9 Anterior Triangle of the Neck E-learning

8/3/2019 9 Anterior Triangle of the Neck E-learning

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Anterior TriangleAnterior Triangleof The Neckof The Neck


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Anterior TriangleAnterior Triangle

Boundaries

Ant.:

Imaginary Midline

(mid-sagittal line)

Post.:

ant. border of SCM

Sup.:

inf. border of the mandible

Inf. apex:ant. & post. meet together


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Roof:

Skin

Superficial Fascia:

platysma

cervical facial n.

transverse cervical n.

ant. Jugular v.

Deep Fascia:

investing layer


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Subdivisions of Ant. TriangleSubdivisions of Ant. Triangle

By:

digastric m. (both bellies)

sup. Belly of omohyoid m.

4 Triangles:Submental

Submandibular (Digastric)

Carotid

Muscular


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Submental TriangleSubmental Triangle

* One unpaired triangleBoundaries

Lat. Sides:

2 ant. bellies of digastric

Base:body of hyoid bone

Apex:

symphysis menti

Floor:

mylohyoid muscle


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Contents

Small veins Ant. Jugular v.

Submental L.N. (2)


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Submandibular TriangleSubmandibular Triangle

Boundaries

Anteromedial:

ant. belly of digastric

Anterolateral:

lower border of mandible

Posterior:

post. belly of digastric

& stylohyoid m.

Floor:

mylohyoid & hyoglossus m.


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Contents

1. Superficial part ofsubmandibular gland

2. Facial a. & v.:

deep to the gland

3. Hypoglossal n.:

deep to the gland

on hyoglossus m.

4. n. To mylohyoid:

between ? & ?

5. Submandibular L.N.


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Submandibular GlandSubmandibular Gland


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Carotid TriangleCarotid Triangle

BoundariesSup.:

post. belly of digastric

Antero-inferiorly:

sup. Belly of omohyoid

Post.:

ant. border of SCM

Floor:

part of hyoglossus

part of thyrohyoid m.

middle & inf. costrictors


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Contents

Carotid sheath contents (4?)

Ansa Cervicalis

ant. aspect of the sheath

Cervical Sympathetic chain

post. aspect of the sheath

Hypoglossal n. (part)

ECA & some of its branches

mainly ant. branches


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Ansa CervicalisAnsa Cervicalis

Loop of cervical spinal nerves

of C1, C2 & C3

That supply:

infrahyoid muscles Except?


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Common Carotid Artery (CCA)Common Carotid Artery (CCA)

Starts:

Rt.? & Lf.?

Ascends in carotid sheath

(most medial)

Sup. Border of thyroid cartilage

(IV disc of C3-C4)

Divides into ICA & ECA

* No branches from CCA


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Carotid SinusCarotid Sinus

Localized dilatation in terminal

CCA & beginning ICA

That contains many n. endings

from IX

Fxn.:

mechanoreceptor

(pressoreceptor)

* Monitors bld. pressure


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Carotid BodyCarotid Body

A small str. Lies post. or at the

bifurcation area of CCA into

ICA & ECA

Fxn.:chemoreceptoe

* Monitors O2 level in bld.

Innervation:

carotid branch of IX


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ECAECA

* Extent?

Branches (8):

Medially (1)

Ant. (3)

Post. (2)

Terminations (2)


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Muscular TriangleMuscular Triangle

Boundaries

Ant.:

midline of the neck

Supero-posterior:

sup. Belly of omohyoid

Infero-posterior:

SCM


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Contents:

Infra hyoid Muscles

Thyroid gland

Larynx & trachea


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Thyroid GlandThyroid Gland

2 Lobes (C5-T1)

&

isthmus

(2nd & 3rd tracheal rings)

Covered by pretracheal layer

Of deep cervical fascia


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Thyroid RelationsThyroid Relations

Anterolateral:

sup. Belly of omo. (upper)

ant. border of SCM (lower)

sternohyoid & sternothyroid

muscles (middle)

Medial:

thyroid & cricoid cartilages(upper)

upper 6 tracheal rings (lower)

Posterior:

CCA

inf. thyroid a.

parathyroid glands


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Vasculature of Thyroid GlandVasculature of Thyroid Gland

Read your text for detailed

arterial bld. Supply & venous

drainage of the thyroid gland

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9 Anterior Triangle of the Neck E-learning