SM: Week 1 Flashcards
1
Q
Innervation, arterial/venous supply, and action of: trapezius
A
Innervation: Accessory Nerve (CN XI)
A/V: Transverse Cervical A/V
Action: elevate scapula
2
Q
Innervation, arterial/venous supply, and action of: latissmus dorsi
A
Innervation: Thoracodorsal Nerve
A/V: Thoracodorsal A/V
Action: Extend, adduct, and medially rotate humerus
3
Q
Innervation, arterial/venous supply, and action of: levator scapulae
A
Innervation: Dorsal Scapular Nerve
A/V: Dorsal Scapular A/V
Action: elevate scapula
4
Q
Innervation, arterial/venous supply, and action of: rhomboids (major/minor)
A
Innervation: Dorsal Scapular Nerve
A/V: Dorsal Scapular A/V
Action: retract scapula, rotate scapula to depress glenoid cavity
5
Q
Innervation, arterial/venous supply, and action of: serratus anterior
A
Innervation: long thoracic nerve
A/V: lateral thoracic A
Action: protracts scapula (holds against body); rotation of scapula
6
Q
Innervation, arterial/venous supply, origin/insertion, and action of: supraspinatus
A
Innervation: suprascapular nerve A/V: suprascapular A/V O: supraspinatus fossa of scapula I: greater tubercle of humerus Action: abduction of arm
7
Q
Innervation, arterial/venous supply, origin/insertion, and action of: infraspinatus
A
Innervation: Suprascapular nerve A/V: suprascapular A/V O: infraspinatus fossa of scapula I: greater tubercle of humerus Action: lateral rotation of arm, adduction of arm
8
Q
Innervation, arterial/venous supply, origin/insertion, and action of: teres minor
A
Innervation: axillary nerve
A/V: circumflex scapular A/V
O: upper 2/3 of lateral border of scapula
I: greater tubercle of scapula
Action: lateral rotation and adduction of arm
9
Q
Innervation, arterial/venous supply, origin/insertion, and action of: subscapularis
A
Innervation: upper and lower subscapular nerve (C5, C6) A/V: subscapular A O: subscapular fossa of scapula I: lesser tubercle of humerus Action: medial rotation of humerus
10
Q
Innervation, arterial/venous supply, and action of: deltoid
A
Innervation: axillary nerve
A/V: posterior circumflex humoral A
Action: main action is to abduct arm at shoulder
11
Q
Innervation, arterial/venous supply, and action of: teres major
A
Innervation: Lower subscapular nerve
A/V: circumflex scapular A/V
Action: adducts, medially rotates, and assists with extension of the arm
12
Q
What is “winged scapula” and how does it result?
A
Winged scapula manifests when the long thoracic nerve is damaged. The long thoracic nerve innervated serratus anterior and results in loss of protraction of the scapula (inability for the scapula to remain close to the ribs).
13
Q
Innervation, arterial/venous supply, origin/insertion, and action of: omohyoid
A
Innervation: ventral ramus via ansa cervicalis
A/V: transverse cervical A
Origin: superior/medial border of scapula
Insertion: inferior border of hyoid bone
Action: depresses/stabilizes the hyoid bone
14
Q
What are the boundaries of the triangle of auscultation? What is the significance of this area?
A
Boundaries:
- Superior: scapula
- Medial: trapezius
- Inferior: latissimus dorsi
Significance: clinically useful for listening to lung sounds; overlies the 6th intercostal space
15
Q
What clinical deficit would be apparent with injury to the thoracodorsal nerve?
A
•The thoracodorsal nerve innervates latissimus dorsi which is responsible for extending, adducting and medially rotating the upper extremity, thus a deficit to the thoracodorsal nerve would result in an inability to extend, adduct, and medially rotate the upper extremity.
16
Q
How would injury to the dorsal scapular nerve effect the position of the scapula?
A
• The dorsal scapular nerve innervates levator scapulae and the rhomboids. An injury to the dorsal scapular nerve would affect the function of these muscles as follows: elevating the scapula and retracting and rotating the scapula to depress the glenoid fossa, respectively.
17
Q
What would be the appearance of the patient’s shoulder sometime following axillary nerve injury?
A
• Patient deficits would result in an inability to abduct the shoulder and laterally rotate and adduct the shoulder, respectively.
18
Q
What is the rotator cuff muscle that initiates abduction?
A
Supraspinatus
19
Q
What is the most commonly torn rotator cuff muscle?
A
Supraspinatus
20
Q
What is a dermatome?
A
A dermatome is a unilateral area of skin innervated by the nerve fibers of a single spinal nerve that originated from a single spinal cord segment; considerable overlap exists between adjacent dermatomes
21
Q
What is a myotome?
A
A myotome is a unilateral muscle mass receiving innervation from the fibers conveyed by a single spinal nerve
22
Q
What is the dermatome C5 landmark?
