Chapter 5 - Integumentary System

Other integumentary Glands

• Mammary Glands - Produce Milk

• Ceruminous Glands - Produces Cerumen (Earwax)

Cytology

Study of cells

Histology

Study of tissues

Systemic Physiology

Functions of organ system

Pathological Physiology

Effects of diseases on organs of system

Tissue Level

A group of cells working together

Organ Level

Made of two or more tissues working together

Chemical Level

Atoms are the smallest stable units of matter

Cellular Level

Cells are the smallest living units in the body

Suspine

Lying Down, Face Up

Prone

Lying Down, Face Down

Abdominopelvic Quadrants

Abdominopelvic Regions

Body Cavities Contain…

Viscera (Internal Organs)

Cutaneous Membrane

• Outer Epidermis - Superficial Epithelium

• Inner Dermis - Connective Tissues

Accessory Structures

Originate in the dermis, Extends through the epidermis to skin surface (Nails, Exocrine Glands, Hairs and Hair Follicles)

Functions of the Integument

• Protection of underlying tissues and organs

• Excretion of salts, water, and organic wastes

• Maintenance of normal body temp

Types of Epithelium

• Simple - One Layer

• Stratified - Many Layers

• Squamous - Flat

• Cuboidal - Cube

• Columnar - Rectangle

Epidermis

• Stratified Squamous Epithelium

• Avascular

• Nutrients and oxygen diffuse from capillaries in the dermis

Thin Skin

Covers most of the body, has 4 layers of keratinocytes

Thick Skin

Covers hands palm, feet soles, and has 5 layers of keratinocytes

Strata of keratinocytes in thick skin

1) Stratum Basale

2) Stratum Spinosum

3) Stratum Granulosum

4) Stratum Lucidum

5) Stratum Corneum

Stratum Lucidum

The “Clear Layer“ - Appears as a glossy layer in thick skin only

Cells of the epidermis

Keratinocytes

Keratinocytes

The body’s most abundant epithelial cells, contains large amount of keratin

Eccrine (merocrine) sweat glands

Coiled, tubular glands that discharge directly onto skin surface, works to regulate body temperature

Apocrine Sweat Glands

• Found in armpits, around ni**les, and in pubic region

• Produce sticky cloudy secretions, nutrient source for bacteria which causes odor

Exocrine Glands in Skin

• Sebaceous Glands (Oil Glands)

• Sweat Glands (Apocrine/Eccrine Sweat Glands)

Types of Hairs

• Vellus Hairs

• Terminal Hairs

Vellus Hairs

Soft, fine hairs that cover most of bodys surface

Hair Production

Hair Bulb → Hair Papilla → Hair Matrix (Cells divide and pushes hair up)

Hair Structure

• Medulla → Central Core

• Cortex → Intermediate Layer

• Cuticle → Surface Layer

Hair Follicles

• Extend deep into dermis

• Produce nonliving hairs

• Wrapped in a dense connective tissue sheath

Microscopic Anatomy

Examines cells and molecules

Anatomy

Describes the structure of the body (Made of, Location)

Physiology

Is the study of anatomical structures

Negative Feedback

The response of the effector negates the stimulus, goes towards homeostasis again (Sweating, Shivers)

Positive Feedback

Initial stimulus produces a response that amplifies the OG change in conditions, away from homeostasis (Child Labor, Blood Clotting)

Autoregulation

Automatic responses in a cell, tissue, or organ to an environmental change

Extrinsic Regulation

Responses controlled by nervous and endocrine system

Receptor

Receives the stimulus

Control Center

Process the signal and sends instruction

Effector

Carries out instructions

Homeostasis

All body systems work together to maintain a stable environment

Mediastinum

• Upper portion filled with blood vessels, trachea, esophagus and thymus

• Lower portion contains pericardial cavity (Heart location)

Thoracic Cavity

• Right and Left pleural cavity (Contains R&L Lungs)

• Mediastinum

Parietal Serosa

Lines cavity

Visceral Serosa

Covers organ

Integumentary system (Integument)

• Largest system of the body

• Divides into cutaneous member and accessory structure

Contusion

Caused by damage to blood vessels in dermis (Bruise)

Dermal Blood Supply

Cutaneous Plexus + Subpapillary Plexus

Cutaneous Plexus

Deep network at arteries along the reticular layer

Subpapillary Plexus

Network of small arteries in papillary layer

Tension Lines

• Produced by parallel bundles of collagen and elastic fibers in the dermis

• Resist forces applied to skin

Skin Damage

Loss of skin turgor is caused by:

• Dehydration

• Aging

• Hormones

• UV Radiation

• Stretch Marks (Pregnancy/Weight Gain)

Dermal Strength and Elasticity

• Collagen Fibers

• Elastic Fibers

• Fibers and Water

Fibers and Water

Provides flexibility and resilience, Skin Turgor

Collagen Fibers

• Strong, Resist Stretching

• Easily bent or twisted, prevent tissue damage

Elastic Fibers

Permit stretching and then recoil to OG length

Reticular Layer

• Consists of dense irregular connective tissue

• Contains collagen and elastic fibers

Papillary Layer

Consists of areolar tissue, contain capillaries, lymphatic vessels, and sensory neurons

Dermis

Located between epidermis and subcutaneous layer, made up of outer papillary layer + deeper reticular layer

Stratum Granulosum

• Keratinocytes produce keratin

• Gradually the plasma membranes thicken, the organelles disintegrate, and the cells die

Stratum Spinosum

Cells appear spiny in histological sections, Produced by division of cells in stratum Basale, some at which continue dividing

Tactile Discs

Tactile (Merkel) cells with sensory nerve endings

Stratum Basale

• Attached to basement membrane by hemidesmosomes

• Forms a strong bond between epidermis and dermis

Vitamin D3

Produced by epidermal cells in presences of UV radiation

Hemoglobin is __ __ when bound to oxygen

Bright red

Carotene

• Orange / Yellow Pigment

• Accumulates in epidermal cells, deep dermis and subcutaneous layer

Hemoglobin turns __ __ when oxygen is released

Dark Red

Melanin

• Red/Yellow or Brown/Black Pigment

• Produced by melanocytes

Effects of aging on skin

Epidermis thins, # of Dendritic cells decreases

Control of glands

• Automatic nervous system

• Eccrine sweat glands

• Thermoregulation

Control of glands: Automatic nervous system

Controls sebaceous and apocrine sweat glands

Control of glands: Thermoregulation

Regulate body temperature

Control of glands: Eccrine sweat glands

Controlled precisely