Download Human Anatomy Lesson1-2

ACE’s Essentials of Exercise Science for Fitness
Professionals
Chapter 1: Human Anatomy
Lesson 1.2
LEARNING OBJECTIVES
• After completing this session, you will be able to:
 Describe the structures and functions of the central
nervous system (CNS) and the peripheral nervous
system (PNS)
 List the different types of muscle tissue and musclefiber types
 Identify muscles that act at the following joints:
shoulder, scapulothoracic articulation, wrist, elbow,
trunk, hip, knee, and ankle
 List the principal endocrine glands
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NERVOUS SYSTEM
• The nervous system
connects the muscles to the
brain and spinal cord
through a network of nerve
circuits.
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PROPRIOCEPTION
• Proprioception is the sense
of knowing where the body
is in relation to its various
segments and the external
environment.
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MUSCULOTENDINOUS RECEPTORS
• Muscle spindle:
 Located in the muscle belly lying
parallel to the fibers
 Causes a reflexive contraction
(stretch reflex) in the muscle when
the muscle senses a stretch force.
 Simultaneously causes the
antagonist to relax (reciprocal
inhibition) when it senses tension
• Golgi tendon organ (GTO):
 Located between the muscle belly
and its tendon
 Causes muscle inhibition
(autogenic inhibition) when it
senses tension
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MUSCULAR SYSTEM
• There are three types of muscles in the human body.
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SKELETAL MUSCLE FIBER TYPES
• Skeletal fibers can be divided into two general categories
based on how quickly they contract.
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MUSCLE-FIBER MICROANATOMY
• Skeletal muscles are made
up of many muscle fibers
held in place by connective
tissue (fascia).
• Muscle fibers are made up of
myofibrils (protein filaments)
composed of a series of
repeating segments called
sarcomeres.
• Sarcomeres, made up of
thick (myosin) and thin
(actin) myofilaments, are
the functional contracting
unit of skeletal muscle.
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MUSCLE CONTRACTION
• Sliding filament model
 When acetylcholine is
released from the CNS
and detected, calcium is
released.
 Calcium exposes
binding sites along the
actin for the myosin to
attach.
 If sufficient ATP is
present, cross-bridges
are formed and the
myosin pulls the actin
toward the center,
shortening the
sarcomere.
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SHOULDER GIRDLE
•
The muscles of the shoulder girdle act on the scapula,
primarily to stabilize it.
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MAJOR MUSCLES THAT ACT AT THE SHOULDER GIRDLE
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MAJOR MUSCLES THAT ACT AT THE SHOULDER
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MOVEMENTS AT THE ELBOW AND WRIST
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TRUNK
• The major muscles of the trunk support, stabilize, and move the spine.
 The abdominal wall, made up of the rectus abdominis, obliques, and
transverse abdominis, has no skeletal support.
 Its strength comes from the multidirectional layers of muscle.
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MAJOR MUSCLES THAT ACT AT THE TRUNK
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HIP FLEXORS
• There are 21 major muscles involved in the actions of the hip joint.
 Actions of the hip joint include flexion, extension, internal rotation,
external rotation, adduction, and abduction.
 More than half of these muscles are involved in multiple actions.
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HIP EXTENSORS
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HIP INTERNAL AND EXTERNAL ROTATORS
• The hip internal rotators include
the tensor fasciae latae,
semitendinosus (slight), and
semimembranosus (slight).
• The hip external rotators include
the iliopsoas, gluteus maximus,
biceps femoris (slight), gluteus
medius and minimus (posterior
fibers), sartorius, pectineus, and
the six deep external
rotators.
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HIP ADDUCTORS
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HIP ABDUCTORS
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KNEE
• The muscles of the thigh are responsible for movement at the
knee.
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ANTERIOR COMPARTMENT OF THE LEG
• The lower leg is divided into three primary compartments:
anterior, posterior, and lateral.
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POSTERIOR COMPARTMENT OF THE LEG
• The posterior compartment is made up of muscles that plantarflex
the foot and/or flex the toes and is divided further into the
superficial posterior and deep posterior compartments:
 Superficial posterior compartment: gastrocnemius, soleus, and
plantaris
 Deep posterior compartment: flexor hallucis longus, flexor digitorum
longus, posterior tibialis, and popliteus
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POSTERIOR COMPARTMENT OF THE LEG
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LATERAL COMPARTMENT OF THE LEG
•
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The lateral compartment is made up of muscles that
plantarflex and evert the foot, including the peroneus
longus and peroneus brevis.
MAJOR ENDOCRINE GLANDS AND THEIR HORMONES
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SUMMARY
• Being able to identify the structures and functions of the CNS
and PNS allows a fitness professional to understand the
contributions of the nervous system to effective movement.
• Understanding the different types of muscle tissue and
muscle-fiber types helps a personal trainer design exercise
programs that target the appropriate energy systems based
on a client’s needs and goals.
• Understanding how the muscles of the upper and lower
extremities and trunk act at the various joints helps a
personal trainer design workouts appropriate for a client’s
needs and goals.
• Having a general understanding of the principal endocrine
glands is important for conceptualizing how the endocrine
system plays a part in general health and function.
© 2014 ACE