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