Cells and Tissue Flash Cards

What is cytology?

The study of cells.

What is microscopy?

Using a microscope to view small structures.

What is the difference between a light microscope and an electron microscope?

Light microscopes use light; electron microscopes use an electron beam and have greater magnification and resolution.

What does a TEM show?

Internal cell structures in $2\text{-D}$.

What does an SEM show?

The surface of a cell in $3\text{-D}$.

What are the $3$ common features of a cell?

Plasma membrane, cytoplasm, and nucleus.

What is the function of the plasma membrane?

Forms the outer barrier and regulates what enters and leaves the cell.

What is cytoplasm?

Everything between the plasma membrane and nucleus.

What is cytosol?

The fluid portion of the cytoplasm.

What is the nucleus?

The cell's control center containing DNA.

What are organelles?

Specialized structures that perform specific cell functions.

What are membrane-bound organelles?

Organelles surrounded by a membrane, such as the ER, Golgi, lysosomes, peroxisomes, and mitochondria.

What are non-membrane-bound organelles?

Ribosomes, centrosomes, proteasomes, and the cytoskeleton.

What are inclusions?

Temporary stored materials in the cytosol that are not organelles.

What are the $3$ main membrane lipids?

Phospholipids, cholesterol, and glycolipids.

What are the $2$ parts of a phospholipid?

A hydrophilic head and $2$ hydrophobic tails.

How are phospholipids arranged in the membrane?

They form a bilayer with tails facing inward and heads facing outward.

What does cholesterol do in the membrane?

Strengthens and stabilizes the membrane.

What do glycolipids help with?

Forming the glycocalyx and cell-to-cell recognition.

What are integral proteins?

Proteins embedded in or extending across the membrane.

What are peripheral proteins?

Proteins loosely attached to the membrane surface.

What do transport proteins do?

Regulate movement of substances across the membrane.

What do cell surface receptors do?

Bind specific molecules called ligands.

What is passive transport?

Movement that does not require cellular energy.

What is active transport?

Movement that requires energy and can move substances against their gradient.

What is diffusion?

Net movement of substances from higher to lower concentration.

What is simple diffusion?

Movement directly through the phospholipid bilayer without a transport protein.

What is facilitated diffusion?

Movement through membrane proteins without using cellular energy.

What is osmosis?

Movement of water across a selectively permeable membrane.

What is an isotonic solution?

A solution with the same relative solute concentration; there is no net water movement.

What happens to a cell in a hypotonic solution?

Water enters the cell, causing it to swell.

What happens to a cell in a hypertonic solution?

Water leaves the cell, causing it to shrink.

What is primary active transport?

Transport that directly uses $1\text{ ATP}$.

What does the sodium-potassium pump do?

Moves $3\text{ Na}^+$ out and $2\text{ K}^+$ into the cell using $1\text{ ATP}$.

What is secondary active transport?

Uses the energy from one substance moving down its gradient to move another substance against its gradient.

What is exocytosis?

A vesicle fuses with the plasma membrane to release substances outside the cell.

What is endocytosis?

The cell takes substances into the cell using a vesicle.

What is phagocytosis?

"Cellular eating" of large particles.

What is pinocytosis?

"Cellular drinking" of extracellular fluid and dissolved substances.

What is receptor-mediated endocytosis?

Specific molecules bind to receptors before being brought into the cell.

What is the rough ER's main function?

Producing and modifying proteins.

What is the smooth ER's main function?

Lipid synthesis, carbohydrate metabolism, detoxification, and other metabolic functions.

What is the function of the Golgi apparatus?

Modifies, packages, and sorts proteins.

What do lysosomes do?

Digest unwanted substances, damaged organelles, and other materials.

What do mitochondria do?

Produce ATP through aerobic respiration.

What do ribosomes do?

Make proteins.

What is the function of the cytoskeleton?

Provides support, organizes organelles, and helps with movement and cell division.

What is the nucleus surrounded by?

A double membrane called the nuclear envelope.

What is DNA made of?

Nucleotides containing deoxyribose, phosphate, and nitrogenous bases.

What are transcription and translation?

Transcription copies DNA information into mRNA; translation uses mRNA to make a protein.

