Nervous and Muscle Tissue
Nerve Tissue
Nervous tissue is divided into two types:
• Neurons
• Supporting cells
Neurons
• These generate and conduct the nerve
impulses
Neurons
• These generate and conduct the nerve
impulses
• The dendrites respond to stimuli
Neurons
• These generate and conduct the nerve
impulses
• The dendrites respond to stimuli
• The nerve impulses are transmitted overlong
distances by the axons.
Support Cells
These are a mixed group of cells which support
and insulate the neurons
Support Cells
These are a mixed group of cells which support
and insulate the neurons Collectively they are
called neuralgia (glial cells).
Support Cells
There are four types:
• Astrocytes
• Microglia
• Ependymal cells
• Oligodendrocytes
Muscle Tissue
• These cells are responsible for movement
Muscle Tissue
• These cells are responsible for movement
• They are highly vascularized and cellular.
Muscle Tissue
• These cells are responsible for movement
• They are highly vascularized and cellular
• Muscle cells are filled with myofilaments
Muscle Tissue
Muscle tissue is divided into three types:
• Skeletal
• Cardiac
• Smooth
Skeletal Muscle
This attaches to bone and is responsible for
voluntary motion.
Skeletal Muscle
This attaches to bone and is responsible for
voluntary motion.
The muscle cells (muscle fibers) are cylindrical
cells that contain many nuclei.
Skeletal Muscle
This attaches to bone and is responsible for
voluntary motion.
The muscle cells (muscle fibers) are cylindrical
cells that contain many nuclei. The skeletal
muscles are called striated because of the
arrangement of the myofibrils.
Meat
Skeletal Muscle
Cardiac Muscle
• This type is found only in the heart where its
contractions propel blood through the body
Cardiac Muscle
• This type is found only in the heart where its
contractions propel blood through the body
• It is striated but the cells are uninucleated
Cardiac Muscle
• This type is found only in the heart where its
contractions propel blood through the body
• It is striated but the cells are uninucleated
• This muscle in involuntary.
Cardiac Muscle
• The cells are branched and connect to each
other with unique junctions called
intercalated disks.
Heart
Cardiac Muscle
Smooth Muscle Tissue
• These cells have no visible striations
Smooth Muscle Tissue
• These cells have no visible striations
• They are uninucleated and spindle shaped.
Smooth Muscle Tissue
• These cells have no visible striations
• They are uninucleated and spindle shaped.
• They are found lining the hollow organs such
as the intestines, respiratory and urinary tracts
and blood vessels.
Smooth Muscle Tissue
• These cells have no visible striations
• They are uninucleated and spindle shaped.
• They are found lining the hollow organs such
as the intestines, respiratory and urinary tracts
and blood vessels.
• They are involuntary
Smooth Muscle Tissue
Coverings and Membrane Linings
• The four tissues are incorporated into forming
membranes which cover the body and its
cavities.
Coverings and Membrane Linings
• The four tissues are incorporated into forming
membranes which cover the body and its
cavities.
There are three types:
• Cutaneous
• Mucous
• Serous
Cutaneous Membrane
• This covers the exterior of the body and is
commonly known as the skin.
Cutaneous Membrane
• This covers the exterior of the body and is
commonly known as the skin.
• It has a layer of keratinized stratified
squamous epithelium (epidermis) with a layer
of dense irregular connective tissue below it.
Cutaneous Membrane
• This covers the exterior of the body and is
commonly known as the skin.
• It has a layer of keratinized stratified
squamous epithelium (epidermis) with a layer
of dense irregular connective tissue below it.
• Because it is exposed to the air it is considered
a dry membrane.
Mucous Membrane
• These line the body cavities that are open to
the exterior; examples include the digestive,
respiratory and urinary tracts.
Mucous Membrane
• These line the body cavities that are open to
the exterior; examples include the digestive,
respiratory and urinary tracts.
• These are moist membranes
Mucous Membrane
• The epithelium can be stratified squamous,
pseudostratified columnar or simple columnar
epithelium.
Mucous Membrane
• The epithelium can be stratified squamous or
simple columnar epithelium.
• Underneath this is a layer of loose Areolar
connective tissue forming the lamina propria.
Mucous Membrane
• The epithelium can be stratified squamous or
simple columnar epithelium.
• Underneath this is a layer of loose Areolar
connective tissue forming the lamina propria.
• Below this can be a layer of smooth muscle.
Mucous Membrane
Serous Membranes
• These are the moist membranes that cover
the body’s cavities
Serous Membranes
• These are the moist membranes that cover
the body’s cavities
• The membrane consists of a simple squamous
epithelium (Mesothelium) resting on a layer of
Areolar tissue.
Serous Membranes
• These are the moist membranes that cover
the body’s cavities
• The membrane consists of a simple squamous
epithelium (Mesothelium) resting on a layer of
Areolar tissue.
• The Mesothelial cells secrete a fluid which
lubricates the surfaces.
Mesothelioma
Tissue Repair
• Tissue injury is followed by a predictable
series of steps which result in healing of the
wound.
Tissue Repair
• Tissue injury is followed by a predictable
series of steps which result in healing of the
wound.
• These steps involve a nonspecific
inflammatory response followed by repair
which can result in either replacement of the
tissue or fibrosis (scarring).
1. Inflammation
This occurs right after the injury and involves
cells such as the macrophages, mast cells and
lymphocytes (normal residents of the Areolar
tissue) releasing factors which lead to
increased vascular permeability and
stimulation of cell division.
2. Organization
• Once the blood clot is formed, it is replaced by
granulation tissue. This is a collection of
capillaries and fibroblasts which lay down a
new matrix.
3. Regeneration or
Fibrosis
• Epithelial, bone, areolar, dense irregular and
blood tissues regenerate.
3. Regeneration or
Fibrosis
• Epithelial, bone, areolar, dense irregular and
blood tissues regenerate.
• Smooth muscle and dense regular connective
tissue have a moderate capacity to regenerate
while skeletal muscle and cartilage are weak.
3. Regeneration or
Fibrosis
• Epithelial, bone, areolar, dense irregular and
blood tissues regenerate.
• Smooth muscle and dense regular connective
tissue have a moderate capacity to regenerate
while skeletal muscle and cartilage are weak.
• Cardiac and nervous tissues have none.