Chapter 2

Question 1

Human Movement System or Kinetic Chain

Answer 1

The combination and interrelation
of the nervous, muscular,
and skeletal systems

Question 2

Nervous System

Answer 2

A conglomeration
of billions of cells
specifi cally designed to provide
a communication network within
the human body.

Question 3

Sensory Function

Answer 3

The ability
of the nervous system to sense
changes in either the internal or
external environment.

Question 4

Integrative Function

Answer 4

The
ability of the nervous system to
analyze and interpret sensory
information to allow for proper
decision making, which produces
the appropriate response.

Question 5

Motor Function

Answer 5

The neuromuscular
response to the sensory
information.

Question 6

Proprioception

Answer 6

The cumulative
sensory input to the central
nervous system from all mechanoreceptors
that sense body
position and limb movement.

Training the body’s proprioceptive abilities will improve
balance, coordination, and posture, and enable the body to adapt to its surroundings
without consciously thinking about what movement is most appropriate for any given
situation.

Question 7

Neuron

Answer 7

The functional unit of
the nervous system.

A neuron is a specialized cell that processes and transmits information
through both electrical and chemical signals.

Question 8

Sensory (Afferent) Neurons

Answer 8

Transmit nerve impulses from
effector sites (such as muscles
and organs) via receptors to the
brain and spinal cord.

Question 9

Interneurons

Answer 9

Transmit nerve
impulses from one neuron to
another.

Question 10

Motor (Efferent) Neurons

Answer 10

Transmit nerve impulses from the
brain and spinal cord to effector
sites.

Question 11

Central Nervous System

Answer 11

The
portion of the nervous system
that consists of the brain and
spinal cord.

Question 12

Peripheral Nervous System

Answer 12

Cranial and spinal nerves that
spread throughout the body.

Question 13

2 Parts of PNS

Answer 13

The somatic nervous system consists of nerves that serve the outer
areas of the body and skeletal muscle, and are largely responsible for the voluntary control
of movement.

The autonomic nervous system supplies neural input to the involuntary
systems of the body (e.g., heart, digestive systems, and endocrine glands)

Question 14

Motor and Sensory Functions of the PNS

Answer 14

First, they provide a connection for the nervous system to activate different
effector sites, such as muscles (motor function).

Second, peripheral nerves relay
information from the effector sites back to the brain via sensory receptors (sensory
function), thus providing a constant update on the relation between the body and the
environment

Question 15

Mechanoreceptors

Answer 15

Sensory
receptors responsible for sensing
distortion in body tissues.

muscle spindle, Golgi tendon organ, and
joint receptors

Question 16

Muscle Spindles

Answer 16

Receptors
sensitive to change in length of
the muscle and the rate of that
change.

When a specific muscle is stretched, the spindles within
that muscle are also stretched, which in turn conveys information about its length to
the CNS via sensory neurons. Once information from muscle spindles reaches the brain
it can then determine the position of various body parts.

Question 17

Golgi Tendon Organs

Answer 17

Receptors
sensitive to change in tension
of the muscle and the rate of that
change.

Activation of the Golgi tendon organ will cause the muscle to
relax, which prevents the muscle from excessive stress or possibility of injury.

Question 18

Joint Receptors

Answer 18

Receptors
surrounding a joint that respond
to pressure, acceleration, and
deceleration of the joint.

They can also act to
initiate a refl exive inhibitory response in the surrounding muscles if there is too much
stress placed on that joint

Question 19

Skeletal System

Answer 19

The body’s
framework, composed of bones
and joints.

It is important
to note that the growth, maturation, and functionality of the skeletal system are greatly
affected by posture, physical activity, and nutrition status (

Question 20

Bones

Answer 20

Provide a resting ground
for muscles and protection of
vital organs.

Bones serve two vital functions in movement. The fi rst is leverage. Bones act and
perform as levers when acted on by muscles (28,30). The second primary function
of bones relative to movement is to provide support (28). This translates into posture,
which is necessary for the effi cient distribution of forces acting on the body

Question 21

Joints

Answer 21

Junctions of bones,
muscles, and connective tissue
at which movement occurs. Also
known as an articulation.

Question 22

Axial Skeleton

Answer 22

Portion of the
skeletal system that consists of
the skull, rib cage, and vertebral
column.

Question 23

Appendicular Skeleton

Answer 23

Portion of the skeletal system
that includes the upper and lower
extremities.

Question 24

Remodeling

Answer 24

The process of
resorption and formation of bone.

It is also worth noting that remodeling tends to follow the lines of stress placed
on the bone. Exercise and habitual posture, therefore, have a fundamental infl uence
on the health of the skeletal system. Incorrect exercise technique, coupled with
a generally poor alignment, will lead to a remodeling process that may reinforce the
predominating bad posture.