A
Shoulder
23
Q
What is the dermatome C6 landmark?
A
Thumb
24
Q
What is the dermatome C7 landmark?
A
Middle finger
25
What is the dermatome C8 landmark?
Little finger
26
What is the dermatome T4 landmark?
Nipple
27
What is the dermatome T10 landmark?
Umbilicus
28
What is the dermatome L1 landmark?
Groin
29
What is the dermatome L5 landmark?
Medial foot
30
What is the dermatome S1 landmark?
Lateral leg/foot
31
What is the dermatome S 2,3,4 landmark?
Anal area
32
What are the myotome muscles affected by C5?
Upper extremity abductors (biceps brachii, deltoid)
33
What are the myotome muscles affected by C5/6?
Forearm flexors (biceps brachii, brachioradialis), forearm pronators
34
What are the myotome muscles affected by C7?
Forearm extensors (triceps brachii), wrist extensors, finger extensors
35
What are the myotome muscles affected by C8/T1?
Intrinsic muscles of hand (radial, median, ulnar nerves)
36
What are the myotome muscles affected by L2?
Thigh flexion (iliopsoas)
37
What are the myotome muscles affected by L3/4 and what is its associated reflex?
Leg extension (quadriceps) -- knee jerk reflex
38
What are the myotome muscles affected by L4/5?
Foot dorsiflexion, toe extensors (anterior tibial muscles)
39
What are the myotome muscles affected by S1/2 and its associated reflex?
Foot plantar flexors, toe flexors (posterior tibial muscles) -- Achilles tendon reflex
40
What are the myotome muscles affected by S 2,3,4?
Anal contraction
41
How are joints innervated?
Overlying larger nerves supply skin and muscle that move the joint and provide it with a rich nerve supply for proprioception and pain (Hilton’s Law)
42
What are the two main types of joints? How do they differ?
Synarthroses (together joints) and Diarthroses (synovial joints)
- they differ based on degree of joint movement
43
Synarthroses
separated by connective tissue which permits limited movement
44
Diarthroses
moveable joints due to presence of synovial fluid and an articular surface
45
What are the different types of synarthroses?
syndesmosis, synchondrosis, and synostosis
46
Syndesmosis (fibrous joint)
opposed bones are joined by intervening fibrous tissue, i.e. interosseus membrane, sutures
47
Synchondrosis (cartilaginous joint)
two bones are separated from each other by cartilage, i.e. epiphyseal plate, intervertebral disc, symphysis
48
Synostosis
two bones are joined together by bone, i.e. ossified sutures, epiphyseal plates
49
What are some features of diarthroses that differentiate them from synarthroses?
• Synovial space – articular cavity or discontinuity between participating bones
• Synovial fluid – joint lubrication
• Fibrous capsule
• Synovial membrane/sac – lines capsule
• Articular surface – composed of hyaline cartilage that caps underlying bones
• Others:
- Menisci, fat pads, ligaments, bursae (fluid-filled sacs)
50
What are some main types of synovial joints?
- plane joints
- hinge joints
- saddle joints
- condyloid joints
- ball and socket joints
- pivot joints
51
What is a bursa?
fluid-filled sac consisting of serous membrane
52
What are synovial tendon sheaths?
serous membranes that consist of an inner layer (visceral layer) attached to the tendon and an outer layer (parietal layer) with synovial fluid found within the sac or cavity
53
What are the different epidermal layers?
- stratum germinativum (stratum basal)
- stratum spinosum
- stratum granulosum
- (stratum lucidum) -- only in thick skin
- stratum corneum
54
What are some features of stratum germinativum and where is it located, its structure, and status of mitotic activity?
* Features: cells are cuboidal or columnar, form hemidesmosomes and desmosomes, cytoplasm has multiple polyribosomes and intermediate filaments
* Location: adjacent to basal lamina (deepest layer)
* Structure: single layer of cells
* Mitotic Activity: yes
55
What are some features of stratum spinosum and where is it located, its structure, and status of mitotic activity?
* Features: cells are polygonally shaped, have a “prickly” appearance, desmosomes, has intermediate filaments (tonofibrils), membrane-coating granules (keratinosomes) in cytoplasm
* Location: immediately above the stratum germinativum
* Structure: variable thickness, several cell layers deep
* Mitotic activity: some, less than germinativum
56
What are some features of stratum granulosum and where is it located, its structure, and status of mitotic activity?
* Features: flattened polygonally-shaped cells (parallel to basement membrane), keratohyalin granules appear in cytoplasm, nucleus becomes pyknotic (small, dense)
* Location: above stratum spinosum
* Structure: three to five layers thick
* Mitotic activity: none
57
What are some features of stratum corneum and where is it located, its structure, and status of mitotic activity?
* Features: cells appear dead and flattened, cytoplasm becomes keratinized (eleidin from stratum lucidum becomes keratin in thick skin)
* Location: outermost layer of epidermis
* Structure: thickness and number of cells vary considerably
* Mitotic activity: none
58
What are the two dermal layers?
