Question | Answer |
The hard, supportive structure in our bodies is the ___ system | skeletal |
The human body has over 200 ___ made of cells, collagen, and calcium | bones |
The skeletal system provides ___, protection, and movement for the body | support |
___ vessels and nerves enter and leave through holes in bones. | Blood |
The skull, ___, and ribs protect the brain, spinal cord, and heart and lungs,respectively. | vertebrae |
The skeletal system provides attachment points for ___, which allow movement | muscles |
The ___ in the middle of some bones is where blood cells are formed. | marrow |
Bones connect at ___ | joints |
___, which hold bones together at joints, are flexible because they have less calcium | Ligaments |
___, found in ears and noses, is a flexible elastic tissue made of collagen. | Cartilage |
___ joints, found in fingers, elbows, and knees, allow back-and-forth movement | Hinge |
The thumb, the only ___ joint in the body, allows a wider range of motion | saddle |
___-___-___ joints, such as in shoulders and hips, can rotate and move in every direction. | Ball-and-socket |
An ___ joint, such as in knuckles, is similar to a ball-and-socket but cannot move in as many directions | ellipsoid |
In a ___ joint, the cylindrical region of one bone fits into a ring-shaped structure ofanother joint. | pivot |
The joint between the first two neck ___ is a pivot joint. | vertebrae |
Two bones that connect at flat surfaces form a ___ joint, such as in ankles and wrists. | gliding |
An ___ joint holds two bones firmly together, allowing little or no movement. | immovable |
The ___ contains immovable joints. | skull |
The ___ system allows the body to move. | muscular |
Muscle tissue is made of bundles of long muscle cells called muscle ___. | fibers |
Muscle fibers contain bundles of tubes that contain muscle ___. | filaments |
When a muscle ___, the muscle filaments move closer to each other and the muscle shortens | contracts |
When a muscle ___, the muscle filaments move away from each other. | relaxes |
Muscles contract when they receive chemical signals from the ___ system | nervous |
Muscle cells contain more ___ than other cells to produce ___ needed forcontraction. | mitochondria, energy |
Muscles have a large network of ___ vessels that supplies them with oxygen for cellular ___. | blood, respiration |
Muscles can be either voluntary or ___. | involuntary |
A voluntary muscle, such as those in hands, arms, and legs, is one you can ___. | control |
An involuntary muscle, such as the heart or ___, works without you having to thinkabout it. | stomach |
Muscle cells form three types of muscle ___ in the human body. | tissue |
___ muscle tissue causes movement. | Skeletal |
Cardiac muscle tissue is found only in the ___. | heart |
___ muscle tissue, found in internal organs such as your stomach and blood vessels, ___ contracts and relaxes. | Smooth, slowly |
The muscular system must interact with the skeletal system to produce ___. | movement |
___ connect bones to muscles and do not stretch as much as ligaments. | Tendons |
Tendons, ligaments, and cartilage are all ___ tissue. | connective |
The body moves through ___ and extension. | flexion |
In flexion, the bending of a limb ___ the angle between the bones of the limb. | decreases |
In ___, the limb straightens and increases the angle between bones of the limb. | extension |
The ___ system works to move the body. | musculoskeletal |
A ___ is a simple machine made of anything rigid that pivots around a fixed point. | lever |
The ___ is the fixed point around which a lever pivots. | fulcrum |
The ancient Greek mathematician ___ (287-212 B.C.) first described levers. | Archimedes |
Three ___ of levers are determined by location of the fulcrum, load, and applied force. | classes |
___ force is the force needed to move an object over a distance. | Effort |
___ force is the force that opposes the effort force. | Resistance |
The ___ the effort force is to the fulcrum, the more effort force it will take to use the lever. | closer |
The closer the resistance force is to the fulcrum, the ___ resistance force it will take. | less |
In a ___-___ lever, the resistance force and the effort force are on opposite sides of the fulcrum. A ___-___, pliers, and scissors are examples of these. | first-class, see-saw |
In a second-class lever, the ___ force is between the fulcrum and the effort force. ___ ___ are examples of these. | resistance, Wheel barrows |
In a third-class lever, the effort force is between the resistance force and the ___. ___ ___, shovels, and rakes are examples of these. | fulcrum, Baseball bats |
Although ___-___ levers require more effort force, they are the most common levers in the body. | third-class |
First- and second-class levers could perform the same task using ___ force. | less |
___-___ levers make a much better arrangement for muscle attachment. | Third-class |
In biceps, a ___-___ lever would require a counter-balance if the pivot point was theelbow. | first-class |
In biceps, a second-class lever would require that muscles attach at the ___ if the pivot point was the elbow. | fingers |
___ are used to lift heavy objects or to move objects faster and farther. | Levers |
___ ___ is the ability of a machine to increase the amount of force put into the machine. | Mechanical advantage |
Mathematically, mechanical advantage (MA) is the ___ of the resistance force (FR) to theeffort force (FE). | ratio |
First- and second-class levers, such as see-saws and car jacks, make it easier to ___ heavy objects. | lift |
Third-class levers, such as baseball bats, make it easier to move objects ___ and faster. | farther |
Arrangements of muscles and bones in your body function in the same way as mechanical___. | levers |
In our bodies, multiple bones and joints act as levers and fulcrums, and muscles provide___. | force |
___ in your legs and arms allow you to move farther and faster. | Levers |
The ___ of levers in the body affects body strength. | length |
In activities such as arm wrestling or gymnastics, ___ men and women have a natural advantage because the effort force and resistance force are closer together. | shorter |