Biol129_C4 - Integumentary System Integument Means...

Info iconThis preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
1 Integumentary System Integument • Means “covering” • It refers to “skin” and other external structures. • Functions: – Protects body from environment – Contains body tissues/fluids – Assists heat regulation – Detects environment, sensation – Produces vitamin D
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
2 Skin • The one of the largest organs. • There are four layers: – Epidermis –Derm is – Subcutaneous tissue (superficial fascia) – Deep fascia Epidermis • The outermost layer • Composed of – keratinized stratified squamous epithelium • Contains – Melanocytes to provide color – Merkel cells for touch sensation • This layer is NOT vascularized, uses diffusion
Background image of page 2
3 Cells of the Epidermis • Stem cells – At the base, progenitors of keratinocytes • Keratinocytes – Displaced outward, the produce keratin • Langerhan’s Cells (Dendritic Cells) – Immune system, macrophages that fight infection – Found in all epidermis with primary access to environment (oral cavity, esophagus, vagina) Dermis • Deeper than epidermis • Contains many of the structures in skin – Glands, vessels, nerves, sensory organs • Has two defined layers: – Papillary layer • Loose areolar tissue, loosely organized • Permits movement of leukocytes – Reticular layer • Thick layer of dense irregular connective tissue • Thick bundles of collagen present • If disrupted by stretch, collagen tears resulting in striae or stretch marks
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Dermis – 2 • Irregular surface giving rise to “dermal papillae” – The dermal papillae influence the epidermis giving rise to friction ridges on fingertips – Very tall papillae in lips and genitals provide for increased sensitivity Superficial Fascia • Also called hypodermis • Composed of loose connective tissue • Site of hair follicles and sensory organs • Site of many adipose cells – Because of this, skin thickness varies greatly
Background image of page 4
Image of page 5
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 03/31/2008 for the course BIOL 129 taught by Professor Sachshowardgeor during the Spring '08 term at Pennsylvania State University, University Park.

Page1 / 18

Biol129_C4 - Integumentary System Integument Means...

This preview shows document pages 1 - 5. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online