Anatomy 2- Neck and mediastinum Flashcards
location and fn of phrenic nerve
b/w parietal pleura and pericardium, comes from C3,4, and 5
innervates diaphragm, sensory signals from all three of these things
principal and accessory muscles of inspiration
principal: diaphragm and ext intercostals
accessory: SCM, scalenes
muscles of expiration
passive process during quiet breathing, int intercostals and abs during active breathing
differentiate the pleural layers
parietal pleura assoc w/ walls of pleural cavity, visceral pleura w/ surface of the lung
pleural cavity is potential space b/w the two
4 divisions of the parietal pleura
costal, diaphragmatic, mediastinal, cervical (aka sibson’s fascia)
define hilum and root of lung
hilum is the bare location where mediastinal pleura reflects, makes way for the root which contains vessels and airways
pleural recesses
2 regions where lungs are not present except for forced inspiration: costomediastinal recess and costodiaphragmatic
patho of pneumothorax
trauma or damage allows air into pleural cavity, lung collapses due to its inherent elasticity (normally prevented by surface tension b/w parietal layers)
Sx and Tx of pneumothorax
Sx: diminished breath sounds, distended neck veins
Tx: needle decompression, allow air to escap
structure of right lung
3 lobes: superior, middle and inferior,
10 bronchopulmonary segments
oblique fissure divides inferior and superior, horizontal fissure divides superior and middle
left lung structure
superior lobe w/ lingula, inferior lobe and they are divided by oblique fissure
8 bronchopulmonary segments
components of bronchopulmonary segemtns
each gets its own tertiary branch of a pulm artery and bronchus, veins run b/w segments
source of bronchial arteries
from branches of aorta, run along with bronchi
bronchial veins drainage site
drain into azygos system
diff b/w pulmonary and bronchial arteries
pulm bring deoxy blood to alveoli, bronchial bring oxy blood to lung tissues
lymphatic drainage of the lungs
drain into tracheobronchial lymph nodes which send efferent vessels into bronchomediastinal trunks
autonomic innervation
pulmonary plexus has both SNS and PSNS, located at bifurcation of trachea
SNS dilates brochioles and PSNS constricts
differentiate azygos, hemiazygos and accessory hemiazygos
azygos: right side, receives blood from right intercostals and empties into SVC
Hemiazygos: left side, lower 4 intercostals
accessory hemiazygos: middle left 4 posterior intercostals
location and fn of thoracic duct
located b/w aorta and azygos vein, begins in abdomen and empties lymph from RLQ, LLQ, LUQ in junction of left internal jugular and subclavian veins
RUQ drains right lymphatic duct
location and fn of splanchnic nerves
sympathetic nerves from throax to abdomen, innervate organs in this region
3 different layers of deep cervical fascia, why they are useful
investing layer: outer layer around deeper structures
prevertebral layer: around vertebral column and associate muscles
pretracheal layer: around thyroid, trachea, esophagus
can determine spread of infection
carotid sheath
tubular fascial sheath with fascia from other layers, contains common carotid, IJV, and vagus nerve
large veins in order as they empty into the heart
on both sides, internal jugular veins means subclavians to form brachiocephalic, then empty into SVC
venous angle
juntion of IJV and subclavian vein, location where many lymphatic vessels join circulation (thoracic duct in left venous angle)
major branches from aortic arch
brachiocephalic trunk on the right (gives rise to right common carotid and right subclavian), left subclavian, left common carotid
first branch of the external carotid
superior thyroid artery
receptors at the carotid bifurcation
carotid body: chemoreceptor monitoring O2 levels
carotid sinus: dilation near base of internal carotid that acts as baroreceptor
innervation of carotid receptors
glossopharyngeal nerve CN IX
3 parts of subclavian artery
1st is medial to anterior scalene, 2nd is posterior, 3rd is lateral to the muscle- after this is is the axillary artery
4 main branches of subclavian artery
VITamin C:
vertebral artery, Internal thoracic, thyrocervical trunk, costocervical
vertebral artery
ascends w/i transverse foramina to supply brain and spinal cord
main branch of thyrocervical trunk
inferior thyroid artery
development of thyroid gland
forms at base of tongue and descends thru thyroglossal duct in the neck
structure of thyroid
two lobes connected by isthmus, can sometimes have pyramidal lobe as superior projection
blood supply of thyroid
superior thyroid from external carotid, inferior thyroid from thyrocervical trunk off of subclavian
in some ppl thyroid ima artery from brachiocephalic trunk
blood supply of parathyroids
inferior thyroid arteries (branch of thyocervial trunk, itself a branch of the subclavian)
what else to find near anterior scalene
brachial plexus and subclavian artery b/w anterior and middle scalene, subclavian vein is anterior to anterior scalene, phrenic nerve lies on the anterior surface of anterior scalene
3 suprahyoid muscles
mylohyoid, digastric muscle (anterior and posterior bellies), stylohyoid
4 infrahyoid muscles
sternohyoid, sternothyroid, omohyoid, thyrohyoid
names based on first part=origin, second=attachment
innervation of infrahyoid muscles
cervical plexus, specifically the ansa cervicalis
cervical plexus
ventral rami of C1-4, motor branches form loop called ansa cervicalis
sensory branches of the cervical plexus (4)
cutaneous nerves, exit the posterior border of the SCM at Erbs point
lesser occipital, greater auricular, transverse cervical, supraclavicular
anterior triangle
inferior border of mandible, neck midline, anterior SCM
posterior triangle
posterior SCM, clavicle, anterior trapezius
carotid triangle
bordered by the superior belly of omohyoid, anterior SCM, posterior belly of digastric
contains: carotid sheath (IJV, vagus, common carotid), ansa cervicalis, hypoglossal nerve
contents of posterior triangle
spinal accessory nerve (trapezius and SCM), brachial plexus, anterior and middle scalene, phrenic nerve, EJV
EJV clinical use
in right sided heart failure, blood is backed up in EJV and is visible on the neck, amount of distortion is proportional to extent of heart failure
