Anatomy for procedural dermatology Flashcards
The epidermis is 0.1mm thick on the eyelids and genitalia.
F - 0.04mm thick
The epidermis is 1.5mm thick on the palms and soles.
T
Skin thickness varies with age, race, gender and the degree of photodamage.
T
Markedly photodamaged skin has higher elasticity than photoprotected skin
F - less elasticity
Regarding biomechanical skin responses, stress (load) is defined as force delivered to a cross-sectional area.
T
Regarding biomechanical skin responses, strain is the change in length in comparison to the original length.
T
Regarding biomechanical skin responses, creep refers to the ability of skin to stretch over time.
T
Regions with lower vascularisation are better able to withstand tension than those that are highly vascularised.
F - other way around
‘Stretch-back’ refers to the subsequent spread of scars for wounds closed under tension.
T
Age and sun exposure can accentuate the wrinkles that appear along the course of the relaxed skin tension lines
T
There are 5 cosmetic units of the face; forehead, cheeks, nose, lips and skin
F - six units, additionally eyes
The four components of the forehead are;
- superior eyebrow
- glabellar
- temporal
- general forehead
T
Most scar spreading occurs during the first 16 weeks postoperatively and is completed at 20 weeks.
F - First 8 weeks, complete at 12 weeks.
The scalp is divided into 5 layers from superficial to deep: skin, subcutaneous tissue, aponeurosis (galea), loose connective tissue and periosteum.
T mnemonic SCALP
The cutaneous nerves and vessels of the scalp are subcutaneous fat layer.
F - Dermal skin layer + larger vessels in subcut fat.
There are virtually no vessels in the subgaleal space of loose connective tissue, which makes it the ideal plane for undermining scalp tissue.
T
Motor nerves are found on the scalp.
F
All nerves and vessels of the scalp originate below the level of the brow as it is extended circumferentially around the scalp.
T
A galeotomy enhances the ability of the galea to stretch over the periosteum.
T - This involves scoring the underside of the galea.
The galea is an aponeurosis connecting the frontalis muscle of the forehead with the occipitalis muscle of the posterior scalp.
T
The galea extends from the superior occipital line to approximately 5cm below the frontal hairline on the forehead where it interdigitates with the SMAS.
F - 2cm below the frontal hairline.
Everything else is correct.
The eyelid skin lies directly on muscle, with minimal or no fatty layer.
T
Voluntary muscles of the perioral and chin area insert directly into skin.
T
The parotid gland is yellow in colour.
F - Grayish-tan
The linear wrinkles on the face form along the attachments of the fibres of the SMAS.
T
The zygomatic arch is the most prominent bone of the lateral cheek.
T
The mastoid process is the most inferior portion of the temporal bone.
T- Palpates at inferior aspect of postauricular sulcus.
The mastoid process fully protects the facial nerve throughout life as it exists the skull through the stylomastoid forarmen.
F - Mastoid process not fully developed until puberty. Everything else is true.
The nasion is formed by the articulation of the paired nasal bones with the frontal bone.
T
The relaxed skin tension lines generally occur in parallel to the long axis of the underlying musculature.
F - Perpendicular to the long axis.
The supraorbital, infraorbital and mental foramina are found along a vertical line extending from the supraorbital foramen or notch and passing through the centre of the pupil.
T
Using anthopmetric landmarks, the upper face is measured from the trichion (anterior hairline) to the glabella.
T
Using anthopmetric landmarks, the middle third of the face extends from the eyes and nose at the glabella to the subnasale (inferior aspect of the nose at the junction of the columella and cutaneous upper lip).
T
Using anthopmetric landmarks, the lower third of the face extends from the subnasale to the menton (lowest point on the chin contour of the mandible).
T
Using anthopmetric landmarks, the face divides vertically into thirds.
F Fifths. Each segment equal to eye width.
Asking patients to clench their teeth and jaw and palpating the leading edge of muscle on the cheek identifies the masseter muscle.
T It originates on the zygomatic arch and inserts on the ramus, angle and body of the mandible.
The parotid gland lies on the anterior half of the masseter muscle and extends from the tragus to just above the angle of the mandible.
F Posterior half of the masseter.
Everything else is true.
The anterior border of the parotid gland can generally be found by dropping a line down from the lateral canthus.
T
The parotid duct (Stenson’s duct) emerges from the anterior border of the parotid.
T
The parotid duct pierces zygomaticus major to reach the buccal mucosa
F Pierces buccinators
The parotid duct drains into the interior of the mouth as it enters the mouth opposite to the 3rd molar tooth.
F 2nd upper molar.
The parotid duct courses along the middle third of a line drawn from the notch of the ear above the tragus to a point midway between the oral commissure and alar rim. .