What is a tissue?

A group of similar cells and extracellular matrix working together for a common function.

What is histology?

The study of tissues.

What are the $4$ major tissue types?

Epithelial, connective, muscle, and nervous.

What is epithelial tissue?

Closely packed cells with little extracellular matrix that cover surfaces, line cavities, and form glands.

What are the $3$ epithelial surfaces?

Apical, lateral, and basal.

What is the apical surface?

The surface exposed to the external environment or an internal body space.

What is the basal surface?

The surface attached to the basement membrane.

What is the basement membrane?

A structure that attaches epithelial tissue to underlying connective tissue.

Are epithelial tissues vascular?

No, they are avascular.

Why do epithelial tissues regenerate quickly?

They continually replace lost cells.

What are $4$ functions of epithelial tissue?

Protection, selective permeability, secretion, and sensation.

What is simple epithelium?

Epithelium with $1$ cell layer.

What is stratified epithelium?

Epithelium with multiple cell layers.

What is simple squamous epithelium?

$1$ layer of thin, flat cells specialized for functions such as diffusion and filtration.

Where is simple squamous epithelium found?

Alveoli, blood vessel walls, and serous membranes.

What is simple cuboidal epithelium used for?

Absorption and secretion.

What is simple columnar epithelium used for?

Absorption and secretion.

What are microvilli in simple columnar epithelium used for?

Increasing surface area for absorption.

What are goblet cells?

Cells that secrete mucus.

What is pseudostratified epithelium?

Epithelium that appears layered even though all cells contact the basement membrane.

What is the main function of stratified squamous epithelium?

Protection from abrasion.

What is the difference between keratinized and nonkeratinized stratified squamous epithelium?

Keratinized tissue has a protective keratin layer; nonkeratinized tissue does not.

Where is transitional epithelium found?

In the urinary tract.

What makes transitional epithelium special?

Its cells change shape when the tissue is stretched.

What are glands?

Groups of specialized cells that produce and release secretions.

What is the difference between endocrine and exocrine glands?

Endocrine glands release secretions into the blood; exocrine glands release through ducts.

What is the difference between simple and compound exocrine glands?

Simple glands have an unbranched duct; compound glands have branched ducts.

What are merocrine glands?

Glands that release secretions by exocytosis.

What are apocrine glands?

Glands that release secretions when the apical portion of the cell pinches off.

What are holocrine glands?

Glands in which the entire cell becomes part of the secretion.

What is connective tissue's main role?

Support, protection, and binding.

What are the $3$ basic components of connective tissue?

Cells, protein fibers, and ground substance.

What is the extracellular matrix?

Ground substance plus protein fibers.

What are fibroblasts?

Connective tissue cells that produce components of the extracellular matrix.

What are the $3$ major connective tissue fibers?

Collagen, reticular, and elastic fibers.

What is areolar connective tissue?

Loose connective tissue that provides support and surrounds structures.

What is adipose tissue?

Connective tissue specialized for storing fat.

What is dense regular connective tissue?

Connective tissue with parallel collagen fibers that provides strong attachment, such as tendons and ligaments.

What is cartilage?

Supporting connective tissue that contains chondrocytes in lacunae.

What are the $3$ types of cartilage?

Hyaline, fibrocartilage, and elastic cartilage.

What is fibrocartilage specialized for?

Resisting compression and acting as a shock absorber.

What is elastic cartilage specialized for?

Flexibility and resilience.

What are the $2$ types of bone tissue?

Compact bone and spongy bone.

What are osteocytes?

Bone cells located in lacunae.

What are the functions of bone?

Support, protection, movement, mineral storage, and blood-cell formation.

What are the $3$ types of muscle tissue?

Skeletal, cardiac, and smooth.

What is nervous tissue responsible for?

Receiving, transmitting, and processing nerve impulses.

What are the $2$ main types of cells in nervous tissue?

Neurons and glial cells.

What are the $4$ major body membranes?

Mucous, serous, cutaneous, and synovial.

What is the difference between hypertrophy, hyperplasia, and atrophy?

Hypertrophy increases cell size, hyperplasia increases cell number, and atrophy decreases cell size or number.