Intro to Body Cavities

Question 1

what separates the thoracic cavity from the abdominopelvic cavity

Answer 1

Diaphragm separates thoracic cavity from abdominopelvic cavity

Question 2

the thoracic cavity is subdivided into 3 sections; what are they

Answer 2

*Thoracic cavity - subdivided into
* Mediastinum - collection of structures (including heart, etc.)
* Pleural cavity - on either side of mediastinum - house lungs
* Pericardium

Question 3

between which 2 meninge layers is the cerebrospinal fluid (CSF0 found

Answer 3

the CSF is between arachnoid and pia mater layers it is called the subarachnoid (aka ‘beneath arachnoid’) space.

CSF buffers and protects brain + spinal cord; without it our brain would be smashing against the skull

CSF is created in the ventricles; mainly produced by a structure called the choroid plexus in the lateral, third and fourth ventricles. CSF flows from the lateral ventricle to the third ventricle through the interventricular foramen (also called the foramen of Monro).

Question 4

what is meningitis + how do we test for it

Answer 4

inflammation of the meninges of the brain;

to test we sample CSF (cerebrospinal fluid) in subarachnoid place to look for inflammatory markers of meningitis (n.b. cauda equina also has meninges)

Needle inserted into spine, (lumbar puncture done below L3 to avoid spinal cord) because cauda equina has lotta nerves without thick spinal cord

Question 5

visceral pleura tend to have an ____ nerve supply

parietal pleura tend to have a ____ nerve supply

Answer 5

visceral pleura tend to have an autonomic nerve supply (not v sensitive to pain)

parietal pleura tend to have a somatic nerve supply so it is v sensitive to pain

• Parietal lines outer walls of internal chamber - line body cavity so share nerve supply to body wall - somatic NS
• Visceral portion covers organ within body cavity - covers organ so share nerve supply to organ - ANS (visceral) - can’t feel internal organs, they sensitive to stretch, not as sensitive to pain

Question 6

between parietal and visceral pleura, we have a fluid called

Answer 6

Serous fluid is in the cavity between visceral and parietal layers to minimise friction

in the lungs its called pleural fluid

Question 7

what is the mediastinum; what are some of the structures travelling through it

Answer 7

mediastinum which contains the pericardial cavity (containing the heart) - its the collection of structures between pleural cavities, including:

• Pericardial cavity
• Heart
• Great vessels
• Aorta
• Trachea
• Oesophagus
• Vagus nerve
• Phrenic nerve
• Thoracic duct (transports lymph back into the circulatory system)

Question 8

why is the fibrous pericardium so tough?

Answer 8

fibrous pericardium (surrounds heart) it is super tough to limit expansion of heart

if u get excess fluid in pericardial cavity/sac (e.g. blood or pericardial fluid) this will put pressure on heart and it will struggle to pump= this is called a CARDIAC TAMPONADE

Question 9

what does the duodenum curl around?

Answer 9

Duodenum is first part of small intestine - C-shaped, curls around head of pancreas

Question 10

what is the largest gland in the body

Answer 10

liver

• Largest gland in body
• Sits under right dome of diaphragm
• Mainly covered by ribcage so usually cannot be palpated
  Functionally and anatomically, the liver is connected to gall bladder which stores bile produced by liver

Question 11

what large lymphatic organ sits on left side of abdomen underneath diaphragm

Answer 11

spleen its about the size of a fist and it sits on the left side of abdomen; underneath diaphragm

Question 12

which kidney sits higher and why

Answer 12

• Kidneys are paired organs sitting on posterior abdominal wall
• Left kidney sits a bit higher than right kidney since right side has liver so kidney needs to be below liver (think of liver pushing it down to remember)
• Adrenal glands sits on superior pole of kidneys
  Kidneys produce urine, from kidney to urinary bladder via ureter