The Integumentary System Flashcards
1
Q
Integumentary System
A
-
Largest organ in surface aera
- Approximately 3000 square inches
- 16 percent of body weight
2
Q
The Integumentary system
A
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Cutaneous membrane
-
Epidermis
- Accessory structures:
- Hair follicles
- nails
- Exocrine Glands
- Subcutaneous layer
-
Epidermis
3
Q
The Epidermis
A
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Stratified Squamous Epithelium
-
Keratinized epithelium
- produces keratin ex. Fingernails
- Attached to dermis by the basil lamina
-
Cell types include:
- Keratinocytes: produces keratinized epithelium
- Melanocytes: pigment cells
- Langerhans cells: Immune system
- Merkel cells: Sensory cells (touch)
-
Keratinized epithelium
4
Q
Dermis
A
-
Connective tissue proper
- papillary Layer - thin layer of loose areolar connective tissue
- Reticular layer - thick layer of dense irregular connective tissue
-
Provides structural strength and elasticity to skin
- Collagen, reticular, and elastic fibers
- Contains the blood vessels and nerves of the skin
5
Q
Subcutaneous Layer (subQ) (Hypodermis)
A
- Connects skin to underlying tissues
- Loose Fibrous connective tissue (Adipose tissue) for strength and elasticity
- Contains fat (Adipose connective tissue) for padding and insulation -Body shape
- Contains many blood vessels and nerves
- Also called Superficial Fascia
6
Q
The fascia of the body wall
A
7
Q
Integumentary system Functions
A
- Nutrient storage
- temperature regulations
- Excretion
- Vitamin D3 Synthesis
- Sensory Detection
- Protection
8
Q
- *Integumentary system:**
- *Nutrient Storage**
A
-
To meet body’s requirement for constant supply of lipids
- Synthesis of membranes (Phospholipids and Glycolipids)
- Synthesis of lipid hormones
-
ATP Production in mitochondria via breakdown of fatty acids
- Fatty Acids → Acetyl coA
9
Q
- *Integumentary System:**
- *Temperature Regulation**
A
-
Dermis layer blood vessels
- Dilate for heat loss
- Constrict for heat conservation
- Mainly occurring in the reticular/papillary layer of dermis
-
Sweat Glands
- Secretes water which evaporates and cools skin
-
Subcutaneous layer
- Insulating layer of fat
10
Q
- *Integumentary System:**
- *Excretion**
A
- Excretion - Removal of waste products from body
-
Sweat glands secrete waste products along with other molecules
- Water
- Electrolytes (ions including NA+ and CL-)
- Organic waste such as urea (mainly) and ammonia (very little amount)
11
Q
Vitamin D3 Synthesis
A
- Vitamin D3 - Steroid (cholesterol) Derivative
-
Epidermal cells exposed to UV light synthesize cholecalciferol from cholesterol
- Cholesterol → Cholecalciferol → Calcitriol
-
Calcitriol - Hormone affecting Bone growth
- Stimulates Ca2+ and Po42- absorption
- Regulates Ca2+ ion concentration in body
12
Q
- *Integumentary System:**
- *Sensory Detection**
A
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Pain (Nociceptors)
- Free nerves endings (Sensory Dendrites)
- Temperature (Thermoreceptors)
-
Touch, Pressure, Vibration
- Lamellated corpuscles
- Tactile (Meissner’s) Corpuscles
- Tactile Discs (Merkle’s discs and Merkle cells)
- Hair root plexus
13
Q
- *Integumentary System:**
- *Protection of the Body**
A
-
Layers of Keratinized cells
- Abrasion protection
- Water resistant
- Insensible perspiration (uncontrollable water loss) (300-500 ml/d)
- Resistant to Microbial invasion
-
Melanocytes
- Protection against ultraviolet radiation
14
Q
The structure of the epidermis
A
15
Q
Keratinization of the Epidermis
A
- Form by cell division of stem cells in the stratum germinativum (Basal Layer)
- New cells push older cells upward
- Oldest cells in the corneum layer eventually are shed (Flake off)
- 7-14 days to move from stratum germinativum to the stratum corneum
- 30 days (AVG) until shed from corneum
- Accumulate large amounts f keratin in the stratum granulosum and cells dies