Tissues and Body Membranes Lecture

50 question-and-answer flashcards covering definitions, functions, examples, and distinctions related to epithelial, connective, muscle, and nervous tissues, as well as body membranes.

What is a tissue?

A group of closely related cells that work together to carry out a specific function.

What does histology study?

The microscopic anatomy of tissues.

What are the four main tissue types?

Epithelial, connective, muscle, and nervous tissue.

What is the major function of epithelial tissue?

Protection (it also lines cavities and forms secretory glands).

Name the three epithelial arrangements based on layers.

Simple, stratified, and pseudostratified epithelium.

Define simple epithelium.

A single layer of cells.

Define stratified epithelium.

Two or more layers of cells stacked on top of one another.

Define pseudostratified epithelium.

Epithelium that appears layered but is actually a single uneven layer.

List the three epithelial cell shapes.

Squamous, cuboidal, and columnar.

What is the function and appearance of squamous epithelium?

Diffusion and filtration; cells are flat, plate-like or scale-like (e.g., air sacs of lungs, blood vessel lining).

What is the function and appearance of cuboidal epithelium?

Secretion and absorption; cube-shaped cells with more cytoplasm (e.g., kidney tubules).

What is the function and appearance of columnar epithelium?

Absorption and mucus secretion; tall, cylindrical cells (e.g., digestive tract).

In stratified epithelium, which layer is used to classify the tissue type?

The top (apical) layer.

Where is pseudostratified ciliated epithelium typically found?

Respiratory passages.

What is a gland?

A collection of epithelial cells that secrete substances such as mucus, sweat, saliva, enzymes, hormones, or milk.

What do goblet cells secrete?

Mucus.

Which gland is the largest salivary gland?

The parotid gland.

How do exocrine glands differ from endocrine glands?

Exocrine glands have ducts and secrete to a body surface; endocrine glands lack ducts and release hormones into tissue fluid and blood.

Give an example of an exocrine gland.

Sweat gland or salivary gland.

Give an example of an endocrine gland.

Thyroid gland or adrenal gland.

What is the primary role of connective tissue?

To support, protect, and join other body tissues together.

How are connective tissue cells arranged compared to epithelial cells?

They are separated by an intercellular substance (matrix) containing fibers.

Which cell type produces fibers in connective tissue?

Fibroblasts.

Name the three types of connective tissue fibers.

Collagen fibers, reticular fibers, and elastic fibers.

Describe collagen fibers.

Most numerous; contain collagen protein; strong, flexible, and resistant to stretching.

Describe reticular fibers and a location.

Fine, branching collagen fibers that support small structures such as capillaries, nerve fibers, and soft organs.

Describe elastic fibers and a location.

Made of elastin; stretch and recoil easily, found in skin, lungs, and blood vessel walls.

List the seven connective tissue categories mentioned.

Loose (areolar), adipose, cartilage, bone, blood, lymph, and blood-forming tissue.

Where is loose (areolar) connective tissue found and what is its function?

As a thin layer between body parts; reservoir for water and salts; with adipose it forms the subcutaneous layer attaching skin to underlying tissues.

State three functions of adipose tissue.

Stores fat for energy, insulates the body, and cushions/shapes organs.

What are chondrocytes?

Cartilage cells that secrete the rubbery cartilage matrix and collagen fibers.

Give two locations where cartilage is found.

Intervertebral discs and the ends of some bones.

What makes bone tissue hard?

A mineralized (hard) matrix surrounding osteocytes in lacunae.

What is the liquid matrix of blood called?

Plasma.

Where are red blood cells produced in adults?

Red bone marrow, primarily in the axial skeleton.

What is the basic cell of muscle tissue called?

A muscle fiber.

List four characteristics of skeletal muscle fibers.

Striated, attached to bones, multiple nuclei per fiber, voluntary control.

List four characteristics of cardiac muscle fibers.

Striated, intercalated disks present, found in heart walls, 1–2 nuclei per fiber (involuntary).

List four characteristics of smooth muscle fibers.

Non-striated, one nucleus per fiber, found in walls of hollow organs and vessels, involuntary control.

What is the fundamental cell of nervous tissue?

The neuron.

What is the function of dendrites?

To receive impulses and carry them toward the neuron’s cell body.

What is the function of an axon?

To transmit impulses away from the neuron’s cell body.

What are glial cells?

Supportive cells that protect and assist neurons.

Name the two broad categories of body membranes.

Epithelial membranes and connective tissue membranes.

Describe mucous membranes and give examples of locations.

Line cavities open to the exterior, secrete mucus for lubrication (e.g., digestive, respiratory, urinary, and reproductive tracts).

Describe serous membranes and list their three subdivisions.

Line cavities not open to the exterior, secrete lubricating serous fluid; pleura (lungs), pericardium (heart), peritoneum (abdominal organs).

What is the cutaneous membrane?

The skin: epithelium resting on connective tissue; the body’s largest membrane.

What is the function of synovial membranes?

Line joint cavities and secrete lubricating fluid to reduce friction during movement.

Define intercellular substance.

Material (fluid or solid) present between cells within a tissue or organ.

What is elastin?

A fibrous protein that forms elastic fibers, enabling tissues to stretch and recoil.