Histology

What is histology?

the study of the microscopic structure of tissues.

What are the four main classes of tissue?

Epithelial tissue, muscle tissue, nervous tissue, and connective tissue.

What is a cell?

the basic building blocks of all living things.

What is a nucleus?

a membrane-enclosed organelle that stores and uses genetic material (DNA).

What is cytoplasm?

all of the material within a cell, enclosed by the cell membrane, except for the cell nucleus.

What is a plasma membrane?

the membrane found in all cells that separates the interior of the cell from the outside environment.

What does section mean in anatomy?

when tissue is trimmed and mounted on a cutting device called a microtome.

What does apical surface mean?

the outward-facing side of the tissue.

What does basal surface mean?

the bottom edge of a cell or tissue that is adjacent to the basement membrane.

What is basement membrane?

A thin membrane of protein fibers and glycosaminoglycans separating an epithelium from underlying tissue.

What does lumen mean?

the internal space of a hollow structure such as a blood vessel or intestine.

What is a simple squamous epithelium?

A single layer of flat cells in contact with the basal lamina of the epithelium.

What is mesothelium?

a membrane composed of simple squamous epithelium lining several body cavities.

What is a simple cuboidal epithelium?

A type of epithelium consisting of a single layer of cuboidal cells.

What do the kidneys do?

remove wastes and extra fluid from the body and maintain a healthy balance of water, salts, and minerals.

What is a tubule?

A very small tube, especially as an anatomical structure.

What is simple columnar epithelium?

A single layer of cells that are taller than they are wide, lining the small intestine.

What does the small intestine do?

carries out most of the digestive process, absorbing nutrients into the bloodstream.

What is a villus?

a small, slender projection that increases the surface area of a membrane.

What is the plural form of the word villus?

villi

What does brush border mean?

the microvilli-covered surface of certain epithelial tissues.

What are microvilli?

are microscopic protrusions of the plasma membrane that increase surface area for diffusion.

What does a goblet cell produce and secrete?

secrete mucins and create a protective mucus layer.

What is a pseudostratified columnar epithelium?

A type of epithelium that appears to be stratified but is actually a single layer of cells.

What is the function of cilia in the respiratory tract?

moves mucus and trapped debris away from the lungs.

What is the trachea?

The windpipe that carries oxygen-rich air to the lungs and carbon dioxide out of the lungs.

What are cilia?

Organelles found on eukaryotic cells that project from the cell body; can be motile or non-motile.

What does pseudostratified mean?

It refers to an epithelium that appears layered but is actually a single layer attached to the basement membrane.

What is a stratified squamous epithelium?

Tissue formed from multiple layers of cells resting on a basement membrane, with the surface layer consisting of squamous cells.

What is the esophagus?

A muscular tube connecting the throat (pharynx) with the stomach.

What does stratified mean?

Arranged in stable layers or strata.

What is a transitional epithelium?

A special type of epithelium found in the bladder and ureters that can contract and expand.

What does transitional mean in the context of an epithelium?

It refers to epithelial cells that can adapt to varying degrees of distension.

Is transitional epithelium simple or stratified?

Stratified.

What is areolar connective tissue?

A type of loose connective tissue named for its airy appearance.

Where is areolar connective tissue found in the body?

Surrounding blood vessels, nerve bundles, muscles, and organs.

What part of the fibroblast can be seen in areolar connective tissue?

Nucleus.

What does the fibroblast secrete?

components of the extracellular matrix (ECM) and ground substance.

What is the difference between extracellular matrix and ground substance?

Ground substance is composed of glycosaminoglycans and proteoglycans, while ECM includes fibers and structural proteins.

What is adipose tissue?

A loose connective tissue composed mostly of adipocytes.

What does the suffix -cyte mean?

It means 'cell'.

What is a vacuole?

A space or vesicle within a cell's cytoplasm, typically containing fluid.

What is dense regular connective tissue?

Connective tissue made up of densely packed collagen fibers arranged parallel to each other.

Where is dense regular connective tissue found?

In ligaments and tendons where tensile strength is required.

What is dense irregular connective tissue?

Connective tissue consisting mostly of collagen fibers that are not arranged in parallel bundles.

Where is dense irregular connective tissue found?

In the reticular layer of the dermis, sclera of the eye, and joint capsules.

What is hyaline cartilage?

A glass-like cartilage found on joint surfaces, ribs, nose, larynx, and trachea.

What does the root 'chondr-' mean?

It refers to cartilage.

What is a lacuna?

A small cavity in an anatomical structure.

What does the prefix 'peri-' mean?

It means 'about' or 'around'.

What is a chondrocyte?

A cell that is isolated in a lacuna of cartilage.

Where in the body is hyaline cartilage found?

Many joint surfaces, ribs, nose, larynx, and trachea.

What is elastic cartilage?

A type of cartilage that provides both strength and elasticity.

Where in the body is elastic cartilage found?

Outer ear, Eustachian tubes, and epiglottis.

What is fibrocartilage?

A tough, very strong tissue similar to fibrous tissues but contains cartilage ground substance and chondrocytes.

Where in the body is fibrocartilage found?

Intervertebral discs, menisci of the knees, and at the insertions of ligaments and tendons.

What is bone?

Mineralized connective tissue with four types of cells: osteoblasts, bone lining cells, osteocytes, and osteoclasts.

What does the root 'osteo-' mean?

Relating to the bones.

What is a canal?

A tubular passage or channel connecting different regions of the body.

What is a lamella?

A thin layer, membrane, or plate of tissue, especially in bone.

What is the plural form of lamella?

Lamellae.

What is a canaliculus?

A small channel or duct.

What is the plural form of canaliculus?

Canaliculi.

What is an osteon?

Cylindrical structures containing a mineral matrix and living osteocytes connected by canaliculi.

What is blood?

An atypical connective tissue composed of blood cells suspended in plasma.

What are the functions of erythrocytes, leukocytes, and thrombocytes?

Erythrocytes deliver oxygen, leukocytes fight infection, and thrombocytes function in blood clotting.

Which of the four major tissue types is blood?

Connective tissue.

What is nervous tissue?

Tissue found in the brain, spinal cord, and nerves, consisting of neurons and glial cells.

What is a process in anatomy?

A projection or outgrowth from a larger structure.

What are glial cells?

Supporting cells for neurons in nervous tissue.

What is skeletal muscle tissue?

A form of striated muscle tissue under voluntary control, attached to bones by tendons.

What does sarcolemma mean?

The plasma membrane of a muscle cell.

What does sarcoplasm mean?

The cytoplasm of a muscle cell.

What are striations?

Stripes visible in cardiac and skeletal muscle tissue due to aligned contractile fibrils.

What is cardiac muscle tissue?

Muscle tissue found only in the heart, allowing coordinated contractions.

What are intercalated discs?

Microscopic features of cardiac muscle that connect individual heart muscle cells.

What is smooth muscle tissue?

Muscle tissue used by various systems to apply pressure to vessels and organs.

What is skin?

The largest organ of the body, composed of the epidermis and dermis.

What is hypodermis?

A layer below the dermis connecting skin to underlying fascia.

What does the prefix 'epi-' mean?

Above or upon.

What are the four types of tissue?

Connective, muscle, nervous, and epithelial tissues.