Integumentary System

Functions of the Body Membranes

1) cover body surfaces

2) line body cavities

3) form protective sheets around organs

body membranes are classified according to tissue types t/f?

true

What are the 3 types of epithelial membranes?

1) cutaneous

2) mucus

3) serous membranes

What is the only type of connective tissue membrane?

synovial membrane

cutaneous membrane (type of epithelial membrane)

1) known as skin

2) has a dry, outermost protective boundary

3) avascular

4) located in the superficial epidermis—made of keratinized stratified squamous epithelium

5) located in the dermis—made up of dense (fibrous) connective tissue (has lots of blood vessels)

What do keratin fibers do?

strengthen

Mucous membrane (type of epithelial membrane)

1) lines all body cavities open to exterior body surface

2) moist membrane adapted for absorption or secretion

3) made of stratified squamous epithelium (mouth, esophagus)

4) made of simple columnar epithelium (rest of digestive tract)

5) has underlying loose connective tissue (lamina propria)

serous membrane (serosa) (type of epithelial membrane)

1) surface is a layer of simple squamous epithelium

2) underlying layer is a thin layer of areolar connective tissue

3) lines open body cavities that are closed to the exterior of the body

4) has visceral and parietal layer

visceral layer

covers the outside of the organ

parietal layer

 lines a portion of the wall of the ventral body cavity

3 types of serous membranes

peritoneum, pleura, pericardium

peritoneum serous membrane

lines around organs in the abdominal cavity

pleura serous membrane

lines around the lungs; connects lungs to ribcage

pericardium serous membrane

lines around the heart

synovial membrane (type of connective tissue membrane)

1) made up of only connective tissue only

2) lines fibrous capsules surrounding joints

3) bursae, tendon sheaths

4) secretes synovial fluid (lubricating)

What does the Integumentary system include?

skin (cutaneous membrane), sweat glands, oil glands, hair nails (ALL are skin duratives)

skin functions

protects deeper tissues from:

1) mechanical, chemical, bacterial, ultraviolet, thermal damage 

2) desiccation (drying out)

T/F? keratin protects skin from water loss

true

skin functions (cont.)

1) aids in lost or retention of body heat (controlled by the nervous system)

2) aids in secretion of urine

3) makes vitamin D

4) has cutaneous sensory receptors (detects touch, temperature, pressure, pain)

What are the 3 structures of the skin?

epidermis, dermis, hypodermis (subcutaneous)

epidermis (skin layer)

1) outmost layer of the skin

2) made of stratified squamous epithelium

3) keratinized to prevent water loss—most cells are keratinocytes

4) avascular

layers of the epidermis (deepest to outermost)

1) stratum basale

2) stratum spinosum 

3) stratum granulosum

4) stratum lucidum

5) stratum corneum

*BOB SAYS GOOD LUCK CHARLEY

stratum basale

1) deepest layer of epidermis

2) wavy borderline w/ dermis anchors the epidermis and dermis

3) undergoes mitosis (keratinocytes) -cells get pushed upward to become superficial layers

stratum spinosum

-makes keratin

stratum granulosum

-cells died

stratum lucidum

1) formed from dead cells of the deep strata

2) occurs only in thick, hairless skin of palms and feet

stratum corneum

1) outermost layer of epidermis

2) dead cells are filled with keratin (protective protein)

Dermis (skin layer)

1) deep to the epidermis

2) made of dense connective tissue

3) highly fibrous (collagen and elastic fibers)

4) highly vascular - blood vessels contribute to temperature regulation

5) nerve supply sends messages to CNS

collagen promotes…

toughness

elastic fibers promote…

elasticity

2 layers of the Dermis

papillary and reticular layers

Papillary Layer

1) upper dermal region

2) some has capillary loops

3) some has pain receptors (free nerve endings) and touch receptors

Reticular Layer

1) deepest skin layer

2) has blood vessels, sweat/oil glands

3) has deep pressure receptors (lamellar corpuscles)

subcutaneous tissue (hypodermis) (skin layer)

1) deep to dermis

2) anchors skin to underlying organs

3) not part of the skin (technically)

