BIOD 151a&p module 5.
BIOD 151a&p module 5.
BIOD 151a&p module 5.
Anatomy of the Muscular System: Introduction &
Muscles of the Head, Neck, and Trunk
Notice: To optimize your learning in this course, we advise that you complete the labs and modules
as indicated in the BIOD 151 Lab Schedule.
The muscular system and the skeletal system work together to provide movement for the human
body. Muscle tissue is found in three distinct types in the body; skeletal, smooth, and cardiac.
Skeletal muscles must have a blood and nervous supply to provide movement. Skeletal muscles are
under conscious control, meaning that a person can consciously decide to use these muscles to
complete an action. Communication within the body to coordinate movement starts in the brain with
a message that is sent through the spinal cord and eventually attaches to a muscle. Peripheral
nerves carry the signal from the central nervous system (brain and spinal cord) to a specific
muscle destination to provide movement. Messages from the central nervous system to a muscle
are called a motor actions. Nerves also carry information from the external environment to the
central nervous system, called sensation or sensory input. (see Figure 5.1 and Figure 5.2) Spinal
nerves combine to form complex networks of peripheral nerves throughout the body.
,BIOD 151a&p module 5.
Figure 5.1 Posterior view of the nervous system. The brain and spinal cord (central nervous
,BIOD 151a&p module 5.
system) connect to the peripheral nervous system. Examples of peripheral nerves are spinal nerves
(cervical, thoracic, and lumbar), the upper trunk of the brachial plexus, and the radial nerve.
Figure 5.2 Peripheral nerves carry the communication from the central nervous system (brain and
spinal cord) to the muscle. Peripheral nerves also carry information from the environment to the
central nervous system.
Tendons are connective tissues that connect skeletal muscle to bone at each end (see Figure 5.3).
Tendons are flexible, can bend at the joints, and help cushion against sudden
movement. Ligaments are connective tissue that connects bone to bone, helping to stabilize joints
where bones meet.
, BIOD 151a&p module 5.
Figure 5.3 Skeletal muscles attach to bones via tendons at points called the origin and insertion.
The origin is the fixed point while the insertion is the place that is moved during a muscle
contraction.
All skeletal muscles have an origin, insertion, and action. The origin is the bony site of attachment
which is stationary during the movement. The insertion of a muscle is the bony site of attachment
that is moved by the muscle contraction. (see Figure 5.3)
The origin and insertion can be reversed in different types of movement. For this module, the
standard origin and insertion points are referenced from anatomical position.
The action of the muscle is what effect is produced by the muscle’s contraction. For example, the
triceps is the primary extensor of the forearm. The innervation is the peripheral nerve that supplies
a muscle with the message from the brain. For example, the innervation of the biceps brachii is the
musculocutaneous nerve. (see Figure 5.4)
BIOD 151a&p module 5.
BIOD 151a&p module 5.
Anatomy of the Muscular System: Introduction &
Muscles of the Head, Neck, and Trunk
Notice: To optimize your learning in this course, we advise that you complete the labs and modules
as indicated in the BIOD 151 Lab Schedule.
The muscular system and the skeletal system work together to provide movement for the human
body. Muscle tissue is found in three distinct types in the body; skeletal, smooth, and cardiac.
Skeletal muscles must have a blood and nervous supply to provide movement. Skeletal muscles are
under conscious control, meaning that a person can consciously decide to use these muscles to
complete an action. Communication within the body to coordinate movement starts in the brain with
a message that is sent through the spinal cord and eventually attaches to a muscle. Peripheral
nerves carry the signal from the central nervous system (brain and spinal cord) to a specific
muscle destination to provide movement. Messages from the central nervous system to a muscle
are called a motor actions. Nerves also carry information from the external environment to the
central nervous system, called sensation or sensory input. (see Figure 5.1 and Figure 5.2) Spinal
nerves combine to form complex networks of peripheral nerves throughout the body.
,BIOD 151a&p module 5.
Figure 5.1 Posterior view of the nervous system. The brain and spinal cord (central nervous
,BIOD 151a&p module 5.
system) connect to the peripheral nervous system. Examples of peripheral nerves are spinal nerves
(cervical, thoracic, and lumbar), the upper trunk of the brachial plexus, and the radial nerve.
Figure 5.2 Peripheral nerves carry the communication from the central nervous system (brain and
spinal cord) to the muscle. Peripheral nerves also carry information from the environment to the
central nervous system.
Tendons are connective tissues that connect skeletal muscle to bone at each end (see Figure 5.3).
Tendons are flexible, can bend at the joints, and help cushion against sudden
movement. Ligaments are connective tissue that connects bone to bone, helping to stabilize joints
where bones meet.
, BIOD 151a&p module 5.
Figure 5.3 Skeletal muscles attach to bones via tendons at points called the origin and insertion.
The origin is the fixed point while the insertion is the place that is moved during a muscle
contraction.
All skeletal muscles have an origin, insertion, and action. The origin is the bony site of attachment
which is stationary during the movement. The insertion of a muscle is the bony site of attachment
that is moved by the muscle contraction. (see Figure 5.3)
The origin and insertion can be reversed in different types of movement. For this module, the
standard origin and insertion points are referenced from anatomical position.
The action of the muscle is what effect is produced by the muscle’s contraction. For example, the
triceps is the primary extensor of the forearm. The innervation is the peripheral nerve that supplies
a muscle with the message from the brain. For example, the innervation of the biceps brachii is the
musculocutaneous nerve. (see Figure 5.4)
