Download Muscular System

Animal, Plant & Soil
Science
Lesson C2-4
The Integumentary,
Muscular, and
Urinary Systems
Interest Approach

Begin by asking students if they have ever
eaten muscle tissue. Show students a
piece of raw meat, and ask them to
identify the type of muscle (or even the
animal the meat came from). Most
students eat meat, but the thought of raw
muscle tissue is not very appetizing. Lead
into a discussion of the skin, muscle, and
urinary systems of livestock animals.
Objectives

Explain the integumentary system,
and describe the two layers of skin.
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Examine the muscular system,
describe the three types of muscle
tissue, and explain how muscles
contract to create movement.
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Describe the creation and utilization
of energy for muscle contractions.
Objectives

Identify common muscles found in
livestock and companion animals.
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Identify components of the urinary
system, examine its role, and
describe the function of the kidneys,
ureters, urinary bladder, and urethra.
Terms
abdominal
obliques
 actin
 adenosine
 triphosphate
 aerobic
 anaerobic
 biceps brachii
 biceps femoris

bladder
 cardiac muscle
 dermis
 epidermis
 gluteals
 integumentary
system
 keratin
 kidney
 lattisimus dorsi
 masseter
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Terms
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myosin
pectorals
sebaceous glands
serratus ventralis
skeletal muscle
tendon
trapezius
triceps brachii
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urea
ureters
urethra
urine
What is the integumentary system,
and what are the two layers of skin?
The integumentary system (skin) is the
largest organ of the body.
 Its main function is to protect
the body from foreign
substances, such as bacteria,
but it also keeps fluids and
nutrients in the body.
 In addition, the integumentary system
helps regulate body temperature through
hair, fur, and/or sweat glands.
 Directing blood flow to and from skin can
also regulate body temperature.

