upper portion of the vagina
External Os
-opening of cervix into vagina
Vagina
- plays a key role in both beginning and end of reproductive process
- receives the male erect penis during intercourse and acts as a birth canal during childbirth
- 10 to 15cm long muscular tube that extends from the cervix to the vestibule on the exterior
- located posterior to the urethra and anterior to the rectum
Fornices
- aka fornix
- the recesses of vagina around cervix
- posterior fornix is longer than anterior fornix due to cervical angle
- posterior fornix is related to rectouterine pouch
If a surgical instrument penetrated the rectouterine pouch, what could it cause?
- hemmorage
- peritonitis
Why is the anterior wall of the vagina shorter than the posterior wall?
-because the cervix projects into the vagina on an angle
Vulva (aka pudendum)
-collective term referring to all portions of the external female genitalia
Mons Pubis
- subcutaneous fat pad anterior to symphysis pubis
- area where pubic hair grows
Labia Majora
-2 large folds of skin filled with subcutaneous fat located at the lateral margins of the vulva
Labia Minora
- 2 thin, delicate folds of skin located medial to the labia majora, but lateral to the urethral and vaginal openings
- united anteriorly to form the prepuce over the clitoris
Clitoris
-inferior to mons pubis and between the anterior ends of labia minor
Vestibule
- narrow cleft between the 2 labia minor
- bordered by the clitoris at the anterior end
Urethral Orifice
-opens into the anterior portion of the vestibule
Vaginal Orifice
-opens within the vestibule, posterior to the urethra
Paraurethral and Greater Vestibular Glands
- secrete mucous for lubrication
- located on either side of urethral and vaginal offices
Male Reproductive Organs
- testes
- scrotum
- vas deferens
- ejaculatory duct
- seminal vesicles
- prostate
- bulbourethral glands
- penis
*all of these organs are located in the pelvic cavity, except the testes and penis
What are the best imaging modalities for the brain?
-CT or MRI
Why is the fetal brain easier to see on US than the adult brain?
-fetal brain has thinner bone structure
How is the fetal brain visualized with US?
- through unclosed fontanels of the cranium
- can assess bleeding
How can vasculature of the Circle of Willis be assessed?
- transcranial doppler (TCD)
- using windows of thinner bone (temporal area)
Layers of the Scalp
- skin
- CT
- aponeurosis
- loose areolar tissue
- periosteum
CT Layer of Scalp
-subcutaneous fat and fibrous tissue that holds nerves and vessels
Aponeurosis Layer of Scalp
-dense fibrous tissue
Loose Areolar Tissue of Scalp
- contains collagen
- allows upper layers to move
Brain Layers
- bone
- meninges: dura mater, arachnoid mater and pia mater
Dura Mater
- tough, outer layer
- pierced only by cranial nerves, carotid and vertebral vessels
- 2 layer: endosteal and meningeal
Arachnoid Mater
- thin, delicate, middle layer
- vessels flow through
Arachnoid Villi
-protrude into dural venous sinuses (CSF reabsorption)
Pia Mater
- inner, thin, vascular layer
- continuous with contours of he brain
Gyrus
-outpouching part of brain tissue (mountain)
Sulcus
-portion of brain that is recessed (valley)
Central Sulcus
- lg coronal sulcus
- divides frontal and parietal lobes
Sylvian Fissure
- x2
- lateral
- divides temporal lobe (below) from frontal and parietal lobes (above)
- ends in the insula
Fontanelles
-junctions of skull sutures that have not yet ossified
When do fontanelles ossify by?
-18 months
How many cranial bones are there?
8
What are the paired cranial bones?
- temporal
- parietal
What are the unpaired cranial bones?
- frontal
- occipital
- sphenoid
- ethmoid
How many facial bones are there?
14
What are the facial bones?
- maxillae (2)
- nasal (2)
- zygomatic (2)
- lacrimal (2)
- mandible
- vomer
- inferior nasal conchae (2)
- palatine (2)
How many brain lobes are there?
6
What are the brain lobes?
- frontal
- parietal (2)
- occipital
- temporal (2)
What are the skull sutures?
- coronal
- sagittal
- lambdoidal
- lateral (2)
What are the brain fontanelles?
- anterior
- posterior
- sphenoid (2)
- mastoid (2)
How many skull sutures are there?
5
How many brain fontanelles there?
