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Connective Tissue Subgroups
Dense Connective Tissue:
Tendons and Ligaments
 Marked by a regular arrangement of
tightly packed protein fibers,
ligaments (connecting bone to bone
in a joint) have tough collagen
combined with flexible elastin fibers.
 Tendons (connecting muscle to bone)
are bright white bands primarily
composed of collagen.
Connective Tissue Subgroups
Dense Connective Tissue: Cartilage
 Cartilage is composed of large round
cells with spherical nuclei called
chondrocytes, enclosed in tiny
cavities called lacunae.
 The 3 types of cartilage (elastic,
hyaline, and fibrocartilage) contain
differing amounts of collagen and
elastin within the matrix, resulting
in varying levels of flexibility and/or
strength.
muscular tissue
Characteristics


Highly cellular, wellvascularized tissues
Responsible for
movement of the body
Cell Types
Muscle cells are called
muscle fibers
 skeletal muscle
 Cardiac muscle
 Smooth muscle
Location
 In all muscles
 All organs
Primary Functions
 Bone movement
 Facial expressions
 Propel blood through the
heart and blood vessels
 Propel substances
through the digestive
system
Muscle Tissue: 3 Types
 Muscle Tissue enables the movement of body
structures. Smooth, Cardiac, Skeletal
Muscle Types: Smooth Muscle
 Smooth muscle is nonstriated, and acts in a
number of involuntary
processes in the body.
 elongated, tapering
and non-striated cells
Muscle Types: Smooth Muscle
 allows the expansion and contraction of arteries and
veins
 lines the bladder and reproductive tracts
 lines the entire gastrointestinal tract
Did you know?...
 Tiny smooth muscle fibers in the skin called
Arrector pili are responsible for “goose bumps.”
Muscle Types: Cardiac Muscle
 Cardiac muscle (heart
muscle) is striated but
functions involuntarily. It is
solely responsible for
propelling blood
throughout the body.
 Nucleus positioned in the
center of the cell.
Muscle Types: Skeletal Muscle
 Skeletal muscle is striated, and associated with
voluntary movement. It also provides structure
and support for organs and tissues.
 Nucleus is located in the periphery of the cell.
Anatomy of skeletal muscles
tendon
Muscle
Fascicle
Skeletal
muscle
Skeletal
muscle
fiber (cell)
How Do Muscles Work?
 Individual muscle fibers are
composed of small cylindrical
structures called myofibrils. The
functional component within the
myofibril is called the sarcomere.
 Within the sacromere, protein
filaments called actin and myosin
allow the cell to expand and
contract in a
3 step process:
3 Steps
1) Before the muscle is stimulated, actin and myosin
filaments partially overlap one another.
2) A nerve cell releases a signal which causes the actin and
myosin filaments to “slide” along one another and overlap
even more.
3) This contracts the myofibril and subsequently the entire
muscle cell. When the nervous signal changes, the
filaments relax and return to their original state.
Muscle fiber
sarcomere
Z-line
myofibril
Actin
myosin
Thin myofilament
Myosin molecule of
thick myofilament
Sarcomere