Respiratory

Question 1

What are the paranasal sinuses? Role?

Answer 1

Pneumatised (air filled cavities) areas of the frontal, maxillary, ethmoid, sphenoid bones. They are arranged in pairs.
Create resonance of the voice.

Question 2

Describe the frontal sinuses: position, nerve supply.

Answer 2

Within the frontal bone on the midline septum, over the orbit and across the superciliary arch (between eyes and between eyebrows).
Nerve supply: ophthalmic division of the 5th cranial nerve (V nerve).

Question 3

Describe the maxillary sinuses: position, shape.

Answer 3

Located within the body of the maxilla (either side of nose, on cheekbones).
Pyramidal in shape: base at lateral wall of the nose, apex on zygomatic process of the maxilla, roof on the floor of the orbit and floor on alveolar process.
Open into the middle meatus (sinus openings)& hiatus semilunaris (groove, location of the openings for the frontal sinus, maxillary sinus, and anterior ethmoidal sinus).

Question 4

Describe the ethmoid sinuses: position, nerve supply.

Answer 4

Labyrinth of air cells - looks like an aero. Opens into semilunar hiatus of the middle meatus.
Located between eyes.
Nerve supply - ophthalmic & maxillary V nerve.

Question 5

Describe the sphenoid sinuses: position, nerve supply.

MOST IMPORTANT FOR EXAM

Answer 5

Medial to the cavernous sinus - [contains the third cranial (oculomotor) nerve, the fourth cranial (trochlear) nerve, parts 1 (the ophthalmic nerve) and 2 (the maxillary nerve) of the fifth cranial (trigeminal) nerve, and the sixth cranial (abducens) nerve. Carotid artery also runs through here.]
Inferior to the optic canal, dura and pituitary gland.
Empties into the sphenoethmoidal recess, lateral to the attachment of the nasal septum(e.g. either side of the middle of the nose).
Nerve supply is ophthalmic nerve V

Question 6

Describe in brief the pharynx

Answer 6

A connecting system allowing movement of air and food.
Constituents:
- nasopharynx (behind nose, eustachian tube orifices open into nasopharynx and supply air to the middle ear).
- oropharynx (back of mouth)
- larynx/hypopharynx (throat, prevents liquids and food entering lungs, rigid support structure of 9 cartilages)

Question 7

Describe the 9 laryngeal cartilages

Answer 7

SINGLE:
epiglottis - stops food going down trachea
thyroid - adams apple
cricoid - ‘postbox’ below vocal cords
DOUBLE:
arytenoid - pyramidal, rotates on the cricoid cartilage to change position of vocal cords
corniculate - elongation/extension of arytenoid
cuneiform (not important)

Question 8

describe the innervation of the larynx

Answer 8

Innervated by the vagus nerve which branches at the top of the neck into the superior and recurrent laryngeal nerves.
Recurrent innervates all the muscles except the cricothyroid.
Superior innervates lateral pharyngeal wall and inferior ganglion. Divides into internal and external, the former is a sensory nerve to the larynx above the vocal cords, latter innervating the cricothyroid muscle.

Question 9

What does the carotid sheath consist of?

Answer 9

the vagus nerve between the internal jugular vein and the carotid artery (either common or internal carotid depending on the level - divides).

Question 10

Trace the carotid artery up the neck. Innervation?

Answer 10

Bifurcates into the external and internal carotid arteries. At the origin of the internal carotid artery there is a swelling (the carotid sinus) which is innervated by the glossopharyngeal nerve.
Carotid sinus has baroreceptors which detect changes in blood pressure.

Question 11

Describe the glossopharyngeal nerve

Answer 11

Innervates carotid artery, leaves skull through jugular foramina. IX cranial nerve, gives sensory fibres to the posterior third of the tangy and to the oropharynx. Tympanic branch supplies middle ear and Eustachian tube. Also supplies stylopharyngeus muscle.

Question 12

Platysma muscle:

• where
• origin
• path

Answer 12

Superficial muscle of the neck that overlaps the sternocleidomastoid.
Origin = subcutaneous tissue of infraclavicular and supraclavicular regions.
Rises over clavicle proceeding up sides

Question 13

Sternocleidomastoid muscle

• origin
• insertion
• function
• innervation

Answer 13

Paired muscle in the superficial layers of the side of the neck.
Origin: manubrium and medial portion of the clavicle.
Insertion: mastoid process of temporal bone.
Function: rotation of head, flexion of neck.
Innervation: CN 9

Question 14

What are the infra hyoid muscles? (strap muscles)

Answer 14

Group of 4 muscles in anterior part of neck inferior to the hyoid bone.
Function is depression of the hyoid. - thyrohyoid also elevates larynx
1. Sternohyoid
2. Omohyoid - 2 bellied muscle separated by an intermediate tendon
3. Thyrohyoid
4. Sternothyroid

Question 15

What are the suprahyoid muscles?

Answer 15

Group of 4 muscles above the hyoid.
Elevate the hyoid and initiate swallowing.
1. Stylohyoid
2. Digastric - anterior and posterior bellies
3. Mylohyoid
4. Geniohyoid

Question 16

Innervation of stylohyoid and posterior digastric muscles of the neck

Answer 16

CN VII - facial nerve

stylohyoid/digastric branch

Question 17

Innervation of mylohyoid and anterior digastric muscles of the neck

Answer 17

CN 5 - trigeminal

Mandibular branch

Question 18

Innervation of geniohyoid muscle of the neck

Answer 18

CN XII - hypoglossal

Question 19

Function of thyroid gland

Answer 19

One of the largest endocrine glands in body
 Controls how quickly the body uses energy, makes proteins and controls the body’s sensitivity to
other hormones
 Thyroid hormones regulate growth and rate of function of many systems in the body
 Regulated by TSH from anterior pituitary

Question 20

Structure of the thyroid gland

Answer 20

2 lateral lobes connected by a midline isthmus.

Parathyroid glands

Question 21

why does the thyroid move when you swallow?

Answer 21

it is bound to the trachea and larynx by the pre-tracheal fascia - band/sheet of connective tissue

Question 22

Blood supply of the thyroid gland

Answer 22

• superior thyroid artery: branch of the external carotid artery. Enters upper pole of the gland
• inferior thyroid artery: branch of thyrocervical trunk of the subclavian, enters middle of posterior aspect

Question 23

Venous drainage of the thyroid vein

Answer 23

Venous plexus formed from superior, middle and inferior thyroid veins.
Superior and middle drain into the internal jugular vein.
Inferior thyroid veins drain into brachiocephalic/subclavian veins.

Question 24

anatomical location of the thyroid gland?

Answer 24

In the anterior neck, C5-T1.
Inferior to the thyroid cartilage of the larynx. Behind the sternohyoid and sternothyroid muscles, wrapping around the cricoid cartilage and superior tracheal rings.

Question 25

anatomical location of the larynx

Answer 25

Below the tongue and the hyoid bone. Lies at C4,5,6.

Covered by infrahyoid strap muscles

Question 26

Structure of the nose

Answer 26

Anterior: nares open into enlarged vestibule. Skin lined with stiff thick hairs.
Turbinates increase surface area.

Question 27

Types of turbinate and functions

Answer 27

Superior meatus:
- olfactory epithelium
- cribiform plate (olfactory nerves)
- sphenoid sinus
Middle meatus:
- sinus openings
Inferior meatus
- nasolacrimal ducts

Question 28

epithelium of nasal entrance vs rest of nose

Answer 28

nasal entrance = keratinised columnar epithelium

rest = non-keratinised columnar epithelium