- papillary layer
| - reticular layer
59
What is the location and structure of the papillary layer of dermis?
- Location: superficial layer of dermis immediately beneath basement membrane
- Structure: composed of loose areolar CT (collagen, reticular, elastic fibers), more cellular than reticular layer (fibroblasts, mast cells, macrophages, smooth/skeletal muscle)
60
What are the two types of papillae and what makes them significant?
* Vascular – papillae contain capillary loop projections, are the only source of nourishment for epithelial cells, have thermoregulatory devices
* Nervous - contain special nerve terminations such as meissner’s corpuscles and pacinian corpuscles (encapsulated nerve endings)
61
What is the location, structure, and some features of the reticular layer of the dermis?
* Location: deep layer of dermis
* Structure: composed of dense irregular CT (type I collagen fibers, some reticular and many elastic fibers, less cellular than papillary layer)
* Features: the predominant direction of all fibers is parallel to surface (Langer Lines)
62
What is the process of keratinization?
There are two phases:
• Synthetic phase: intermediate filaments, keratohyalin granules, membrane-coating granules (MCGs) and filaggrin and trichohyalin proteins found in large numbers
• Degradative phase: MCGs lipid contents discharged into intercellular space, lysosomal enzymes degrade synthetic organelles, filaments and keratohyalin condense into a fibrous-amorphous mass
63
What are three factors that influence skin pigmentation?
- Presence of carotene in skin
- Blood capillaries impart a reddish hue
- Melanin pigment imparts shade(s) of brown
64
How is melanin produced?
- Melanin is produced by melanocytes which are usually present in the stratum basal layer of the epidermis. Melanocytes are highly branched, dendritic cells which insinuate themselves between other epidermal cells (these branches contain pigment granules that eventually are released into the epidermis giving rise to colored skin). These pigment granules are made from melanosomes.
65
What is the process for melanosome granule formation?
First, the rough ER forms enzymes with tyrosinase activity. The golgi then packages these tyrosinase enzymes into membrane-bound vesicles that contain tyrosinase and melanin. As the pre-melanosome matures, there is a gradual decline in tyrosinase activity until the pre-melanosome has become a melanin granule which can bud off from the dendritic process and go into surround epidermal cells.
66
What is the difference between skin pigmentation for white and black people?
• Blacks: melanosomes are larger, more numerous, and dispersed throughout keratinocyte cytoplasm
• Whites: melanosomes are smaller, fewer, and close to nucleus
- Difference in number due to how fast the melanosomes are degraded, not on initial number
67
Describe the structure and function of hair.
• Structure: hair shaft (medulla, cortex, and hair cuticle), follicle (internal root sheath, external root sheath), hair bulb (matrix, dermal papilla)
- Note: hair cuticle and the internal root sheath cuticle layer interdigitate to keep hair shaft in follicle
• Function: provide warmth
68
Describe the structure and function of nails.
* Structure: nail plate, nail bed, nail matrix (most proximal portion of nail bed, site of mitotic activity), eponychium, hyponycium, lunula
* Function: protect finger tips
69
Describe the structure and function of eccrine glands.
• Structure: simple coiled tubular glands
- Secretory portion – secretes KCl, NaCl, ammonia, and urea, has dark (mucous secretion), clear (watery secretion), and myoepithelial cells (contractile properties)
- Excretory portion – passes through epidermal portion of skin, reabsorb K, Na, and Cl
• Function: empty secretions into epidermal ridges
70
Describe the structure and function of apocrine glands.
• Structure:
- Secretory portion: lumen is large, myoepithelial cells present, probably do not lose portion of cell during secretion
- Excretory portion: ducts empty into hair follicle
• Function: found in restricted body regions: axilla, areola of nipple, anogenital region; secretory product is odorless unless encounters cutaneous bacteria to make it odoriferous
- Note: Have sympathetic innervation (neurotransmitter = ACh)
71
Describe the structure and function of sebaceous glands.
* Structure: simple, branched alveolar gland; short duct empties holocrine secretion product into hair follicle
* Function: lubricate hair follicle, source of oil associated with hair
72
Describe the structure and function of arrector pili muscles.
* Structure: bundles of smooth muscle associated with hair follicles; one end anchored to CT sheath of follicle and other end anchored to papillary layer of dermis
* Function: constrict due to sympathetic innervation forming goose bumps or secretions from sebaceous glands on skin
73
What are the two different types of nerve endings (sensory structures)?
- Free nerve endings (naked)
| - Encapsulated nerve endings
74
Describe the structure and function of free nerve endings.
* Structure: endings wrap around CT sheath of hair follicles
| * Function: carry sensations of touch (Merkel) and pain, hot and cold
75
What are two different types of encapsulated nerve endings?
- Meissner's corpuscles
| - Pacinian corpuscles
76
Describe the structure and function of Meissner's corpuscles.
