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 chin
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