Lecture Exam 2 Required Terms to Know

Flashcards covering key anatomical and physiological terms, tissue types, skin layers, and related structures for Lecture Exam 2.

What is adipose tissue?

A specialized connective tissue composed primarily of adipocytes that stores triglycerides for energy, insulates the body, and cushions organs.

Where are apocrine glands located and what are their key characteristics?

Sweat glands located mainly in the axillary and groin regions that secrete a thicker, protein-rich sweat into hair follicles; become active at puberty and are associated with body odor.

What is the basement membrane and what are its components and functions?

A thin extracellular layer beneath epithelial tissue composed of the basal lamina and reticular lamina; anchors epithelium to underlying connective tissue and acts as a selective barrier.

What is blood composed of and what are its functions?

A fluid connective tissue consisting of plasma and formed elements (erythrocytes, leukocytes, platelets) responsible for transport, regulation, and protection.

How are first-degree, second-degree, and third-degree burns distinguished?

First-degree: Epidermis only; redness, pain. Second-degree: Epidermis + partial dermis; blisters. Third-degree: Full thickness; destroys epidermis and dermis, possibly deeper tissues.

What are the structural features and location of cardiac muscle?

Involuntary, striated muscle found only in the heart; contains branching cells with intercalated discs for synchronized contraction.

What is carotene and how does it affect skin color?

A plant pigment (provitamin A) that can accumulate in the stratum corneum and subcutaneous fat, giving skin a yellow-orange tint.

What is cartilage composed of and what is its function?

A firm, flexible connective tissue composed of chondrocytes in lacunae within a gel-like matrix; provides support and reduces friction in joints.

What are cleavage lines and what is their clinical significance?

Lines of natural tension in the dermis formed by collagen fiber orientation; incisions parallel to these lines heal more easily.

What are columnar epithelial cells specialized for?

Tall, rectangular epithelial cells specialized for secretion and absorption.

What are the roles, cell types, and functions of connective tissue?

Role: Support, bind, protect, transport. Cells: Fibroblasts, adipocytes, macrophages, mast cells, etc. Function: Structural framework, energy storage, immune defense.

What is the shape and function of cuboidal epithelial cells?

Cube-shaped epithelial cells; function in secretion and absorption (e.g., kidney tubules).

What is the function of dendritic cells in the epidermis?

Immune cells in the epidermis (Langerhans cells) that present antigens to activate the immune response.

What is the dermis and what does it contain?

The connective tissue layer beneath the epidermis; contains blood vessels, nerves, glands, and hair follicles.

What are eccrine (merocrine) sweat glands and what is their function?

Widely distributed sweat glands that produce watery sweat for thermoregulation.

What is an endocrine gland?

Ductless gland that secretes hormones directly into the bloodstream.

What are the primary functions of the epidermis?

Protection, prevention of water loss, vitamin D synthesis, immune defense.

What are the roles and cell types of epithelial tissue?

Role: Protection, absorption, secretion, filtration. Cells: Squamous, cuboidal, columnar (simple or stratified).

How does evaporation function as a heat loss mechanism?

Heat loss mechanism where liquid sweat converts to vapor, removing body heat.

What is an exocrine gland?

Gland that secretes substances through ducts onto epithelial surfaces.

What are the main functions of sweat?

Cools body, excretes small amounts of waste, contributes to acid mantle protection.

What are the functions of nails?

Protect distal digits, enhance fine motor function, assist in grasping.

What are the distinct functions of neurons and glial cells?

Neurons: Transmit electrical impulses. Glial cells: Support, insulate, nourish, and protect neurons.

What is ground substance in connective tissue?

Gel-like extracellular matrix component of connective tissue that surrounds cells and fibers.

What is a hair follicle, and what are the three types of hair?

Hair follicle: Epidermal tube that produces hair. Hair types: Lanugo (fetal), vellus (fine), terminal (coarse).

How does a holocrine gland release its secretions?

Gland that releases secretions by cell rupture (e.g., sebaceous glands).

How does the body respond to cold temperatures?

Vasoconstriction, shivering, decreased sweating, increased metabolic rate.

What is the hypodermis?

Loose connective tissue layer beneath dermis; contains adipose tissue and anchors skin.

What does the term integumentary refer to?

Refers to the skin and its accessory structures (hair, nails, glands).

What does the term intramuscular mean?

Located within a muscle.

What is intrapleural fluid and its role?

Serous fluid between pleural layers that reduces friction during breathing.

What does it mean for epithelial cells to be keratinized?

Epithelial cells filled with keratin and dead at maturity; provides waterproof protection.

What are keratinocytes?

Primary epidermal cells that produce keratin.

What type of tissue composes ligaments, and what is their function?

Dense regular connective tissue connecting bone to bone.

What is melanin and what is its role?

Pigment produced by melanocytes; protects against UV radiation.

What are melanocytes and where are they located?

Cells in stratum basale that produce melanin.

How does merocrine secretion occur?

Secretion via exocytosis without cell damage (most common gland type).

What are the primary functions of muscular tissue?

Produces movement, maintains posture, generates heat.

What are nails?

Hard keratin plates covering distal phalanges.

What is nervous tissue composed of and how does it function?

Composed of neurons and neuroglia; coordinates body activities via electrical signaling.

What is an organ?

Structure composed of two or more tissue types performing a specific function.

What are the causes of osteoporosis?

Bone resorption exceeds formation; aging, hormonal changes ($\downarrow$ estrogen), inactivity, poor calcium/vitamin D intake.

What is the parietal pleura?

Outer pleural layer lining thoracic cavity walls.

What are the main parts of a nerve cell and their functions?

Dendrites: Receive signals. Cell body: Integrates input. Axon: Conducts impulse. Axon terminals: Transmit to next cell.

What is the pleura?

Double-layered serous membrane surrounding lungs.

What is pseudostratified epithelium?

Single layer of cells of varying heights appearing multilayered.

What are sebaceous glands and what do they secrete?

Oil glands associated with hair follicles; secrete sebum.

What is sebum?

Oily secretion that lubricates skin and hair.

What does simple mean when describing epithelial tissue?

Single layer of epithelial cells.

What are the characteristics of skeletal muscle and its cells?

Voluntary, striated muscle attached to bones; composed of long multinucleated muscle fibers.

What are the characteristics of smooth muscle?

Involuntary, non-striated muscle in walls of hollow organs.

What is the shape and function of squamous epithelial cells?

Flat epithelial cells specialized for diffusion and filtration.

What does stratified mean when describing epithelial tissue?

Multiple layers of epithelial cells for protection.

What characterizes the stratum basale?

Deepest epidermal layer; mitotically active stem cells and melanocytes.

What is the stratum corneum?

Outermost epidermal layer of dead, keratinized cells.

What occurs in the stratum granulosum?

Layer where keratinization intensifies; cells accumulate keratohyalin granules.

What characterizes the stratum spinosum?

Layer of keratinocytes connected by desmosomes; provides strength.

What does the term subcutaneous mean?

Beneath the skin.

What is the subcutaneous layer?

Hypodermis; adipose-rich layer for insulation and energy storage.

How do thin and thick epidermis compare?

Thin: Covers most body; 4 layers; has hair. Thick: Palms/soles; 5 layers; no hair; thicker stratum corneum.

What characterizes third-degree burns?

Full-thickness burns destroying epidermis and dermis; may damage nerves (often painless initially).

What does transdermal mean?

Medication delivery across the skin into systemic circulation.

What is transitional epithelium and where is it found?

Stratified epithelium that stretches; found in urinary bladder.

What is the visceral pleura?

Inner pleural layer covering lung surface.