Anatomy: Lecture 10 / Lab 11 & 12

What are the cranial limits of the thoracic cavity?

thoracic inlet

What are the dorsal limits of the thoracic cavity?

vertebral bodies

What is the thoracic inlet?

the first pair of ribs and their costal cartilage

What are the lateral limits of the thoracic cavity?

ribs and intercostal muscles

What are the ventral limits of the thoracic cavity?

sternebrae

What are the caudal limits of the thoracic cavity?

diaphragm

What are the three cavities inside the thoracic cavity?

pericardial cavity and 2 pleural cavities

What is pleura?

simple squamous cell layer located within the thoracic cavity

Differentiate between the thoracic cavity and pleural cavity

the pleural cavity is space between pleural and is inside the thoracic cavity

What is mesothelium?

simple squamous epithelial layer that secretes serous fluid and lines cavities

What is serous fluid?

watery fluid that lubricates structures with more pressure and keeps junk out of the body

the mesothelium that lines the thoracic cavity is?

pleura

What is Visceral pleura?

pleura that surrounds the lungs

What is parietal pleura?

pleura that lines the thoracic cavity

What are the different types of parietal pleura?

costal, mediastinal, and diaphragmatic

What is costal pleura?

parietal pleura that lines the ribs and intercostal muscles

What is mediastinal pleura?

parietal pleura that reflects on the midline covering the structures there

which 2 pieces of mesoderm come together to form the diaphragm

septum transversum and pleuroperitoneal folds

What is diaphragmatic pleura?

parietal pleura that lines the diaphragm

Where does the spinal nerve originate from?

intervertebral foramina and innervates the neck trunk and limbs

What is the line of pleural reflection?

imagined line along the horizontal parts of the 8th/9th costal cartilages, across the 10th/11th costal cartilages at costochondral junction and across the middle of last rib

if you stick a needle behind the line of pleural reflection you will be where?

in the abdominal cavity

What is an example of connecting pleura?

pulmonary ligament (not a real ligament but a fold of pleura)

What does the central nervous system include?

brain and spinal cord

what does the peripheral nervous system include?

cranial nerves and spinal nerves

How many pairs of cranial nerves are there?

12

What is cranial nerve 1?

olfactory - smell

What is cranial nerve 2?

optic - sight

what is cranial nerve 3?

oculomotor - eye muscles

What is cranial nerve 10?

vagus - parasympathetic motor and sensory fibers

How many pairs of spinal nerves are present?

35; 8 cervical pairs, 13 thoracic pairs, 7 lumbar pairs, and 3 sacral pairs

How do the spinal nerves arise?

from the dorsal and ventral roots

What type of fibers does the dorsal root carry?

sensory (afferent)

What type of fibers does the ventral root carry?

motor (efferent)

Where do the dorsal and ventral roots join to form a mixed spinal nerve?

within the vertebral foramen

What fiber types does a mixed spinal nerve contain?

both sensory and motor fibers

What are the three immediate branches of a spinal nerve?

dorsal, ventral, and communicating branch (ramis communications)

What muscles does the dorsal branch supply?

epaxial muscles

What muscles does the ventral branch supply?

hypaxial muscles

What is the function of the communicating branch (ramus communicans)?

Connects with the sympathetic trunk (autonomic fibers)

How do spinal nerves exit from C1?

lateral foramen in atlas

How do spinal nerves C2-7 emerge from the axis to C7?

through the intervertebral foramen

How does Cn8 emerge?

Caudal to numerically responding vertebrae because there is no C8

In the thorax, what do the ventral branches of thoracic spinal nerves become?

ventral branches of thoracic spinal nerves become intercostal nerves

What is the source of the dorsal intercostal arteries?

aorta

What superficial vessels and nerves are present in the thoracic wall?

dorsal intercostal arteries, ventral intercostal branches of internal thoracic artery and vein, intercostal nerves, and the axilla

Where do dorsal intercostal arteries run?

along caudal surface of rib

What is the superficial vein of the neck that we’ve covered?

external jugular

What is cranial nerve 11?

accessory nerve

What does the accessory nerve supply?

extrinsic muscles of thoracic limb (omotransversarius and trapezius)

