Chapter 5 NASM
type II muscle fibers
"fast twitch muscle fibers", muscle fibers that are larger in size, generate higher amounts of force, and are faster to fatigueImportant for physical activity that requires a lot of force: running/jumping, big muscles that have the primary function of moving the body tend to have more type II muscle fibers than smaller muscles, fewer capillaries, mitochondria and myoglobin, decreased oxygen delivery, low oxidative capacity - "referred to as white fibers" Short term contractions (force and power)
type IIA muscle fibers
"intermediate fast-twitch fibers"; Use both aerobic and anaerobic metabolism almost equally to create energy; Represent the middle ground between type I and type IIx
gliding joints
(aka plane joint) is a nonaxial joint that has the simplest movement of all joints ex) joints between the carpal bones of the wrist
Vertebral Column
(aka spinal column) consists of a series of irregularly shaped bones called vertebrae that ouse and protect the bundle of nerves (spinal cord)
what are the classification of synovial joints?
1) gliding joints 2) condyloid joints 3) hinge joints 4) saddle joints 5) pivot joints 6) ball and socket joints
how many cranial nerves are in the PNS
12 cranial nerves
approximately how many bones are in the appendicular skeleton
126
in the human skeleton system, how many bones are there
206: approx 177 used in voluntary movement
At what age is the adolescent brain considered to be fully developed?
25
bones in the body form about how many joints?
300+
how many spinal nerves are in the PNS
31 pairs of spinal nerves that branch out from the brain and spinal cord
how many categories of bones are there in the vertebral column
5 - depends on where they are located
approximately how many bones are in the axial skeleton
80
2 principles within the slinding filament theory
A sarcomere shortens as a result of the Z-lines moving closer together (converging), The Z-lines converge as the result of the myosin filaments' heads attaching across the myosin resulting in a shortening of the muscle fiber
muscle contraction steps
Nerve impulse begins in CNS annd travels down motor neuron, which is facilitated by sodium and potassium electrolytes to the neuromasticular junction Acetylcholine is released into the neuromuscular junction, which helps the nerve impulse cross the synapse into the muscle Nerve impulse travels into the muscle infrastructure, stimulating a small organ called the sarcoplasmic reticulum to release the electrolye calcium Calcium is then released into the muscle, stimulating a chain of events that results in the myosin heads binding to actin Myosin heads pull the actin toward the sarcomere center, which slides the overlapping filaments past each other, shortening the entire muscle
central nervous system (CNS)
a division of the nervous system that includes the brain and spinal cord; primary function is to coordinate activity to all parts of the body
nonaxial joints
a gliding joint that moves only in one plane of motion: back and forth, side to side
Adenosine Triphosphate (ATP)
a high-energy molecule that serves as the main form of energy in the human body; known as the energy currency of the body; provides power to myosin heads
synovial joints
a joint with a fluid filled joint capsule; comprise approx 80% of all joints in body and have greatest capacity for motion
syapse
a junction or small gap between the motor neuron and muscle cells
motor unit
a motor neuron and all of the muscle fibers that it innervates with
efferent pathway
a motor pathway that relays info from the CNS to the rest of the body (PNS)
Acetycholine (ACh)
a neurotransmitter that helps the action potential cross the synapse into the muscle, initiating the steps in a muscle contraction
effector site
a part of the body, such as a muscle or organ, that receives a signal from a neuron to produce a physiological response
collagen
a protein found in connective tissue, muscles, and skin that provides strength and structure; most abundant protein found in human body; provides ligaments with ability to withstand tension
elastin
a protein that provides elasticity to the skin, tendons, ligaments and other structures; gives ligament some flexibility or elastic recoil to withstand the bending and twisting it may have to endure
growth plate
a specialized cartilage disc located in the epiphysis that is responsible for longitudinal bone growth; bones get stronger and denser with age
condyles are
a type of process located on inner and outer portions at the bottom of the femur (thigh bone) and the top of the tibia (shin bone) to form knee joint
integrative functions
ability of nervous system to analyze and interpret the sensory information to allow for proper decision-making which produces an appropriate response
sensory function
ability of the nervous system to sense changes in either the internal or external environment
what age is skeletal bone mass most stable
ages 30-35; may decline after this range; resistance training/weight bearing exercises improve bone mass
the spinal cord connects...
all parts of the body to the brain
pivot joints
allow movement predominantly in one direction; joints found at the base of the skull (top of spine) and the proximal radioulnar joint at the elbow
Which division of the skeleton is made up of the arms, legs, and pelvic girdle?
