Sample Outline: Integumentary

Skin is the largest organ of the body

3 Functions of the Skin:

1. Protection – protect the body against infection by acting as a barrier

2. Sensation- serve as interface between outside environment and afferent nervous system

3. Regulation- regulates body temperature and fluid balance in conjunction with circulatory system

Layers of the skin

1. Epidermis

5 Layers:

Stratum Corneum- horny layer aka Stratum Disjunctivum

Stratum Lucidum – where you can find the elieden, clear layer

Stratum Granulosum – where you can find keratin

Stratum Spinosum

Stratum Basale aka Stratum Germanitvum where mitosis takes place

*Stratum Malphigi is the combination of stratum spinosum and basale

2. Dermis aka Corium

- Thicker in the hand and soles of the foot

2 Layers:

Papillary Layer- uppermost layer, vascular layer

Reticular layer- dry portion, more numerous in the regions of hair follicles, sebaceous and sweat glands

Accessory Organs

1. Hair follicles- keratinous filament from the matrix cells of follicular invaginations

2. Sweat Glands- Eccrine- found all over the body and the most numerous

Apocrine- found in axilla, eyelids, areola, external genitalia

3. Sebaceous Gland- found in hair and scalp, it produces sebum

Sensory Receptors of the Skin:

Mechanoreceptors: response to physical stimuli that causes mechanical displacement

Thermoreceptors: heat and cold receptors

Nociceptors: noxious stimuli

Electromagnetic receptors: rods and cons of the eye

Specific Skin Receptors:

Free nerve endings- detect touch and pressure

Merkel’s Disk- detects sustained touch and pressure

Meissner’s Corpuscles- change in texture

Pacinian Corpuscles- detects vibration and proprioception

Ruffini Endings- warm receptors

Krause end bulb- cold receptors