AP chapter 8 Flashcards
Each fine thread is a muscle cell usually called a ___
muscle fiber
What are three muscle fibers types?
skeletal, cardiac, and smooth
Threadlike cylindrical ___ cells appear in bundles
skeletal muscle
What are the 3 names for Skeletal muscle?
#1 skeletal muscle because it attaches to bone #2 striated muscle because of its cross stripes or striations #3 voluntary muscle because its contractions can be controlled voluntarily
The bulk of the heart is made up of ___
cardiac muscle
What two muscles are involuntary?
Cardiac muscle and smooth muscle
___ fibers are tapered at each end and have a single nucleus
smooth muscle
What are 4 names for the Smooth muscle?
#1 smooth muscle #2 nonstriated muscle fibers, because they lack cross stripes on striations #3 involuntary, because we normally do not have control over their contractions #4 visceral muscle
___forms an important part of the walls of blood vessels and of many hollow internal organs (viscera) such as the gut, urethra, and ureters
smooth muscle
Group of muscle fibers are called
fascicles
___ is the loose connective tissue outside the muscle organs that forms a flexible, sticky “packing material” between muscles, bones, and the skin
Fascia
The muscle’s attachment to the more stationary bone is called its ___
origin
The muscle’s attachment to the more movable bone is called the muscle’s ___
insertion
The entire muscle (except its two ends) is called the ___
body of the muscle
Small fluid-filled sacs called ___ lie between some tendons and the bones beneath them
bursae
The synovial membrane secretes a slippery lubricating fluid, called synovial fluid, that fills the ___
bursae
___ reduces friction and makes it easier for a tendon to slide over a bone when the tendon’s muscle shortens
bursa and tendon sheaths also
What encloses some tendons?
tendon sheaths
The fiber’s internal framework is organized into many long cylinders, each made up of two kinds of thread-like microfilaments called ___ and ___
thick and thin myofilaments
The thick myofilaments are formed from a protein called ___
myosin
thin myofilaments are composed mainly of the protein called ___
actin
Muscle fibers are also called ___
contractile cells
The basic contractile unit of skeletal muscle
sarcomere
The repeating units, or sarcomeres, are separated from each other by dark bands called ___
Z lines or Z disks
An explanation of how a skeletal muscle contracts is provided by the ___
sliding filament model
Tendons attach ___ to ___
muscle to bone
cartilage attach ___ to ___
bone to bone
ATP is an ___
energy
Functions of Skeletal Muscle (3)
#1 produces movement #2 responsible for posture #3 Produces heat therefore helps maintain homeostatic balance of body temperature
What energy is need for contraction?
ATP
As a rule, only the ___ bone moves
insertion
The ___ bone moves toward the ___ bone
insertion ; origin
Tension during muscle lengthening is often called ___
eccentric contraction
Of all the muscles contracting simultaneously, the one that is mainly responsible for producing a particular movement is called the ___
prime mover
Of all the muscles contracting simultaneously, the one that is mainly responsible for producing a particular movement is called the prime mover. The other muscles that help in producing the movement are called ___
synergist muscles
As prime movers and synergist muscles at a joint contract, other muscles, called ___, relax
antagonist muscles
We are able to maintain our body position because of a continuous, low strength muscle contraction called muscle tone or ___
tonic contraction
Muscle tone maintains ___
posture
___ do not move any body parts. They do hold muscles in position, however.
tonic contractions
Any decrease in body temperature below normal, a condition called ___, drastically affects cellular activity and normal body function
hypothermia
___ describes the continually increasing metabolism that must occur in a cell to remove the excess lactic acid that accumulates during prolonged exercise
oxygen debt
Exercise physiologists use a more technical name for oxygen debt - ___ - a term that more directly describes what happens after exercise
excess post-exercise oxygen consumption (EPOC)
Before a skeletal muscle can contract and move a bone, the muscle must first be stimulated by nerve impulses. Muscle fibers are stimulated by a nerve cell called a ___
motor neuron
The point of contact between the nerve ending and the muscle fiber is called a ___
neuromuscular junction (NMJ)
Signal chemicals called ___ are released by the motor neuron in response to a nerve impulse
neurotransmitters
The type of neurotransmitter operating in each NMJ is called ___
acetylcholine (ACh)
A single motor neuron with the muscle fibers it innervates is called a ___
motor unit
In small motor units, a given motor neuron controls only a few muscle fibers. Small motor units are common in the ___ and offer precise control
eye muscles
In large motor units, a given motor neuron controls hundreds, maybe thousands of muscle fibers. Large motor units are common in the ___ and are activated in high-intensity activites
thigh
The minimal level of stimulation required to cause a fiber to contract is called the ___
threshold stimulus
5 types of muscle contraction include :
#1 Tonic contraction #2 Twitch contraction #3 Tetanic conversation #4 Isotonic contraction #5 Isometric contraction
A ___ is a quick, jerky response to a stimulus. ___ can be seen in isolated muscles during research but play a minimal role in normal muscle activity
Twitch ; twitch contractions
A ___ is sustained and steady. It is produced by a series of stimuli bombarding the muscle in a rapid succession.