6
Regions of the Brain
- cerebral hemisphere
- cerebellum
- diencephalon
- brainstem
Parts of the Diencephalon
- thalamus
- hypothalamus
Parts of the Brainstem
- midbrain
- pons
- medulla oblongata
Corpus Callosum
- largest fibre pathway in the brain
- links Lt and Rt cerebral hemispheres
4 Parts of the Corpus Callosum
- rostrum
- genu (ant.)
- isthmus (body)
- splenium (post.)
What forms the anterior, superior and posterior border around the lateral ventricles?
-corpus callosum
Where are ventricles of the brain located?
-within the brain parenchyma
What are the ventricles of the brain responsible for?
-communication network of cavities
What are the ventricles of the brain filled with?
-CSF
What is the ventricular system composed of?
- lateral ventricles (2)
- 3rd ventricle
- cerebral aqueduct
- 4th aqueduct
Choroid Plexus’
- located within ventricles
- produce CSF
What does CSF fill?
- fills ventricles and subarachnoid space
- follows cycle of constant production and reabsorption
What is another word for the intervetricular foramen?
-Foramen of Monroe
Basal Ganglia
- clusters of grey matter
- lateral to diencephalon
What separates the diencephalon from grey matter?
-internal capsule (white matter)
Brain Vascular Supply
2 Sets of Arteries:
- vertebral arteries
- internal carotid arteries
Circle of Willis
- anastomotic system of arteries
- at base of brain
- supplies blood to brain and surrounding structures
What does the structure of the Circle of Willis allow for?
-preservation of brain tissue
What happens if there is a blockage in the Circle of Willis?
-blood moves around the circle, supplying the same area from a different direction
Where are dural venous sinuses located?
-between the endosperm layer and meningeal layer of the dura mater
Where do dural venous sinuses receive blood from?
-veins in the brain (do NOT run along arteries)
Where do the dural venous sinuses mainly drain into?
-internal jugular vein
Where do dural venous sinuses receive CSF from?
-arachnoid villi in the subarachnoid space
What are the 4 major components of the brain?
- vertebral compartment
- visceral compartment
- vascular compartments (x2)
What are the 4 major components of the brain enclosed in?
-the musculofascial collar
Visceral Compartment
-contains thyroid, thymus and parts of larynx and pharynx that pass between head and thorax
Vertebral Compartment
-contains cervical vertebrae and associated postural muscles
Vascular Compartments (x2)
-contains major blood vessels and the vagus nerve
How many cervical vertebrae are there?
7
Why are the osseous components of the neck easily distinguishable?
-due to their transverse foramina where the vertebral arteries pass through
Shape of Osseous Components
- bifid spinous processes
- except C7, which is long, pointed and palpable
C1
- atlas
- carries weight of head
C2
- axis
- allows head to rotate on neck
Structures of the Visceral Compartment of the Neck
- epiglottis
- hyoid bone
- thyroid cartilage
- thyroid gland
- trachea
- esophagus
Where is the hyoid bone located?
- superior to the thyroid gland
- anterior midline of neck
- between the chin and the thyroid cartilage
What is the shape of the hyoid bone?
-horseshoe
What does the hyoid bone provide attachment for?
-the floor of the mouth muscles, larynx and tongue
What is another name for thyroid cartilage?
-adams apple
What forms the anterior wall of the larynx?
-thyroid cartilage
What does the thyroid cartilage protect?
-vocal cords
Where is thyroid cartilage located?
-mid anterior of neck
superior to thyroid gland
Is thyroid cartilage visualized on US?
No.
What forms the attachment for laryngeal muscles?
-thyroid cartilage
What is the largest gland in the neck?
-thyroid gland
What is the shape of the thyroid gland?
- butterfly/bowtie
- wings representing Rt and Lt lobes (wrap around the trachea)
Where is the thyroid gland located?
- anterior
- deep to the skin and muscle layers
What connects Rt and Lt lobes of the thyroid gland?
-isthmus
What lobes can sometimes be seen on superior aspects of both thyroid lobes?
-pyramidal lobes
What projects superiorly from the isthmus level and inferior to the hyoid bone?
-thyroid gland
How many parathyroid glands are there?
4
Where are the parathyroid glands located?
- posterior aspect of the thyroid gland
- adjacent to each lobe
- medial and posterior to thyroid lobes
Are parathyroid glands easy to see?
- no
- unless enlarged
What is located posterior to sternocleidomastoid and the strap muscles?
-thyroid gland
What is medial to carotid artery and internal jugular vein?
