Pre-Practical 1

Question 1

What structures organise the neck?

Answer 1

The deep fascia.

Split into 4 fascias it seperates the neck into compartments

Question 2

What are the neck compartments and their surrounding fascia?

Answer 2

• Deep Cervical fascia surround the whole neck
• Prevertebral fascia surrounds spine and bulk of muscle (Muscular Compartment)
• Pretracheal Fascia surrounds the visceral compartment (Oesophagus and trachea etc)
• Carotid Sheath surrounds the carotid/jugular etc on left and right forming two neurovascular compartments

Question 3

How many bones make up the skull?

Answer 3

22

• 8 make up cranium
• 14 make up the facial skeleton

Question 4

What are the layers of the scalp?

Answer 4

Skin
Connective Tissue
Aponeurosis
Loose Connective Tissue
Periosteum of cranium (Pericranium)

Question 5

What type of skin is the the skin of the scalp?

Answer 5

Thin skin

Meaning it contains hair follicles and sebaescous glands (unlike the thick skin of the palms etc)

Question 6

Why do you bleed so profusely from the scalp?

Answer 6

Because the connective tissue layer is bound tightly to the aponeurosis which cant contract so vasoconstriction is limited in the event of injury

Question 7

Explain the venous supply of the scalp?

Answer 7

• Valveless Emissary veins traverse the scalp & Cranium connecting intercranial venous sinuses to superficial veins in the skin.
• They also pass through the diploe of spongy bones in the cranium making contact with the red marrow.
• They’re the main route of intracranial infection.

Question 8

What nerves supply the dermatomes of the head and neck?

Answer 8

The trigeminal nerve (Cr N V) supplies the skin of the face/anterior scalp (basically everything in front of the ear)

C2-4 supply the skin of the posterior scalp/head and the neck

Question 9

Are cranial nerves sensory/motor or sympathetic?

Answer 9

Some are sensory
Some motor
Some parasympathetic (e.g. Oculomotor nerve [Cr N 3] contains some parasympathetic fibres)
Some are a mix of the above

Question 10

What types of sensory nerve fibres are there?

Answer 10

General sensory - Touch temp pain etc

Special Sensory - Vision/hearing/olfaction/taste

Question 11

How do sympathetic fibres reach regions supplied by cranial nerves?

Answer 11

The postgangionic fibres from the sympathetic chain form a plexus then hitch a ride on blood vessels

Question 12

What are the 3 main branches of the trigeminal nerve?

Answer 12

Forms a ganglion then divides:
Sup -> Inferior
V1 - Ophthalmic division
V2 - Maxillary Division
V3 - Mandibular Division

Question 13

What fibres are contained in hte main branches of the trigeminal nerve? (Cr N V)

Answer 13

Mainly general sensory

V3 (Mandibular division) also contains motor fibres

Question 14

What are the key muscles of facial expression?

Answer 14

Orbicularis Oculi - round eye
Obicularis Oris - round mouth
Occipitofrontalis - connects to eyebrows and aponeurosis of scalp, which stretches to the occipital bone
Buccinator - Provides cheek shape and prevents you chewing your own cheek by accident

Question 15

What nerve innervates the muscles of facial expression?

Answer 15

Cr N 7, the facial nerve innervates the muscles of facial expression such as the buccinator/occiptofrontalis/obicularis oculi/oris

Question 16

What fibres are in the facial nerve (Cr N 7) and what are their functions?

Answer 16

Motor - Muscles of facial expression
Special Sensory - Taste from front 2/3rds of tongue
Parasympathetic - Innervates all glands in head/neck except parotid salivary gland

Question 17

Why doesn’t the facial nerve innervate the parotid salivary gland?

Answer 17

It passes through it but after it exits the head through the stylomastoid foramen at which point it is purely motot fibres.

Question 18

What structures pass through the parotid gland?

Answer 18

• Motor fibres of facial nerve (Cr N 7)
• External carotid splits into its terminal branches here
• Retromandibular vein
• Also gives off parotid duct

Question 19

Terminal branches of the external carotid artery?

Answer 19

• Maxillary

- Superficial temporal artery (the one on people temples, can take a pulse off it)

Question 20

How do we divide the neck from the side?

Answer 20

Into 2 triangles:
Anterior triangle -> SCM -> Posterior triangle -> Trapezius

Each triangle contains arteries/veins/nerves/muscles

Question 21

How does Sternocleidomastoic contraction move the neck?

Answer 21

The headtilts to the same side but turns at the same time to face away from the contacting SCM

Question 22

What structures are found in the neurovascular compartments?

Answer 22

The carotid arteries
Internal jugular vein
Vagus nerve

All surrounded by the deep fascia known as the carotid sheaf

Question 23

What do the internal vs external carotid supply?

Answer 23

The external supplies the neck, face and scalp

The internal passes inside the cranial cavity to supply the brain

Question 24

How do we deliniate the internal vs external jugulars and what do they supply?

Answer 24

Internal:

• Thick
• Internal to SCM
• Drains brain

External:

• Thin
• External to SCM
• Drains much of the scalp/upper face

Question 25

What do we call veins in the cranial cavity?

Answer 25

Intracranial venous sinuses

Question 26

What nerves form the cervical plexus and what does it do?

Answer 26

C1-C4 and part of C5

From here arises sensory and motor branches to the skin and muscles of the neck

Question 27

What are the “strap Muscles”

Answer 27

The suprahyoid and infrahyoid muscles

They link the hyoid bone to the voice box skeleton and move it.

Question 28

What are the nerves and blood supply of the thyroid gland?

Answer 28

Nervous:
- External Laryngeal Nerve branch of superior laryngeal nerve
- Recurrent laryngeal nerve
Both are sources from the vagus

Arterial:

• Sup Thyroid Art - Branch of the ECA
• Inf Thyroid Art - Branch of the Subclavian

Venous:

• Sup & middle thyroid vein drain to IJV
• Inf Thyroid vein drains to brachiocephalic