Question 25

Osteoclasts

Answer 25

A type of bone
cell that removes bone tissue.

Question 26

Osteoblasts

Answer 26

A type of cell
that is responsible for bone
formation.

Question 27

Types of Bones

Answer 27

Long - Long, cylindrical shaft and irregular or
widened ends Humerus, femur

Short - Similar in length and width and appear
somewhat cubical in shape Carpals of hand, tarsals of feet
Flat - Thin, protective Scapulae, patella

Irregular - Unique shape and function Vertebrae

Sesamoid - Small often round bones embedded in a
joint capsule or found in locations where a tendon passes over a joint Patella

Question 28

Epiphysis (Long Bone Anatomy)

Answer 28

The end of long
bones, which is mainly composed
of cancellous bone, and house
much of the red marrow involved
in red blood cell production. They
are also one of the primary sites
for bone growth.

Question 29

Diaphysis (Long Bone Anatomy)

Answer 29

The shaft portion of
a long bone.

Question 30

Epiphyseal Plate (Long Bone Anatomy)

Answer 30

The region
of long bone connecting the
diaphysis to the epiphysis. It is a
layer of subdividing cartilaginous
cells in which growth in length of
the diaphysis occurs

Question 31

Periosteum (Long Bone Anatomy)

Answer 31

A dense membrane
composed of fi brous connective
tissue that closely wraps (invests)
all bone, except that of the articulating
surfaces in joints, which are
covered by a synovial membrane.

Question 32

Medullar Cavity (Long Bone Anatomy)

Answer 32

The central
cavity of bone shafts where
marrow is stored.

Question 33

Articular (Hyaline) Cartilage (Long Bone Anatomy)

Answer 33

Cartilage that covers the articular
surfaces of bones.

Question 34

Bone Depressions

Answer 34

Flattened or
indented portions of bone, which
can be muscle attachment sites.

Question 35

Bone Processes

Answer 35

Projections
protruding from the bone where
muscles, tendons, and ligaments
can attach.

Question 36

Vertebral Column

Answer 36

A series of
irregularly shaped bones called
vertebrae that houses the spinal
cord.

Question 37

Vertebral Column Sections

Answer 37

Cervical spine (C1–C7) 1st seven vertebrae starting at the top of the spinal column

Thoracic spine (T1–T12) Twelve vertebrae located in the upper/middle back behind the ribs

Lumbar spine (L1–L5) Five vertebrae of the low back below the thoracic spine

Sacrum Triangular bone located below the lumbar spine

Coccyx Located below the sacrum, more commonly known as the tailbone

Question 38

Vertebral Major Curvatures

Answer 38

The optimal arrangement of curves is referred to as a neutral spine and represents
a position in which the vertebrae and associated structures are under the least amount
of load. The adult human spine has three major curvatures:
■ a posterior cervical curvature—a posterior concavity of the cervical spine
■ an anterior thoracic curvature—a posterior convexity of the thoracic spine
■ a posterior lumbar curvature—a posterior concavity of the lumbar spine

Question 39

Arthrokinematics

Answer 39

Joint motion.

Joints serve numerous functional requirements of the musculoskeletal system; most
importantly, joints allow for motion and thus movement (30,31). Joints also provide
stability, allowing for movement to take place without unwanted movement.
All joints in the human body are linked together, which implies that movement of
one joint directly affects the motion of others (7,31). This is an essential concept for
personal trainers to understand because it creates an awareness of how the body functionally
operates and is the premise behind kinetic chain movement (

Question 40

Types of Joints

Answer 40

Nonsynovial - No joint cavity and fi brous connective tissue; little or no movement Sutures of the skull

Synovial - Produces synovial fluid, has a joint cavity and fi brous connective tissue Knee

Gliding - No axis of rotation; moves by sliding side-to-side or back and forth Carpals of the hand

Condyloid - Formed by the fi tting of condyles of one bone into elliptical cavities of another; moves predominantly in one plane Knee

Hinge - Uniaxial; moves predominantly in one plane of motion (sagittal) Elbow

Saddle - One bone fi ts like a saddle on another bone; moves predominantly in two planes (sagittal, joint of thumb frontal) Only: carpometacarpal

Pivot - Only one axis; moves predominantly in one plane of motion( transverse) Radioulnar

Ball-and-socket - Most mobile of joints; moves in all three planes of motion Shoulder

Question 41

Ligament

Answer 41

Primary connective
tissue that connects bones
together and provides stability,
input to the nervous system,
guidance, and the limitation of
improper joint movement.

Question 42

Exercise and Bone Mass

Answer 42

Like muscle, bone is living tissue that responds to exercise by becoming stronger. Individuals
who exercise regularly generally achieve greater peak bone mass (maximal bone
density and strength) than those who do not. Exercising allows us to maintain muscle
strength, coordination, and balance, which in turn help to prevent falls and related
fractures. This is especially important for older adults and people who have been diagnosed
with osteoporosis.