appendicular
internal structures of long bones
articular (hyaline) cartilage, epiphysis (epiphyses), diaphysis, epiphyseal plate, medullary cavity, periosteum
what functions to bones serve in movement
as levers and supporters of movement
What are the two divisions of the skeletal system?
axial and appendicular
the skeleton is divided into two parts
axial and appendicular skeleton
lumbar spine
bone category of the vertebral column; L1-L5, first 5 vertebrate of the low back below the thoracic spine; largest segments in the spinal column, support most of bodys weight and are attached to many back muscles
cervical spine
bone category of the vertebral column; bones C1-C7, first 7 vertebrate at the spinal column, form a flexible framework and provide support and motion for the head
thoracic spine
bone category of the vertebral column; bones T1-T12; 12 vertebrae located in the upper and middle back behind ribs, each one articulates with a rib helping form the rear anchor of the rib cage, increase in size from top to bottom
coccyx
bone category of the vertebral column; located below sacrum, more commonly known as the tailbone, composed of 3-5 small fused bones
sacrum
bone category of the vertebral column; triangular bone located below lumbar spine, composed of 5 vertebrate that fuse together as body develops into adulthood
breakfast-lunch-dinner bone analogy
breakfast at 7 (7 cervical vertebrae at the neck) lunch at 12 - (12 thoracic vertebrae at the mid back, dinner at 5 - (5 lumbar vertebrae at the low back
the brain stem regulates
breathing; stem connects the spinal cord to the brain
examples of short bones
carpals of the wrist. tarsals of the ankle
nucleus
cellular structure of organelle that contains the majority of the cell's genetic material in the form of chromosomes
nervous system composed of two interdependent divisions
central and peripheral nervous systems
neurotransmitters
chemical messengers that cross the synapse between neuron and muscle and assist with nerve transmission; translation of the nervous systems electrical message into a form the muscle cells can understand and act on; released into gap when action potential reaches junction
3 stages of development of motor skills
cognitive: client learning skill, associative: client begins to understand skill, autonomous: client has mastered skill
the human movement system
collective components and structures that work together to move the body: muscular, skeletal and nervous systems if one isn't working, others affected thus affecting movement
kinetic chain
concept that describes human body as a chain of interdependent links - muscles, bones, joints, that work together to perform movement synonymous with human movement system
osteoporosis
condition of reduced bone mineral density which increases risk of bone fracture; negative effects on skeletal health and human movement
perimysium
connective tissue surrounding a muscle fascicle
endomysium
connective tissue that wraps around individual muscle fibers within a fascicle
myofibrils
contractile components of a muscle cells; actin and myosin (the myofilaments) are contained within a myofibril
the brain is the center of
coordination and intellectual and nervous system activity in the body
axon
cylindrical projection from the cell body that transmits nervous impulses to other neurons or effector sites; provides communication from brain and spinal cord to other parts of body
arthrokinematics
description of joint surface movement (interaction of 2 bone surfaces) that one cannot see; 3 types: roll, slide, spin
skeletal system
description of the bones of the body; forms shape of body, protects/supports internal organs, provides structure from which movement is created, produces blood for the body, stores minerals
surface markings
distinct structural features of bones; necessary for increasing stability in joints and providing attachment sites for muscles; divided into depressions and processes
axial skeleton
division of skeletal system consisting of: skull, rib cage and vertebral column
parasympathetic nervous system
division of the autonomic nervous system that works to decrease neural activity and put the body in a more relaxed state; opposite of sympathetic nervous system and puts body into rest and digest
autonomic nervous system
division of the peripheral nervous system that supplies neural input to organs that run the involuntary processes of the body; circulating blood, digesting food, producing hormones
appendicular skeleton
division of the skeletal system consisting of the arms, legs and pelvic girdle
type IIx muscle fibers
division of type II, lower oxidative capacity and fatigue quick
epiphysis (epiphyses)
end of long bones that contains red marrow that produces red blood cells and is also one of the primary sites for bone growth
lack of water or electrolyte balance may lead to
exercise-associated muscle cramps
What surrounds the skeletal muscles and connects them to other surrounding muscles?