* Structure: found in hairless skin within the dermal papillae
* Function: senses touch
77
Describe the structure and function of Pacinian corpuscles.
* Structure: thick fibrous capsule, has many layers, looks like an onion; found in hypodermis
* Function: senses deep pressure
78
What are the functions of Merkel cells?
senses touch, associated with unmyelinated sensory nerves
79
What are the functions of Langerhans cells?
APC, derived from monocytes, has immunological function -- Fc and complement receptors, phagocytose and process foreign antigens
80
What are the functions of melanocytes?
produce melanin granules (melanosomes) to give skin color
81
What are the functions of keratinocytes?
provide protection for underlying tissue
82
What are the functions of the vascular supply to the dermal layers?
- nourishment to tissue (rete systems)
| - thermoregulation (AVA)
83
What is the rete subpapillare system?
It is the vascular network between papillary and reticular layers of dermis.
84
What is the rete cutaneum system?
It is the vascular network that send branches in two directions: subcutaneous and dermal.
85
What is an arteriovenous anastomosis?
It is a capillary network involved in thermoregulation due to the multiple loops present. In cold conditions, blood flow primarily goes through the closest loop to the vein. In hot conditions, blood flow goes to the closest loop to the surface to release heat.
86
What is the process of wound healing?
1. Fibrin clot forms at bottom of cut
2. Epidermis extends down sides of incision until both epidermal extensions meet
3. Fibroblasts and capillaries repair connective tissue
- Fibroblasts come from hypodermis
4. New dermal tissue pushes cleft to surface until surface is level
87
What are the two different types of skin grafts?
- Split-skin grafts
| - full thickness grafts
88
What is a split-skin graft?
It involves a piece of skin cut at level halfway down the dermis, placed in denuded area where needed, tissue eventually becomes revascularized, donor site is able to proliferate due to remaining epidermal cells (preferred method).
89
What is a full thickness graft?
It requires the removal of all the dermis and epidermis from the donor and the donor site cannot re-epithelialize itself.
90
What are some general functions of skin?
- Shield the body from: organism invasion, excessive fluid loss
- Temperature regulation
- Has endocrine and exocrine functions
91
Cutaneous blood flow involves _______________ innervation.
sympathetic
92
When the body is hot, what is the action of the sympathetic nerves?
Both the pre- and post-ganglionic nerves release ACh as their neurotransmitter.
Mechanism: pre-ganglionic nerve -- (release ACh) --> nicotinic receptor on post-ganglionic nerve -- (release ACh) --> muscarinic receptor on blood vessel --> --> vasodilation
93
What is different about the way sympathetic nerves work on the skin and sweat glands compared to other sympathetic innervation?
Typically, the post-ganglionic nerve releases norepinephrine instead of ACh as seen in skin and sweat gland activation.
94
How are sweat gland secretions regulated?
Control of sweat gland secretions is ultimately regulated by temperature sensors in the hypothalamus which then act on sympathetic nerves to release:
- ACh from post-ganglionic nerve on muscarinic receptors to increase sweat production (eccrine)
- NA from post-ganglionic nerve on a1 and ß receptors to increase sweat production (apocrine)
95
After being stimulated by sympathetic innervation, describe the processes of secretion and reabsorption for sweat glands.
• Secretion: Na, Cl, and K are actively secreted by sweat glands involving NKCC
- CLCA and CFTR allow Cl into the sweat gland lumen
- Na and H2O follow by electrochemical gradient and osmosis
• Reabsorption: once ions and water are in lumen of sweat duct, Na and Cl can be reabsorbed by ENaC and CFTR, respectively. H2O remains in lumen due to lack of aquaporins
96
What are two types of sensory ganglia and what type of neuron is found in these ganglia?
- Spinal ganglia, such as the dorsal root ganglia (DRG)
- Cranial ganglia (V, VII, VIII, IX, X)
- All of these ganglia are pseudounipolar, except VIII sensory ganglia are bipolar
97
What are the different types of cranial sensory ganglia?
- Trigeminal (V): trigeminal (semilunar or Gasserian)
- Facial (VII): geniculate
- Vestibulocochlear (VIII): spiral (cochlear), vestibular (Scarpa's)
- Glossopharyngeal (IX): superior, inferior (petrosal)
- Vagus (X): superior (jugular), inferior (nodose)
- Remember: all of these ganglia have pseudounipolar neurons except VIII which has bipolar neurons
98
In the spinal cord, what composes the gray matter?
Gray matter is composed of cell bodies and synapses.
99
What are the three different sections of the gray matter in the spinal cord and what types of neurons do they contain?
o Dorsal Horn: contains multipolar neurons
o Lateral Horn (only T1 - L2): contains multipolar neurons and an intermediolateral cell column
o Ventral Horn: contains alpha (lower motor) and gamma motor neurons, both are multipolar; innervate extrafusal skeletal muscle fibers and intrafusal muscle fibers, respectively
100
In the spinal cord, what composes the white matter?
