Curious About Muscles

PODCAST 232: CURIOUS ABOUT MUSCLES

RELEASE DATE: SUNDAY, MARCH 12TH, 2023

D:  HELLO, AND WELCOME BACK TO THE CURIOUS KID PODCAST.  WE GOT CURIOUS ABOUT BONES WAY, WAY, WAY BACK IN EPISODE 15, WHICH WAS 217 WEEKS AGO.  IT WAS OUR SECOND EVER LISTENER SUGGESTION EPISODE, AND IT WAS OUR FIRST EPISODE EXPLORING A PART OF THE HUMAN BODY.  TODAY, MORE THAN FOUR YEARS LATER, WE ARE GOING TO LEARN ABOUT ANOTHER VERY IMPORTANT PART OF OUR BODIES THAT WORK CLOSELY WITH BONES.  LET’S GET TO IT.

O:  MAILBAG!

D:  MAILBAG!

“HI JACOB AND OLIVIA,

MY NAME IS KOZMA AND I AM 10 YEARS OLD AND MY SISTER KIRA IS 7 YEARS OLD.  WE LIVE IN TWAIN HARTE, CALIFORNIA.  WE LOVE YOUR PODCAST.  WE LISTEN TO IT EVERY TIME WE DRIVE TO SOCCER OR GYMNASTICS PRACTICES.  OUR FAVORITE EPISODE IS THE ONE ABOUT SOCCER.  CAN YOU PLEASE MAKE AN EPISODE ABOUT THE HISTORY OF SPORTS?  WE WOULD LOVE TO HEAR ABOUT GREAT INVENTOR TESLA TOO.  WE ARE ALSO INTERESTED IN FINDING OUT MORE ABOUT THE HUMAN BODY, ESPECIALLY MUSCLES.  KEEP UP THE GREAT WORK!  BRAVO!

KOZMA AND KIRA”

O:  THAT WAS AN AWESOME EMAIL FROM LISTENERS ACROSS THE COUNTRY FROM WHERE WE LIVE.  WE CAN’T WAIT TO LEARN ALL ABOUT MUSCLES THIS WEEK FOR KOZMA AND KIRA.  

D:  MUSCLES ARE SUPER IMPORTANT, AND THEY ACTUALLY MAKE UP ABOUT 40% OF OUR BODY WEIGHT.  THERE ARE WELL OVER 600 MUSCLES IN OUR BODIES, AND YOU MAY HAVE EVEN HEARD THE NAMES OF SOME OF OUR MUSCLES BEFORE.

O:  THE QUESTION OF THE WEEK IS, WHERE IN THE BODY CAN YOU FIND THE DELTOID MUSCLES?

D:  WHILE YOU’RE THINKING ABOUT THE ANSWER LET’S START LEARNING ABOUT MUSCLES.

O:  ANY TIME YOU MOVE YOUR BODY, THE MOVEMENT IS CONTROLLED BY MUSCLES.  

D:  ALSO, EVEN WHEN YOU’RE NOT MOVING YOUR BODY, THERE ARE STILL MUSCLES IN YOUR BODY THAT ARE HARD AT WORK.  

O:  THERE ARE THREE DIFFERENT TYPES OF MUSCLES.  THE TYPE THAT PEOPLE USUALLY THINK OF WHEN THEY THINK OF MUSCLES IS CALLED SKELETAL MUSCLES.  THESE MUSCLES HELP US MOVE AROUND.  THEY ARE MADE UP OF LITTLE CELLS CALLED MUSCLE FIBERS.  THE MUSCLE FIBERS HAVE DARK AND LIGHT PARTS, SO IF YOU WERE TO ABLE TO LOOK AT YOUR SKELETAL MUSCLES, YOU WOULD NOTICE THAT THEY LOOK STRIPED.  THAT’S WHY THESE MUSCLES ARE OFTEN CALLED STRIATED MUSCLES INSTEAD OF SKELETAL MUSCLES.  STRIATED IS JUST ANOTHER  WAY OF SAYING STRIPED.     

D:  SKELETAL MUSCLES ARE VOLUNTARY MUSCLES, WHICH MEANS THAT YOU ARE ABLE TO CONTROL YOUR SKELETAL MUSCLES.  SKELETAL MUSCLES ARE CONNECTED TO OUR BONES USING TENDONS, WHICH JUST LOOK LIKE CORDS THAT CONNECT OUR MUSCLES AND BONES TOGETHER.  