fascia
breakdown of muscles (layers) - outer to inner
fascia, epimysium, fascicles, perimysium, endomysium
lower body long bones
femur (thigh bone) tibia and fibula (shin bones) metatarsals and phalanges (toe bones)
intervertebral discs
fibrous cartilage between vertebrae that act as shock absorbers and assist with movement
tendons
fibrous connective tissue that connects muscles to bones
ligaments
fibrous tissues that connect bone to bone and provide dynamic/static stability and sensory input to the nervous system that aids proprioception; made up of collagen and some elastin; have poor vascularity (blood supply) indicating ligaments do not heal or repair very well and may be slower to adapt to stresses from exercise placed on the body
myofilaments
filaments of a myofibril; include actin and myosin
depressions
flattened or indented portion of the bone; commonly called "fossa" or "sulcus"ex) infraspinous fossa located on scapula; or intertubercular sulcus located on lesser tubercles of humerus (groove for biceps tendon)
dendrites
gather info from other structures and transmits it back to neuron
glycogen
glucose that is deposited/stored in bodily tissues such as the liver and muscle cells; the storage form of carbohydrates
each individual muscle fiber contains cellular components
glycogen, minerals, oxygen-binding myoglobin and mitochondria which transform food into energy for cells
what does the vertebral column do?
helps humans stand upright, maintain balance, supports head and arms while permitting freedom of movement, provides attachment sites for many muscles, the ribs, and connective tissue
upper body long bones
humerus (upper arm bone), clavicle (collar-bone) radius and ulna (forearm bones) metacarpals and phalanges (finger bones)
epimysium
inner layer of fascia that directly surrounds an entire muscle " deep fascia"
articular (hyaline) cartilage
internal structure of long bone; cartilage that covers the articular surfaces of bones
the cervical curve of the spine
is concave - hollowed/rounded inward
the lumbar curve of the spine
is concave - hollowed/rounded inward
the thoracic curve of the spine
is convex - curved/rounded outward
when looking at the spinal column from the side,
it has a shape of the letter s - optimal arrangement of curves
bones form junctions that are connected by muscles and connective tissues known as
joints
Nonsynovial joints
joints that have no joint capsule, connective tissue, or cartilage in the uniting structure; exhibit little to no movement ex) structures of the skull
proprioception
key sensory function that allows the body to naturally sense its general orientation and relative position of its parts; training this can improve balance, coordination and posture enabling the body to accept its surroundings without consciously thinking about what movement is appropriate for a situation
resting length
length of a muscle when it is not actively contracting or being stretched
tropomyosin
located on actin filament and blocks myosin binding sites located on the actin filament - keeping myosin from attaching to actin when the muscle is in a relaxed state
troponin
located on actin filament and plays a role in muscle contraction by providing binding sites for both calcium and tropomyosin when a muscle needs to contract
long bones
long, cylindrical shaft with irregular or widened ends; have light curvature necessary for efficient force distribution; spongy bone tissue for shock absorption
5 types of bones in skeletal system
long, short, flat, irregular, sesamoid
smooth muscle
makes up tissues of internal organs
electrolytes
minerals that have an electrical charge to help transmit nerve impulses throughout the body; sodium, potassium, magnesium, water; adequate amounts must be maintained to produce proper nerve function
ball-and-socket joints
most mobile of the joints, allowing movement in all three directions; shoulder and hips
all or nothing principle
motor units cannot vary the amount of force they generate; they either contact maximally or not at all; Type of motor units making up a particular muscle will relate directly to the function of that muscle; Muscles that control the eyes/fingers will have fewer fibers per unit; Muscles involved in powerful movements - quads during squat - have more fibers per motor unit
osteokinematics
movement of a limb that is visible - flexion and extension
cardiac muscle
muscle tissue of the heart
skeletal muscle
muscle tissue that connects to bones and generates the forces that create movement;
activation of GTO's cause
muscles to relax, preventing them from excessive stress and possible injury
where are mechanoreceptors located
muscles, tendons, ligaments and joint capsules; includes: muscle spindles, golgi tendon organ, joint receptors
each individual muscle fiber is made up of structures called
myofibrils
power stroke
myosin heads bind to actin and pull them toward the sarcomere center, which slides the filaments past each other, shortening the muscle
action potential
