Integument

Question 1

Seven functions of the Integument System

Answer 1

1 Physical protection from environmental hazards 2 Thermoregulation 3 Excretion 4 Synthesis/storage of lipid reserves 5 Synthesis of vitamin D3 6 Provides sensory information 7 Coordinates immune response to pathogens and malignancies of the skin

Question 2

The Skin’s 3 layers and their respective tissues

Answer 2

Epidermis–Epithelium, variable thickness Dermis–Connective tissue, variable thickness Hypodermis (Subcutaneous)–Loose Connective Tissue, superficial fascia.

Question 3

Describe the Epidermis (4 facts)

Answer 3

Stratified squamous epithelium Keratinized Number of layers varies Distinct layers better recognized in thick skin

Question 4

Layers of the epidermis

Answer 4

Basal lamina Stratum basale Stratum spinosum Stratum granulosum Stratum lucidum (thick skin only) Stratum corneum Surface

Question 5

The two names for the lowest layer of the epidermis

Answer 5

Stratum basale Stratum germinativum

Question 6

Stratum germinativum: How many layers of cells? What is the shape of the cells?

Answer 6

Single cell layer on the basement membrane. Cells are Cuboidal/columnar in shape.

Question 7

Stratum germinativum: Different cell types

Answer 7

Keratinocyte–most common, produce keratin Melanocyte–few, produce melanin (pigment) granules to distribute to adjacent cells Langerhans cell–associated with immune system (contact dermatitus) Merkel cell–part of nervous system, has sensory neuron attached. (nutritional and environmental info)

Question 8

Stratum spinosum: How many layers of cells? Cell type? Type of attachments? What do those attachments do for the skin?

Answer 8

Few to several layers thick Primarily karatinocytes (prickle cells) Distinct intercellular attachments present (Desmosomes) Responsible for mechanical strength (skin isn’t very permeable)

Question 9

Stratum granulosum: How many layers? Cell shape? Type of granules present? Status of the cells?

Answer 9

3-5 layers thick Cells become flattened Granules have Keratohyalin (immature keratin) Cells are starting to die.

Question 10

Stratum lucidum: Found where? Status of keratin? Status of cell apoptosis?

Answer 10

Only found in thick skin. High concentration of immature keratin Most cellular organelles are disrupted.

Question 11

Stratum corneum: Status of cell apoptosis? Composition of substances? Purpose of corneum?

Answer 11

Cells are “bags of keratin” Keratin and glycolipids add water resistance (soft keratin) Corneum layers are sloughed off continuously.

Question 12

Dermis: Location? Nickname? Why is it nicknamed that way? Junction structure? What human feature is a direct result of the dermis structure?

Answer 12

Deep to the epidermis Nicknamed, Anchor–anchored by numerous filaments. The junction is irregular–epidermal ridges, dermal papillae and dermal ridges. Fingerprint.

Question 13

Name the Dermal layers and their features

Answer 13

Papillary layer–Dermal papillae, Capilleries, Nerve axons Reticular Layer–Hair follicles, sweat/sebaceous glands

Question 14

Dermal cells

Answer 14

Fibroblasts Macrophages–Other immune system cells, Neutrophils Smooth muscle–Associated with hair follicle (makes hair stand on end), Erector pili muscles.

Question 15

Hypodermis (Subcutaneous layer): Type of tissue? Is the boundary distinct? What is a third name for this layer?

Answer 15

Loose connective tissue–Immune system, blood cells, adipocytes. Indistinct boundary. Superficial fascia.

Question 16

Hair: Where is it found? Describe the root.

Answer 16

Epithelial pockets (Follicles)–associated with glands. Hair root.Portion in the follicle. Forms hair bulb.(Deepest portion of follicle. Center of mitotic activity.)

Question 17

Hair structure: Layers? Describe each layer, at least two characteristics.

Answer 17

Medulla–Innermost layer. Cuboidal cells/keratohyalin (hard keratin) granules. absent in vellus hair Cortex–Thickest portion, flate cells w/ hard keratin, location of melanocytes. Cuticle–forms keratinized scales–absorb melanin.

Question 18

What are the three types of hair?

Answer 18

Terminal–Typical hair of scalp. Vellus–“Peach fuzz” present in infants. Intermediate–Growth associated with sex hormones.

Question 19

Growth patterns: Describe the cyclical pattern.

Answer 19

Active-mitosis occurring, hair is growing. Usually longest portion of cycle. 30% of cycle. Phase is 3 years. Resting–mitosis stopped, club hair occupies follicle. 1 year. Short except in baldness–go into rest.

Question 20

Sebaceous Glands

Answer 20

Associated with hair follicles. Outrgrowth of external root sheath. Exceptions, lubrication: Lip margin, nipple, glans and prepuce, genitals. Holocrine type secretion. (explosion)

Question 21

Sweat Glands: Types of secretion? Modified types?

Answer 21

Merocrine and Apocrine Modified types, Ceruminous–wax production in ear, no hair, merocrine. Mammary–Hormonal regulation–estrogen in development. Prolactin–milk production. Apocrine type secretion.

Question 22

Merocrine Sweat Glands Distribution? Cell type? tricky Function

Answer 22

Wide distribution Simple tubular with myoepithelial cells Merocrine secretion Temperature regulation

Question 23

Apocrine Sweat Glands Size and location compared to merocrine glands? Distribution? What instigates their function? Secretion type?

Answer 23

Misnamed, not apocrine secretion type. Larger than Merocrine and deeper. Distribution confined–axilla, groin, and genital regions. Stimulated by steroid hormones (puberty). Merocrine type secretion.

Question 24

Nails What are they? Functions?

Answer 24

Plates of hard keratin. Protects skin. Prevents distortion of finger and toe tips. Improves manual dexterity.

Question 25

Nail structure 2 parts.

Answer 25

Nail plate–Body, Free edge, Lunula (Immature keratin) Nail fold–Lateral, proximal, nail groove.

Question 26

Nail root 4 components

Answer 26

Matrix–hard keratin, Germinative zone, thickened stratum germinativum Nail bed Eponychium–cuticle Hyponychium

Question 27

Coloring of nail bed

Answer 27

capillary refill integrity of blood cells.