Fluid Balance

Balance: Fluid Balance: Fluid Balance: When the water coming into the body precisely equals the water being lost by the body each day. When the water coming into the body precisely equals the water being lost by the body each day. Electrolyte Balance: Electrolyte Balance: Gains and losses of electrolytes are equal. Gains and losses of electrolytes are equal. Acid-base balance: Acid-base balance: When the production of H + is precisely offset by H+ loss and/ or HCO 3 - production. When the production of H + is precisely offset by H+ loss and/ or HCO 3 - production.

Overall body composition:

Ionic composition of body fluids:

Electrolyte balance:

Acid-base balance

Respiratory acid-base regulation

Metabolic acid-base regulation

The Integumentary System: An Overview

Protection Protection Excretion Excretion Temperature maintenance Temperature maintenance Nutrient storage Nutrient storage Vitamin D3 synthesis Vitamin D3 synthesis Sensory detection Sensory detection Integumentary system functions:

Cutaneous membrane Cutaneous membrane Epidermis Epidermis Dermis Dermis Accessory structures Accessory structures Subcutaneous layer Subcutaneous layer The integumentary system consists of

The Components of the Integumentary System

The epidermis is composed of layers of keratinocytes The epidermis is composed of layers of keratinocytes Thin skin = four layers (strata) Thin skin = four layers (strata) Thick skin = five layers Thick skin = five layers Thin Skin and Thick Skin

Provides mechanical protection Provides mechanical protection Prevents fluid loss Prevents fluid loss Keeps microorganisms from invading the body Keeps microorganisms from invading the body The epidermis

Stratum germinativum Stratum germinativum Stratum spinosum Stratum spinosum Stratum granulosum Stratum granulosum Stratum lucidum (found in thick skin only) Stratum lucidum (found in thick skin only) Stratum corneum Stratum corneum Layers of the epidermis:

Figure 5.3 The Epidermal Ridges of Thick Skin

Cells accumulate keratin and eventually are shed Cells accumulate keratin and eventually are shed Epidermal ridges are interlocked with dermal papillae Epidermal ridges are interlocked with dermal papillae Fingerprints Fingerprints Improve gripping ability Improve gripping ability Langerhans cells (immunity) in s. spinosum Langerhans cells (immunity) in s. spinosum Merkel cells (sensitivity) in s. germinativum Merkel cells (sensitivity) in s. germinativum Epidermal characteristics:

The Structure of the Epidermis

Blood supply Blood supply Carotene and melanin Carotene and melanin Melanocytes produce melanin and protect from UV radiation Melanocytes produce melanin and protect from UV radiation Epidermal pigmentation Epidermal pigmentation Interrupted blood supply leads to cyanosis Interrupted blood supply leads to cyanosis Skin color depends on

Melanocytes

Synthesize vitamin D3 (cholecalciferol) when exposed to UV Synthesize vitamin D3 (cholecalciferol) when exposed to UV Respond to epidermal growth factor Respond to epidermal growth factor Growth Growth Division Division Repair Repair Secretion Secretion Epidermal cells

Papillary layer Papillary layer Contains blood vessels, lymphatics, sensory nerves of epidermis Contains blood vessels, lymphatics, sensory nerves of epidermis Reticular layer Reticular layer Contains network of collagen and elastic fibers to resist tension Contains network of collagen and elastic fibers to resist tension Dermal Organization

Cutaneous plexus arteries found in subcutaneous layer/ papillary dermis Cutaneous plexus arteries found in subcutaneous layer/ papillary dermis Cutaneous sensory receptors (light touch, pressure) Cutaneous sensory receptors (light touch, pressure) Dermal Circulation and innervation

Caused by excessive stretching of the dermis Caused by excessive stretching of the dermis Patterns of collagen and elastic fibers form lines of cleavage Patterns of collagen and elastic fibers form lines of cleavage Stretch marks

Lines of Cleavage of the Skin

Stabilizes skins position against underlying organs and tissues Stabilizes skins position against underlying organs and tissues Hypodermis

Originate in hair follicle Originate in hair follicle Composed of root and shaft Composed of root and shaft Root base (hair papilla) surrounded by hair bulb and root hair plexus Root base (hair papilla) surrounded by hair bulb and root hair plexus Hairs have soft medulla and hard cortex Hairs have soft medulla and hard cortex Cuticle = superficial dead protective layer Cuticle = superficial dead protective layer Hairs

Vellus hairs (peach fuzz) Vellus hairs (peach fuzz) Terminal hairs ( heavy) Terminal hairs ( heavy) Club hair (cessation of growth) Club hair (cessation of growth) Shed and grow according to hair growth cycle Shed and grow according to hair growth cycle Arrector pili muscle attaches to hair Hair types

The Anatomy of a Single Hair

Hair Follicles

Sebaceous (oil) Sebaceous (oil) Suderiferous (sweat) Suderiferous (sweat) Mammary Mammary Ceruminous Ceruminous Glands in the skin

Discharge waxy sebum onto hair shaft when associated with hairs Discharge waxy sebum onto hair shaft when associated with hairs Sebaceous follicles discharge onto epidermal surface Sebaceous follicles discharge onto epidermal surface Sebaceous glands

Sebaceous Glands and Follicles

Apocrine sweat glands Apocrine sweat glands Produce odorous secretion Produce odorous secretion Merocrine (eccrine) sweat gland Merocrine (eccrine) sweat gland Sensible perspiration Sensible perspiration Suderiferous glands

Figure 5.12 Sweat Glands Figure 5.12a, b

Mammary glands Mammary glands Structurally similar to apocrine sweat glands Structurally similar to apocrine sweat glands Ceruminous glands Ceruminous glands In ear, produce waxy cerumen In ear, produce waxy cerumen Other glands

Nail body covers the nail bed Nail body covers the nail bed Nail production occurs at the nail root Nail production occurs at the nail root Eponychium (cuticle) overlies root Eponychium (cuticle) overlies root Free edge of nail extends over hyponychium Free edge of nail extends over hyponychium Nails

The Structure of a Nail

Regenerates easily Regenerates easily Regeneration process includes formation of Regeneration process includes formation of Scab Scab Granulation tissue Granulation tissue Scar tissue Scar tissue Injury and repair

Integumentary Repair

Integument thins Integument thins Blood flow decreases Blood flow decreases Cellular activity decreases Cellular activity decreases Repairs occur more slowly Repairs occur more slowly With age