White matter is composed of myelinated axons which form tracts.
101
What are the different sections of white matter in the spinal cord?
- dorsal column/funiculus
- lateral column/funiculus
- ventral column/funiculus
- anterior white commissure
102
What are some features of the dorsal column/funiculus?
o Dorsal column/funiculus: cell bodies located in the DRG, carry discriminative touch and proprioception
- Funiculus gracilis (only above T6)
- Funiculus cuneatus (only above T6)
103
What are some features of the lateral column/funiculus?
o Lateral column/funiculus: has ascending sensory and descending motor tracts
- Sensory fibers have cells of origin in gray matter of dorsal horn
- Motor fibers have cells of origin in upper levels of neuraxis (brain stem or cerebrum)
104
What are some features of the ventral column/funiculus?
o Ventral column/funiculus: has ascending sensory and descending motor tracts
- Sensory fibers have cells of origin in gray matter of dorsal horn
- Motor fibers have cells of origin in upper levels of neuraxis (brain stem or cerebrum)
105
What are six differences in the gray and white matter columns at different cord levels?
o Cord gets smaller caudally.
o Progressive decrease in white matter at lower levels: number of nerve fibers decreases caudally as descending tracts gradually terminate and ascending tracts aren't yet complete.
o Shape of cord: cervical segments are large and oval, while lumbar and sacral segments are smaller and rounder.
o Gray matter larger at cervical (C4-T1) and lumbosacral (L2-S3) levels: due to larger number of nerve cells associated with innervation of the limbs.
o Lateral horn present in T1-L2 segmental levels (aka intermediolateral cell column): contains the cell bodies of preganglionic sympathetic neurons.
o Dorsal or posterior funiculus divided into two fasciculi (f. gracilis and f. cuneatus) above T6.
106
Where do the cell bodies of upper and lower motor neurons originate and terminate?
* Upper motor neurons originate (cell bodies) in the CNS and terminate (synapse) in the CNS
* Lower motor neurons originate (cell bodies) in the CNS and terminate (synapse) in the PNS
107
What are the two divisions of nerve types in the PNS?
Somatic and Visceral
108
Both somatic and visceral components of the PNS are divided further into ___________ and __________. Which can also be called _________ and ___________.
sensory, motor; afferent, efferent
109
Where are the nerve cell bodies for somatic sensory nerve located? Where are the nerve fibers located for the general and special somatic sensory divisions.
- Nerve cell bodies are located in the cranial and spinal sensory ganglia
- general somatic sensory (GSA) - nerve fibers are from the body and head to the CNS
- special somatic sensory (SSA) - cranial nerve fibers from "special" body parts such as eye and ear to CNS.
110
Where are the nerve cell bodies for somatic motor nerve located? Where are the nerve fibers located for the general and special somatic motor divisions.
- Nerve cell bodies located in the CNS (brain stem and spinal cord)
- general somatic motor (GSE) - nerve fibers terminate on skeletal muscle
- special somatic motor -- DON'T EXIST!!!
111
Where are the nerve cell bodies for visceral sensory nerve located? Where are the nerve fibers located for the general and special visceral sensory divisions.
- Nerve cell bodies located in the cranial and spinal sensory ganglia
- general visceral sensory (GVA) - nerve fibers from viscera to the CNS
- special visceral sensory (SVA) - cranial nerve fibers from olfactory epithelium and taste buds to CNS
112
Where are the nerve cell bodies for visceral motor nerve located? Where are the nerve fibers located for the general and special visceral motor divisions.
- have two different efferent neurons - 1) located in CNS, 2) located in autonomic/visceral ganglion (sympathetic chain ganglion)
- general visceral motor (GVE) - nerve fibers of ANS (two neuron system - 1) in CNS, 2) in motor ganglion)
- special visceral motor (SVE) - cranial nerve fibers terminating on skeletal muscle derived from branchial or pharyngeal arches
113
The visceral motor division of the PNS has other names. What is the most important synonymous name?
Autonomic Nervous System (ANS)
114
What are the three divisions of the ANS?
- sympathetic (thoracolumbar)
- parasympathetic (craniosacral)
- enteric nervous system (GI tract)
115
What are the differences between the dorsal and ventral roots and where do their cell bodies located?
* Dorsal root has sensory fibers entering from the DRG (pseudounipolar neurons – central and peripheral processes)
* Ventral root has motor fibers from the ventral horn (multipolar neurons - peripheral process)
116
What are the differences between the dorsal and ventral rami and what structures do these nerve groups supply?
* Ventral rami – gives rise to the nerve plexi and intercostal nerves that supply the limbs and remainder of the body wall; supplies muscular and cutaneous branches to the skin and skeletal muscles of lateral and anterior aspects of the trunk, and the skin and muscles of the limbs
* Dorsal rami – supplies muscular and cutaneous branches to the deep muscles and skin of the back and posterior head
117
Cranial nerves can be either sensory, motor, or carry both types of fibers. What is the denotation of all 12 cranial nerves?