Weight-bearing exercise is the best kind of exercise to help strengthen bones because
it forces bones to work against gravity, and thus react by becoming stronger.

Question 43

Muscular System

Answer 43

Muscles generate internal tension that, under the control of the nervous system, manipulates
the bones of our body to produce movements. Muscles are the movers and stabilizers
of our bodies.

Question 44

Epimysium (Parts of Muscle)

Answer 44

A layer of connective
tissue that is underneath the
fascia and surrounds the muscle.

Question 45

Perimysium (Part of Muscle)

Answer 45

The connective
tissue that surrounds fascicles

Question 46

Endomysium (Part of Muscle)

Answer 46

The deepest
layer of connective tissue that
surrounds individual muscle
fi bers.

Question 47

Tendons

Answer 47

Connective tissues
that attach muscle to bone and
provide an anchor for muscles to
produce force.

They are very similar to ligaments in that they have poor vascularity
(blood supply), which leaves them susceptible to slower repair and adaptation

Question 48

Sarcomere

Answer 48

The functional unit
of muscle that produces muscular
contraction and consists of
repeating sections of actin and
myosin.

Question 49

Neural Activation

Answer 49

The contraction
of a muscle generated by
neural stimulation.

Question 50

Motor Unit

Answer 50

A motor neuron
and all of the muscle fi bers it
innervates.

Question 51

Neurotransmitters

Answer 51

Chemical
messengers that cross the neuromuscular
junction (synapse) to
transmit electrical impulses from
the nerve to the muscle.

Question 52

Sliding Filament Theory

Answer 52

Steps in the sliding fi lament theory are summarized as follows:
1. A sarcomere shortens as a result of the Z lines moving closer together.

2. The Z lines converge as the result of myosin heads attaching to the actin fi lament and
 asynchronously pulling (power strokes) the actin fi lament across the myosin, resulting in
 shortening of the muscle fi ber.

Question 53

All or Nothing Law (Muscles)

Answer 53

Motor units cannot, therefore, vary the amount of force they generate; they either contract maximally or not at all
hence the “all or nothing” law.

As a result of the all or nothing law, the overall strength of a skeletal muscle contraction will depend on the size of the motor unit recruited (i.e., how many muscle fi bers are contained within the unit) and the number of motor units that are activated at a given time. It should also be understood that the size of motor units making up a particular muscle will relate directly to the function of that muscle. For example, muscles that have to control precise movements are made up of many small motor units, for example, the
muscles that control eye movements have as few as 10 to 20 muscle fi bers within each motor unit, allowing the fi ne control that eye movement demands. Conversely, large muscles and muscle groups, such as the gastrocnemius muscle, which are required to generate more powerful, gross movements with far less fi ne control, have as many as 2,000 to 3,000 muscle fi bers in each of their motor units.

Question 54

Muscle Fiber Types

Answer 54

Type I (slow-twitch)
More capillaries, mitochondria, and myoglobin
Increased oxygen delivery
Smaller in size
Less force produced
Slow to fatigue
Long-term contractions (stabilization)
Slow twitch

Type II (fast-twitch)
Fewer capillaries, mitochondria, and myoglobin
Decreased oxygen delivery
Larger in size
More force produced
Quick to fatigue
Short-term contractions (force and power)
Fast twitch

Question 55

Muscles as Movers

Answer 55

Agonist
Prime mover
Chest press
Overhead press
Row
Squat
Pectoralis major
Deltoid
Latissimus dorsi
Gluteus maximus,
quadriceps

Synergist
Assist prime mover
Chest press
Overhead press
Row
Squat
Anterior deltoid, triceps
Triceps
Posterior deltoid, biceps
Hamstring complex

Stabilizer
Stabilize while
prime mover and
synergist work
Chest press
Overhead press
Row
Squat
Rotator cuff
Rotator cuff
Rotator cuff
Transversus abdominis

Antagonist
Oppose prime
mover
Chest press
Overhead press
Row
Squat
Posterior deltoid
Latissimus dorsi
Pectoralis major
Psoas

Question 56

Endocrine System

Answer 56

The endocrine system is a system of glands that secrete hormones into the bloodstream to
regulate a variety of bodily functions, including the control of mood, growth and development,
tissue function, and metabolism (Figure 2.39). The endocrine system consists
of host organs (known as glands), chemical messengers (hormones), and target (receptor)
cells. Once a hormone is secreted from a gland, it travels through the bloodstream
to target cells designed to receive its message

Question 57

Primary Endocrine Glands

Answer 57

The primary endocrine glands are the hypothalamus, pituitary, thyroid, and adrenal
glands.

