Intro Flashcards
What are general visceral efferent fibers?
Motor (efferent) impulses to smooth muscle, cardiac muscle, and glandular tissue, and to the nerves and ganglia in the wall of the GI tract.
Somatic fiber types create what type of pain? In what organs?
Sharp, well-localized pain
Bones, skeletal, body wall
Visceral fiber types create what type of pain? In what organs?
Dull and not well-localized
Visceral organs
What body parts do NOT develop from somites?
Nerves and blood vessels
What are general visceral afferent fibers?
Sensory input from visceral organs and blood vessels to integrating centers in the CNS.
What thoracic level do you find the nipple?
T4
What muscle fibers do you find in the nipple?
Circular smooth muscle
What makes up the parenchyma of breast?
15-20 lobules of glandular tissue
What is the origin of the sympathetic nervous system?
Thoracolumbar
What is the origin of the parasympathetic nervous system?
Craniosacral
Where does the lymph from the breasts drain (mostly)?
To the axilla.
Thus, metastases of breast cancer first spread to axillary nodes.
It CAN spread to parasternal nodes, however.
What is the origin of the vagus nerve?
Cranial
What is the path of sympathetic nerves?
Pass through the sympathetic chain lateral to the spinal cord (may or may not synapse there) and then pass to the target organ
What is the path of parasympathetic nerves?
Synapse in the ganglia of the organs they target
Each lobule of the breast drains to a _______ _____, which then converge on the areola where they expand to a _____ where milk collects.
Lactiferous duct, lactiferous sinus
What is the innervation of the breast?
T3-T5 intercostal nerves
Where do ribs attach posteriorly and anteriorly?
Transverse processes of the vertebrae and anteriorly to sternum via costal cartilages.
How are intercostal spaces named?
For the SUPERIOR rib
What is the orientation of external intercostal muscles?
From superior to inferior anteriorly (like putting your hands in your pockets?
What is the orientation of internal intercostal muscles?
From inferior to superior anteriorly
What is the orientation of the innermost intercostal muscles?
Vertical. VERY thin
Where do you find the intercostal artery/vein/nerve?
Immediately below/under the rib in EACH intercostal space
Between internal and innermost layers of intercostal muscles
What is the inferior aperture (??)
??
On what side is the diaphragm higher?
Right
What is the central tendon?
The center of the diaphragm
What 3 things pass through the diaphragm?
IVC
Aorta
Esophagus
At what thoracic level does the IVC pass through the diaphragm?
T8
At what thoracic level does the esophagus pass through the diaphragm?
T10
At what thoracic level does the aorta pass through the diaphragm?
T12
What hole is “center most” of the diaphragm?
IVC (T8!)
What is the least central hole through the diaphragm?
Aorta (T12!)
What is the benefit of having the esophagus in the muscular part of the diaphragm?
When breathing (i.e. diaphragmatic contraction), the esophagus will be constricted to prevent air in/food out
What is the pump handle mechanism?
When inspiring actively, Ribs and sternum rise and increase A-P diameter. Done via scalene and sternocleidomastoid muscles to raise upper ribs.
What is the bucket handle mechanism?
When inspiring actively, ribs elevate to increase M-L diameter.
External intercostal muscles raise the lower ribs.
What happens in forced expiration?
Abdominal muscles contract to increase abdominal pressure and force the diaphragm up.
What is the innervation of the diaphragm?
Phrenic nerve (C3-C5, keep you alive)
What is the blood supply of the diaphragm?
From above, the diaphragm receives blood from branches of the internal thoracic arteries, namely the pericardiophrenic artery and musculophrenic artery; from the superior phrenic arteries, which arise directly from the thoracic aorta; and from the lower internal intercostal arteries.
What is the fatty layer called below the umbilicus?
Campers layer
What is the membranous layer called below the umbilicus?
Scarpas layer
What is the relative orientation of external and internal oblique muscles?
90 deg to one another
What is deep to the transversus muscle?
Transversalis fascia
What 2 muscles are medial to the transversus abdominus muscles?
Quadratus lumborum
Psoas major and minor
What does the quadratus lumborum do?
Anchors lower ribs to iliac crest/closes posterior abdominal wall
What do psoas major and minor do?
Flex the hip
What is the rectus sheath?
Interweaving of aponeuroses of abdominal wall muscles
What does the rectus sheath (interweaving of aponeuroses fibers) encase?
Rectus abdominis muscles
What is the midline of the abdomen called?
Linea alba
Below the arcuate line, what happens?
The fascia of the rectus sheath is 100% ANTERIOR to the muscle (no longer encases the muscles)
What are the tendinous lines that create 6 packs called?
Tendinous inscriptions
What blood vessels run vertical deep to the rectus abdominus muscles?
Inferior/Superior epigastric vessels
What forms the inguinal ligament?
Thickened, under-turned margin of the external oblique aponeurosis
What are the attachments of the inguinal ligament?
ASIS to pubic tubercle
What is the inner doorway to the spermatic cord?
The deep inguinal ring made by the transversalis fascia
What is the outer doorway to the spermatic cord?
Superficial inguinal ring made by the external oblique
What is the inguinal (Hasselbach’s) triangle?
An aera of weakness (just transversalis fascia) where hernias form.
Borders:
Lateral side of rectus abdominis
Inguinal ligament
Inferior epigastric vessels
What is an indirect hernia?
Follows path of descending testes failing to close. Loops of intestine herniate through the inguinal canal.
Inferior epigastric vessels are MEDIAL to the hernia.
All layers of scrotum surround the bowel loop.
Considered congenital because it occurs in infant baby boys.
What is a direct hernia?
Increased intra-abdominal pressure forces the intestine with its peritoneal cover through the weak inguinal triangle.
Inferior epigastric vessels are LATERAL to hernia.
Occurs in adult men.
What are the layers of the abdomen and thorax?
Pleura and peritoneum
TWO layers: one on the organ and one attached to the body wall.
How does the pleura/peritoneum innervation work?
The innervation on the body wall behaves like the body wall (i.e. pain can be well localized)
Ilioinguinal and iliohypogastric nerves are ____.
L1
What connects the internal thoracic arteries to the aorta?
Intercostal arteries
What do the internal thoracic arteries become when they cross into the diaphragm?
Superior epigastric vessels
Which layer of the pleura tightly adheres to the body wall?
Parietal
In the lung, where does pleura transition from parietal to visceral?
The hilum
What is the recess/lowest point of the pleural cavity?
Costodiaphragmatic recess
What is pleurisy?
Inflammation of the pleura
What separates superior and inferior mediastinum?
T4/T5 (where the manubrium meets the bottom f the sternum). Also where rib 2 attaches
What are the contents of the superior mediastinum?
Thymus
What is in the middle mediastinum?
Heart
Roots of the great vessels
Pericardium
What is in the posterior mediastinum?
Esophagus
Descending aorta
Thoracic duct
Azygous, hemi-a, accessory hemiazygous veins (IVC of the thorax)
What are the superior phrenic arteries?
Paired parietal branches to upper surface of diaphragm
What do the paired branches of arteries off the aorta do?
Almost entirely to body wall.
Exception = bronchial arteries to the lungs
What do the UNpaired branches (down the midline) of the aorta do?
To organs (e.g. esophagus)
What is the venous drainage of the LEFT side of the thorax?
Accessory hemiazygous
Hemiazygous
What is the venous drainage of the RIGHT side of the thorax?
Azygous
What is the action/path of the vagus nerve?
Parasympathetic to viscera
Gives rise to the esophageal plexus and recurrent laryngeal nerves
What is the sympathetic trunk?
Gives rise to sympathetic nerves