T The tragolabial line
The parotid duct can be palpated as it runs across the masseter when the teeth are clenched
T
At the anterior border of the masseter muscle, the parotid duct makes a sharp right angle and passes through the buccinator muscle to enter the buccal mucosa at the position of the first upper molar
F Second upper molar
Cutting into the parotid duct results in a chronic draining sinus that requires surgical repair.
F This occurs if you cut through the duct, rather than into it.
The facial nerve is not associated with the parotid gland.
F
Branches of the facial nerve generally lie on the superficial fascia of the masseter muscle.
F Deep fascia.
The superficial temporal artery traverses the posteroinferior aspect of the parotid gland from infralobular to pretagal and enters the subcutaneous fat at the superior pole of the parotid gland at the zygomatic arch.
T
The boundaries of the temporal fossa are delineated by the zygomatic arch, the tail of the eyebrow, the coronal suture line, and the temporal hairline.
T
The lateral margin of the frontalis muscle generally extends to the lateral tip of the eyebrow along the coronal suture line.
T
Lateral to the brow, the temporal branch of the facial nerve overlies the SMAS and is only protected from injury by a very thin fatty layer.
T
The facial artery is a branch of the external carotid artery.
T
The muscles of facial expression all originate or insert into the skin itself.
T
The orbital component of the orbicularis muscle is further divided into preseptal and pretarsal components.
F This is true for the palpebral component.
The orbicularis oculi muscle opens the eyelid.
F The levator palpebrae superioris does.
Loss of function of the orbicularis oculi muscle results in the levator superioris working unopposed so the eyelids do not close.
T
The orbicularis orculi muscle is innervated primarily by the temporal branch of the facial nerve.
F Zygomatic br primarily. Temporal br partially innervates upper portion of muscle.
Bilateral corrugator supercilii muscles contribute to the formation of the deep vertical furrow of the glabella.
T
The procerus is a bilateral midline muscle that pulls the medial aspect of the eyebrows inferior and is innervated by the temporal branches of the facial nerve.
F Solitary midline muscle.
Everything else is true.
Elevators of the lip are the levator labii superioris, levator labii superioris alaeque nasi, zygomaticus major and minor, and levator anguli oris.
T
The mentalis muscle is innervated by the buccal branch of the facial nerve.
F Mandibular branch of the facial nerve.
The depressors of the mouth are the depressor anguli oris and depressor labii inferioris.
F And the platysma.
The depressor muscles of the mouth are innervated by the marginal mandibular branch of the facial nerve.
T
Injury to the marginal mandibular branch of the facial nerve can result in a sneer.
T
The risorius muscle arises from the parotid fascia and pulls the labial commissure laterally, widening the mouth by making a smirk.
T
The platysma muscle plays a large functional role is mastication, neck movement and facial expression.
F Little functional role, but important anatomically.
The temporalis and masseter muscles contribute to facial expression.
F These are muscles of mastication.
The superficial musculoaponeurotic system (SMAS) is composed of muscle and a thin superficial layer of fascia that invests nearly all of the muscles of facial expression.
T
The SMAS ensures that the muscles of facial expression act in concert by distributing the pull of muscles evenly over the skin.
T
The SMAS acts as a deterrent to spread of infection from the superficial to the deep areas of the face.
T
The sub-SMAS layer contains blood vessels.
F Relatively bloodless.
All motor nerves lie above the SMAS, whereas all sensory nerves lie just deep to the SMAS.
F Other way around.
The three branches of the trigeminal nerve are: V1 ophthalmic, V2 maxillary, and V3 mandibular.
T
Erb’s point refers to the area of emergence of the greater auricular, lesser occipital, transverse cervical and spinal accessory nerve.
T
Cervical nerves derived from C2 to C4 form a plexus deep to the sternocleidomastoid muscle.
T
Injury to the spinal accessory nerve results in loss of function of the trapezius muscle with chronic aching in the shoulders, paraesthesia in the arm, dropped shoulder, and inability to actively abduct the shoulder to more than 80
T
In general, the branches of the facial nerve enter the muscles that they innervate at their anterior and superficial surfaces. .
F Posterior and deep surfaces
The branches of the facial nerve generally travel above the SMAS fascia.
F Below.
The major effect of injuring the temporal branch of the facial nerve is flattening of the forehead with drooping of the eyebrow and inability to close the eye tightly.
T
In the majority of people, the marginal mandibular nerve is found to descend 1-2cm into the neck at the mandibular angle.
F This only occurs in 10-20%. Usually it remains at or above the lower level of the mandible.
Hypertextension of the head does not affect the position of the mandibular nerve.
F Nerve may move as much as 2cm or more below the mandible.
If the marginal mandibular nerve is transected there is permanent loss of the ability to smile and whistle.
T
In general, lymphatic drainage occurs from superficial to deep, and from medial to lateral, and caudad in a downward diagonal direction.
