Respiratory Flashcards
(28 cards)
What are the paranasal sinuses? Role?
Pneumatised (air filled cavities) areas of the frontal, maxillary, ethmoid, sphenoid bones. They are arranged in pairs.
Create resonance of the voice.
Describe the frontal sinuses: position, nerve supply.
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).
Describe the maxillary sinuses: position, shape.
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).
Describe the ethmoid sinuses: position, nerve supply.
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.
Describe the sphenoid sinuses: position, nerve supply.
MOST IMPORTANT FOR EXAM
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
Describe in brief the pharynx
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)
Describe the 9 laryngeal cartilages
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)
describe the innervation of the larynx
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.
What does the carotid sheath consist of?
the vagus nerve between the internal jugular vein and the carotid artery (either common or internal carotid depending on the level - divides).
Trace the carotid artery up the neck. Innervation?
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.
Describe the glossopharyngeal nerve
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.
Platysma muscle:
- where
- origin
- path
Superficial muscle of the neck that overlaps the sternocleidomastoid.
Origin = subcutaneous tissue of infraclavicular and supraclavicular regions.
Rises over clavicle proceeding up sides
Sternocleidomastoid muscle
- origin
- insertion
- function
- innervation
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
What are the infra hyoid muscles? (strap muscles)
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
What are the suprahyoid muscles?
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
Innervation of stylohyoid and posterior digastric muscles of the neck
CN VII - facial nerve
stylohyoid/digastric branch
Innervation of mylohyoid and anterior digastric muscles of the neck
CN 5 - trigeminal
Mandibular branch
Innervation of geniohyoid muscle of the neck
CN XII - hypoglossal
Function of thyroid gland
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
Structure of the thyroid gland
2 lateral lobes connected by a midline isthmus.
Parathyroid glands
why does the thyroid move when you swallow?
it is bound to the trachea and larynx by the pre-tracheal fascia - band/sheet of connective tissue
Blood supply of the thyroid gland
- 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
Venous drainage of the thyroid vein
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.
anatomical location of the thyroid gland?
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.