What is the integumentary system,
and what are the two layers of skin?
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Skin consists of two layers: the epidermis
and the dermis.
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The epidermis is composed of hard, flattened
dead cells.
Beneath the epidermis are larger cells that are
living.
Larger and more round cells are found in the
deeper layers of skin.
At the bottom layer, new cells are growing and
pushing toward the surface.
As cells are pushed toward the surface, they
become flattened and lose most of their water
content.
What is the integumentary system,
and what are the two layers of skin?
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A. The epidermis is the outer layer of
epithelial cells.
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It is the protective layer of skin, but it is also
the thinnest skin layer.
The epidermis produces hair, nails, beaks, and
feathers.
The skin of all mammals is covered with hair.
Sweat glands are found in the epidermis of
many animals.
In addition, keratin is produced in the
epidermis.
Keratin is a fibrous protein used to produce
horns, hooves, nails, hair, feathers and the
outer sheath of beaks and claws.
What is the integumentary system,
and what are the two layers of skin?
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B. The dermis is the thick and sturdy
inner layer of skin that is composed of
dense connective tissue.
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The dermis contains lymph and blood vessels,
nerves, muscle cells, sweat and sebaceous
glands, and hair follicles.
The sebaceous glands secrete oily
substances that lubricate the hair and skin.
The dermis layer composes about 90 percent
of the skin’s thickness, which varies with
species, breed, sex, and body location.
For example, skin is thinnest in the eyelids and
thickest at the soles of the feet.
What is the integumentary system,
and what are the two layers of skin?
What is the muscular system, what are the
three types of muscle tissue, and how do
muscles contract to create movement?
The muscular system creates bodily
movement, maintains posture, and
produces heat.
 It consists of three types of
muscle tissue: skeletal,
smooth, and cardiac.
 In addition, muscles can be classified as
voluntary or involuntary.
 Voluntary muscles are under the control of
the animal; involuntary muscles are not.
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What is the muscular system, what are the
three types of muscle tissue, and how do
muscles contract to create movement?
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A. Skeletal muscle, or striated voluntary muscle,
contracts to produce bodily movement.
Skeletal muscles are the largest
component of red meat animal products
and are usually attached to bones by
tendons.
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A tendon is connective tissue that attaches
muscle to bone.
Movement is made possible when
muscles shorten.
A muscle shortens because its cells are shortening,
and a muscle cell shortens because basic units of
contraction within the cell (sarcomeres) are
shortening.
What is the muscular system, what are the
three types of muscle tissue, and how do
muscles contract to create movement?
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Sarcomeres contain two types of protein
filaments: myosin and actin.
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Myosin is a thick filament, and actin is a thin
filament.
During muscle contraction, the actin
filaments slide past the myosin filaments,
causing the sarcomere to shorten.
 A muscle consists of thousands of muscle
fibers, or muscle cells, in bundles.
 An entire muscle fiber is called a myofiber,
and the sarcomeres are found within the
myofibers.
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What is the muscular system, what are the
three types of muscle tissue, and how do
muscles contract to create movement?
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B. Smooth muscle, or unstriated
involuntary muscle, is located in
reproductive, digestive, and urinary
organs.
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The contraction of smooth muscle is
involuntary and is necessary for proper
functioning of internal organs.
For example, smooth muscle contractions in
the intestines permit the movement of food
products.
What is the muscular system, what are the
three types of muscle tissue, and how do
muscles contract to create movement?
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C. Cardiac muscle is striated muscle
found only in the heart.
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Contraction of the cardiac
muscle is involuntary and
is essential for proper
blood circulation.
What is the muscular system, what are the
three types of muscle tissue, and how do
muscles contract to create movement?
How is energy created and utilized
for muscle contractions?
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All cells require adenosine triphosphate
(ATP).
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ATP is an energy source for cells; ATP is broken
down into adenosine diphosphate (ADP) and a
phosphate radical, releasing energy.
In muscle cells, ATP provides the energy
for muscle contractions.
 At the beginning of muscle contractions,
the cells only have small amounts of ATP
and, therefore, must rely on aerobic (in
the presence of oxygen) and anaerobic (in
the absence of oxygen) reactions to supply
further ATP.
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How is energy created and utilized
for muscle contractions?
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A. A quick but short-term source of ATP is
available from creatine phosphate, which is a
storage form of high-energy phosphate.
An enzyme transfers phosphate from creatine
phosphate to ADP to create ATP in an anaerobic
reaction.
Once all of the creatine phosphate is depleted,
mitochondria should be producing enough ATP for
muscle contractions.
If that is not the case, a temporary anaerobic
source is made through a fermentation process
that breaks down muscle glycogen into lactic acid
and produces ATP.
How is energy created and utilized
for muscle contractions?
B. During moderate
exercise, aerobic
respiration can typically
provide the necessary
ATP for muscle
contractions.
 The muscle cell receives its energy from
glucose from the bloodstream and from
the breakdown of glycogen in cells.
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What are the common muscles
found in livestock and companion
animals?
Many muscles can be found that are
common to livestock and companion
animals.
 Knowledge of these muscles is important
to an effective health care and production
management plan.
 A. The masseter is the superficial muscle
of the cheek that aids in chewing and
biting movements.
 B. The trapezius is the superficial,
triangular muscle of the shoulder that
helps move front appendages.
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What are the common muscles
found in livestock and companion
animals?
C. The latissimus dorsi is a long muscle
that connects the humerus bone of the
forearm to the back of the animal.
 D. The abdominal obliques are large
muscles that run along the sides of the
animal and help support the internal
organs of digestion and reproduction.
 E. The gluteals are the large muscles in
the upper hind quarter region of the
animal that aid in rear leg movement.
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What are the common muscles
found in livestock and companion
animals?
F. The biceps femoris is a large muscle
found in the rear leg of an animal.
 G. The biceps brachii is the
muscle responsible for the
flexing of the front legs
(elbow joint) of an animal.
 H. The triceps brachii is
the muscle responsible for
the extension of the front
legs
(elbow joint) of an animal.
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What are the common muscles
found in livestock and companion
animals?
I. The pectorals are large muscles that
run across the chest of the animal and are
responsible for the primary movement of
the front legs.
 J. The serratus ventralis are muscles
that connect the forelimbs (or front legs)
to the trunk of the animal.
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What are the components and role of the
urinary system? What
are the functions of the kidneys, ureters,
urinary bladder, and urethra?
The urinary system is probably one of the
most underappreciated organ systems in
the animal body.
 Without the removal of wastes from the
bloodstream, the accumulation of toxins
would quickly poison the body, causing
sickness and eventually death.
 The role of the urinary system is to filter
the blood and rid the body of excess
nitrogen, which is a byproduct of cellular
functions.
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What are the components and role of the
urinary system? What
are the functions of the kidneys, ureters,
urinary bladder, and urethra?
This nitrogen is commonly
bound with hydrogen to
create ammonia, which
dissolves in water.
 The solution of ammonia
in water is called uric acid (urea).
 This urea is excreted as a white paste in
birds in order to conserve water.
 In most mammals, however, urea is
mixed with more water and excreted as
urine.
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What are the components and role of the
urinary system? What
are the functions of the kidneys, ureters,
urinary bladder, and urethra?
There are four main components of the
urinary system: kidney, ureter, bladder,
and urethra.
 A. The kidney is the organ responsible for
filtering wastes from the blood.
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There are two kidneys working together to
filter wastes while reabsorbing water back into
the bloodstream.
B. The ureters are muscular tubes that
use a contracting action to move urine
from the kidneys to the bladder.
What are the components and role of the
urinary system? What
are the functions of the kidneys, ureters,
urinary bladder, and urethra?
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C. The bladder is a holding sac for the
temporary storage of urine before it is
expelled from the body.
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The bladder has a muscular lining that can
contract to expel the urine.
The bladder will indicate a feeling of “fullness”
when it is actually half full of urine.
D. The urethra is the tube that carries
the urine from the bladder to outside of
the animal body.
Review

What is the integumentary system, and
what are the two layers of skin?

What is the muscular system, what are
the three types of muscle tissue, and how
do muscles contract to create movement?

How is energy created and utilized for
muscle contractions?
Review

What are the common muscles found in
livestock and companion animals?

What are the components and role of the
urinary system? What are the functions of
the kidneys, ureters, urinary bladder, and
urethra?