O:  LIKE ALL MUSCLES, SKELETAL MUSCLES WORK BY CONTRACTING AND RELAXING.  WHEN A MUSCLE CONTRACTS, THE BONES THAT IT’S CONNECTED TO COME CLOSER TOGETHER.  WHEN A MUSCLE RELAXES, THE BONES DRIFT FURTHER APART.

D:  IN MANY CASES, OUR MUSCLES WORK IN PAIRS.  A GREAT EXAMPLE WOULD BE OUR BICEPS AND TRICEPS.  THE BICEPS AND TRICEPS ARE LOCATED IN THE UPPER ARM.  

O:  HAVE YOU EVER MADE A MUSCLE BEFORE?  WHEN YOU MAKE A MUSCLE, YOU ARE CONTRACTING YOUR BICEPS AND RELAXING YOUR TRICEPS.

D:  BY CONTRACTING THE BICEPS AND RELAXING THE TRICEPS, THE ARM BENDS AT THE ELBOW.  WHEN YOU STRAIGHTEN YOUR ARM BACK OUT, THE OPPOSITE WILL HAPPEN.  THE BICEPS WILL RELAX AND THE TRICEPS WILL CONTRACT.  

O:  THE NEXT TYPE OF MUSCLE IN OUR BODIES IS SMOOTH MUSCLE.  UNLIKE SKELETAL MUSCLES, SMOOTH MUSCLES DO NOT CONNECT WITH OUR BONES.  INSTEAD, THEY HELP CONTROL ORGANS IN OUR BODIES.  SMOOTH MUSCLES ARE CONSIDERED TO BE INVOLUNTARY MUSCLES, BECAUSE THEY WORK AUTOMATICALLY, WITHOUT US THINKING ABOUT IT.    

D:  ONE EXAMPLE OF SMOOTH MUSCLES ARE THE MUSCLES THAT CAN BE FOUND IN OUR DIGESTIVE SYSTEM.  OUR DIGESTIVE SYSTEM HELPS US DIGEST THE FOOD WE EAT.  WHEN YOU EAT FOOD, THE FOOD TRAVELS DOWN THE ESOPHAGUS BEFORE ENDING UP IN THE STOMACH.  IT’S OUR SMOOTH MUSCLES THAT CONTRACT AND RELAX, PUSHING THE FOOD DOWN INTO OUR STOMACHS.  

O:  SMOOTH MUSCLE CAN ALSO HELP US BREATHE.  THEY MOVE A PART OF THE BODY CALLED THE DIAPHRAGM, ALLOWING US TO BREATHE.  

D:  IT’S A GOOD THING THAT SMOOTH MUSCLES ARE INVOLUNTARY, AND WE DON’T HAVE TO THINK ABOUT THEM, BECAUSE THEY CONTROL DIFFERENT THING THAT NEED TO TAKE PLACE ALL THE TIME, LIKE DIGESTION AND BREATHING.  

O:  THE LAST, BUT ALSO VERY IMPORTANT, TYPE OF MUSCLE IS CALLED CARDIAC MUSCLE.  THIS TYPE OF MUSCLE HELPS PUMP OUR HEART AND IT HELPS MOVE BLOOD AROUND OUR BODIES.  

D:  THE MUSCLES OF THE HEART, WHICH ALSO HAVE THE COOL NAME MYOCARDIUM, CONTRACT TO PUMP BLOOD AROUND THE BODY, AND THEN RELAX TO LET BLOOD BACK INTO THE HEART.  THE CARDIAC MUSCLES ARE RESPONSIBLE FOR PUMPING AROUND 2500 GALLONS OF BLOOD EACH DAY.  THANKFULLY, CARDIAC MUSCLE IS ALSO INVOLUNTARY.  IT’S A REALLY GOOD THING THAT WE DON’T NEED TO PUT ANY THOUGHT INTO OUR HEART BEATING AND SUPPLYING THE REST OF OUR BODIES WITH BLOOD.  IT JUST HAPPENS AUTOMATICALLY.