nerve impulse that is relayed from the central nervous system, through the peripheral nervous system and into the muscle across the neuromuscular junction; electrolytes sodium and potassium help relay impulse down the nerves to neuromuscular junction
peripheral nervous system (PNS)
nerves that connect the rest of the body to the central nervous system (and external environment); provides sensory information via the afferent pathway
nervous system
network of specialized cells (neurons) that transmit and coordinate signals, providing a communication network within the human body; provides sensory info, stimulates human movement through muscle contractions, keeps heart and organs functioning
stretch reflex
neurological signal from muscle spindle that causes a muscle to contract to prevent excessive lengthening; when muscle spindle stretched, impulse immediately sent to spinal cord and a response to contract muscle is received in 1-2 milliseconds
motor function
neuromuscular (or nervous and muscular systems) response to integrated sensory information via efferent pathway; causes muscles to contract when stretched too fat or changing ones walking pattern
interneurons
neurons located within the spinal cord brain that transmit impulses between afferent and efferent neurons
saddle joint
one bone looks like a saddle with the articulating bone straddling it like a rider; found only in the carpometacarpal joint in the thumb; movement predominantly in two directions
rolling joint movement
one joint rolls across the surface of anther; bike tire on street ex) femoral condyles roll over the tibial condyles during a squat
spinning joint movements
ones joint surface rotates on another; twisting lid off a jar; head of the radius rotating on end of humerus during pronation and supination of the forearm
sliding joint movement
ones joint surface slides across another; bike skidding across street; tibial condyles slide across femoral condyles during knee extension or squat
what are the two ways to describe the movement of skeletal componenets
osteokinematics and arthrokinematics
fascia
outermost layer of muscle, connective tissue that surrounds muscles and bones
mitochondria
parts of the cell that use nutrients to create energy for the cell; "powerhouse of the cell"
growth, maturation and functionality of the skeletal system are affected by
physical activity and nutrition status
excitation-contraction coupling
physiological process of converting an electrical stimulus to a muscle contraction
the rapidness of the stretch reflex is designed to
prevent over-stretching and potential muscle damage
remodeling
process by which bone is constantly renewed by the resorption and formation of the bone structure by special cells
What is the name for projections protruding from the bone to which tendons and ligaments attach?
processes
what do synovial joints do
produce synovial fluid that resembles egg whites and works like engine oil; secreted within joint capsules and are essential for lubricating the joint surfaces to reduce excessive wear
processes
projections protruding from the bone to which tendons and ligaments can attach: common ones being process, condyle, epicondyle tubercle and trochanters
myoglobin
protein-based molecule that carries oxygen molecules into muscles
joint receptors
receptors located in and around the joint capsule that respond to pressure, acceleration and deceleration of the joint; act to initiate a reflexive (autonomic) inhibitory response in surrounding muscles if there is too much stress being placed on that joint
epiphyseal plate
region of long bone connecting the diaphysis (shaft) to the epiphysis (end)
What is the process by which bone is constantly renewed?
remodeling
neutral spine
represents a position in which the vertebrae and associated structures are under the least amount of load and can most optimally support functional movement
levers
rigid rods where muscles attach; when a muscle contracts, it pulls on respective bone which produces movement
3 types of arthrokinematic motion
roll, slide/glide, spin
examples of flat bones
scapulae (shoulder blades), sternum (breast plate), ribs, ilium (pelvis) and cranial (skull) bones
Wolff's Law
scientific explanation of how bone remodeling occurs along the lines of stress placed on the bone
the nerves of the PNS are how the CNS receives
sensory input, the CNS integrates that info and sends a response to the rest of the body
afferent pathway
sensory pathway that relays information to the central nervous system
muscle spindles
sensory receptors sensitive to change in length of the muscle and the rate of that change; run parallel to muscle fibers; helps regulate contraction of muscles through stretch reflex mechanism
what are the 3 primary functions of the nervous system
sensory, integrative, motor functions
diaphysis
shaft portion of a long bone
What is a characteristic of a type II muscle fiber?
short-term contractions
short bones
similar in length and width and appear somewhat cubical in shape; consist primarily of spongy bone tissue to maximize shock absorption
joints
sites/junction where two bones meet and movement occurs as a result of muscle contraction
what are the 3 types of muscles in the body?