What is the only motor nerve in the trapezius?

accessory nerve

What would happen if the accessory nerve is damaged?

other extrinsic muscles are weakened but trapezius loses motor supply resulting in atrophy and impaired scapular movement

Where are the superficial cervical lymph nodes located?

they lie on the serratus ventralis and scalenus cranial to the supraspinatus

What is the superficial cervical lymph node covered by?

omotransversarius and brachiocephalicus

Where are the axillary lymph nodes located?

latissimus dorsi muscle and deep pectorals (axilla)

Where are the tracheobronchial lymph nodes located?

tracheal bifurcation where windpipe splits

What organs are in the thoracic cavity?

esophagus, trachea, lungs, heart and thymus

Where is the aorta in the thorax?

dorsally (from left ventricle)

What is the cardiac notch?

V-shaped gap in ventral border of R lung (bw cranial and middle lobes)

Where is the cardiac notch located?

low in third and fifth intercostal space and not present on the left

What side and view is this lung and what lobe is located on the left?

left lung, ventral view, caudal lobe

What side and view is this lung and what lobe is located on the middle?

left lung, ventral view, and cranial caudal lobe

What side and view is this lung and what lobe is located on the right?

left lung, ventral view, and cranial lobe

What side and view is this lung and what is the red lobe?

right lung, dorsal view, cranial lobe

What side and view is this lung and what is the green lobe?

right lung, dorsal view, and middle lobe

What side and view is this lung and what is the blue lobe?

right lung, dorsal view, and caudal lobe

What side and view is this lung and what is the yellow lobe?

right lung, dorsal view, and accessory lobe

What are the first 2 branches off the ascending aorta?

L + R coronary arteries

What two structures does the aorta branch into?

brachiocephalic trunk and left subclavian artery

What does the brachiocephalic trunk branch into?

left common carotid, right common carotid, and right subclavian arteries

What does the left subclavian branch into?

4 branches: vertebral artery, costocervical artery, internal thoracic artery, and superficial cervical artery

What does the left subclavian artery continue as?

axillary artery

What structures form the cranial vena cava?

L + R brachiocephalic veins

What forms from the brachiocephalic vein?

side-specific subclavian and side-specific external jugular

What does the cranial vena cava drain?

front of animal

What does the right brachiocephalic vein drain?

Right head/neck/thoracic limb

What does the left brachiocephalic vein drain

left head/neck/thoracic limb

What does the external jugular vein drain?

head

What do the subclavian veins drain?

thoracic limb on each side

Where does the brachiocephalic trunk supply blood?

to the head, neck, and R forelimb

Where does the right subclavian artery supply blood?

thoracic limb

Where do the common carotid arteries supply blood?

head

Where does the vertebral artery take blood?

brain

Where does the costocervical artery supply blood?

deep neck (first few intercostals)

Where does the internal thoracic artery supply blood?

ventral thoracic and mammaries

Where does the superficial cervical artery supply blood?

base of neck

What do the right and left coronary arteries supply?

myocardium of heart

what lines the thoracic cavity beneath the intercostal muscles?

parietal pleura

what muscles are found within a given intercostal space?

external and internal intercostal muscles

the intercostal artery, intercostal vein, and intercostal nerve run along what side of each rib?

caudal

if you need to make a longitudinal incision in the intercostal space, where should you aim to cut?

cranial area of intercostal space

What is the origin of the phrenic nerve?

C5,C6,C7

How does the phrenic nerve enter the thorax?

thoracic inlet

What is the course of the phrenic nerve?

runs caudally along pericardium

What is the function of the phrenic nerve?

supply the diaphragm for inspiration

Where do the right and left crura of the diaphragm attach?

lumbar vertebrae

Where are the lateral attachments of the diaphragm?

inner surfaces of the rib

What are the three passageways of the diaphragm?

aortic hiatus, esophageal hiatus, and caval foramen

What is the aortic hiatus?

dorsal passageway between the crura for the aorta, the azygous vein, and the thoracic duct

What is the esophageal hiatus?

musclar part of the right crus that transmists the sophagus, vagal nerve trunks, and esophageal vessels