unit 5

Question 1

functions of the musculoskeletal system

Answer 1

supports and gives shape to the body
protects internal organs
stores calcium
hemopoiesis (blood cell production)
movement

Question 2

Four major bone types

Answer 2

Long bones - humerus (arm)
Short bones - carpals ( wrist)
Flat bones - frontal (skull)
Irregular bones - vertebrae (spinal cord)
Sesamoid bone - round - patella - kneecap

Question 3

Diaphysis or shaft

Answer 3

hollow tube of hard compact bone

Question 4

medullary cavity

Answer 4

hollow area inside diaphysis bone that contains yellow bone marrow

Question 5

epiphyses or ends of the bone

Answer 5

spongy bone that contains red bone marrow

Question 6

articular cartilage(Hyaline)

Answer 6

cover epiphyses and functions as cushion

Question 7

endosteum

Answer 7

membrane lining medulla cavity

Question 8

periosteum

Answer 8

strong membrane covering bone everywhere except at joint surfaces

Question 9

structure of flat bones

Answer 9

spongy bone layer sandwiched between two compact bone layers

Question 10

diploe

Answer 10

spongy bone layer of flat bone

Question 11

Bone development

Answer 11

early bone development
consist of cartilage and fibrous structures
osteoblast form new bone, and osteoclasts reabsorb bone
osteocytes are inactive osteoblast
cartilage models are gradually replaced by calcified bone matrix

Question 12

Hyoid bone

Answer 12

in the midline of the neck anteriorly at the base of the mandible and posteriorly at the fourth cervical vertebra

Question 12

Bones of the right arm

Answer 12

Elbow, and forearm (posterior view)

Question 13

Bones of the right arm

Answer 13

Elbow, and forearm (Anterior View)

Question 14

Bones of the right thigh

Answer 14

knee joint and leg

Question 15

bones of the right foot

Answer 15

phalanges/metatarsals/tarsals

Question 16

arches of the foot

Answer 16

Normal longitudinal arch
flatfoot
transverse arch

Question 17

Skeletal vibrations

Answer 17

size - male skeleton generally larger
shape of pelvis - male pelvis deep and narrow
female - pelvis broad and shallow
size of pelvic inlet - female pelvic inlet generally wider, normally large enough for baby’s head to pass through it
pubic angle - angle between pubic bones of female generally wider

Question 18

Male pelvis is a lot smaller compared to female pelvis

Question 19

Skeletal Variations
Age differences

Answer 19

the human skeleton reaches its mature state around age 25
after age 50, the density of bone often decreases slowly

Question 20

environmental factors

Answer 20

without enough calcium or vitamin D, the skeleton may show signs of degeneration
exercise has a profound effect on the skeleton

Question 21

Hemopoiesis

Answer 21

blood cell production

Question 22

Articulation of bones

Answer 22

Joints are also called articulations
Joints hold our bones together and make it possible for movement to occur
Every bone except the hyoid (which anchors the tongue) connects to at least one other bone

Question 23

kinds of joints

Answer 23

diarthroses - free movement
synarthroses - no movement (skull)
amphiarthroses - slight movement (vertebrae)

Question 24

Diarthroses

Answer 24

Most joints belong to this class structures freely moveable joints: joints capture and ligaments hold adjoining bones together but permit movement at joint

Question 25

articular cartilage

Answer 25

cover joints ends of bones and absorbs joints

Question 26

synovial membrane

Answer 26

lines joints capsule and secretes lubricating fluid

Question 27

joint cavity

Answer 27

space between joint ends of bones

Question 28

bursa

Answer 28

fluid filled pouch that absorbs shock inflammation of bursa called bursitis

Question 29

Diarthroses

Answer 29

functions of freely moveable joints ball and socket = shoulder and hip joints hinge joint - elbow joint = pivot - dens of axis rotation against atlas/ head of radius rotating against ulna = neck saddle - carpometacarpal joint of thumb = gliding - articular processes between vertebrae = intercarpal = intertarsal condyloid - atlantoocipital joint = jaw = finger allow different kinds of movements determined by the structure of each joint