```
CN I -- Sensory
CN II -- Sensory
CN III -- Motor
CN IV -- Motor
CN V -- Both
CN VI -- Motor
CN VII -- Both
CN VIII -- Sensory
CN IX -- Both
CN X -- Both
CN XI -- Motor
CN XII -- Motor
```
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118
Of the sensory cranial nerves, only five have at least one sensory ganglion. What are these cranial nerves and their ganglion(a)?
- Trigeminal (V): trigeminal (semilunar or Gasserian)
- Facial (VII): geniculate
- Vestibulocochlear (VIII): spiral (cochlear), vestibular (Scarpa's)
- Glossopharyngeal (IX): superior, inferior (petrosal)
- Vagus (X): superior (jugular), inferior (nodose)
119
Are sensory ganglia sympathetic or parasympathetic or both?
ONLY parasympathetic!
120
What are the three cranial nerves that have parasympathetic ganglia?
Oculomotor
Facial
Glossopharyngeal
121
macule
A flat, circumscribed region of skin with different color or texture (example: freckle)
122
patch (macule)
A large macule (> 1 cm) or a coalescence of macules (example: vitiligo)
123
papule
A palpable, circumscribed change in consistency or contour of the skin (example: acne vulgaris)
124
nodule
A papule larger than 1 cm in diameter (example: neurofibroma)
125
tumor
A large nodule (example: lymphoma)
126
plaque
A coalescence of papules (example: psoriasis)
127
cyst
An encapsulated nodule filled with soft material (example: epidermal cyst)
128
vesicle
A circumscribed, clear fluid filled lesion; a blister (example: Herpes simplex)
129
bulla
A large vesicle (example: bullous pemphigoid)
130
pustule
A vesicle filled with inflammatory cells, typically white (example: acne vulgaris, pustular psoriasis)
131
wheal
A palpable, circumscribed, area of edema with central pallor and peripheral erythema (example: hives) that usually disappears relatively quickly.
132
purpura
Discoloration of the skin due to the presence of blood in the tissue, outside of blood vessels; will not blanch with pressure (example: vasculitis)
133
petechiae
A punctate region of purpura (tiny dots)
134
comedo
A plug within a hair follicle canal which is composed of keratin and sebum; a blackhead (example: acne vulgaris)
135
milium
A white papule composed of whorls of keratinized epidermal cells beneath the skin surface (example: milia)
136
burrow
A horizontal tunnel in the stratum corneum produced by a parasite (example: scabies)
137
scaly
Characterized by exfoliation of surface keratin cells (example: psoriasis)
138
hyperkeratotic
having very thick scale (example: icthyosis)
139
crusted
Displaying dried exudate of fluid and/or cellular components on the skin surface
140
serous crust
- Composed of serum or tissue fluid (example: contact dermatitis)
141
purulent crust
Containing pus (example: infection)
142
hemorrhagic crust
Containing red cells; a scab (example: healing herpes zoster)
143
eroded
Showing a superficial defect in the skin surface which does not penetrate through the epidermis (example: abrasion)
144
ulcerated
Showing a skin defect which penetrates through the epidermis (example: diabetic foot ulcer)
145
excoriated
Eroded or ulcerated, often in a linear fashion, due to scratching (example: dermatitis factitia)
146
fissure
split horizontally (example: chronic dermatitis)
147
erythematous
Reddened; due to vasodilation with increased blood flow. Blanches with pressure (example: viral exanthem)
148
edematous (edema)
Swollen; due to extravasation of serum and lymph into tissue (example: urticaria)
149
pigmented
Showing changes in color due to melanin pigment
150
hyperpigmentation
Dark; due to increased amount of melanin (example: nevus)
151
hypopigmentation
Light; due to decreased amount of melanin (example: vitiligo)
- occurs due to the loss of melanocytes amongst other things...
152
lichenified
Showing thickening with accentuation of the normal skin markings; usually a sign of chronicity associated with scratching or rubbing (example: atopic dermatitis)
153
verrucous
Characterized by velvety or roughened wart-like change (example: verruca vulgaris)
154
telangiectatic
Showing dilated small arterioles or capillaries coursing parallel to the skin surface (example: spider telangiectasia)
155
atrophic
Emaciated or thinned (example: striae)
156
scarred
Showing fibrous connective tissue replacement; a result of dermal injury (example: keloid)
157
What are the most prominent causes of bacterial skin infections?
- Staphylococcus aureus
- Streptococcus pyogenes
- Pseudomonas aeruginosa
- Lyme disease (Borrelia burgdorferi)
- RMSF (Rickettsia rickettsii)
158
What are some distinguishing characteristics, attributes of pathogenicity, and specific prevention/treatment procedures for stapylococcus aureus?
