Anatomy Lec 1

USC Summer Anatomy

Boundaries of the neck: ______ Aspect & _______ Aspect. & contents

Boundaries of the Neck

•Anterior Aspect:

• Superior: Inferior border of the mandible

• Inferior: Superior surface of the manubrium and clavicle

•Posterior Aspect:

• Superior: Superior nuchal line

• Inferior: Horizontal line between C7 and T1

  

Platysma muscle:

1. Describe appearance

2. innervated by…

3. covers ______ aspect of ______

4. origin:

5. insertion:

6. Function:

1. paperthin ; superficial muscle of the neck responsible for facial expression.

2. cervical branch of facial nerve (CNVII)

3. covers (entire) anterior aspect of neck

4. origin: deltoid + Pectoralis fascia

5. insertion: inferior border of mandible and skin/hypodermis

6. depression of lower lip +
   corner of mouth.

What is a cervical Plexus?

a network of nerves located in the neck that provides both sensory and motor innervation to the head, neck, and upper chest. It's formed by the anterior rami of spinal nerves C1-C4.

This plexus is essential for various functions, including sensation in the neck and upper chest and controlling muscles in the neck, including the diaphragm. 

Cervical Plexus involves both _____ and _______ innervation

motor and sensory

What does somatosensory mean? I mean like what is it?

special senses - vision, hearing, taste, and smell. + And general somatic senses, involved in the sense of touch, proprioception, pain, and temperature.

__,__,__, & form the cervical plexus and are __________.

-C1, C2, C3, and most of C4 form
the cervical plexus
-Somatosensory

Nerve Innervation on Front of Neck (3) + Their corresponding C letters

1. Great Auricular Nerve (C2 & C3)

2. Transverse Cervical Nerve (C2 , C3)

3. Supraclavicular nerve (C2 & C4)

   -anterior (medial)

   -Middle (intermediate

   -Posterior (lateral)

Red=great auricular

Blue=Transverse Cervical

Green=Supraclavicular

Great Auricular Nerve emerges from ….

emerges from posterior border of sternocleidomastoid muscle

Ansa Cervicalis: is a _____ _____…

1. Location

2. description of what it looks like

3. has 2 ______ formed by __,__ ,& __. They are called: _____ & _______. first one travels with ___and second one is from ___ ___.

4. is a _______ nerve

5. Function:

6. innervations

The ansa cervicalis is a nerve loop located in the neck that is part of the cervical plexus

1. anterior OR IN carotid sheath IM NOT SURE (fascia that protects the big 3

   -Common Carotid artery

   -internal jugular vein

   -Vagus Nerve)

2. U shaped

3. roots, C1,C2,C3, superior, inferior, CN XI, Cervical Region

4. somatoMOTOR nerve

5. Motor innervation of sternohyoid, sternothyroid, omohyoid (NOT thyrohyoid, its innervated by nerve to thyrohyoid)

6. same as 5 hehe

number 1

Accessory nerve (CN __)

1. __ components of fibers: __& __

2. function: innervation of ___ & ___

CN XI

1. 2, cranial root, spinal root

2. -Sternocleidomastoid muscle (scm)

   -trapezius muscle

Best way to find accessory nerve?

Cut SCM 4-5 cm from its origin of sternum part, move the scm muscle flap upwards, find the border of mandible, and move over a little bit and u find it

Phrenic Nerve cervical components __, _, & _

Motor function?

Sensory Function?

C3, C4, C5

Motor: Diaphraghm

345 keep the diaphragm alive

Sensory: Mediastinal pleura and pericardium of the heart

What are the 3 boundaries for the anterior triangles of the neck?

RED TRIANGLE = Anterior Triangle

1. Top part: inferior border of mandible

2. front part: midline of neck

3. back part: Anterior border of SCM

Anterior Triangle of Neck has ____ subtriangles.

They are:

4

1. Muscular Triangle

2. Carotid triangle

3. Submandibular Triangle

4. Submental Triangle

Boundaries of Muscular Triangle:

Top: ___________________

lower: _____________________

Anterior: _____________________

What are the contents/what is contained within this triangle? What is each of these contents innervated by? All found within the ______ region. They are also known as ____ muscles bc they are somewhat _____.

Top: superior belly of omohyoid

lower: lower half- anterior border of SCM

Anterior: Midline

1. sternohyoid (ansa)

2. sternothyroid (ansa)

3. thyrohyoid (C1 via CN XII)

4. omohyoid (ansa)

Infrahyoid Region

stripe? vertical up and down

what is the name of CN XII and what is it innervated by

Hypoglossal nerve innervated by C1

What are the muscles that are above the hyoid bone called

Suprahyoid muscles

sternohyoid;

originates in the ——- and goes into the ———-

the longest?
originates in the sternum and goes into the hyoid

_______ + _______ muscles help to suspend the hyoid bone

infrahyoid + suprahyoid

Gotta learn how to label these. Make a purposegames lol

what is a good spot for opening an emergency airway?

Median Cricothyroid ligament

The median cricothyroid ligament sits between the ___ & ___

thyroid cartilage and cricoid cartilage

Where would we do a tracheotomy? where is this location hiding behind?

2nd and 3rd ring of trachea, isthmus portion of thyroid gland

hypoglossal nerve CN __

XII

Thyroid Gland; dev starts from __ __

dev starts from oral cavity

where?

foramen of secum?

What will we not find in many patients because it gives rise to the thyroglossal gland and then disappears? But in some patients it can remain and turn into a ___

thyroglossal duct, cyst

thyroglossal duct descend into ——- neck region then expands to —— side

anterior

lateral

in order to do tracheotomy u have to pull what aside in order to access the trachea

the isthmus of the thyroid, bc it covers the 2nd and 3rd rings of trachea

Carotid Triangle Boundaries?

Boundaries:

Superior: Posterior belly of digastric muscle
Inferior: Superior belly ofomohyoid
Posterior: Anterior border of SCM

Anterior belly of digastric arises from (which also gives rise to __ & __) during dev.

1st pharyngeal arch

mandible & maxilla

Associated with the 1st pharyngeal arch is the ____ nerve (CN __). Thats why the anterior belly of digastric receives motor innervation from this nerve.

trigeminal (CN V)

The posterior belly of digastric is derived from the __ __ __ , which is associated with/innervated by the ___ nerve (CN __).

2nd pharyngeal arch

facial (CN VII)

In dissection, how do we get to the contents of the carotid traingle?

First, cut the SCM, push that flap back.

Then, will need to cut the carotid sheath.

What is the carotid Sheath? What is inside it?

fascia covering that protects the big 3

1. -Common Carotid artery

2. -internal jugular vein

3. -Vagus Nerve

Contents of Carotid triangle

Contents:

a. common carotid artery - internal carotid artery - external carotid artery

b. internal jugular vein

c. vagus N (CN X)

d. ansa cervicalis

**Carotid Sinus and Carotid Body

Common carotid artery arises from ___ part of ___, ascends, then when it gets to the level of about __, most common area to bifurcate;tunring into __ and __ carotid

lower

neck

C4/or thyroid cartilage level

external

internal

How do we tell the internal carotid apart from the external carotid?

the internal carotid doesnt branch out vs external branches out into many branches. ECA more medial

Function of Carotid Sinus + Nerve Number? why important

baroreceptors - BP regulator, CN IX

Ex: If someone is losing a lot of blood, senses that and prioritizes brain

Function of Carotid body + Nerve Number? Why important?

Chemoreceptor, CN IX

senses level of oxygen and CO2 in blood