-thyroid gland
Where is the trachea located?
- posterior to isthmus of thyroid gland
- medial to both lobes
- midline
Is the trachea seen on US?
- no
- air filled
Why is the trachea a landmark for US?
-casts a shadow
Where is the esophagus located?
- posterior and slightly Lt lateral to trachea
- inferomedial to Lt thyroid lobe
Why is the esophagus not assessed on US?
- air filled
- can be a landmark
What do the muscular components of the neck deal with?
- swallowing
- movement of head, neck and shoulders
Can neck muscles be imaged?
- yes
- they are small and hard to visualize
What are neck muscles divided into?
-2 triangles (anterior and posterior)
What are the 2 triangles (anterior and posterior) of neck muscles separated by?
-sternocleidomastoid muscle (SCM)
What are the anterior neck muscles?
- sternocleidomastoid muscle (lateral)
- longus colli muscle (deep)
- strap muscles
Strap Muscles (ant. neck muscles)
- omohyoid muscle (lateral)
- sternohyoid muscle (middle)
- sternothyroid muscle (medial, deepest and shortest)
Where are the anterior neck muscles located?
- extend from midline of neck to anterior margin of SCM
- superiorly from mandible to manubrium inferiorly
What is the largest, paired neck muscle?
-sternocleidomastoid
Where are the sternocleidomastoid muscles located?
- antero lateral
- transverse, obliquely across the side of neck
Where do the sternocleidomastoid muscles extend from?
-the mastoid process to the sternum
What do the sternocleidomastoid muscles aid in?
-flexion and rotation of the head
What is the most anterior neck muscles?
-sternohyoid
What attaches the hyoid bone to the sternum?
-sternohyoid muscles
Where are the sternothyroid muscles located?
- posterior to the medial border of the sternohyoid muscle inferiorly, and the lateral border of it superiorly
- shorter and deeper
Where do the sternothyroid muscles extend from?
-sternum to thyroid cartilage
Location of Omohyoid Muscles
- anterolateral
- extends from scapula to hyoid bone
- posterior to sternocleidomastoid muscle
Location of Longus Colli Muscles
- posterior border of thyroid gland
- anterior to vertebrae
Posterior Neck Muscles
- trapezius
- semispinalis capitus
- splenius capitus
- splenius cervices
What are the posterior neck muscles responsible for?
-rotating, extending and flexing the neck
Where is the trapezius muscle located?
- superficial
- extends from occipital bone to lower T spine
- laterally to scapular spine
What does the trapezius move?
- moves scapula
- supports the arm
What are the neck muscles from deepest to most superficial?
Deepest: semispinalis capitis
Middle: splenius capitis and splenius cervicis
Superficial: trapezium
Vasculature of the Neck
- bilateral common carotid arteries
- bilateral internal jugular veins
Bilateral Common Carotid Arteries
-arise from the brachiocephalic artery (RT) and aortic arch (LT) and supply the brain, face and scalp
Bilateral Internal Jugular Veins
-drain into the Rt and Lt brachiocephalic veins
Where are the common carotid arteries located?
- lateral to thyroid gland
- medial to internal jugular vein
- posterior ot strap muscles
Where are the internal jugular veins located?
- lateral to the common carotid arteries
- medial to the SCM
- posterior to strap muscles
What are the most frequently imaged lymph nodes?
-internal jugular (deep chain)
Where are lymph nodes located?
-follow the SCM, lateral to the internal jugular vein
Salivary Glands
- exocrine glands
- secrete saliva to help break down food
3 Paired Salivary Glands
1) parotid
2) submandibular
3) sublingual
Which paired salivary glands are easily seen on US?
- parotid
- submandibular
Which paired salivary gland is not seen easily on US due to position?
-sublingual
Parotid Glands
- paired
- anterior to mastoid process
- lateral to internal carotid artery
- wraps around posterolateral aspect of mandibular ramus
Submandibular Glands Location
-paired on each side of midline inferior to the mandibular body
What is inferomedial to the submandibular glands?
-hyoid bone
Where are sublingual glands located?
- under the tongue
- medial to mandibular body
Are the sublingual glands visualized on US?