- Distinguishing characteristics: produce several toxins, localized skin infection (impetigo, cellulitis, folliculitis, furuncles, carbuncles)
- AoP: evade host defense mechanisms: protein A (binds to Fc portion of IgG), coagulase (forms a fibrin coat around organism), hemolysins/leukocidins --> neutrophil localization
- Treatment: cephalosporins, naficillin, dicloxacillin, IV vancomycin (reserved for severe cases)
159
What are some distinguishing characteristics, attributes of pathogenicity, and specific prevention/treatment procedures for streptococcus pyogenes?
- Distinguishing characteristics: localized infection (impetigo, erysipelas, cellulitis), toxin-mediated (TSS, necrotizing fasciitis)
- AoP: colonize on skin which leads to inflammation and pusular lesions and honeycomb-like crusts (impetigo), deeper infections result in erysipelas and cellulitis
- Treatment: penicillin, amoxicillin; penicillin allergy? use cephalosporin, clarithromycin, azithromycin, clindamycin
160
What are some distinguishing characteristics, attributes of pathogenicity, and specific prevention/treatment procedures for pseudomonas aeruginosa?
- Distinguishing characteristics: burn wound infection (cellulitis) and folliculitis (hot tub infection)
- AoP: inhabits soil, water, and large intestine; infection arises due to breach of host defense barriers
- Treatment: ticarcillin (clavulanate), piperacillin (tazobactam)
161
What are some distinguishing characteristics, attributes of pathogenicity, and specific prevention/treatment procedures for lyme disease (Borrelia burgdorferi)?
- Distinguishing characteristics/AoP:
• Stage 1 (10 days after bite): erythema chronicum migrans
• Stage 2 (weeks later): affects different systems -- CNS, CV, Skin, Joints
• Stage 3 (months to years later): chronic arthritis, encephalopathy, acrodermatitis chronicum atrophicans
- Treatment:
• Adults/children older than 8 -- doxycycline
• Adults, younger children, pregnant women -- amoxicillin or cefuroxime (2nd gen cephalosporin)
• if spread to CNS -- IV antibiotics for 14-28 days
162
What are some distinguishing characteristics, attributes of pathogenicity, and specific prevention/treatment procedures for Rocky Mountain Spotted Fever (Rickettsia rickettsii)?
- Distinguishing characteristics: rash, fever, headache
- AoP: bacteria carried in dogs, rodents; inflammation of endothelial lining of small blood vessels, maculopapular rash on palms and soles, widespread vasiculitis, headache and CNS changes, renal damage
- Treatment: doxycycline (fever should resolve within 24-72 hrs following administration, if not then it probably wasn't RMSF)
163
What are the virulence factors associated with Staphylococcus aureus?
```
o Hyaluronidase (breaks down connective tissue)
o Staphylokinase (lyses formed clots)
o Lipase (breaks down fat)
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164
What are the virulence factors associated with Streptococcus pyogenes?
o Streptokinase (converts plasminogen to plasmin)
o M protein (resists phagocytosis)
o Hyaluronidase (breaks down connective tissue)
o DNase (digests DNA)
o Superantigen
o Streptolysin O (destroys RBCs)
o Streptolysin S (destroys WBCs)
- Streptokinase and hyaluronidase are encoded by a lysogenized prophage
165
Describe maculopapular rash.
This is a skin condition wherein the sufferer may have either macules, papules or both. Thus, it is named after the fusion of these words. Macules usually appear as flat, small, non-elevated and discolored regions of the epidermal layer of the skin; whereas, papules are small and swollen bumps on the skin. In the medical world, this is otherwise known as HIV rash.
166
Describe vesicular rash.
Blisters arise on the skin as a result of viral infection. It appears on almost all areas of the skin of human body. These rashes can also arise on skin regions where the mucous membrane is present.
167
Folliculitis
infection of the hair follicles = small, erythematous, often puritic lesions. Local therapy is typically sufficient treatment
168
Furuncles and carbuncles
Usually develop from folliculitis. Carbuncles involve deeper tissues and may have systemic symptoms but rarely involve bacteremia. Antibiotic therapy and sometimes surgery are needed.
169
Impetigo
superficial infection involving the epidermis usually due to group A streptococcus (GAS) infection. Presents as a purulent discharge with crusting and is highly contagious
170
Erysipelas
acute inflammation of the dermis involving lymphatic vessels. Usually caused by group A strep. Fever and leukocytosis may occur. Butterfly wing rash on face
171
Cellulitis
involves all layers of skin to the subcutaneous tissue. Causes fever and leukocytosis and sometimes bacteremia. Group A strep and Staphylococcus aureus most common
172
Abscess
localized collection of purulent material (pus), formation is caused by host defenses trying to wall off the infection
173
Gangrene
advanced stage of cellulitis that has led to significant tissue necrosis and gas in the soft tissues. Typical organisms are streptococci, mixed infection with anaerobes, and clostridial infection (classic gas gangrene)
174
Necrotizing fasciitis
rare but life-threatening infection of subcutaneous tissues. Commonly caused by group A strep.
