Lecture 18 - The Neck II Flashcards
What is the primary blood supply to the head and neck?
Common carotid
Where does the supplemental supply for blood to the head and neck come from?
Subclavian arteries
What is the artery of common origin for the carotid and subclavian arteries?
Brachiocephalic trunk
What is different about pigs and dogs in regards to their brachiocephalic trunk?
Left subclavian has separate origin off of the aorta
What artery supplies branches to the vertebral muscles and spinal cord?
Vertebral artery
What path does the vertebral artery take?
Passes through the foramina of 6th through 1st cervical vertebra
What two arteries provide minor branches to the neck?
Deep cervical artery and superficial cervical artery
Where does the common carotid artery divide?
The level of the hyoid
What are the two divisions of the common carotid artery/.
Internal and external
What carotid branch supplies most of the head?
External carotid artery
Where does the cranial thyroid artery come from?
Common carotid artery
What does the cranial thyroid artery supply?
Viscera and ventral musculature
What are two important structures of the internal carotid artery?
Carotid sinus and carotid body
What is the carotid sinus?
Dilation at the origin of the ICA
What is contained within the carotid sinus?
Baroreceptors
What is the carotid body?
A small mass, adjacent to carotid sinus that contains chemoreceptors
What is the path of the ICA?
Goes dorsally to the skull and enters through the carotid canal
What is different about the ICA in ruminants?
Develops but ends perinatally
What are the four main branches of the ECA?
Cranial laryngeal - Ascending pharyngeal - Lingual - Occipital
What are the two jugular veins?
Internal and external
What drains into the external jugular?
Primary drainage of the head and neck, including superficial and deep regions
What occurs at the internal jugular?
Not much, not very important in most animals
Where is the internal jugular?
Within the carotid sheath
Where does the external jugular form?
Near angle of the mandible
What muscle does the external jugular cross over?
Sternocephalicus
What muscle does the external jugular dive into?
Brachiocephalicus
What does the external jugular contribute to?
Formation of the cranial vena cava
Where is the external jugular found in horses?
In the jugular groove between the brachiocephalicus and the sternocephalicus
What are the two branches of the primary lymph drainage in the neck?
Superficial cervical lymph nodes
– and —
Deep cervical lymph nodes
Where are the superfical cervical lymph nodes?
Deep to the superficial neck muscles, cranial to the shoulder
Where are the deep cervical lymph nodes?
Run along length of trachea, often divided into cranial and caudal groups
What drains the lymph of the head/neck?
Paired tracheal ducts that run the length of the neck
Where does the lymph on the left side of the neck drain into?
Thoracic duct
Where does the lymph on the right side of the neck drain into?
Right lymphatic duct
What are the three category of nerves found in the neck?
Cervical spinal nerves - cranial nerves - autonomic nerves
What cranial nerves come out the jugular foramen?
CN IX, X, and XI
What is CN IX?
Glossopharyngeal
What is CN X?
Vagus
What is CN XI?
Accessory
What cranial nerves are found in the hypoglossal canal?
CN XII
What is CN XII?
Hypoglossal
What is the ansa cervicalis?
C1 (and some C2) of the ventral ramus join with fibers carried by the hypoglosssal nerve to form loop
What function does the ansa cervicalis provide?
Motor to the caudal hyoid group, NO SENSORY
What muscle do C2 -C5 ventral rami pierce through?
Omotransversarius
What function do C2-C5 provide?
Motor and sensory to the neck
What is special about the ventral rami of C5?
Provide motor and sensory to the proximal thoracic limb
What are the nerves from the ventral ramus of C2?
Great auricular n. and Transverse cervical n.
What is the sensory distribution for the greater occipital nerve?
Rostral portion of ear and top of head
What is the greater occipital nerve?
dorsal ramus of C2
What is the sensory distribution for the great auricular nerve?
most rostral part of neck and ear
What is the sensory distribution for the transverse cervical nerve?
Ventral portion of the neck
What is the sensory distribution for the C3 dorsal and ventral rami?
Rostral portion of the neck close to the base of the ears
What is the sensory distribution for the C4 dorsal and ventral rami?
Most caudal of the nerves, and will go into the brachial plexus
Where is the vagosympathetic trunk?
Within the carotid sheath
What is in the vagosympathetic trunk?
Cervical sympathetic chain and the vagus nerve
What does the cranial cervical ganglion do?
Provide sympathetics for most of the head and neck
What are the two parts of the salivary glands?
Parotid and mandibular
Where is the thyroid gland located?
Endocrine gland located along the sides of the proximal trachea
What does the cranial thyroid vein drain into?
Internal jugular
What does the caudal thyroid vein drain into?
Internal jugular
– OR –
Brachiocephalic
What are the lobes of the thyroid associated with?
Crainal and caudal parathyroid glands
Where is the caudal parathyroid gland?
Embedded in the thyroid tissue
What is the thyroid isthmus?
Additional tissue bridging between the two lobes ventral to the trachea
Where is the thyroid isthmus found?
Cattle, pigs, and horses
What animal has the biggest thyroid isthmus
Pig