O:  WHEN WE EXERCISE, WE ARE MAKING OUR MUSCLES BIGGER AND STRONGER.  EXERCISE IS IMPORTANT IN KEEPING US HEALTHY.  WITHOUT ENOUGH EXERCISE, OUR MUSCLES WOULD ATROPHY.  THAT JUST MEANS THAT THEY WOULD SHRINK AND BECOME WEAKER.

D:  THERE IS ALSO SOMETHING YOU MAY HAVE HEARD OF CALLED MUSCLE MEMORY.  WHEN WE PRACTICE SOMETHING OVER AND OVER, WE DEVELOP MUSCLE MEMORY.  THAT JUST MEANS THAT OUR MUSCLES TEND TO REMEMBER WHAT WE NEED TO DO TO PERFECT SOMETHING.  ONE EXAMPLE IS SHOOTING A BASKETBALL.  IF YOU PRACTICE TAKING FREE THROWS OVER AND OVER AGAIN, YOUR MUSCLES WILL REMEMBER HOW THEY NEED TO MOVE TO TAKE A GOOD SHOT.  THAT HELPS YOU GET BETTER AT SOMETHING WHEN YOU PRACTICE IT OVER AND OVER AGAIN.

O:  MUSCLE MEMORY ALSO WORKS FOR ME WHEN I PLAY THE PIANO.  SOMETIMES, I’LL START WORKING ON A DIFFICULT SONG, AND I WILL GET FRUSTRATED, BECAUSE I CAN’T GET MY FINGERS TO WORK THE WAY I WANT THEM TO.  THEN, I’LL JUST PRACTICE THE SONG A BUNCH OF TIMES, AND WITH LOTS OF PRACTICE, MY FINGERS WILL GET MORE COMFORTABLE PLAYING THE SONG.  

D:  MUSCLES ARE AMAZING, BUT THEY DON’T ALWAYS DO WHAT WE WANT THEM TO DO.  HAVE YOU EVER BEEN IN BED, TRYING TO FALL ASLEEP, WHEN YOU HAVE THIS TWITCH THAT SUDDENLY WAKES YOU BACK UP?  IT’S HAPPENED TO ME A FEW TIMES.  IN FACT, IT JUST HAPPENED TO ME A FEW NIGHT AGO.  WELL, THOSE TWITCHES ARE CALLED HYPNIC JERKS.  THEY ARE INVOLUNTARY MUSCLE CONTRACTIONS THAT HAPPEN AS PEOPLE FALL ASLEEP.  AS MANY AS 70% OF PEOPLE EXPERIENCE HYPNIC JERKS FROM TIME TO TIME.  THEY ARE ANNOYING, BUT THEY ARE ALSO ABSOLUTELY HARMLESS.  

O:  THE LARGEST MUSCLE IN THE BODY IS CALLED GLUTEUS MAXIMUS.  WHAT AN AWESOME NAME FOR THE LARGEST MUSCLE.  IT SOUNDS LIKE THE NAME OF A GLADIATOR.  THE GLUTEUS MAXIMUS IS LOCATED IN THE HIP AND BUTT.  IT HELPS US DO A LOT OF DAILY ACTIVITIES, AND IT IS THE MOST IMPORTANT MUSCLE NEEDED TO CLIMB STAIRS.

D:  THE SMALLEST MUSCLE IN THE BODY IS CALLED THE TENSOR TYMPANI, AND IT CAN BE FOUND IN THE INNER EAR.  THAT IS ALSO WHERE THE SMALLEST BONES IN OUR BODY ARE LOCATED.  

O:  THE STRONGEST MUSCLES IN THE BODY ARE FOUND IN THE JAW.  THEY ALLOW OUR JAWS TO APPLY A FORCE OF ABOUT TWO HUNDRED POUNDS.  THAT’S SOME STRONG CHEWING.

D:  THE LONGEST MUSCLE IS CALLED THE SARTORIUS.  IT GOES FROM THE HIP TO THE KNEE, AND IT HELPS US BEND OUR KNEES AND TWIST OUR LEGS.

O:  THE RIGHT SIDE OF THE BRAIN CONTROLS MUSCLE MOVEMENT ON THE LEFT SIDE OF THE BODY, WHILE THE LEFT SIDE OF THE BRAIN CONTROLS MUSCLE MOVEMENT ON THE RIGHT SIDE OF THE BODY.  THAT’S SO STRANGE.

