Integumentary System Skin Diseases/Disorders Integumentary System Skin Diseases/Disorders.
Integumentary System HST I 2010-2011. Integumentary system (Skin) Considered to be both: (a)...
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Transcript of Integumentary System HST I 2010-2011. Integumentary system (Skin) Considered to be both: (a)...
Integumentary System
HST I 2010-2011
Integumentary system (Skin)Considered to be both:• (a) Membrane – covers the
body• (b) Organ – contains several
types of tissue– Largest organ in body -
covering (c) 3,000 square inches
– About (d) 15% total body weight
Tissue:• 3 layers of tissue
1. (e) Epidermis – outermost layer of skin• (f) NO blood vessels or nerve cells (avascular)
2. (g) Dermis – corium or “true skin”• Includes:–Elastic connective tissue–Blood vessels–Lymph vessels–Nerves– Involuntary muscle–Sweat and oil glands–Hair follicles
Tissue:
3. (h) Subcutaneous layer (hypodermis) – the innermost layer• Made of:• Elastic and fibrous connective tissue• Adipose (fatty) tissue
• Connects the skin to underlying muscles
Fingerprints?
• The top layer of the dermis has ridges which form lines or striations on the skin which give us our unique fingerprints
Major Organs/Structures
• Skin• Sweat and oil glands• Nails• Hair
Two Main Types of Glands1. (i) Sudoriferous (sweat)
glands• Sweat eliminated by these
glands contains water, salts, and some body wastes
• Sweat is odorless until it interacts with bacteria on the skin
• Perspiration (sweating) removes excess water from the body and cools the body
Two Main Types of Glands2. (j) Sebaceous (oil) glands• Usually open onto hair
follicles• Produce sebum (oil) which
keeps skin and hair from becoming dry and brittle
• Slightly acidic nature helps prevent infection
• Oil glands plugged with dirt and oil result in blackheads or pimples.
Hair• Consists of a root
(which grows in a hollow tube called a (k) follicle)
• A (l) hair shaft– Helps protect the body– Covers all body surfaces
except the palms of the hands and the soles of the foot
(m) Alopecia (baldness)• Genetically inherited• Males (and some females)• Permanent loss of hair of the scalp
Nails• Protect the fingers and toes from injury• Made of (n) dead, keratinized epithelial cells• Formed in the nail bed• If lost, nails will regrow if the nail bed is not
damaged
Functions of Skin:1. (o) Protection –barrier against UV rays and
infection, and helps prevent dehydration2. (p) Sensory perception – nerves help the body
respond to pain, pressure, temperature, and touch sensations
3. (q) Body temperature regulation • when blood vessels in the skin (r) dilate (get
larger) – excess heat can escape• when blood vessels (s) constrict (get smaller) –
heat is retained
Functions of Skin:4. (t) Storage – tissue temporarily stores fat,
glucose, water, vitamins, and salts; adipose (fatty) tissue is a source of energy
5. (u) Absorption – certain substances are absorbed through the skin, such as medicine and nicotine patches; medication patches are (v) transdermal
6. (w) Excretion – eliminates salt, waste, excess water and heat through perspiration
7. (x) Production – skin helps produce vitamin D using UV rays
Pigmentation:• Basic skin color is inherited– (y)Melanin – brownish-black pigment produced in the epidermis
• Everyone has the same number of (z) melanocytes but genes determine the amount of melanin produced
• Freckles are small concentrated areas of melanin
– (aa)Albino – absence of color pigments in the skin• Skin has pinkish tint• Hair is pale yellow or white• Eyes lack pigment; are red; very sensitive to light
Abnormal Pigmentation:• (bb)Erythema – reddish color that can be caused
by burns or a congestion of blood in the vessels• (cc)Jaundice – yellow discoloration; indicates
bile in the blood resulting from liver and gallbladder disease; also seen in diseases that involve destruction of RBC
• (dd)Cyanosis – bluish discoloration caused by insufficient oxygen; associated with heart, lung, and circulatory diseases or disorders
• (ee)Chronic poisoning – may cause gray or brown skin discoloration
Skin Eruptions:• (ff)Macules – flat
spots on the skin, such as freckles
• (gg)Papules – firm, raised areas such as pimples and the eruptions seen in some stages of chickenpox and syphilis
• (hh)Vesicles – blisters, or fluid-filled sacs, such as those seen in chickenpox
Skin Eruptions:• (ii)Pustules – pus-
filled sacs such as those seen in acne, or pimples
• (jj)Crusts – areas of dried pus and blood, commonly called scabs
Skin Eruptions:• (kk)Wheals – itchy,
elevated areas with an irregular shape; hives and insect bites are examples
• (ll)Ulcer – a deep loss of skin surface that may extend into the dermis; may cause periodic bleeding and the formation of scars
Diseases and Abnormal Conditions:• (ss)Eczema –
noncontagious, inflammatory skin disorder caused by allergens or irritants
Diseases and Abnormal Conditions:• (tt)Psoriasis – chronic,
noncontagious skin disease with periods of (uu)exacerbations (symptoms present) and (vv)remission (decrease or disappearance of symptoms)
• (ww) Ringworm – highly contagious fungal infection of the skin or scalp