4) composed of mostly adipose tissue

5) shocker absorber and insulates deeper tissue

melanin

1) pigment produced by melanocytes

2) yellow, brown, black

3) melanocytes are mostly present in the stratum basale

4) amount of melanin relies on genetics and sunlight

melanosomes

membrane-bound granules that accumulates melanin

epidermal dendritic cells

alerts and activate immune cells to a threat (bacterial or viral invasion)

merkel cells

1) associated with sensory nerve endings

2) serve as touch receptors called Merkel discs

3 pigments that contribute to skin color

1) melanin

2) carotene

3) hemoglobin (red coloring from blood cells in dermal capillaries, oxygen content determines how much red there is)

Different alterations of the skin

redness (erythema), pallor (blanching), jaundice (yellowing, bruises (blue and black)

What causes erythema?

embarrassment, inflammation, hypertension, fever, allergy

What causes pallor (blanching)?

emotional stress, anemia, low blood pressure, impaired blood flow to an area

Jaundice is a sign of?

liver disorder

Bruises are a sign of?

hematomas

Appendages (addition) of the skin

cutaneous glands (sebaceous-oil and sweat glands), hair, hair follicles, nails

cutaneous glands are all EXOCRINE glands, which means?

they have ducts that push substances (sweat, saliva) toward the epithelial membrane

sebaceous (oil) gland

1) produces sebum (oil) which acts as a lubricant for skin, prevent brittle hair, and kills bacteria

2) activate during puberty

sweat (sudoriferous) glands

produce sweat and is distributed across the skin

apocrine gland (type of sudoriferous gland)

1) ducts empty into hair follicles

2) starts at puberty

3) releases swat, fatty acids, and proteins (milky and yellow)

sweat

1) water, salts, vitamin C, metabolic waste, fatty acids and proteins (apocrine only -armpits/genital)

2) helps get rid of extra heat

3) excretes waste products

4) acids inhibit bacteria growth

hair

1) made from hair follicle

2) consists of keratinized epithelial cells

3) grows in the matrix of hair bulb in the stratum basale

Burns

1) tissue damage and cell death caused by heat, electricity, UV radiation, or chemicals

2) causes: dehydration, electrolyte imbalance, circulatory shock (losing fluids), infection

rule of nines

1) used to determine how bad a burn is

2) body is divided into 11 sections

3) each body surface represents 9% (includes ant. and pos.)

4) genital represents 1%

first-degree burns

1) partial-thickness burns

2) epidermis is damages

3) skin is red and swollen

second-degree burns

1) partial-thickness burn

2) epidermis and upper dermis (papillary layer) damaged

3) skin has blisters and is red

third-degree burn

1) full-thickness burn

2) destroys entire skin layer; painless

3) requires skin grafts: skin from butt, thighs, cadavers

4) skin is gray-white and black 

When are burns considered critical?

1) over 25% of the body has second-degree burns

2) over 10% of the body has third-degree burns

3) third-degree burns on the face, hands, feet

athlete's foot

1) known as tinea pedis

2) caused by fungal infection

boils and carbuncles

1) bubbles

2) caused by bacterial infection

cold sores

caused by virus

infections and allergies

1) contact dermatitis

2) exposure causes allergic reactions

impetigo

caused by bacterial infection (skin to skin)

psoriasis

1) no known cause

2) triggered by stress, infection, trauma 

cancer

abnormal cell mass

2 classifications of cancer

benign and malignant

benign

does not spread to other body parts (encapsulated), but grows

malignant

cancer moves to other body parts

What is the most common type of cancer?

skin cancer

basal cell carinoma (type of skin cancer)

1) least malignant

2) most common

3) arises from stratum basale

squamos cell carcinoma

1) squamous cell carcinoma

2) metastasizes (moves) to lymph nodes if it isn’t removed

3) sun-induced

4) arises from stratum spinosum 

malignant melanoma

1) most deadly of skin cancers

2) cancer of melanocytes

3) metalizes to lymph, blood vessels, brain

4) uses ABCD rule

ABCD rule

A- asymmetry

B- border irregularity

C- color

D- diameter (bigger than 6mm)

When you age, what does skin lose?

elasticity - looses adipose cells

Proteins denature at…

high heat, so cells die