the MUSCULar SYSteM 117muscle tissue and
the muscular system
The muscular system works with
the skeleton to bring about body
movements. Contractions of skeletal
muscles also stabilize joints and body
positions. Muscle tissue produces
much of the body’s metabolic heat.
Smooth muscle forms the walls of
hollow organs, blood vessels, ducts,
and tubes. Its contractions move
substances including blood and
food that is being digested. Internal
sphincters that control the passage of
food, feces, and urine also consist of
smooth muscle.
Cardiac muscle forms the wall of
the heart. Its contractions move
blood throughout the body via the
cardiovascular system.muscles and the muscular system in homeostasis
Immunity and the lymphatic system
Smooth muscle forms the walls of lymphatic
system vessels. Skeletal muscle helps support
lymph nodes in various parts of the body.Respiratory system
The diaphragm and skeletal muscles attached
to the ribs function in breathing and help clear
airways by coughing. Smooth muscle in airways
allows changes in air flow to and from the lungs.Urinary system
Abdominal muscles help support the kidneys
and bladder. Smooth muscle in the bladder is
strong and stretchable enough to store urine; its
contractions move urine out of the body.
Nervous system
All types of muscle tissue respond to nerve
impulses to carry out a wide variety of body
functions. Skeletal muscles help support the
spine and head.
Sensory systems
Skeletal muscles move the eyes and contain
sensory receptors that provide information about
changes in body position.Endocrine system
Skeletal muscles help support endocrine organs
such as the pancreas and thyroid gland and
produce a hormone that indirectly influences the
metabolism of stored body fat.Cardiovascular system and blood
Contractions of cardiac (heart) muscle pump blood.
Smooth muscle in blood vessels allows adjustments
in blood flow in different body regions. Contraction
of leg muscles helps return blood to the heart.Reproductive system
Muscle contractions move eggs and sperm.
Contraction of smooth muscle in the uterus expels
a fetus during childbirth and assists with shedding
of the uterine lining (menstruation).Unless otherwise indicated, all art on this page is © Cengage Learning.Integumentary system
Skeletal muscle provides
support for skin. Many facial
muscles, especially those used
for making facial expressions
such as smiling, attach to skin
instead of to bones.Digestive system
Abdominal muscles support many digestive
organs. Other skeletal muscles operate in chewing
and swallowing. Contractions of smooth muscle
move material through the system.Skeletal system
Skeletal muscles attach to
bones, which serve as levers for
body movements. The muscles
also stabilize movable joints.6.9
ConnECtions
Copyright 2016 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s).