Muscular System
The muscular system is Muscle tissue is also also found
Each of this muscle is a discrete
responsonsible for the movement inside of heart, digestive organs
organ constructed of skeleton
of human body. It is attached to % → they serve to move
Bg muscle tissue, blood vessels,
the bones and has about 700 substances throughout the body,
tendons and nerves
named muscles that make up 3 types of muscles: visceral,
roughly half of a person's body cardiac and skeletal
weight.
Visceral Muscle
%
.
Visceral muscle (smooth muscle) is found inside of organs like stomach, intestine, and blood vessels. It the weakest of all muscles
but makes organs contract to move substances through the organ
Visceral is controlled by the unconscious part of brain called involuntary muscle
It is called smooth muscle because it has very smooth, uniform appearance when
viewed under microscope. This smooth appearance starkly contrasts with the
banded appearance of cardiac and skeletal muscle.
Smooth muscle
Cardiac muscle
§ Found only in heart, cardiac muscle help pump blood throughout the body. It cannot be controlled consciously so it is an involuntary
muscle
While hormones send signals from the brain adjust the rate of contraction, cardiac Cardiac muscle
Striations
muscles stimulates itself to contract. The natural pacemaker of heart is made of
cardiac muscle tissue that stimulates other cardiac muscles to contract. Its called
autorhythmic or intrinsically controlled.
The cells are striated, they appear to have light eand dark stripes when viewed
under a light microscope (protein fibres cause these) they indicate that the muscle
is very strong unlike visceral muscles Nucleus
Intercalations
The cells of cardiac muscle are branched x and y shaped cells tightly connected together by special junction called
intercalated disks. They are made up of fingerlike projections from 2 neighbouring cells that interlock and provide strong
bonds between cells
The branded structure and intercalated disks allow the muscle cells to resist high bp and strain of pumping
blood throughout lifetime > they also also spread electrochemical signals quickly from cell to cell so that
heart can beat as a Unit
, Skeleton Muscle
BB Skeleton muscle is the only voluntary muscle tissue → controlled consciously. The function of skeleton
system is to contract to move parts of the body closer to bone that it is attached to.
Most of these are attached to muscles serve to more parts of those bones closer to each other
These form when many smaller progenitor cells lump together to form long, straight multinucleated
fibres → very strong
The name comes from the tact that skeleton muscles always connect to the skeleton system
Gross anatomy of skeleton muscle
a- Most skeleton muscles are attained to 2 bones through tendons. Tendons are tough bands of dense regular connective teasel
whose strong collagen fibre firmly attach muscles to bones
Muscles move by shortening their length, pulling on tendons, and moving bones closer Tendon Muscle
to each other. One bone is pulled toward the other bone, which remains stationary.
The place on stationary bone that is connected via tendons to muscle is called origin. The Bony attachment
place on the moving bone that is connected to muscle via tendons is called insertion. The
belly of the muscle is the fleshy part of the muscle in between tendons that does the
Origin
actual contraction.
Name of skeleton muscle Insertion
•
go These are named based on many factors: location, origin and insertion, number of origins, shape, size, direction and function
Location Origin and insertion
• Many of these muscles derive their names from their anatomical sq Some are name based on their stationary and
region moving bone
Examples include: rectus abdominis and transfers abdominis Examples include: sternocleidomastoid →
are found in abdominal region. which connects sternum and clavicle to
• Other muscles use a hybrid of these 2 the mastoid process of skull
Examples include: branchioradialis which is named other a Another example includes:
region: bronchial and a bone: radius occipitofrontalis that connects occipital
bone and the frontal bone
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