T
20-50% of normal individuals have palpable lymph nodes in their neck.
T
With the exception of the lobule, the landmarks of the ear and formed by the shape of the auricle, which stems from a single piece of elastic cartilage.
T
The African ear is generally longer and the Asian ear is generally shorter, compared to the Caucasian ear.
F African shorter, Asian longer.
The dorsal surface of the hand is innervated by the sensory branch of the radial nerve.
T
The palmar surface of the hand is innervated by the median and ulnar nerves.
F Also the radial nerve.
When facial nerve injury is the result of blunt trauma, inflammation or heat, the nerve may recover over 2-6 months.
T
Transection of the zygomatic branch of the facial nerve causes paralysis of the upper lid, resulting in epiphora and exposure keratitis.
T
The parotid nodes are both within the gland and in the surrounding glandular fascia
T
The palmar surface of the hand is innervated by the radial, median and ulnar nerves
T
Age and sun exposure can accentuate the wrinkles that appear along the course of the relaxed skin tension lines
T
There are 5 cosmetic units of the face
F 6 – forehead, cheeks, eyes, nose, lips and chin
There are 4 components of the forehead unit
T General forehead, glabellar, superior eyebrow, temporal
The tragolabial line connects the tragus to the middle of the upper lip
T
The point where the parotid duct crosses the posterior border of the masseter muscle is plotted along the tragolabial line
F The anterior border of the masseter muscle
Orbicularis oculi is innervated mainly by the zygomatic branch of the facial nerve but the upper portion also receives partial innervation by the temporal branch of the facial nerve
T
Paralysis of the zygomatic and temporal branches of the facial nerve results in inability to fully or tightly close the eyelid and possible ectropion formation
T
The SMAS invests the muscles of mastication
F Invests nearly all the muscles of facial expression
The SMAS acts as a deterrent to spread of infection from the superficial to the deep areas of the face
T
The axial arteries are found in the deep subcutaneous tissue
F Either in the superficial aspect of the SMAS or at the SMAS-subcutaneous fat border
All sensory nerves lie deep to the SMAS
F All sensory nerves lie above (superficial) to SMAS
All motor nerves lie deep to the SMAS
T ‘just deep’ to SMAS
The greater auricular nerve supplies the skin of the lateral neck and at the angle of the jaw
T
The spinal accessory nerve emerges at Erb’s point
T
In addition to the spinal accessory nerve, the other nerves found in the region of Erb’s point include the great(er) auricular, lesser occipital and transverse (cervical) nerves
T Also the supraclavicular nerve – the 4 superficial branches of the cervical plexus
Injury to the spinal accessory nerve results in loss of function of trapezius, chronic painful aching shoulder(s), paraesthesia in the arm, dropped shoulder, inability to shrug, winging of the scapula and inability to abduct the shoulder >80˚
T
The branches of the facial nerve generally travel above the SMAS fascia, as opposed to sensory nerves which run below the SMAS
F Generally travel ABOVE fascia, sensory run over
The major effect of inuring the zygomatic branch is flattening of the forehead with drooping of the eyebrow and inability to close the eye tightly
F Temporal branch
Most normal individuals have palpable benign lymph nodes in the neck
F 20-50%
The parotid nodes, both preauricular and infra-auricular, are both located within the gland and in the surrounding glandular tissue
T
The submental and submandibular nodes are best palpated with the chin drawn inferiorly to relax the platysma
T Further enhanced by bimanual examination with a finger in the floor of the mouth and fingers of other hand pushing upwards
The submental nodes are often palpable in healthy people
T
The spinal accessory nerve emerges from the posterior aspect of the sternocleidomastoid within the posterior triangle of the neck
T
In the posterior triangle the spinal accessory nerve is covered by a thick layer of muscle
F Covered only by skin and superficial cervical fascia
Trauma to the spinal accessory nerve results in winging of the scapula, inability to shrug the shoulder, difficulty abducting the arm and chronic shoulder pain
T
When the spinal accessory nerve is transacted it has no ability to regenerate
T
Erbs point is located by turning the head away and transecting the horizontal lines connecting the angle of the jaw to the styloid process with a vertical lines drawn from the mid-point to the posterior borders of the sternoclediomastoid
F Mastoid process, not styloid process
The parotid nodes are palpated on the pretragal area
T
The palmar surface is innervated by the radial, median and ulnar nerves
T
The medial malleolus is in close approximation to:
The flexor retinaculum
T
The medial malleolus is in close approximation to:
The medial plantar nerve
T
The medial malleolus is in close approximation to:
The posterior tibial artery
T
The medial malleolus is in close approximation to:
The Achilles tendon
F
The medial malleolus is in close approximation to:
The tibialis posterior muscle
F Is close to the tendon of this muscle
