Normal Cells and Matrix Flashcards
(46 cards)
Cells
Cell are the organizational unit of an animal
Building blocks of tissues and organs
Provide a focal point for learning pathology
All cells originate form a singel primordial cells
This single cell differentiates into a diverse population of different cells
Cell functions are highly interrelated
Cell components:
Plasma Membrane
- Lipid bilayer interspersed with membrane proteins
- Membrane proteins are critical for cell function and communication
- The membrane is fliud and constantly changing
Cell Component:
Cytosol
Cytosol is fluid that bathes all intracytoplasmic organelles
site of most intermediary metabolism
Accounts for 50-60% of the total cell volume

Cell Component:
Mitochondria
Responsible for energy production
Oxidative phosphorylation - 18x more effectient than anaerobic glycolysis
Energy is released as electrons move down the electron transport chain - ATP
May have originated as an intracellular prokaryote
Down side - reactive oxygen molecules, oxudative damage to the cells
Cell Component:
Endoplasmic Reticulum
Membrane-bound spave where proteins, lipids, and carbohydrates are produced.
These can be incorporated into organelles or are secreted
Rough ER produces proteins - contains ribosomes
Smooth ER produces lipids - detoxification reactions also occur here
Cell Component:
Golgi Apparatus
Membrane-bound sacs that are closely associated with the ER
Modifies, sorts and exports products of the ER
Cell Component:
Lysosomes
- Membrane-Bound sace of enzymes
- Primary lysosomes bud from the golgi apparatus
- Secondary lysosmes are primary lysosomes that fuse with other organelles or cytoplasmic vacuoles
- They degrade macromolecules and extracellular material taken up by the cell
- Contents are predominately hydrolases
Cell Component:
Peroxisomes
Small enzyme-containing vesicles
Mainly a site of oxidative reactions
Catalase accounts for 40% of protein content
Catalase converts H2O2 to H2O
Detoxification and fatty acid breakdown also occur here
Cell Component:
Cytoskeleton
The cytoskeleton provides properties of shape, organization, and movement to a cell
Consists of a variety of proteins
Microfilaments - actin / myosin
Microtubules
Intermediate filaments
Regulatory proteins
Cytoskeleton assebly and disassembly is regulated by calcium
Cell Component:
Nucleus
The nucleus is the location of chromatin
Chromatin consists of cellular DNA and associated proteins
Chromatin is organized into chromosomes
Separated from the cytoplasm by a two-layered membrane - Nuclear Envelope
Life History of a cell:
Origins
All cells are derived from a single primordial cell; the zygote
There are 3 main embryogenic cell types:
Ectoderm
Mesoderm
Endoderm
Ectoderm
Forms a cephalic disc and the neural tube
Cells and tissues derived from ectoderm include:
Central and peripheral nervous systems
Sensory epithelium
Epidermis
Mesoderm
Somites located adjacent to the neural tube
Cells and tissues derived form mesoderm include:
Connective tissues (mesenchyme)
Fibroblasts, osteoblasts, chondroblasts
Muscle
Kidney
Heart and Blood vessels

Endoderm
Originates as a flat disc by the ectoderm
Cells and tissues derived from endoderm include:
Gastrointestinal Epithelium
Respiratory Epithelium
Parenchymal Organs:
Liver
Pancreas
Endocrine Glands
Life History of a cell:
Replication
The Cell Cycle
The cell cycle is complex adn critical to normal cell development and homeostasis

Cell Differentiation
Most cells are adapted to perform a specific Function
Neurons
Osteoblasts
Hepatocytes
Functions of cells are highly interrelated.
Developmental Anomalies
Growth and differentiation of each cell line needs to occur in a well orchestrated and corrdinatied manner of sad things can happen
How cells talk to eachother
A cell must be able to interact with it’s environment as well as other cells
Exchange nutrients and wastes, secretions of products, responding to stimuli, communication
Homeostasis
Coordination of activity
Cell Interactions
- Mechanisms of interaction
- Membrane pumps and enzyme systems
- Receptors
- hormones and cytokines
- Cell-to-cell connections
- Membrane interactions
- Channels between adjacent cells
- Exocytosis
- Endocytosis
- Pinocytosis
- Phagocytosis
Cell Function
Of critical importance is the interaction of a cell with other cells
This is essential for homeostasis
Mechanisms:
- Autocrine
- Self stimulation of a cell
- Paracrine:
- Stimulation of local cells only
- Endocrine:
- Stimulation of cells throughout the body
Extracellular Matrix
This is the structural framework in which cells organize, move and interact
It provides sites for cell adhesion and a conduit for exchange of cell nutrients, and waste
It has structural, adhesive and absorptive components
Properties of the ECM
Dictates tissue architecture and organizations
It has specific features for each tissue/organ
It regulates or modifies many cell activities
Serves as a reservoir of growth factors and bioactive molecules
It is constantly remodeling and changing
Components of the ECM
the “Matrisome” consists of over 300 different protiens
These components fall into 3 categories:
- Structural
- Absorptive
- Adhesive
Extracellular Matrix:
Structural
Structural components of the ECM build the framework for cells to exist upon and within
Structural Components Include:
- Collagen
- Many different types exist for different situations
- Elastin
- most prominent where elasticity is needed