175
Arthropod-borne infections
common and often have multisystem involvement. Rocky mountain spotted fever (RMSF) is the most severe of the tick-borne infections (30% mortality). Lyme disease is also common (especially in Minnesota).
176
Vitiligo
partial or complete loss of melanocytes causes by an autoimmune attack of lymphocytes on melanocytes
177
Albinism
no melanin is produced (or is decreased) due to an inherited defect in tyrosinase (have normal melanocytes, but cannot produce melanin)
178
Melasma
melanocytes have enhanced pigment transfer to keratinocytes or macrophages; occurs due to pregnancy or drug – resolves upon cessation
179
Solar lentigo
hyperpigmentation of basal epidermis due to excess melanin production; sun protective mechanism of melanocytes
180
Lentigo simplex
not sun related, localized hyperplasia of melanocytes
181
Common Nevi
- most common pigemented lesion
- most start life within epidermis
- congenital = large nevi that have an increased risk of developing into melanoma
182
Junctional Nevi
melanocytes that grow along the junction of the epidermis and dermis
183
Compound Nevi
nevi that enters the dermis and becomes more nodular
184
Halo Nevi
have an area of hypopigmentation around the nevus caused by an immune reaction to nevus
185
Spitz Nevi
bright red dome-shaped nodule that usually has abrupt growth associated with it (must be excised!!!)
186
Blue Nevi
non-invasive dark blue/brown papules that are benign but are a concern for potential melanoma
187
Nevus of Ota/Ito
- Ota: peri-ocular, intra-ocular dermal melanocytic nevus
| - Ito: Mongolian spot, same type of lesion, different site
188
Dyspastic Nevi (DPN)
- Multiple DPN is a marker for increased risk of melanoma
| - Isolated DPN is probably at no or minimal risk of melanoma
189
Malignant Melanoma
- malignant neoplasm of melanocytes
- risk factors: fair skin, sun exposure, many DPN
- usually asymptomatic but may bleed, itch, or ulcerate
- look for changes in the ABCD's (>6mm)
- Two growth phases:
• radial growth (in situ) - superficial, cannot metastasize
• vertical growth - dermal invasion, nodule formation, potential to metastasize
190
Breslow Depth Test
- best method to test probability of metastasis
- Usually for melanoma >1mm thickness:
• 4mm: 5-year survival is 37-50%
191
Actinic Keratosis
* Benign neoplasm of epidermis (may precede SCC if untreated)
* Risk factors: sunlight, ionizing radiation, etc.
* Characterized by: rough spots less than 1cm
* Histology: atypical cells tend to line up at the basal layer
* Produce an abnormal stratum corneum
* Treatment: liquid nitrogen, curettage, topical chemo
192
Squamous Cell Carcinoma (SCC)
* Malignant counterpart to actinic keratosis
* Risk factors: sunlight, carcinogens, chronic ulcer, XP, etc
* In situ: contained about basement membrane
* Invasive: invades basement membrane and dermis
193
Basal Cell Carcinoma (BCC)
* Most common human malignancy
* Risk factors: sun exposure, light pigment, XP
* Characterized by: pearly papule with telangiectasia (dilated blood vessels)
* Arise from base of epidermis
194
Cowden's Syndrome
• Hereditary condition due to mutation in PTEN (tumor suppressor gene)
• Clinical presentation:
o Skin – multiple trichilemmomas (face), benign keratosis on acral skin, mucosal papules, cobblestoning tongue
o Internal – breast, endometrial, and thyroid carcinoma
195
Muir-torre Syndrome
• Hereditary condition due to germline mutations in DNA mismatch repair proteins: MLH1, MSH2, MSH6, PMS2
• Clinical presentation:
o Skin – sebaceous adenoma and carcinoma, keratoacanthomas
o Internal – colon/rectal, endometrial, ovarian cancers
196
Sebaceous hyperplasia
acquired, localized increase in sebaceous glands, not neoplastic; yellow papule
197
Sebaceous adenoma
benign neoplasm, lobular proliferation of sebocytes
198
Sebaceous carcinoma
malignant neoplasm, most are periocular; extraocular forms more common with Muir Torre syndrome
199
Dermatofibroma
- benign
o Dermal proliferation of histiocytes and fibroblasts
o Tan brown firm papules
o Pinch test – will dimple
200
Shave biopsy
use for superficial lesions (many BCC, AK, SCC in situ, pigmented macules)
• Better cosmetics, no sutures, electrocautery
201
Punch biopsy
use for neoplasms involving the dermis (nodular BCC, SCC, melanoma, etc.) and most rashes
• Requires sutures
• Various sizes 1.5 mm – 8 mm