Question 58

Pituitary Gland

Answer 58

“Master” gland of the endocrine
system, because it controls the functions of the other endocrine glands. The pituitary
has three different sections or lobes, the anterior, intermediate, and posterior lobes,
and each lobe secretes specifi c types of hormones.

Question 59

Insulin

Answer 59

Insulin helps regulate energy and glucose metabolism in the body. After consuming a
meal, glucose enters the blood at the small intestine, causing a rise in blood glucose
levels. As the blood is circulated through the pancreas, elevated levels of glucose trigger
the release of insulin. The circulating insulin binds with the receptors of its target
cells (in this case skeletal muscle or liver cells), and the cell membrane becomes more
permeable to glucose. Glucose then diffuses out of the bloodstream and into the cell.
The net result is a drop in blood glucose levels. Thus insulin causes cells in the liver,
muscle, and fat tissue to take up glucose from the blood, storing it as glycogen in the
liver and muscle (50,51).

Question 60

Glucagon

Answer 60

Glucagon is one of the two hormones secreted by the pancreas that regulate blood glucose
levels. Its effect is opposite to that of insulin, as it functions to raise blood glucose
levels by triggering the release of glycogen stores from the liver (glycogen is the stored
form of glucose). Hours after a meal, or as a result of a combination of normal metabolic
processes and physical activity, the body will begin to exhibit lower blood glucose
levels. The drop in circulating blood glucose levels triggers the release of glucagon from
the pancreas. In contrast to insulin, glucagon has a much more specifi c effect, stimulating
the liver to convert its glycogen stores back into glucose, which is then released into
the bloodstream.

Question 61

Effects of Exercise on Insulin and Glucagon

Answer 61

Understanding the effects of exercise is helpful to understanding the interrelationship
between insulin and glucagon. As activity levels increase, glucose uptake by the body’s
cells also increases. This is the result of an increased sensitivity of the cells to insulin;
thus, insulin levels will drop during physical activity (52). At the same time glucagon
secretion by the pancreas increases, thus helping maintain a steady supply of blood
glucose.

Question 62

Catecholamines

Answer 62

The two catecholamines—epinephrine (also known as adrenaline) and
norepinephrine—are hormones produced by the adrenal glands, which are situated on
top of each kidney. These hormones help prepare the body for activity; more specifi -
cally, they are part of the stress response known as the fi ght or fl ight response. In preparation
for activity, the hypothalamus (part of the brain) triggers the adrenal glands to
secrete more epinephrine. This will have a number of specifi c physiological effects that
will help sustain exercise activity (51,52):
■ increases heart rate and stroke volume
■ elevates blood glucose levels
■ redistributes blood to working tissues
■ opens up the airways

Question 63

Cortisol

Answer 63

Under times of stress, such as exercise, cortisol is secreted
by the adrenal glands and serves to maintain energy supply through the breakdown of
carbohydrates, fats, and protein. High levels of cortisol brought about through overtraining,
excessive stress, poor sleep, and inadequate nutrition can lead to signifi cant
breakdown of muscle tissue, along with other potentially harmful side effects

Question 64

Growth Hormone

Answer 64

The name of this hormone has particular reference to its primary functions. Growth
hormone is released from the pituitary gland in the brain and is regulated by the
nearby hypothalamus. Growth hormone is stimulated by several factors including
estrogen, testosterone, deep sleep, and vigorous exercise. Growth hormone is primarily
an anabolic hormone that is responsible for most of the growth and development
during childhood up until puberty, when the primary sex hormones take
over that control. Growth hormone also increases the development of bone, muscle
tissue, and protein synthesis; increases fat burning; and strengthens the immune
system.

Question 65

Thyroid Hormones

Answer 65

This gland releases vital hormones that are primarily responsible for human metabolism. The release of thyroid hormones is regulated by
the pituitary gland. Thyroid hormones have been shown to be responsible for carbohydrate,
protein, and fat metabolism, basal metabolic rate, protein synthesis, sensitivity
to epinephrine, heart rate, breathing rate, and body temperature. Low thyroid function
has become a well-recognized disorder leading to low metabolism, fatigue, depression,
sensitivity to cold, and weight gain.

Question 66

Effects of Exercise on Thyroid Hormones

Answer 66

Research has indicated that testosterone and growth hormone levels increase after
strength training and moderate to vigorous aerobic exercise. A similar pattern also
seems to emerge for cortisol (53). The presence of cortisol in the bloodstream is often
taken to be indicative of overtraining. This is perhaps a little simplistic as cortisol is a
necessary part of maintaining energy levels during normal exercise activity and may
even facilitate recovery and repair during the postexercise period (53). Problems may
arise, however, as a result of extremely intense or prolonged bouts of endurance training,
which have been found to lower testosterone levels while raising cortisol levels.
Under these circumstances, catabolism (breakdown) is likely to outstrip anabolism
(build up) and give rise to symptoms of overtraining (52,53).