Question 30

Types of joints movements

Question 31

flexion

Answer 31

reduces angle, as bending the elbow

Question 32

extension

Answer 32

increases the angle, as in straightening the elbow

Question 33

abduction

Answer 33

to move a part away from midline

Question 34

adduction

Answer 34

to add or move a part toward the midline

Question 35

rotation

Answer 35

spins one bone and relative to another

Question 36

circumduction

Answer 36

moves the distal end of a bone in a circle, proximal end relatively stable

Question 37

Synarthroses

Answer 37

no movement fibrous connective tissue grows between articulation bones sutures of skull

Question 38

amphiarthroses

Answer 38

slight movement cartilage connects articulating bones symphysis pubis

Question 39

MUSCLE

Question 40

Muscular tissue enables the body and its parts to move Three types of muscle tissue exist in body movement caused by muscle cells (fibers) shortening or contracting Muscle movement occurs when chemical energy (food converted to energy)

Question 41

Skeletal muscle

Answer 41

Also called striated or voluntary muscle microscope reveals crosswise stripes or striations contractions can be voluntarily controlled

Question 42

Cardiac muscle

Answer 42

Compose of bulk of heart cardiac muscle fibers are branched cardiac muscle fiber intercalated disks cardiac muscle fiber, interconnections allow heart to contract efficiently as a unit

Question 43

smooth muscle

Answer 43

also called nonstriated or visceral muscle lacks cross stripes or striation when seen under a microscope; appears smooth found in walls of hollow structures, such as digestive tract, blood vessel, and so on contraction not under voluntary control

Question 44

structure of skeletal muscle

Answer 44

muscle organs: mainly striated muscle fibers and connective tissue connective tissue forms wrappers around each muscle fiber, around the fascicles of muscle fiber, and one around the entire muscle; fascia surrounds muscle organa and nearby

Question 45

regions of skeletal muscle

Answer 45

origin; attachment to the bone that remains relatively stationary or fixed when movement at the joint occurs Insertion: point of attachment to the bone that moves when a muscle contracts Body: main part of the muscle

Question 46

muscle attach to the bone by tendons

Answer 46

strong cords or sheets of fibrous connective tissue that extend from them muscle organ some tendons enclosed in synovial tubes and are lubricated by synovial fluid

Question 47

bursae

Answer 47

small synovial lined sacs containing small amount of synovial fluid: located between some tendons and underlying bones

Question 48

structure of skeletal muscle

Answer 48

Structure of muscle fibers (Figure 8-3) and contraction of muscle fibers Contractile cells are called muscle fibers; connective tissue holds muscle fibers in parallel groupings Fibers of the cytoskeleton form cylinders that contain thick myofilaments (containing myosin) and thin myofilaments (containing mainly actin)

Question 49

Basic functional (contractile) unit called sarcomere Sarcomeres separated from each other by dark bands called Z lines Sliding filament model explains mechanism of contraction Thick and thin myofilaments slide past each other to contract Contraction requires calcium and energy-rich adenosine triphosphate (ATP) molecules

Question 49

Movement Muscles produce movement by pulling on bones 
as a muscle contracts The insertion bone is pulled closer to the origin bone Movement occurs at the joint between the origin 
and the insertion

Question 50

Groups of muscles usually contract to produce a single movement Prime mover: Mainly responsible for producing a given movement Synergist muscles: Help the prime mover produce a given movement Antagonist muscles: Oppose the action of a prime mover in a given movement

Question 50

Posture A continuous, low-strength muscle contraction called tonic contraction (muscle tone) enables us to maintain body position Only a few of a muscle’s fibers shorten at one time Produce no movement of body parts Maintain muscle tone called posture Good posture favors best body functioning Skeletal muscle tone maintains good posture by counteracting the pull of gravity

Question 51

Heat production Survival depends on the body’s ability 
to maintain a constant body temperature Fever: An elevated body temperature; often a sign of illness Hypothermia: A reduced body temperature Contraction of muscle fibers produces most 
of the heat required to maintain normal body temperature

Question 52

muscle fatigue

Answer 52

a decrease in maximal force or power production in response to contractile activity

