Histology Questions and Answers

Cell Structure and Function

Question	Answer
What are cells?	The fundamental units of life. Also recognized as teh basic building block and smallest living cimponent of an organism.
What does the body consist of?	Millions of cells grouped into highly specialized units that functions together.
What do cells form?	Tissues, such as muscle, blood, and bone.
What do tissues form?	Organs, such as the brain, heart, liver, and kidney. They are integrated into systems such as CNS, cardiovascular system, digestive system, and renal system.
Also known as the plasma membrane	Cell Membrane
Composed of lipids and a protein bilayer with highly selective filter that shields cell contents from the outside environment.	Cell Membrane
Cell Membrane	Impermeable to most water-soluble substances including ions, glucose, and amino acids. Permeable to lipid soluble substances, such as oxygen and steroid hormones.
What is the lipid bilayer composed of?	Cholesterol, phospholipids, and glycolipids.
What are the functions of the Cell Membrane?	-Transport nutrients and waste products-Cell recognition-Communication with other cells-Growth regulation-Respond and adapt to changes in the environment.
Fluid-like substance within the cell that is used as a cushion.	Cytoplasm
What is the function of Cytoplasm?	Surrounds and protects the nucleus and other organelles within the cell.
The "brain" or the control center of the cell that carries most of the genetic material in the form of DNA.	Nucleus
What is the function of the Nucleus?	Major function is to PROTECT and PRESERVE the genetic information so it can be replicated exactly and passed on during cell division.
A single continuous membrane component that extends throughout the cytoplasm.	Endoplasmic Reticulum (ER)
What are the functions of the ER?	Main function is the SYNTHESIS OF MEMBRANE COMPONENTS including lipids and proteins for the cell/plasma membrane and the other organelles. Synthesis of products to be secreted from the cell.
Complexes of protein and RNA which are formed in the nucleus and transported to the cytoplasm.	Ribosomes
What is the primary function of the Ribosomes?	The synthesis of protein. Ribosomes may bind to the ER or float free in the cytoplasm.
Rough ER	Has ribosomes attached (proteins).
Smooth	Has no ribosomes (lipids).
What are lipoproteins an example of?	Smooth ER.
Composed of a stack of smooth compartments resembling a stack of hollow plates.	Golgi Apparatus
What are the functions of the Golgi Apparatus?	-Receives newly synthesized proteins and lipids by way of transport vesicles.-Transport vesicles diffuse into the GA and become part of the GA.-Proteins move from the Cis Face (entry), Cisternae, to the Trans Face (exit).
Where does the Golgi Apparatus attach?	To the sugar molecules and then they package into the Golgi transport vesicles (secretory vesicles). *The way they are arranged with sugar determines their destination, whether to the PLASMA MEMBRANE or LYSOSOMES.
Bags of acidic digestive enzymes; "The cell's digestive system."	Lysosomes
What are the functions of the Lysosomes?	-Acidification (bags of acid)-Destruction of damaged and obsolete parts of the cell-Ingestion of cell particles
What are the final products of Lysosome digestion?	-Amino acids and fatty acids which are used by the cells OR-Cellular wastethat is secreted at the cell surface
Where are Lysosomes especially important?	In the liver, to detoxify alcohol, and in the kidney, to excrete waste.
Powerhouses of the cell.	Mitochondria
What are the functions of the Mitochondria?	-Convert energy to forms that can be used to drive cellular reactions.-Cells with high energy needs such as cardiac (brain) and skeletal muscle, have a high number of mitochondria.- ^energy, ^mitochondria
What are the simple molecules known as?	Amino acids, fatty acids, and cellular waste.