Figure 4-18 Muscle Tissue Skeletal Muscle Tissue Cardiac Muscle
Tissue Smooth Muscle Tissue Smooth muscle Cardiac muscle Skeletal
muscle Cells are long, cylindrical, striated, and multinucleate.
LOCATIONS: Combined with connective tissues and neural tissue in
skeletal muscles FUNCTIONS: Moves or stabilizes the position of the
skeleton; guards entrances and exits to the digestive, respiratory,
and urinary tracts; generates heat; protects internal organs Cells
are short, branched, and striated, usually with a single nucleus;
cells are interconnected by intercalated discs. FUNCTIONS:
Circulates blood; maintains blood (hydrostatic) pressure LOCATION:
Heart Cells are short, spindle-shaped, and nonstriated, with a
single, central nucleus. LOCATIONS: Found in the walls of blood
vessels and in digestive, respiratory, urinary, and reproductive
organs FUNCTIONS: Moves food, urine, and reproductive tract
secretions; controls diameter of respiratory passageways; regulates
diameter of blood vessels Nuclei Muscle fiber Striations LM 180 LM
450 LM 235 Nucleus Cardiac muscle cells Intercalated discs
Striations Nucleus Smooth muscle cell
Slide 3
Three types of muscle Skeletal, smooth and cardiac muscle
Epithelia lined outside and inside of body and cavities Connective
supported and connected parts Major function of many organs and
organ systems involves MOVEMENT; either of a substance (digestive
system and circulatory system) or of the body (skelato-muscular)
Muscle cells distinct organelles and properties Muscle cells and
muscle tissue are specialized to CONTRACT
Slide 4
Skeletal Muscle Very long, very slender muscle cells called
muscle fibers Multinucleate Can divide Muscle usually grows because
satellite stem cells called myosatellite cells divide Can repair
after injury Fibers made of proteins called actin and myosin
Contractile Appear banded or striated Voluntary Most predominant
form of tissue in human body Held together by elastin and collagen
and blended with tendons Which are attached to bones, contraction
moves bone at joint ( think hinge)
Slide 5
Figure 4-18a Muscle Tissue Skeletal Muscle Tissue Skeletal
muscle Cells are long, cylindrical, striated, and multinucleate.
LOCATIONS: Combined with connective tissues and neural tissue in
skeletal muscles FUNCTIONS: Moves or stabilizes the position of the
skeleton; guards entrances and exits to the digestive, respiratory,
and urinary tracts; generates heat; protects internal organs Nuclei
Muscle fiber Striations LM 180
Slide 6
Cardiac Muscle Located only in the heart Cardiocytes Most with
one nucleus Prominent striations Branching highly interconnected;
fan out of message to contract = heart beat Connections are called
intercalated discs and contain desmosomes, proteoglycans and gap
junctions = cells are locked tight together and ions responsible
for beat can flow through Limited ability to repair damaged/dead
cells pace maker cells vs nerve cells Striated INVOLUNTARY
Slide 7
Figure 4-18b Muscle Tissue Cardiac Muscle Tissue Cardiac muscle
Cells are short, branched, and striated, usually with a single
nucleus; cells are interconnected by intercalated discs. FUNCTIONS:
Circulates blood; maintains blood (hydrostatic) pressure LOCATION:
Heart LM 450 Nucleus Cardiac muscle cells Intercalated discs
Striations
Slide 8
Smooth Muscle Located in walls of blood vessels and hollow
organs like intestine and bladder Often in layers Smaller cells;
tapered at each end with oval nucleus Because of nuclei, they can
regenerate after injury Actin and myosin arranged differently no
striations Under nervous control, but not conscious control = 8 m
of intestine and miles of blood vessels would be a lot to think
about! Non-striated, involuntary
Slide 9
Figure 4-18c Muscle Tissue Smooth muscle Cells are short,
spindle-shaped, and nonstriated, with a single, central nucleus.
LOCATIONS: Found in the walls of blood vessels and in digestive,
respiratory, urinary, and reproductive organs FUNCTIONS: Moves
food, urine, and reproductive tract secretions; controls diameter
of respiratory passageways; regulates diameter of blood vessels LM
235 Nucleus Smooth muscle cell Smooth Muscle Tissue
Slide 10
Nervous Tissue
Slide 11
Neural or Nervous Tissue Conducting electrical impulses 98%
within brain and spinal cord (CNS) Neurons = nerve cells Many
without nuclei Very limited ability to repair Neuroglia =
supporting cells; connective tissue; glue Support Supply nutrients
Some repair Electrical impulses are transmembrane potentials
Slide 12
Figure 4-19 Neural Tissue NEURONS NEUROGLIA (supporting cells)
Maintain physical structure Repair tissue framework Perform
phagocytosis Regulate the composition of the interstitial fluid
surrounding neurons of tissues after injury Provide nutrients to
neurons Axon Nucleolus Nucleus of neuron Dendrites (contacted by
other neurons) Axon (conducts information to other cells) Cell body
Dendrites Mitochondrion Nucleus Microfibrils and microtubules
Nucleolus Cell body (contains nucleus and major organelles) A
representative neuron (sizes and shapes vary widely) Contact with
other cells Nuclei of neuroglia LM 600
Slide 13
Transmembrane Potential Cell membranes have an associated
electrical potential This means that the ion concentrations of the
cytoplasm and the extracellular fluid are slightly different and
there is a charge difference from one side of the CM to the other
side Long, thin wires = rapid conduction Measured in millivolts mV
/ microsecond Nerve impulses temporarily reverse this charge or
polarity Na, K, Ca, Cl Must be restored before it can refire