Midweek Writer-Rummage - The Truth About Blood ... and the Heart.

Tying in with last week’s post about ‘fight scenes’, I thought it timely to share what I’ve compiled about blood

Even if descriptions of injuries are kept basic, I still think it’s helpful to have some knowledge of biology; if nothing else, it grounds the story, no matter how fantastical, in a reality that will, hopefully, not jar the reader out of the story.  Just to say, in a sort of disclaimer, I did not study biology at school, nor am I a medical practitioner – my knowledge comes from reading and research.  I apologise for any mistakes I may have inadvertently made; if I have, please point out said mistakes.

First, the heart – the body’s hardest-working muscle, it is basically 2 pumps, and each pump has 2 spaces called chambers.  The right side of the heart pumps blood to the lungs, where it picks up oxygen, and the left side pumps the oxygen-rich blood out into the body.  The pumps work in tandem as a precisely timed team.

Every heartbeat has 2 sounds – doctors call them ‘lub-dub’ noises, they are the sounds of the heart valves as they click open and shut.  ‘Lub’ is the sound of the tricuspid and mitral heart valves shutting (the valves on the top chambers); this is followed by a pause as the top chambers relax.  Then ‘dub’, which is the sound of the semilunar heart valves closing (these valves shut off the big vessels leaving the heart).  This is followed by a longer pause.  So what is heard is: lub-DUB – lub-DUB …

Now, on to blood. I have read many times, and been guilty of writing it myself, things like, “The ground was red with blood”.  While not actually wrong, it is misleading.  When blood is first spilled, it is red, very red.  That is because it is full of oxygen.  Once the blood has left the body, it is no longer being fed oxygen, and so begins to decay.  ‘Old’ blood is no longer red, but more of a dark brown.

Blood is also sticky.  Another thing I have been guilty of: “she slipped on the bloody ground”.  That is only realistic if it’s the beginning of a battle and blood is freshly spilled.  Any longer and the ground is more likely to be covered in a wet, sticky substance.  What the characters are most likely slipping on are the internal organs.  [Altogether now – yuck!]  And while we’re on the subject of internal organs …

Intestines are delicate and fragile.  Small intestines are about, on average, 22-23 feet in length.  If they’re ripped out, can you imagine trying to get them back in?  Gut wounds are extremely unpleasant.  If impaled, especially in the abdomen, do not pull the offending item out - this is basic first aid.  The very thing that is impaling you is the only thing holding your intestines in and stopping them falling out.

Bruises.  A common mistake is assuming that if a person hits a hard object, the bodily point of contact will immediately bruise – “She swung her fist at him.  He sidestepped; she hit the wall instead.  Cradling her hand against her body, she frowned at the sight of her bruised knuckles.”  (Excuse the poor example, just wanted to include something to illustrate.)  It is possible for bruises to appear within minutes, but they never form instantly.  It usually takes hours.  The injured flesh reddens, obviously, and then swells, but the swelling isn’t huge.  In the example above, ‘she’ would not see ‘bruised knuckles’; what ‘she’ would see are reddened knuckles, maybe even some swelling.  It’s only after an hour or so will ‘she’ see bruises.

Areas of the body that are blood-rich and unprotected by bone or hard muscle, like the head, can bruise quickly; again, ‘quickly’ still means minutes, not seconds.

To begin with, a bruise will be reddish in colour, reflecting the colour of the blood under the skin.  After a couple of days, it will appear purplish black; about a week later, it will change to green, and gradually to brownish-yellow as it heals.  Bruises over skin where the veins are close to the surface may appear bluish-green, reflecting the un-oxygenated blood just under the skin.  The blood is lacking oxygen because a vessel has either been torn and there is minor bleeding just under the skin, or the vessel walls have been weakened.  These kinds of bruises will appear more quickly than other types, tend to swell more and are especially tender to the touch.

I don’t feature modern weapons in my stories (yet …) but found these points about bullet wounds interesting.  Bullets cause bruising, and these can appear within minutes to hours.  Unless they’ve pierced a vital organ or blood supply, bullet wounds do not always bleed immediately.  Bullets are hot coming out of the barrel, and at close range, can cauterise the flesh when they enter the body.  The further the bullet travels, the cooler and slower it becomes.  Because of this, the bullet is more likely to become lodged in the body when fired from a distance.  Depending on where it becomes lodged in the body, it might block the blood supply and slow bleeding time.

Before I leave, I’m going to let my inner geek have some fun … Did you know:

  • The heart pumps between 1-7 gallons of blood a minute, depending on what you’re doing, and will pump as much as 2,000 gallons a day.  In a lifetime, the heart will pump one million barrels of blood.
  • The heart starts beating 4 weeks after conception, and keeps on beating until you die.  It beats 100,000 times a day, and almost one million times a week.  Although the heart can weaken for other reasons, it never tires out.  To get an idea of how hard our heart works, try squeezing a tennis ball (similar to the force of a beating heart) 100,000 times in one day.
  • Although the hearts of men and women look the same, they do not weigh the same.  A man’s heart, on average, weighs 10oz, while a woman’s weighs 8oz.  Because of the smaller size, a woman’s heart beats slightly faster – a man’s average heart rate is 70beats/minute, and a woman’s is 78beats/minute.
  • Your heart is about the same size as your fist.
  • Laid end to end, all the body’s blood vessels would measure about 60,000 miles.
  • The heart isn’t on the left side of the chest.  It actually sits in the centre of the chest between the lungs, just under the breastbone, but is tilted slightly to the left – it is here that it is most easily felt and heard, which is why people think the heart is on the left.
  • The heart will continue to beat even if it has been removed from the body.  This is because the heart has its own electrical system that causes the heart to beat.  So long as is continues to receive oxygen, it will continue to beat.
  • It is possible to suffer from a broken heart.  Emotional stress can cause a sudden temporary weakening of the heart, and this is known as ‘Takotsubo’s cardiomyopathy’ or ‘broken heart syndrome’.  The triggers can be the death of a loved one, supposed ‘fun’ things like a surprise party, even the fear of performing in public.  It primarily affects post-menopausal women, but is only temporary and, once supportive measures are put in place, the heart will, once again, function normally.