A&P wk11 P1 Integumentary System

winniesmith's version from 2017-01-18 20:33

Section 1

Question Answer
What are the components of the ISCutaneous Membrane and accessory structures
What is the function of IS?Protection (from dehydration, pathogens, physical protection(abrasions etc) sunlight) ,Excretion, Maintenance of body temp, production of melanin and keratin, synthesis of vit D,Sensations (Touch,pain,pressure,temperature).
What does Vit D synthesis do?Catalyses the conversion of (7D hydro) cholesterol to vitamin D.
What is melanin?pigment which helps protect is from UV light/radiation
What is keratin?A tough protein, found in hair and nails/ skin outer surface
What is vitamin D important for?Calcium absorption.

Section 2

Question Answer
Cutaneous membrane structureEpidermis, Dermis (Papillary layer, then Reticular layer) then the Hypodermis.
What is the most superficial layer?Epidermis.Epithelial layer, layers of epithelial cells- therefore basement membrane, blood vessels underneath not within membrane.
What is the dermis?Under epidermis layer. Made up of papillary (have little papilli/projections, continuous with basement membrane to increase SA, to increase attachment, also have superficial capillaries) and reticular layers (Reticular connective tissue, 3D structure). Mainly made of connective tissues.
What is the hypodermis?Layer underneath the skin. Includes addipose tissueand large network of blood vessels (cutaneous plexus)
What does the papillary layer of the dermis do?Nourishes and supports epidermis.
What does the Reticular layer of the dermis doHas sensory receptors that detect touch, pressure,pain, vibration, and temperature. Blood vessels assist in thermoregulation.

Section 3

Question Answer
Where are the accessory structures located?mostly in the dermis.
What are the accessory structures?Hair follicle, sweat gland (deep in dermis), pore of sweat glands, sensory receptors (touch and pressure) network of nerve fibres.
What are skin cells calledkeratinocytes, rapid divides.
Apoptosisprogrammed cell death (happens after producing keratin)

Section 4

Question Answer
What is the epidermis made ofstratified squamous epithelium
Describe the epidermis is thin skinThin layer of stratum corneum (4 layers of keratinocytes)
Describe the epidermis is thick skinThick Stratum corneum. Order of layers: Dermis, Basement membrane, Stratum basale, Stratum spinosum, Stratum granulosum, Stratum lucidum, Stratum corneum, Surface.
Describe the dermis and basement membrane.Wavy hills interlocking papillary layer and basement membrane
Describe the stratum basaleBasal keratinocytes divide. Deepest basal layer. Attachment to basement membrane. Contains basal cells (stem cells), melanocytes, and tactile cells (merkel cells)
what are basal cellsstem cells
Describe the stratum spinosumKeratinocytes shruken and dehyrated. Keratinocytes are bound together by desmosomes.
Describe the stratum granulosumKeratin produced; cells start apoptosis. Keratinocytes produce keratohyalin and keratin. Keratin fibers develop as cells become thinner and flatter. Gradually the plasma membranes thicken, the organelles disintegrate and cells die.
Describe the stratum lucidumFlattened clear cells; layer only present in thick skin. Appears as glassy layer.
Descibe the stratum corneumDead, flat keratinocytes lacking organelles. Multiple layers of flattened,dead, interlocking keratinocytes. Water resistant but not waterproof. Permits slow water loss by insensible perspiration.
Describe the surfacecells shed.
What is epidermal growth factor (EGF)growth factor. Promotes cell division, stimulates keratin synthesis, accelerates tissue repair, speeds up glandular function.

Section 5

Question Answer
What are finger prints?Epidermal ridges of thick skin (formed during fetal life, therefore differ slightly in identical twins). Continuous throughout life. Have pores of sweat gland ducts
Thick Vs Thin- locationThick- Fingertips, palms, soles. Thin-everywhere else.
TvT- Epidermal thicknessThick- 0.6-4.5mm. Thin- 0.10-0.15mm
TvT- Epidermal strataThick- Thicker strata lucidum,spinosum and corneum. Thin- No strata lucidum, thinner strata spinosum and corneum.
TvT- Epidermal ridgesThick- Present- well developed dermal papilae. Thin- Absent- fewer and less developed dermal papilae.
TvT- Hair folliclesThick- Absent. Thin- Present
TvT- sweat glandsThick- More numerous. Thin- Fewer
TvT- Sensory receptorsThick- More numerous. Thin-Sparser.

Section 6

Question Answer
What are melanocytespigment producing/storing cells, produce melanin, secreted into melanosomes, to be incorperated into keratinoocytes. Protection from sun exposure, absorbs ultraviolet.
Skin (EPIDERMAL) pigment; Caroteneyellowish
Skin pigment; Melaninbrown, protects from UV radiation. Contributes to freckles and tan
Skin pigment; Bloodcontributes to pink (or blue) colouration.
Describe melaninUsually brown or black, increases in conc during sun exposure, protects DNA from UV radiation. Produced from the AA tyrosine. Produced by cells called melanocytes.

Section 7

Question Answer
What does the dermis do?supports the epidermis, consists of a lot of connective tissue fibers (collagen and elastin fibres) to give it strength. Contains lots of sensory receptors/nerves
What makes up the papillary layerLoose connective tissue- areolar tissue. Network of superficial capillaries, called the capillary plexus.
What is the capillary loop for?in papilla,provide the epidermis with nutrition.
What is the reticular layer made of?Reticular tissue, tough network fibers.
What is the cutaneous plexusBlood vessels, branches from papillary plexus.

Section 8

Question Answer
Where is the hypodermis (also called superficial fascia)layer underneath integument, covers deep fascia.
What is the hypodermis made ofloose connective tissue (areolar and adipose tissue). Connective tissue fibres interwoven with reticular layer of dermis.
What does it do?allows skin to be mobile relative to underlying structure (permits independent movement of deeper structures).

Section 9

Question Answer
Functions of hairprotection, insulation, sensation.
What is the exposed shaft of hair made ofdead cells
Sebaceous glandsecretes onto base of hair
Arrector pilli muscletightens and makes hair stand up
Hair root in connective tissue sheathfirmly embedded in dermis.
Root hair plexusnerve endings and blood vessels

Section 10

Question Answer
Hair structure, Medullacentral part of hair with softer flexibie keratin
Cortexlayer surrounding medulla, thick layers of hard keratin, which provide stiffness (hard outer bit, soft inner bit, allows hairs to bend)
Cuticlelayer surrounding cortex, flat scales around surface, thin but tough, contains hard keratin. Provide smooth surface.
What does the hair follicle includeInternal and external root sheath, glassy membrane and connective tissue sheath.
Internal root sheathsurrounds the hair root and deeper portion of shaft.
External root sheathextends from skin surface to the hair matrix.
Glassy membranethickened clear layer wrapped in the dense connective tissue sheath