Unit 2: Chapter 5: integumentary System

This unit contains a study of the cells, tissues and the Integumentary system.

What is the Integumentary system?

Consists of the Skin and its accessory structures, including hair, nails, and glands

What is another name for skin?

Cutaneous membrane and it’s the largest organ

What are the 2 regions of the skin?

Epidermis and Dermis

What is the Epidermis?

Keratinized stratified squamous epithelium

What is the Dermis?

Inside layer of the skin, it is loose CT and dense irregular CT

What are the Accessory structures?

Sweat glands, sebaceous glands, hair, nails

What are the Sensory receptors for?

Detect heat, cold, pain, pressure

What is the Arrector pili muscles?

Smalls bands of SMC associated with hair

What SMC means?

It means Smooth Muscle Cell, associated with the hair

What is the Epidermis?

• It is avascular

• It transports of oxygen and nutrients via diffusion

Is the dermis vascular or avascular?

The dermis is vascular (blood)

What is the Hypodermis?

• It is also known as superficial fascia or subcutaneous fat, is deep to dermis

• Not part of skin, anchors skin to deeper structures

• Loose CT and adipose

• Vascular

What is Cellulite?

• Dimpled or “orange peel” appearance of skin when collagen bands form around adipose tissue

• Thighs, hips and gluteal area; due to genetics, gender age, adipose tissue

• Normal Condition (Not disorder)

• Minimize with a healthy diet and regular exercise

What are the Functions of the Integumentary System?

1) Protection - Mechanical trauma, pathogens and environment

2) Sensation - Perceive changes in the body’s internal or external environment

3)Thermoregulation - Relies on negative feedback loops to maintain stable internal temperature (due to muscle activity and metabolism)

4) Excretion - Process where waste products and toxins are eliminated (sweat)

How Negative feedback loops works when is too hot? (Thermoregulation)

Stimulus- Body is too hot

Receptor- Detect an increase in temperature

Control Center- in brain (hypothalamus) acts as a thermostat

Effector//Response- Control center stimulates sweating and vasodilation (VD) of vessels in dermis

Return to normal range (homeostasis)

How Negative feedback loops works when is too cold? (Thermoregulation)

• Stimulus- body temperature drops below normal range, too cold

• Thermoreceptors- detect drop in temperature and relay information to hypothalamus

• Control center reacts

• Effector/response- blood vessels in dermis vasoconstrict (VC), decreased sweating; shivering

• Return to normal range (Homeostasis)