Transcript Nerve activates contraction

PowerPoint® Lecture Slide Presentation
by Patty Bostwick-Taylor,
Florence-Darlington Technical College
Cells and
Tissues
3
PART A
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Cells and Tissues
 Carry out all chemical activities needed to sustain
life
 Cells are the building blocks of all living things
 Tissues are groups of cells that are similar in
structure and function
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Overview
 Made of 5 Main Elements
 Carbon
 Hydrogen
 Oxygen
 Nitrogen
 And Phosphorus
 Living cells are about 60% Water
 Cells are constantly bathed in a saltwater-like
solution called INTERSTITIAL FLUID.
 All exchanges between CELLS and BLOOD are
made through this fluid
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Cells Vary in Anatomy
 STRUCTURE defines FUNCTION
 What organelles are present?
 How big/small is the cell?
 What is the SHAPE of the cell?
 Where in the body is the cell located?
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Cells Vary in Physiology
 Ability to move throughout the blood/body?
 What products are made by the cell?
 Do these products impact other cells?
 Is it able to communicate with other cells?
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Anatomy of the Cell
 Cells are not all the same
 All cells share general structures
 All cells have three main regions
 Nucleus
 Cytoplasm
 Plasma membrane
Figure 3.1a
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
The Nucleus
 Control center of the cell
 Contains genetic material (DNA)
 Three regions
 Nuclear envelope (membrane)
 Nucleolus
 Chromatin
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
The Nucleus
Figure 3.1b
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
The Nucleus
 Nuclear envelope (membrane)
 FUNCTION: Control what enters/exits the
nucleus.
 CHARACTERISTICS:
 Consists of a double phospholipid
membrane
 Contains nuclear pores that allow for
exchange of material with the rest of the
cell
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
The Nucleus
 Nucleoli
 FUNCTION: Sites of ribosome assembly
 CHARACTERISTICS: Nucleus contains one or
more nucleoli
 Dark-staining round body(s)
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
The Nucleus
 Chromatin
 FUNCTION: DNA carries instructions for cell
structure and function through the production
of proteins.
 CHARACTERISTICS:
 When cell is not dividing DNA is present
as chromatin (spaghetti on a plate)
 When the cell is dividing (mitosis) DNA
condenses to form chromosomes (“X”)
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Plasma Membrane
 Barrier for cell contents
 Double phospholipid layer
 Contains
 Hydrophilic heads
 Hydrophobic tails
 Also contains
 Proteins that act as channels
 Cholesterol that makes cell membrane more rigid
 Glycoproteins provides cell surface identity
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Plasma Membrane
PLAY Membrane Structure
Figure 3.2
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Plasma Membrane Specializations
 Microvilli
 Finger-like projections that increase surface area for
absorption
 Membrane junctions
 Tight junctions
 Impermeable junctions
 Bind cells together into leak-proof sheets
 Desmosomes
 Anchoring junctions that prevent cells from being
pulled apart
 Gap junctions
 Allow communication between cells
Plasma Membrane
Specializations
PLAY Tight Junctions
PLAY Desmosomes (Anchoring Junctions)
Cytoplasm
 Cytoplasm is the material outside the nucleus and inside
the plasma membrane
 Contains three major elements
 Cytosol
 Jelly-like fluid that suspends other elements
 Organelles
 Metabolic machinery of the cell
 “Little organs” that perform functions for the cell
 Inclusions
 Chemical substances such as stored nutrients or
cell products
Cytoplasmic Organelles
Figure 3.4
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ORGANELLE
Mitochondria
Contains own circular piece of DNA
GENERAL FUNCTION
Produce ATP (energy) from glucose
Ribosomes
Free in cytoplasm and attached on ER
Assemble proteins
Endoplasmic reticulum
2 forms, smooth and rough
Smooth - transport
Rough – transports proteins
Golgi Apparatus
Packages mainly lipids for transport
Lysosomes
Double membrane structure for protection
Contains digestive enzymes
Peroxisomes
Specialized lysosomes
Contains catalase to breakdown hydrogen
peroxide
Cytoskeleton
Cell support, structure, and framework
Centrioles
Creates spindle fibers during mitosis for
separation of chromosomes.
Specialized Structures
Cilia – moves substances over surface of
cell (respiratory cells)
Flagella – moves the cell itself (sperm)
Cell Diversity
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings
Cell Diversity
PLAY Tour of the Cell
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings