MAP Unit 4: Histology and Integument

What is the cell membrane?

The outer boundary that separates the inside of the cell from its environment.

What are the main functions of the cell membrane?

Protects the cell, controls what enters and exits, and helps identify the cell.

What is the phospholipid bilayer?

Two layers of phospholipids that make up the cell membrane.

What does hydrophilic mean?

Attracts water.

What does hydrophobic mean?

Repels water.

Which part of a phospholipid is hydrophilic?

The phosphate head.

Which part of a phospholipid is hydrophobic?

The fatty acid tails.

Which way do phospholipid heads and tails face?

Heads face outward toward water; tails face inward away from water.

What do membrane proteins do?

Transport substances, act as receptors, identify cells, and help chemical reactions.

What does cholesterol do in the cell membrane?

Stabilizes the membrane and helps maintain its structure.

What do membrane carbohydrates do?

Help cells recognize and identify one another.

What are transport proteins?

Proteins that help substances move across the cell membrane.

What are receptor proteins?

Proteins that receive signals such as hormones.

What are membrane enzymes?

Proteins that speed up specific chemical reactions.

What is a tissue?

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

What does epithelial tissue do?

Covers body surfaces, lines cavities and organs, and forms glands.

Does epithelial tissue have its own direct blood supply?

No.

How are epithelial cells arranged?

Closely packed together.

What is simple epithelium?

A single layer of cells used for absorption, diffusion, and filtration.

What is stratified epithelium?

Multiple layers of cells that provide protection from wear and tear.

What is pseudostratified columnar epithelium?

One layer of cells that looks like multiple layers.

What do goblet cells produce?

Mucus.

What do cilia do in the respiratory tract?

Move mucus and trapped debris away.

What is squamous epithelium?

Flat, scale-like cells.

What is cuboidal epithelium?

Cube-shaped cells.

What is columnar epithelium?

Tall, column-shaped cells.

What is transitional epithelium?

Stretchable epithelium that changes shape.

Where is transitional epithelium found?

The urinary bladder.

Where is pseudostratified ciliated columnar epithelium commonly found?

The trachea.

What are the four main types of tissue?

Epithelial, connective, muscle, and nervous tissue.

What are the main functions of connective tissue?

Supports, protects, binds, and connects body structures and stores energy.

What is the matrix of connective tissue?

The material between cells that supports the tissue.

What are fibroblasts?

Cells that produce fibers and other components of connective tissue.

What is adipose tissue?

Fat-storing connective tissue.

What are adipocytes?

Cells that store fat.

Where is adipose tissue found?

Under the skin and around organs and the eyes.

What is cartilage?

Strong, flexible connective tissue that supports structures and cushions joints.

Does cartilage contain blood vessels or nerves?

No; cartilage heals slowly.

What is hyaline cartilage?

The most common type of cartilage; smooth tissue that reduces friction at joints.

Where is hyaline cartilage found?

Ends of long bones, nose, ribs, tracheal rings, and growth plates.

What is dense fibrous connective tissue made of?

Closely packed collagen fibers and fibroblasts.

What is dense regular connective tissue?

Parallel fibers that resist tension in one direction.

Where is dense regular connective tissue found?

Tendons and ligaments.

What do tendons connect?

Muscle to bone.

What do ligaments connect?

Bone to bone.

What is dense irregular connective tissue?

Fibers arranged in different directions to resist tension from multiple directions.

Where is dense irregular connective tissue found?

The dermis, fascia, and capsules around organs.

What is blood classified as?

Liquid connective tissue.

What is plasma?

The straw-colored, mostly water liquid portion of blood.

What are formed elements?

The blood cells and cell fragments.

What are erythrocytes?

Red blood cells that transport oxygen and some carbon dioxide.

What are leukocytes?

White blood cells that help fight infections and support immunity.

What are thrombocytes?

Platelets that help blood clot.

What are osteocytes?

Mature bone cells.

What makes bone hard?

Mineral salts, especially calcium compounds, in its matrix.

What provides flexibility and strength to bone?

Collagen fibers.

What is the main function of muscle tissue?

Produces tension and movement and helps generate body heat.

What are the three types of muscle tissue?

Skeletal, cardiac, and smooth.

What does voluntary mean?

Under conscious control.

What does involuntary mean?

Not under conscious control.

What does striated mean?

Having alternating light and dark bands.

What is skeletal muscle?

Voluntary, striated muscle usually attached to bones.

How many nuclei do skeletal muscle fibers usually have?

Many nuclei; they are multinucleated.

What is cardiac muscle?

Involuntary, striated muscle that makes up most of the heart wall.

What is special about cardiac muscle cells?

They branch and usually have one centrally located nucleus.

What are intercalated discs?

Connections between cardiac muscle cells that help the heart contract together.

What are gap junctions?

Connections that allow electrical signals to pass between cells.

What is smooth muscle?

Involuntary, nonstriated muscle found in the walls of hollow organs.

Where is smooth muscle found?

The stomach, intestines, blood vessels, and urinary bladder.

What is the main function of skeletal muscle?

Produces voluntary body movements.

What is the main function of cardiac muscle?

Pumps blood through the body.

What is the main function of smooth muscle?

Moves substances through hollow organs and controls the diameter of blood vessels.

What are the two main arrangements of dense fibrous connective tissue?

Regular and irregular.

What is the function of dense regular connective tissue?

Resists pulling forces in one direction.

What is the function of dense irregular connective tissue?

Resists pulling forces from multiple directions.

What are the main components of bone matrix?

Mineral salts and collagen fibers.

What is the difference between simple and stratified epithelium?

Simple has one cell layer; stratified has multiple layers.

What is the difference between skeletal and cardiac muscle?

Skeletal muscle is voluntary and attached to bones; cardiac muscle is involuntary and found in the heart.

What is the difference between cardiac and smooth muscle?

Cardiac muscle is striated and found in the heart; smooth muscle is nonstriated and found in hollow organs.

What are the main functions of the cell membrane?

Separates the cell from its environment, controls movement of substances, receives signals, and identifies the cell.