tetanic contraction
A sustained contraction is called
tetanus
What is a maximal contraction
each muscle fiber responds at the same time
___ of muscle produces movement at a joint. With this type of contraction, the muscle changes length and the insertion end moves relative to the point of origin
isotonic contraction
There are two types of isotonic contraction. One is ___, in which the muscle shortens
concentric contraction
There are two types of isotonic contraction. One is ___, in which the muscle lengthens but still provides work
eccentric contraction
Walking, running, breathing, lifting, twisting, and most body movements are examples of __
isotonic contraction
When the muscle contracts and no movement results, it is called an ___
isometric contraction
___ means equal measure
isometric
Pushing against a wall or other immovable object is a good example of ___ exercise. Although no movement occurs and the muscle does not shorten, its internal tension increases dramatically
isometric
Muscles shrinking in mass is
disuse atrophy
Increase in muscle size is called
hypertrophy
___ involves contracting muscles against heavy resistance
strength training
___ training, or aerobic training, does not usually result in muscle hypertrophy. Instead, this type of exercise program increases a muscle’s ability to sustain moderate exercise over a long period
Endurance training
___ is a movement that decreases the angle between two bones at their joint
Flexion
___ increases the angle between two bones at their joint
Extension
___ is a movement around a longitudinal axis
rotation
___ moves a part so that its distal end moves in a circle
circumduction
___ means face up and ___ means face down
supine and prone
In ___ the top of the foot is elevated with the toes pointing upward
dorsiflexion
In ___ the bottom of the foot is directed downward, as when you are standing on your toes
plantar flexion
Contraction of the ___ muscle allows you to raise and furrow your eyebrows
frontal
The ___, called the kissing muscle, puckers the lips
orbicularis
The ___ elevates the corners of the mouth and lips and has been called the smiling muscle
zygomaticus
The -__ muscles are responsible for closing the mouth and producing chewing movements
mastication
What is All or None
When a muscle fiber is subjected to a threshold stimulus, it contracts completely. On the other hand, if a threshold stimulus is not reached, the muscle will not contract. Because of this, muscle fibers are said to respond in an “all or none” manner
Striations are found where
skeletal muscle and cardiac muscle
Intercalated disks are found where
between the myocardial cells of the heart
function of biceps brachii
flexes the elbow
What is the function of the deltoid
abducts arm insertion
Function of Sartorius
flexes thigh and rotates leg
Function of rectus abdominis
flexes trunk
What is the function of the Masseter
closes jaw
What part of the body does the pectoralis major move
flexes and helps adduct arm
What percentage of your weight is skeletal muscle
40%
What happens when calcium is released in the sarcomere
When the muscle is stimulated to contract by the nerve impulse, calcium channels open in the sarcoplasmic reticulum (which is effectively a storage house for calcium within the muscle) and release calcium into the sarcoplasm (fluid within the muscle cell).
Know which muscles move the lower extremities
Iliopsoas, Sartorius, Gluteus maximus, Adductor Group, Hamstring Group, Quadriceps Group, Fibularis Group
Identify muscles of the trunk
External oblique, internal oblique, transversus abdominis, rectus abdominis, diaphragm
Know which muscles move the upper extremities
Pectoralis major, Latissimus dorsi, Deltoid, Biceps brachii, triceps brachii
Identify muscles of the head and neck
Frontal, orbicularis oculi, orbicularis oculi, orbicularis oris, zygomaticus, masseter, temporal, sternocleidomastoid, trapezius
Opposite of Rotation
Supination
What produces smooth movement at a joint?
Synovial
What is an adductor muscle
any several muscles that adduct a joint, moving a body part in from the side (lateral) and thus toward the midline (median or midsagittal plane) of the body or of the body region
What is aerobic training
continuous vigorous exercise requiring the body to increase its consumption of oxygen and develop the muscles’ ability to sustain activity over a long period
What is an antagonist
any agent that has the opposite effect of the agent to which it is compared
What is biomechanical engineering
Discipline of engineering that applies principles of mechanical engineering to biological systems, as in biomedical engineering
