Neural Tissue Flashcards
Also called nervous or nerve tissue
• Neural Tissue
- Specialized for conducting electrical impulses
- Rapidly senses internal or external environment
- Processes information and controls responses
• Neural Tissue or nervous or nerve tissue
is concentrated in the central nervous
system
• Neural Tissue or nervous or nerve tissue
central nervous
system includes
brain and spinal cord
Two Types of Neural Cells
- Neurons: Nerve cells, perform electrical
communication - Neuroglia: Supporting cells, repair and supply
nutrients to neurons
perform electrical
communication
Neurons or nerve cells
repair and supply
nutrients to neurons
Neuroglia or supporting cells
Cell Parts of a Neuron
• Cell body
• —–Contains the nucleus and nucleolus
• Dendrites
• —–Short branches extending from the cell body
• —–Receive incoming signals
• Axon (nerve fiber)
• —–Long, thin extension of the cell body
• —–Carries outgoing electrical signals to their
destination
Contains the nucleus and nucleolus
Cell body
- —–Short branches extending from the cell body
* —–Receive incoming signals
Dendrites
• —–Long, thin extension of the cell body
• —–Carries outgoing electrical signals to their
destination
Axon
Functions of neuroglia (supporting cells)
• Maintain physical structure of tissues • Repair tissue framework after injury • Perform phagocytosis • Provide nutrients to neurons • Regulate the composition of the interstitial fluid surrounding neurons
Why do Tissues Respond to Injuries ?
• To maintain homeostasis
• Cells restore homeostasis with two processes which are
- Inflammation
2. Regeneration
The tissue’s first response to injury
• Inflammation = Inflammatory Response
Signs and symptoms of the inflammatory response
include:
- Swelling
- Redness
- Heat
- Pain
• Inflammatory Response Can be triggered by:
- Trauma (physical injury)
* Infection (the presence of harmful pathogens)
physical injury is aka
trauma
the presence of harmful pathogens is aka
infection
• The Process of Inflammation: Damaged cells release chemical signals into the surrounding interstitial fluid . This affects:
- Prostaglandins
- Proteins
- Potassium ions
As cells break down, what two things happen?
• Lysosomes release enzymes that destroy the
injured cell and attack surrounding tissues
• Tissue destruction is called necrosis
What is Tissue destruction called?
necrosis
The Process of Inflammation is:
- Necrotic tissues and cellular debris (pus)
accumulate in the wound
• Abscess — pus trapped in an enclosed area - Injury stimulates mast cells to release:
• Histamine
• Heparin
• Prostaglandins
Injury stimulates mast cells to release:
- Histamine
- Heparin
- Prostaglandins
pus trapped in an enclosed area
• Abscess
• Dilation of blood vessels
- Increases blood circulation in the area
- Causes warmth and redness
- Brings more nutrients and oxygen to the area
- Removes wastes
• Plasma diffuses into the area
• Causes swelling and pain
• Phagocytic white blood cells
Clean up the area
• When the injury or infection is cleaned up, what happens?
Healing (regeneration) begins
• Describe The Process of Regeneration
• Fibrocytes move into necrotic area
• —Lay down collagen fibers
• —To bind the area together (scar tissue)
• New cells migrate into area
• —Or are produced by mesenchymal stem cells
• Not all tissues can regenerate
• —Epithelia and connective tissues regenerate well
• —Cardiac cells and neurons do not regenerate (or
regenerate poorly)
do not regenerate (or
regenerate poorly)
Cardiac cells and neurons
regenerate well
Epithelia and connective tissues
move into necrotic area
Fibrocytes
When an injury damages connective
tissue, mast cells release a variety of
chemicals. This process, called ____ _____ _______, stimulates inflammation.
mast cell activation
_________ produces several familiar indications of injury, including swelling, redness, heat (warmth), pain, and sometimes loss of function.
_________ may also result from the presence of pathogens, such as harmful bacteria, within the tissues. The presence of these pathogens constitutes an _______
Inflammation
Inflammation
Infection
The presence of these pathogens constitutes an _______
infection
is the repair that
occurs after the damaged tissue has
been stabilized and the inflammation
has subsided.
Regeneration
move into
the area, laying down a collagenous
framework
fibroblasts
a collagenous framework laid down by fibroblasts
scar tissue.
True or false: Over time, scar tissue is usually
“remodeled” and gradually assumes
a more normal appearance.
True
• Speed and efficiency of tissue repair decrease
with age, due to:
- Slower rate of energy consumption (metabolism)
- Hormonal alterations
- Reduced physical activity
• Effects of Aging
Chemical and structural tissue changes
• Thinning epithelia and connective tissues
• Increased bruising and bone brittleness
• Joint pain and broken bones
• Cardiovascular disease
• Mental deterioration
• Cancer rates ______ with age
increase
• __ percent of all people in the United
States develop cancer
25%
_____ is the #2 cause of death in the United
States
Cancer
_________ _______ and ______ _____
cause cancer
Environmental chemicals and cigarette smoke
