Midterm 1 Flashcards
Proximal vs Distal
Proximal: towards point of attachment of limb to trunk
Distal: away from point of attachment of limb to trunk
Lateral vs medial
Lateral: away from midline
Medial: towards midline
Superficial vs deep
Superficial: at/near/close to body surface
Deep: towards interior, farther from surface
Crainal/ Superior/ Cephalic vs Caudal/ Inferior
Crainal/ Superior/ Cephalic: towards head
Caudal/ Inferior: towards tail or coccyx
Anterior/ Ventral vs. Posterior/ Dorsal
Anterior/ Ventral: front surface
Posterior/ Dorsal: back surface
Intermediate
between medial and lateral structure
2 divisions of the body?
Axial part (head, neck, trunk)
Appendicular part (appendages/limbs attached to axis)
4 body planes/ sections?
Sagittal plane- vertical plane divides body into right and left parts
Frontal/ coronal plane- vertical plane divides body into anterior and posterior parts
Transverse plane- horizontal plane from right to left, divides body into superior and inferior parts
Oblique- tilted plane, not at 90
2 parts of dorsal cavity?
Cranial cavity- enclosed by skull and houses brain
Vertebral cavity- enclosed by vertebrae and houses spinal cord
2 parts of ventral cavity?
Thoracic cavity- 2 lateral pleural cavities, medial mediastinum conataining central pericardial cavity
Abdominopelvic cavity- superior abdominal cavity (stomach, intestines), inferior pelvic cavity (bladder, rectum)
Membranes in the body cavity?
Serosa: thin double layered membrane, cover surfaces in ventral cavity
Parietal Serosa: lines internal body cavity walls
Visceral Serosa: internal organs (viscera)
9 abdominal regions: From right to left, top to bottom
right hypochondriac region, epigastric region, left hypochondriac region, right lumbar region, umbilical region, left lumbar region, right iliac region, pubic (hypogastric) region, left iliac region
Regional terms: Cephalic, Cervical
Thoracic, Manus, Pedal, Dorsal
Cephalic: head
Cervical: neck
Thoracic: lungs, upper chest
Manus: hand
Pedal: foot
Back (dorsal): complete back
Structure of skin (3 layers)
1.4 to 4mm
Epidermis ( superficial epithelial, keratinized stratified squamous epithelia)
Dermis (dense connective tissue, vascularized)
Hypodermis (superficial fascia, not part of skin, adipose tissue)
4 types of cells in the epidermis:
Keratinocytes
Melanocytes
Dendritic (Langerhans) cells
Tactile (Merkel) cells
Keratinocytes and Melanocytes
Keratinocytes- most common, make keratin protein, epidermal growth factor is hormone that acts on layer to make new cells, come from epidermal stem cells
Melanocytes- produce melanin, packed in melanosomes, branching for melanin transfer to adjacent cells
Dendritic and Tactile cells
Dendritic (Langerhans) cells- epidermal, migrate from bone marrow, macrophages activate immune
Tactile (Merkel) cells- epidermis boundary, touch receptors
How many layers does each type of skin have?
Thick skin- 5 strata
Thin skin- 4 strata
5 layers of skin?
Stratum corneum
Stratum lucidum (corresponds with less melanin in these areas) thick skin
Stratum granulosum
Stratum spinosum
Stratum basale (mitotic cells, bottom layer towards dermis)
what is the dermis?
Strong, flexible connective tissue
Cells include fibroblasts, macrophages, mast cells, WBCs
Semi-fluid matrix embedded with collagen, elastin, reticular fibers (bind body together)
2 layers of the dermis?
Papillary (thin superficial)
Interwoven mat of areolar CT fibers with blood vessels
Deermal papillae: superficial region of the dermis that indents overlying epidermis
Reticular (Thick deep)
Deeper thick dense irregular CT, source of cleavage lines (lines of tension)
Collagen fibers give strength, elastic fibers provide recoil
What are friction ridges?
Dermal papillae lie on top of dermal ridges which give rise to epidermal ridges (friction ridges)
Enhance gripping ability
Sense of touch, fingerprint
Develop pre-birth, unique details
Striae
Stretch marks, stretching skin happens faster than cells can keep up, skin tears to create “marks”
Blister
Rubbing against surface causes separation of dermis from epidermis, fluid leaks into “injured” area
Flexure lines
The dermis is tightly layered to underlying structure, skin must fold instead of stretching
What is the hypodermis?
Superficial fascia, subcutaneous tissue
Areolar CT, blood vessels, adipose tissue
Anchors skin to underlying structures, shock absorber, insulation
What 3 things contribute to skin color?
Melanin- made in skin derived from tyrosine
Skin color dependant of type, relative amount and keratinocyte retention of pigment
Carotene- yellow/orange pigment in plant products, deposits in keratinocytes and hypodermis
Hemoglobin- from capillary circulation, gives pinkish hue
what is hair?
Flexible strands of dead, kerantinized cells, produced by hair follicles
None on palms, soles, lips, nipples, external genitalia
Functions: sense, guard head, heat loss, filter particles
Composition: hard keratin, more cysteine, more strength
Parts of the hair shaft? (3)
Medulla: large cells separated by air spaces
Cortex: several layers of flattened keratinocytes
Cuticle: single layer of overlapping cells
Shape of shaft determines if hair is straight or curly
Structure of hair? (6 parts)
Shaft: part that projects from skin: has 3 layers
Root: part embedded in skin
Bulb: deep end of follicle, has papilla and root hair plexus
Follicle: outer CT root and inner epithelial root
Arrector pili muscle: contract to pull hair and dimple skin
Sabaceous gland: holocrine that secrets sebum
Parts of the hair follicle (4)
Hair papilla: dermal tissue with capillaries that supply nutrients to hair
Hair matrix: actively diving area of bulb that produces hair cells
Arrector pili: small band of smooth muscle attached to follicle
Melanocytes: produce melanin, transferred to cells
What are nails?
Scale like modification of epidermis
Free edge, body, nail fold- 2 lateral and 1 proximal
Eponychium: nail fold that projects onto surface of nail body (cuticle)
Hyponychium: area under free edge of plate that accumulates dirt
Nail Matrix: thickened portion of bed responsible for nail growth
2 types of sweat glands?
Eccrine (merocrine): simple coiled tubular glands with pore, abundant on palms, soles, forehead, function in thermoregulation
Apocrine: axillary and anogenital areas, larger, ducts empty into hair follicles, - odourless until decomposed by skin bacteria leading to body odour, function as equivalent of sexual scent
Terminal vs Vellus hair
Terminal hair: hair on head, you can see, have medulla, cortex, cuticle
Vellus hair: peach fuzz, no medulla
How does the skin protect?
Chemical barrier : acidic skin secrention retards bacterial replication, melanin protects against UV damage
Physical: barrier to trauma & bacterial invasion; also waterproof, not impermeable
Biological: Langerhans cells of epidermis & macrophages in dermis
Thermoregulation?
sweating, insensible vs. sensible (you can see sweat)
What are cutaneous senses?
sense of touch
Metabolic effects of skin?
Vit. D synthesis needed for absorption of Ca2+, conversion of topically-applied cortisone to hydrocortisone
Excretion and blood reservoir?
Excretion: NaCl & H2O loss via sweat
Blood Reservoir: dermis can hold 5% of blood
3 kinds of burns?
First degree: only epidermis damaged
Second degree: epidermis and upper dermis
Third degree: epidermis and dermis
How to evaluate burns?
Evaluated by rule of nines, used to estimate volume of fluid lost
Body broken into 11 sections, each representing 9% of surface