skeletal, cardiac, smooth
type 1 muscle fibers
slow-twitch, muscle fibers that are small in size, generate lower amounts of force and are more resistant to fatigue, contract slowly, have more capillaries, mitochondria and myoglobin (more oxygen delivery), long-term contractions (stabilization), Myoglobin similar to hemoglobin: red oxygen carrying pigment found in red blood cells - thus type I muscle fibers are often called "red fibers"
sesamoid bones
small, often round bones embedded in a joint capsule or found in locations where a tendon passes over a joint; patella (knee cap) and in hands and feet; serve to improve leverage and protect joints from damage; develop within particular tendons at a site of considerable friction or tension
capillaries
smallest blood vessels and the site of exchange ov elements between blood and tissues
osteoclasts
special cells that break down and remove old bone tissue; contribute to bone remodeling
osteoblasts
special cells that form and lay down new bone tissue; contribute to bone remodeling
neurons
specialized cells that are the functional units of the nervous system; allow nervous system to communicate with itself and outside environment, process/transmit info through electrical and chemical signals, form core of nervous system: brain, spinal cord and peripheral nerves
golgi tendon organ (GTO)
specialized sensory receptor located at the point where skeletal muscle fibers insert into the tendons of skeletal muscle; sensitive to changes in muscular tension and the rate of that tension change
neuromuscular junction
specialized site where the nervous system communicates directly with muscle fibers
sensory receptors
specialized structures located throughout the body that convert environmental stimuli (heat/light/sound/taste/motion) into sensory info that the brain and spinal cord use to produce a response; use afferent pathway
mechanoreceptors
specialized structures that respond to mechanical forces (touch and pressure) within tissues and then transmit signals through sensory nerves
motor skills
specific movements through the coordinated effort of the sensory and motor subsystems; nervous system helps individuals perform these skills; necessary to perform physical activity
calcium helps
stimulate actin and myosin activity inside muscles
medullary cavity
structure of long bone; central cavity of bone shaft where marrow is stored
periosteum
structure of long bone; dense fibrous membrane that covers the bone, provides an attachment site for tendons, and connects nerves, blood vessels, and bone-producing sites
somatic nervous system
subdivision of the PNS, serves the outer areas of the body and skeletal muscle and are largely responsible for the voluntary control of movement
sympathetic nervous system
subdivision of the autonomic nervous system that works to increase neural activity and put the body into a heightened state; during exercise, signals endocrine organs to release hormones like adrenaline which increase heart rate, breathing and alertness "fight or flight"
the autonomic nervous system is divided into
sympathetic and parasympathetic nervous systems
Which joints are most associated with human movement?
synovial
structure of synovial joints
synovial capsule (collagenous structure surrounding the entire joint), synovial membrane (inner layer of the capsule, and cartilage that pads the end of the articulating bones
Muscles are connected to bones by
tendons
what are the connective tissues that support bone articulations of joints?
tendons and ligaments
sensory information is transferred via
the afferent pathway (PNS to CNS)
neuroplasticity
the concept that the brain will continually change or grow, reforming neural pathways throughout an individuals entire lifespan
condyloid joints
the condyle of one bone fits into the elliptical cavity of another bone to form the joint; due to shape, movemnent predominantly occurs in one direction with minimal movement in others ex) joints of the fingers
motor information is transferred via
the efferent pathway
the info from the CNS is relayed to the PNS via
the efferent pathway
neurocircuitry
the interconnection of neurons in the brain and spinal cord; occur with acquisition of new skills; as we get older these skills are harder to learn
water is considered
the main electrolyte of the body; electrically conductive
z-line
the meeting point of each sarcomere
the muscular system links
the nervous and skeletal systems; responsible for generating forces that move the human body
neural activation
the nervous systems signal that tells a muscle to contract; link between muscular and nervous system
sliding filament theory
the series of steps in muscle contraction involving how myosin (thick) and actin (thin) filaments slide past one another to produce a muscle contraction, shortening the entire length of the sarcomere
a muscle contraction is (in terms of the myofilaments)
the shortening of sarcomeres that contain actin and myosin
the PNS is divided into
the somatic and autonomic nervous system
sarcomere
the structural unit of a myofibril composed of actin and myosin filaments between two Z-lines; the specific site where muscle contraction occurs
actin
the thin, string-like myofilament that acts along with the myosin to produce muscular contraction
myosin
thick myofilament that acts along with actin to produce muscular contraction
flat bones
thin, protective surfaces that provide broad surfaces for muscles to attach; have two layers of compact bone tissue to protect internal structures and provide broad attachment sites for muscles
organelles
tiny cellular structures that perform specific functions within a cell
potassium and sodium help
transmit motor signals down nerve axon
Which of the following protein structures is important for muscular contractions by providing a binding site?
troponin
smaller muscles with the primary purpose of stabilizing the body are mostly made up of
type 1 muscle fibers
muscles are divided into motor units
type 1 muscle fibers (small motor units) and type 2 muscle fibers (larger motor units)
type II muscle fibers are further divided into
type IIA and IIX (based on their chemical and mechanical properties)
trochanters
type of process; located at the top of the femur (thigh bone) and are attachment sites for hip musculature
tubercles
type of process; located at top of humerus at the glenohumeral (shoulder) joint - greater and lesser tubercles are attachment sites for shoulder musculature
epicondyles
type of process; located on the inner and outer portion of the humerus to help form elbow joint
hinge joints
uniaxial joint allowing movement predominantly in one direction; elbow, ankle
irregular bones
unique shape and function from all other bone types; vertebrate (spinal column)
sprain
when a ligament is torn/overstreched
strain
when a tendon is torn/overstretched
fascicles
within muscles, largest bundles of fibers within a muscle, surrounded by perimysium
