THE ITEGUMENTARY SYSTEM
The system is composed of the following:
Skin, hair, nails and glands (sebaceous glands, sweat/sudoriferous glands, ceruminous glands).
The following is its functions (SYSTEM)
1. Protects the body from the body by acting as barriers to microorganisms, water and excessive sunlight.
2. Protects it against dehydration (dessication) and water absorption.
3. Regulates body temperature through heat loss from dilated vessels, evaporation from perspiration, and retention from restricted vessels.
4. Serves for cutaneuos sensation by its sensory receptors that respond to heat, cold, pressure, touch, vibration and pain.
5. Performs metabolic functions as I he ...view middle of the document...
• Stratum spinosum – layers are thick and has dark nuclei and spiny projections.
• Stratum basale- deepest part of the epidermis. Consists of a single layer of actively dividing cells. The Keratinocytes, Melancocytes, and Merkel cells are present in this layer.
Note: a hick skin cositss all the five layer while the thin sin only has four layers. Stratum lucidum is not found in the thin skin.
Deeper than the epidermis. This is made up elastic and collagenous fibers which functions for stretch and strength respectively. Contains also the sebaceous glands, sweat glands, nerve endings, and hair follicles and is composed of two layers.
1. Upper papillary layer- made up of loose connective tissues with lots of blood vessels. Also contains papillae, fingerlike projections that bring blood vessels near the epidermis and help hold the two layers. The arrangement of papillae determines the fingerprints.
2. The reticular layer- is deeper and thicker than the papillary layer. Composed of dense and stretchable connective tissues.
Another is the hypodermis, though not a part of the skin yet it connects the dermis to the other organs. This stores fats, acts shock absorber, and anchors the skin to the underlying structures. Fat stored in the adipose tissues of the hypodermis cause “beer belly” in men and thick thighs and buttocks in women.
Found almost everywhere in the human body except in the palms, soles, lips, and the genitals of men and women.
1. The primary functions of the hair are for protection: from injury, sunlight and heat loss (the scalp hair’s function); from foreign particles (eyebrows and eyelashes); and from airborne particles (hairs in the nostrils).
2. While it’s secondary function of hair is as a sexual attractant.
PARTS OF THE HAIR ARE:
Shaft- the dead portion of the hair that projects from the surface. The shaft determines the curliness of the hair:
Round shaft-straight hair
Oval shaft- wavy hair
Flat shat- kinky hair
Root- this is he terminal end of the hair shaft. It is encased in an internal or epithelial root sheath/covering. It contains erector pili muscles whose contractions in mammals raises the hair and increases thickness of its coat.
Composed of three tubes namely:
• Outer cuticle- heavily keratinized.
• Middle cortex- several layers of cells which contains pigments in the dark hair and bubbles in the white hair.
• Inner medulla- contains pigments and air spaces.
Bulb- enlarged base of he follicle. Contains the papilla and sensory nerve endings. The papilla is composed of loose connective tissues that protrudes inside the hair bulb. Also contains capillaries that supply nutrients o the growing hair. While the sensory nerve endings surround the bulb.
There are two types of hair fond in our bodies. These are:
Vellus hair - the fine body hair of children and adult women.
Terminal hair – the coarser hair of he scalp, eyebrows and etc.