D:  MUSCLES ARE MADE UP OF ABOUT 79% WATER.  

O:  I LOVE READING.  DID YOU KNOW THAT YOUR EYE MUSCLES MAKE ABOUT 10,000 MOVEMENTS PER HOUR WHILE YOU ARE READING?  THAT’S INCREDIBLE!

D:  BEFORE WE GET TO THE QUESTION OF THE WEEK, PREPARE YOURSELF FOR THE STRANGEST FACT ABOUT MUSCLES WE WERE ABLE TO FIND.  EVEN STRANGER THAN THE WHOLE RIGHT SIDE, LEFT SIDE THING.  THE WORD MUSCLE COMES FROM THE LATIN WORD MUSCULUS.  DO YOU WANT TO TAKE A GUESS WHAT THE LATIN WORD MUSCULUS MEANS?

O:  I’M GOING TO GUESS STRENGTH.  

D:  THAT’S A GREAT GUESS, BUT IT’S NOT CORRECT.  THE WORD MUSCULUS IN LATIN IS ACTUALLY AN ANIMAL.  IT KIND OF SOUNDS LIKE MUSCULUS.  TAKE ANOTHER GUESS.

O:  A MOUSE?

D:  THAT’S RIGHT.  MUSCULUS MEANS “LITTLE MOUSE”.  WHY WOULD THAT WORD BE USED TO DESCRIBE MUSCLES?  IT MIGHT BE BECAUSE SOME MUSCLES RESEMBLE A MOUSE, OR PERHAPS THAT A MUSCLE CONTRACTING UNDER THE SKIN KIND OF LOOKS LIKE A MOUSE MOVING UNDER A RUG.  

O:  THAT’S JUST A STRANGE FACT RIGHT THERE.

D:  IT SURE IS.  NOW, YOU’VE PROBABLY HEARD THE NAMES OF SOME MUSCLES BEFORE.  THE MOST COMMON MUSCLE NAMES ARE THE ONES THAT PEOPLE USUALLY WORK ON WHEN THEY ARE EXERCISING.  FOR EXAMPLE, THE PECTORALIS MUSCLE, SOMETIMES CALLED THE PECTORALS, OR JUST PECS, ARE MUSCLES THAT CAN BE FOUND IN THE CHEST.

O:  THE QUADRICEPS MUSCLES, OR QUADS FOR SHORT, CAN BE FOUND ON THE FRONT OF THE THIGHS.  PEOPLE WHO DO A LOT OF RUNNING OR BIKING OFTEN HAVE LARGE AND STRONG QUADS.

D:  THE QUESTION OF THE WEEK IS, WHERE IN THE BODY CAN YOU FIND THE DELTOID MUSCLES?

O:  THE DELTOID MUSCLES ARE LOCATED IN THE SHOULDERS.  THEY HELP MOVE YOUR SHOULDERS ALL AROUND.  THE DELTOID MUSCLES ARE REALLY IMPORTANT, ESPECIALLY WHEN YOU WANT TO SHOW SOMEONE THAT YOU ARE UNSURE OF SOMETHING BY SHRUGGING YOUR SHOULDERS.

D:  WELL, THAT’S A WRAP FOR THIS WEEK’S EPISODE.

O:  232 - MUSCLES.

D:  GREAT JOB OLIVIA, AND GREAT JOB KOZMA AND KIRA FOR THE EPISODE TOPIC SUGGESTION THAT TOTALLY WORKED OUT.  BEFORE WE SAY GOODBYE, WE HAVE A VERY SPECIAL LISTENER TO THANK.

O:  WE WANT TO THANK FLYNN FOR THE EPIC 5 STAR REVIEW.

D:  IT SAYS “ME AND MY FAMILY LOVE TO LISTEN TO YOUR PODCAST IN THE MORNING.  I BELIEVE IT’S VERY EDUCATIONAL AND I LEARN A LOT!”

O:  THANKS FLYNN, YOU’RE AWESOME.

D:  JOIN US NEXT WEEK, WHEN WE WILL GET CURIOUS ABOUT MOUNTAINS FOR LISTENERS IN TEXAS, NORTH CAROLINA, AND NEW ZEALAND.  AS ALWAYS, THANK YOU SO MUCH FOR LISTENING AND GETTING CURIOUS WITH US