EXAM 2 A&P

What is histology?

The study of tissues under a microscope.

What is a tissue?

A group of similar cells that work together to perform a specific function.

What are the 4 primary tissue types?

Epithelial, connective, muscle, and nervous.

What is the main function of epithelial tissue?

Covers and lines surfaces; protection, absorption, filtration, and secretion.

What is the main function of connective tissue?

Supports, binds, protects, stores, and transports.

What is the main function of muscle tissue?

Contraction and movement.

What is the main function of nervous tissue?

Communication through electrical signals.

Which tissue has abundant extracellular matrix?

Connective tissue.

Which tissue has cells that are tightly packed with little extracellular matrix?

Epithelial tissue.

What are the two ways epithelial tissue is classified?

By number of layers and cell shape.

What does "simple" mean?

One cell layer.

What does "stratified" mean?

Multiple cell layers.

What does "squamous" mean?

Flat cells.

What does "cuboidal" mean?

Cube-shaped cells.

 What does "columnar" mean?

Tall, column-shaped cells.

What is the apical surface?

The free surface facing the outside of the body or a body cavity/lumen.

What is the basal surface?

The surface attached to the basement membrane

What does the basement membrane do?

Anchors epithelial tissue to the underlying connective tissue.

Is epithelial tissue vascular?

No. It is avascular.

 How does epithelial tissue receive nutrients if it has no blood vessels?

 Nutrients diffuse from the underlying connective tissue.

 What is simple squamous epithelium?

One layer of thin, flat cells.

What is the main function of simple squamous epithelium?

Rapid diffusion and filtration.

Where is simple squamous epithelium found?

Alveoli and blood vessels.

 How do you identify simple squamous tissue on a slide?

 Look for a very thin layer of flat cells with flattened nuclei.

What is simple cuboidal epithelium?

One layer of cube-shaped cells.

What are the main functions of simple cuboidal epithelium?

Absorption and secretion.

 Where is simple cuboidal epithelium commonly found?

Kidney tubules and glands.

How do you identify simple cuboidal tissue?

One layer of cells that are about as tall as they are wide, usually with round nuclei.

 What is simple columnar epithelium?

One layer of tall, column-shaped cells.

What are the main functions of simple columnar epithelium?

Absorption and secretion.

Where is simple columnar epithelium commonly found?

Digestive tract/intestines.

 How do you identify simple columnar tissue?

Tall cells with nuclei usually located toward the basal side.

Why is pseudostratified epithelium confusing?

 It looks multilayered but is actually one layer.

What is the key identification clue for pseudostratified epithelium?

All cells touch the basement membrane, but nuclei appear at different heights.

Where is pseudostratified columnar epithelium commonly found?

Respiratory tract.

What structures are commonly associated with respiratory pseudostratified epithelium?

Cilia and goblet cells.

 What is stratified squamous epithelium mainly used for?

Protection against abrasion.

What is keratinized stratified squamous epithelium?

Stratified squamous epithelium with a surface layer of keratinized dead cells.

Where is keratinized stratified squamous epithelium found?

Epidermis of the skin.

Where is nonkeratinized stratified squamous epithelium found?

 Moist surfaces such as the mouth and esophagus.

What is transitional epithelium specialized for?

Stretching

Where is transitional epithelium found?

Urinary bladder and ureters.

 What makes transitional epithelium unique?

Its surface cells change shape when the tissue stretches.

What do cilia do?

MOVE material across the cell surface.

What do microvilli do?

 INCREASE surface area for absorption.

Easy way to remember cilia vs. microvilli?

Cilia = MOVE. Microvilli = ABSORB.

What are the major components of connective tissue?

Cells + extracellular matrix.

 What are the 3 major connective tissue fibers?

Collagen, elastic, and reticular.

What does collagen provide?

Strength.

What do elastic fibers provide?

 Stretch and recoil

What do reticular fibers provide?

A supporting network/framework.

What is areolar connective tissue?

Loose connective tissue with loosely arranged fibers and abundant space.

 What are the functions of areolar tissue?

Wraps, cushions, binds, and supports tissues.

What is adipose tissue?

Connective tissue specialized for fat storage.

 What are the major functions of adipose tissue?

 Energy storage, insulation, and cushioning.

How do you identify adipose tissue on a slide?

Large cells with a large empty-looking lipid space and nuclei pushed toward the edge.

What is dense regular connective tissue?

Connective tissue with parallel collagen fibers.

Where is dense regular connective tissue found?

Tendons and ligaments.

What is dense irregular connective tissue?

Connective tissue with collagen fibers arranged in many directions.

 Where is dense irregular connective tissue important in the skin?

Reticular layer of the dermis.

What are the 3 types of cartilage?

Hyaline, elastic, and fibrocartilage.

What is the most common type of cartilage?

Hyaline cartilage.

How do you identify hyaline cartilage?

Smooth/glassy-looking matrix with chondrocytes sitting in lacunae.

What is elastic cartilage specialized for?

 Flexibility and support.

 Where is elastic cartilage found?

EAR

What is fibrocartilage specialized for?

Strength and resistance to compression.

Where is fibrocartilage found?

Intervertebral discs and pubic symphysis.

What are the 3 types of muscle tissue?

Skeletal, cardiac, and smooth.

Which muscle is voluntary and striated?

Skeletal muscle.

Which muscle is involuntary and has intercalated discs?

Cardiac muscle.

 Which muscle is involuntary and nonstriated?

Smooth muscle.

Where is smooth muscle found?

Walls of hollow organs and blood vessels.

 What are the two major cell types in nervous tissue?

Neurons and neuroglia.

 What do neurons do?

Transmit electrical signals.

What do neuroglia do?

Support, protect, and assist neurons.

 What is an exocrine gland?

A gland that secretes through a duct.

What is an endocrine gland?

A ductless gland that releases hormones into the blood/interstitial fluid.

What is merocrine secretion?

 Product is released by exocytosis without losing cell material.

What is apocrine secretion?

Part of the cell's apical portion pinches off with the secretion.

What is holocrine secretion?

The entire cell breaks down to release its product.

Which major gland uses holocrine secretion?

 Sebaceous gland.

What is a mucous membrane?

A membrane lining a cavity that opens to the outside.

 What is a serous membrane?

A membrane lining a closed body cavity and covering organs within it.

What is the cutaneous membrane?

Skin

What is a synovial membrane?

A membrane lining freely movable joints.

What structures make up the integumentary system?

Skin, hair, nails, sweat glands, and sebaceous glands.

What are major functions of the skin?

Protection, sensation, temperature regulation, preventing water loss, excretion, and vitamin D production.

What are the 3 major layers associated with the skin?

Epidermis, dermis, hypodermis.

Is the hypodermis technically part of the skin?

no

What type of epithelium forms the epidermis?

Keratinized stratified squamous epithelium

 Is the epidermis vascular?

No. It is avascular.

What are the epidermal layers from deep → superficial?

Basale → Spinosum → Granulosum → Lucidum → Corneum.

What is the memory trick for the epidermal layers?

B-S-G-L-C.

Which epidermal layer is deepest?

Stratum basale.

Which epidermal layer is most superficial?

Stratum corneum.

Which epidermal layer is found only in thick skin?

Stratum lucidum.

Where is thick skin found?

Palms of hands and soles of feet.

Does thick skin contain hair follicles?

no

 Does thick skin contain sebaceous glands?

no

 Does thick skin contain sweat glands?

yes