Question 52

motor unit

Answer 52

stimulation of a muscle by a nerve impulse 
is required before a muscle can shorten and produce movement A motor neuron is the specialized nerve that transmits an impulse to a muscle, causing contraction Neuromuscular junction (NMJ): Point of contact between a nerve ending and the muscle fiber Motor unit: Combination of a motor neuron with the muscle fibers it controls (Figure 8-5)

Question 52

Reduced strength of muscle contraction Caused by repeated muscle stimulation without adequate periods of rest Repeated muscular contraction depletes cellular ATP stores and outstrips the ability of the blood supply to replenish oxygen and nutrients Contraction in the absence of adequate oxygen produces lactic acid, which contributes to muscle soreness

Question 53

Oxygen debt: Used to describe the metabolic effort required to burn excess lactic acid that may accumulate during prolonged periods of exercise Labored breathing after strenuous exercise is required to “pay the debt” This increased metabolism helps restore energy and oxygen reserves to pre-exercise levels

Question 54

role of the other body system in movement

Answer 54

Muscle functioning depends on the functioning of many other parts of the body Most muscles cause movements by pulling 
on bones across moveable joints Respiratory, circulatory, nervous, muscular, 
and skeletal systems play essential roles 
in producing normal movements Multiple sclerosis, brain hemorrhage, and spinal cord injury are examples of how pathological conditions in other body organ systems can dramatically affect movement

Question 55

cytokines

Answer 55

fix or repair the damaged muscles

Question 56

thin Actin

Question 57

Thick myosin

Question 58

Sliding filament theory

Answer 58

The muscle contracts when these filaments slide past each other, resulting in a shortening of the sarcomere and thus muscle

Question 60

muscle contraction is initiated when muscle fibers are stimulated by nerve impulse and calcium ions are released

Question 61

the troponin units on the actin myofilaments are bound by calcium ions

Question 62

The point of contact between the nerve ending and the muscle fiber is called

Answer 62

neuromuscular junction

Question 63

what role does acetylcholine plays in muscle contraction?

Answer 63

excite the activation of muscle function properly

Question 64

muscle will only contract if an applied stimulus reaches a certain level on intensity Threshold stimulus: minimal level of stimulation required to cause a muscle fiber to contract

Question 65

types of skeletal muscle contractions

Answer 65

twitch = is a quick, jerky response to stimulus tetanic = more sustained and steady isotonic = produces movement at a joint isometric = muscle contracts and no movement

Question 66

concetric contraction

Answer 66

muscle shortens

Question 66

eccentric contraction

Answer 66

muscle lengthens but still provides work

Question 66

isotonic contraction = examples

Answer 66

bicep burls, push-ups, pull-ups, and contractions occurring in the legs while running.

Question 67

isometric example

Answer 67

planking, isometric exercise is any type of exercise that holds the body in one position

Question 68

performing heavier task or duty, motor neuron will signals to all our body to help achieve the goal

Question 68

brain signals to motor neuron, when they receives the message, muscle begins to contract the bigger the challenges we face, bigger signals will create

Question 69

injured cells released

Answer 69

cytokines active the immune system to repair the injuries = makes the muscle bigger and stronger

Question 70

hypertrophy

Answer 70

focuses mostly on developing your muscles

Question 71

muscle atrophy

Answer 71

the decrease in size and wasting of muscle tissue.

Question 72

why do we need smooth ER?

Answer 72

production of lipids and some carbs

Question 74

ribosomes are attached to the rough ER

Question 75

underneath the golgi, their are granules called lysosomes

Question 76

why do we need the nucleus?

Answer 76

DNA = master code = codon

Question 77

ribosomes makes the protein = protein factories = will move around ER then goes to golgi = packaged and shipped

Question 78

why do we need smooth eR?

Answer 78

production of lipids

Question 79

golgi apparatues

Answer 79

packaged the proteins

Question 80

why do we need mitochondria?

Answer 80

produces energy = power plant

Question 81

what lysosomes do?

Answer 81

digestive bags

Question 82

cell membrane