-no, unless enlarged
Bony Framework of Thorax
- thoracic spine
- ribs
- sternum
Cavities in Thorax
- thoracic
- mediastinal
- pleural
- pericardial
Vital Organs Within the Thorax
- heart
- lungs
Vascular Structures of Thorax
- AO
- IVC
- SVC
- pulmonary vessels
Boundaries of Thorax
Anterior: sternum, ribs, intercostal and chest wall muscles, skin
Posterior: spine, scapula, ribs, intercostal and back muscles, skin
Superior: thoracic inlet
Inferior: diaphragm, thoracic outlet
True Ribs
-attach directly to the sternum
False Ribs
- first 3 attach to the cartilage of the rib above it
- aka vetebrochondral ribs
Floating Ribs
- last 2 false ribs
- cartilage ends in the abdominal wall muscles
3 Parts of Sternum
- manubrium: superior
- body: middle
- xiphoid process: inferior
Function of Thoracic Bones
- protection of organs
- suport of head and neck
Thoracic Inlet
- superior portion of thorax
- aperture ring of bone
Which vital structures pass through the thoracic inlet?
- trachea
- esophagus
- carotid arteries
- jugular veins
- nerves
- lymphatics
What is the inferior boundary of the thorax?
-convex upper surface of diaphragm
What separates the thoracic and abdominal cavities?
-diaphragm
Diaphragm
- extends across the bottom of the rib cage
- muscle fibres converge into a central tendon
Where do the 3 hiatus’ for the IVC, AO and esophagus pass through?
-diaphragm
What are the anterior chest wall muscles from superficial to deep?
- pectoralis major
- pectoralis minor
- serratus
- intercostal muscles
3 Layers of Intercostal Muscles
- external intercostal
- internal intercostal
- innermost intercostal
Posterior Chest Wall Muscles
- rhomboid
- latissmus dorsi
- trapezius
- shoulder girdle muscles
Where is the pericardial cavity?
-within the mediastinal cavity
Mediastinum
-area found in the middle of thorax between the 2 pleural cavities
What is the mediastinum divided into?
- superior
- inferior: anterior, middle, posterior
What is inside of the superior mediastinum?
- trachea
- esophagus
- thymus
- nerves and nervous plexuses
- SVC, brachiocephalic veins
- aortic arch, CCA, Lt subclavian and brachiocephalic arteries
What is in the middle mediastinum?
- heart and pericardium
- ascending AO
- pulmonary trunk
- SVC
Anterior Mediastinum Contents
- thymus remnants
- lymph nodes
Posterior Mediastinum Contents
- esophagus
- thoracic AO and it’s branches
- nerve plexuses from the sympathetic NS
Is there a gap between the visceral and parietal pleura?
Yes, with serous fluid.
Parietal Pleura
-serous membrane lining the chest cavity
Visceral Pleura
-serous membrane covering the lung surface
Where does the trachea bifurcate?
- T5
- aka carina
Where is the lung hilum in relation to the AO?
-anterior
Where is the bronchus in relation to the pulmonary arteries?
-posterior to pulmonary arteries
Where are the pulmonary arteries in relation to the pulmonary veins?
-pulmonary arteries are superior to pulmonary veins
What does the heart do?
-pump that circulates the blood between the lungs and body cells
What does blood do?
- delivers oxygen from lungs to body cells
- delivers carbon dioxide to lungs to be exhaled
Where is the esophagus in relation to the trachea?
-esophagus is posterior to trachea
Which vein is to the Rt of the ascending AO?
-SVC
Where does the main pulmonary trunk arise from?
-Rt ventricle
What does the main pulmonary trunk bifurcate into?
-Lt and Rt pulmonary arteries
What does the main pulmonary trunk carry?
-deoxygenated blood
How many pulmonary veins drain the oxygenated blood from the lungs into the left atrium?
4
Branches of Aortic Arch
- brachiocephalic trunk
- Lt common carotid artery
- Lt subclavian artery
**alphabetical order from anterior to posterior
2 Chamber View of Heart
-long axis view that demonstrates the Lt ventricle and Lt atrium
4 Chamber View of Heart
-demonstrated 4 chambers of the heart
- 2 ventricles
- 2 atrium
- bicupsid valve
- tricupsid valve
5 Chamber View of Heart
-demonstrates the 4 chambers of the heart with the aortic root/ascending aorta leaving the ventricle
- 2 ventricles
- 2 atrium
- AO
3 Vessel View of Heart
-demonstarted the great vessels leaving/entering the heart
- SVC
- AO
- main pulmonary artery
- ductus arteriosus (fetus)
Short Axis (OWL view) of Heart
-demonstrated the wall of the Lt and Rt ventricles as well as the papillary muscles