unit 4 Cell Biology and Histology Review for Exam

Flashcards covering cellular structures, organelles, cell types, imaging, and junctions from the lecture notes.

What are squamous cells and where are they especially useful?

Thin, flat, elongated cells; provide protection, especially in the integumentary (skin) system.

What are cuboidal cells and what is their primary function?

Cube-like cells involved in secretion and absorption; common in secretory tissues; notably in urinary system (tubular cells).

What are columnar cells and what feature enhances their absorptive capacity?

Tall, column-like cells with apical cilia or microvilli to increase surface area for absorption (e.g., digestive tract).

What is the difference between cytoplasm and cytosol?

Cytoplasm includes cytosol plus organelles; cytosol is the fluid portion inside the cell, excluding organelles.

What are intracellular and extracellular fluids, and how is body water distributed?

Intracellular fluid is inside cells; extracellular fluid is outside; about two-thirds of body water is intracellular, one-third extracellular.

What are ribosomes, and what are the two locations in which they can be found?

Ribosomes synthesize proteins; free ribosomes operate in the cytosol; bound ribosomes attach to rough endoplasmic reticulum.

What is the function of the rough endoplasmic reticulum (RER)?

RER has ribosomes and synthesizes proteins destined for secretion or for packaging in the Golgi; proteins enter the ER lumen.

What is the function of the smooth endoplasmic reticulum (SER)?

SER lacks ribosomes; synthesizes lipids, stores/releases calcium; important for muscle contraction coupling via calcium.

What does the Golgi apparatus do with proteins?

Modifies, sorts, and packages proteins into transport vesicles for delivery inside or outside the cell; in neurons, to axons and synapses.

What are lysosomes and peroxisomes and how do their contents differ?

Lysosomes contain digestive enzymes for intracellular digestion; peroxisomes contain enzymes for fatty acid breakdown; membranes and contents differ in density.

What are proteasomes and their role?

Protein-degrading complexes that digest damaged or unnecessary proteins into peptides or amino acids.

What is mitochondria and what is notable about its DNA?

The cell's energy powerhouse; contains its own DNA separate from nuclear DNA; numbers vary by tissue and energy demand.

What is enucleation in erythrocytes?

Red blood cells (erythrocytes) lose their nucleus during maturation, becoming enucleated.

What is the cytoskeleton and what is a key component mentioned?

Support network inside the cell; microtubules are a key component.

What are the three main types of membrane junctions and their general roles?

Tight junctions seal membranes; desmosomes anchor cells like a zipper; gap junctions enable fast electrical/ionic communication between adjacent cells.

What is immunofluorescence imaging?

A technique using fluorescent antibodies to label specific proteins for visualization under fluorescence microscopes.

What is Foldscope?

A small, inexpensive microscope suitable for education, enabling viewing of slides and illustrating 3D cell structure beyond 2D images.

Why is 3D consideration important when studying cells?

Cells are three-dimensional; growth changes volume more than surface area; intracellular vs extracellular volumes influence diffusion and ion movement.

What is contraction coupling and which organelle provides calcium for it?

The process that enables muscle contraction; the smooth endoplasmic reticulum (sarcoplasmic reticulum) provides and releases calcium.

What is the role of transport/secretory vesicles in neurons?

Proteins produced in the soma are packaged into transport vesicles and moved to axons and synaptic terminals for use or release.