Week 1 Flashcards
Acanthosis
thickening if stratum spinosum
Dyskeratosis
abnormal, premature keratization within cells below stratum granulosum
Erosion
Thinning of the skin, can lead to break
Exocytosis
Infiltration of the epi by inflammatory cells
Hydropic swelling
Edema of keratinocytes, seen in viral infections
Hypergranulosis
Hyperplasia of stratum granulosum, due to intense rubbing
Hyperkeratosis
thickening of the stratum corneum, associated with abnormality in keratin
Lentiginous
Linear pattern of melanocyte proliferation within epidermal basal cell layer
Papillomatosis
surface elevation caused by hyperplasia and enlargement of dermal papillae
Parakeratosis
- keratinization with retained nuclei in stratum corneum
- on mucous membranes this is normal
Spongiosis
intracellular edema of epidermis
Ulceration
discontinuity of skin showing complete loss of epidermis revealing dermis or cubcutaneous
Vacuolization
formation of vacuoles within or adjacent to cells, usually in basal cell-basement membrane
Acanthosis
- thickening of stratum spinosum
- thickened, hyperpigmented skin
Layers of epidermis: outermost to innermost
- corneum
- lucidum (optional)
- granulosum
- spinosum
- basale
Corneum
15-20 layers of dead keratinocytes, constantly sloughed off
Lucidum
only in thick skin, thin layer of flattened eosinophilic keratinocytes, no nuclei or organelles
Granulosum
3-5 layers of flattened cells, undergoing final step of keratinization
-provide sealing effect with exocytosis of lamellar granules
Spinosum
- layer where keratin in synthesized into tonofibrils
- looks like it has short spines due to desmosomes being seen
- where langerhaans cells are located
Basale
single layer of cells, differentiates progenitor cells into keratinocytes
Melanocyte
in basal layer, makes melanin, will pass melanin to keratinocyte
Layers of dermis
- papillary: include dermal papillae, loose connective tissue, has fibroblasts and mast cells
- reticular: thicker, dense irregular CT;
- both contain blood and lymph vessels
Subcutaneous layer
- consists loose CT and adipocytes
- allows for skin to slide over bones and organs
Epidermal ridges and dermal papillae
connect epidermis and dermis, invaginate both layers
Function of intervetebral discs
shock absorber between vertebrae, protect nerves
Composition of intervertebral discs
anulus fibrsus and nuclei pulposi (elastin, proteoglycans, water, collagen)
How does anterior longitudnal ligament interact with IV disks?
runs from the base of the skull along the front of each vertebral body and disc and down the anterior sacrum
Function of anterior longitudnal ligament
limit flexion and prevent over-extension.
Describe posterior longitudnal ligament
- much narrower, somewhat weaker band than the anterior longitudinal ligament
- runs within the vertebral canal along the posterior aspect of the vertebral bodies. It is attached mainly to the IV discs
What is function of posterior longitudnal ligament?
weakly resists hyperflexion of the vertebral column and helps prevent or redirect posterior herniation of the nucleus pulposus.
Contents of vertebral canal
spinal cord, spinal nerve roots, spinal meninges, neurovascular structures
Where does spinal cord begin and end for an adult?
extends from the foramen magnum in the occipital bone to the level of the L1 or L2 vertebr
Where does spinal cord begin and end for an embryo?
Begins at foramen magnum, ends at L4-L5
Why does adult length change?
The cord grows faster than the spinal vertebrae in an embryo. As the vertebral growth catches up the end of the spinal cord will tend to move up the vertebral column
Where are enlargements of the spinal cord? Why?
Cervical and lumbar areas because they have nerve plexuses
Where to insert needle for lumbar puncture
Between L4-L5 because nerves are now in cauda equina making it harder to puncture since the strands can easily be moved out of the way
Ligamentum flavum
- what is it?
- what does it protect?
- connects the laminae of adjacent vertebrae, from the second vertebra (axis) to the first segment of the sacrum.
- protection to the neural elements of the spine and provides stability by preventing excess motion between vertebrae
What is ligamentum flavum composed of?
