Download Chapter 7 Body Systems

Cells
Chapter 3
B. Souto
Elsevier items and derived items © 2007, 2003, 2000 by Saunders, an imprint of Elsevier Inc.
Slide 1
A Typical Cell

The cell is the structural and functional unit of
all living matter.
Elsevier items and derived items © 2007, 2003, 2000 by Saunders, an imprint of Elsevier Inc.
Slide 2
A Typical Cell - cont’d

Cell Membrane (Plasma Membrane)

The cell membrane is composed of a two-layer
phospholipid and protein.

The cell membrane is selectively permeable.
Elsevier items and derived items © 2007, 2003, 2000 by Saunders, an imprint of Elsevier Inc.
Slide 3
A Typical Cell - cont’d

Structures Inside the Cell

The nucleus is the control center of the cell; it
stores the genetic information.

The cytoplasm is a gel-like substance inside the
cell membrane but outside of the nucleus.

Many different organelles are in the cytoplasm.

The mitochondria are the power plants of the cell.

Ribosomes are concerned with protein synthesis.
Elsevier items and derived items © 2007, 2003, 2000 by Saunders, an imprint of Elsevier Inc.
Slide 4
A Typical Cell - cont’d

Structures Inside the Cell—cont’d

The Golgi apparatus packages and puts the
finishing touches on the newly synthesized
protein.

Lysosomes act as intracellular housekeepers.

The cytoskeleton provides shape and support to
the cell.

Centrioles play a role in cell reproduction.
Elsevier items and derived items © 2007, 2003, 2000 by Saunders, an imprint of Elsevier Inc.
Slide 5
A Typical Cell - cont’d

Structures on the Cell Membrane

Cilia are short, hair like projections.

Flagella are long, hairline projections; the sperm
has a flagellum that allows it to swim.
Elsevier items and derived items © 2007, 2003, 2000 by Saunders, an imprint of Elsevier Inc.
Slide 6
Cell Membrane- Just Passing Thru
Elsevier items and derived items © 2007, 2003, 2000 by Saunders, an imprint of Elsevier Inc.
Slide 7
Movement Across the Cell Membrane

Passive Transport Mechanisms

Passive transport mechanisms require no input of
energy (ATP).

Diffusion is the movement of a substance from an
area of greater concentration to an area of lesser
concentration. It is the most common form of
transport ( see pg. 40).

Facilitated diffusion is the same as diffusion but
uses a helper molecule in the membrane to
increase the rate of diffusion ( see pg. 41).
Although there’s a helper cell it’s still considered
__________ transport?
Elsevier items and derived items © 2007, 2003, 2000 by Saunders, an imprint of Elsevier Inc.
Slide 8
Movement Across
the Cell Membrane - cont’d

Passive Transport Mechanisms—cont’d

Osmosis is a special case of diffusion using a
semipermeable membrane. Osmosis involves the
diffusion of water from an area with more water to
an area of less water. The trapped solute is said
to “pull water” because of osmosis ( see fig 3-9).
Let’s look at the information in your textbook.

So what is osmotic pressure?

Define edema.

So why may a blood clot continue to grow even
when the bleeding stops?
Elsevier items and derived items © 2007, 2003, 2000 by Saunders, an imprint of Elsevier Inc.
Slide 9
Movement Across
the Cell Membrane - cont’d

When two compartments containing different concentrations of
solute ( dissolved substances) interact, the term used to describe
the water concentration is tonicity. The concentrations of a
solution are expressed as tonicity. Solutions are isotonic,
hypotonic, or hypertonic

Isotonic solutions are commonly administered IV. Identify the
solution commonly selected and explain why this solution is
selected (see fig 3-10).

Filtration is the movement of water and dissolved substances from
an area of high pressure to an area of low pressure in responses
a pressure, or force.
• Identify places in the body where filtration occurs
• What instrument was used in the book to illustrate filtration?
Elsevier items and derived items © 2007, 2003, 2000 by Saunders, an imprint of Elsevier Inc.
Movement Across
the Cell Membrane - cont’d

Active Transport Mechanisms include active
transport pumps, endocytosis and exocytosis

Active transport requires an input of energy (ATP).

Active transport pumps move substances from an
area of low concentration to an area of high
concentration ( see fig3-12A).

Endocytosis moves substances into a cell;
pinocytosis is cellular “drinking,” and phagocytosis
is cellular “eating.”

Exocytosis moves substances out of a cell ( see
Fig 3-12C).
Elsevier items and derived items © 2007, 2003, 2000 by Saunders, an imprint of Elsevier Inc.
Slide 11
Cell Division

Mitosis: produces two identical cells ( see Fig 313)


Splits a cell into two identical cells

Necessary for growth and repair throughout life
Meiosis: occurs only in sex cells ( reduces
chromosome number by half & see Reproductive chapter)
Elsevier items and derived items © 2007, 2003, 2000 by Saunders, an imprint of Elsevier Inc.
Slide 12
Cell Cycle

Interphase (G1, S, and G2 phases)

Mitosis (M phase)


The splitting of one mother cell into
two identical daughter cells.

Four phases of mitosis: prophase,
metaphase, anaphase, and
telophase.
Clinical Correlation

Constant proliferation of CA cells

Cell Cycle–Phase Specific Drugs
• Some drugs are aimed at a specific
phase of the cell cycle.
• Some are cell cycle–phase
nonspecific.
Elsevier items and derived items © 2007, 2003, 2000 by Saunders, an imprint of Elsevier Inc.
Slide 13
Cell Differentiation


What does cell
differentiation mean?

Specialization

Example: RBCs, nerve
cells, muscle cells all look
& function differently
Stem Cells


Undifferentiated of
Specialized
What’s the significance of stem
cells?
Elsevier items and derived items © 2007, 2003, 2000 by Saunders, an imprint of Elsevier Inc.
Slide 14
Order, Disorder, and Death



Cell growth is normally orderly
Neoplastic cell growth, especially CA
cell growth, is disorderly and
disorganized with constant proliferation
Classification of neoplasms

Benign
 Cancerous ( metastasis)
• Consequences of metastasis?
 CA acronym= CAUTION

Disorders of Cellular growth:



Atrophy, dysplasia, hyperplasia,
metaplasia, necrosis, neoplasm
Necrosis: cell death ( lack of O2,
poisoned, damaged by bacterial toxins
or damaging effects of radiation)
Dx aids...Pap smear and Bx
Elsevier items and derived items © 2007, 2003, 2000 by Saunders, an imprint of Elsevier Inc.
Slide 15