How does it change between spinal levels?
- 80% elastin and 20% collagen
- It gets thicker with each spinal level (cervical-lumbar)
Which ligament unites spinous processes in verteba
Supraspinous ligament
pathway of needle as it is put into epidural space
skin, subcutaneous/fat, supraspinous ligament, intraspinous ligament, ligamentum flavum
What are the two craniovertebral joints?
type?
What do they not have? why?
- atlanto-occipital and atlanto-axial joint
- synovial
- IV disks, allows for greater motion
Atlanto-occipital joint
- between atlas and occipital bone
- connected by articular surfaces of lateral masses of the atlas and occipital condyles
- condyle joint
- allows for flexion and extension of head
Atlanto axial joint
- contains two lateral joints (between the inferior facets of the lateral masses of C1 and the superior facets of C2; planar) and one median (between the dens of C2 and the anterior arch of the atlas; pivot)
- allows head to be moved side to side
What are partial thickness biopsy techniques?
- Shave excision
- Curettage
What are full thickness biopsy techniques?
- Punch biopsy
- Excisional biopsy
Shave excision
- when used/what lesion
- when not used
- advantages
- best suited to remove the protruding portion of a raised skin lesion when a full-thickness sample is not required; can be used for flat lesion but will use saucer shaped incision
- contraindicated for melanoma because of inability to gauge how deep the invasion is
- Simple and less expensive; Not going to disrupt the normal skin
Curretage
- when used/what lesion
- when would it be disadvantage to use
- removal of basal cell carcinomas and hyperkeratotic epidermal lesions such as warts, molluscum contagiosum, seborrheic keratoses, and actinic keratoses
- multiple fragments of specimen are produced and the presence of disease-free margins cannot be determined.
Discuss when/why punch biopsy is used and for which type of skin lesion
-difference in size
- complete removal of small lesions (<5 mm) or whenever there is doubt as to the diagnosis or optimal treatment for a particular lesion.
- strongly recommended when melanoma is a significant consideration because it provides information on the depth of the lesion.
- 2mm punches are usually reserved for areas where scarring should be spared. Larger biopsies are correlated with a more significant likelihood of scarring.
Discuss when/why excisional biopsy is used for and which type of skin lesion
- used to remove an entire lesion in a manner that obtains a full-thickness specimen of skin.
- used for removal of malignant, or suspected malignant, skin lesions where margins can be assessed
Complications of skin sampling (7)
○ Pain ○ Infection ○ Scarring ○ Misdiagnosis ○ Allergic reaction ○ Recurrence -Bleeding
Pain
generally insignificant
Infection
sample site must be washed 3-4 times per day to keep it moist; Soap and water only
Scarring
Always a possibility. With punch biopsies, there may be an “acne-like” pockmark. Obviously, excision and incision leave a line and possibly suture tracks. All methods can leave hypopigmentation. Some topical hemostatic agents (Monsel’s solution and especially silver nitrate) can leave prolonged hyperpigmentation; can lead to Keloids (overgrowth) or Pock marks
Misdiagnosis
A lesion may be sent for biopsy, but unless it is totally removed, the most significant area could be missed. (Likewise, the practitioner could unknowingly shave and transect through a melanoma; therefore, if there is any doubt, perform the biopsy for depth.)
Allergic reaction
To topical antibiotics, the anesthetic, dressings, and other agents (usually indicated by redness and itching).
Recurrence
Even if it was thought that the entire lesion was removed, both benign and malignant lesions can recur.
Bleeding: Almost nonexistent.
Bleeding
Can occur, may need sutures
Triangle of auscultation:
- borders
- used for
- Superiorly and medially, by the inferior portion of the trapezius. Inferiorly, by the latissimus dorsi. Laterally, by the medial border of the scapula.
- to better auscultate the lungs
Parts of scotty dog and corresponding component of vertebra
- Ear: superior articular process
- Snout: transverse process
- Eye: pedicle
- Neck: isthmus
- Forelimb: inferior articular process
- Body: spinous process and lamina
- Hindlimb: opposite inferior articular process
