5 THE HEAD Flashcards
What was the primary focus of Cesare Lombroso’s work?
The nature of the criminal
Lombroso believed that criminals exhibited anatomical features that indicated their criminal instincts.
How long can a brain function after decapitation?
Estimates range from two seconds to seven seconds
This is assuming a clean removal, which is not always the case.
What did observers claim to have seen in decapitated heads?
Evidence of consciousness
Examples include blinking or moving lips, and a man named Terier turning his gaze after fifteen minutes.
What two disciplines rose in the nineteenth century regarding the study of the head?
Phrenology and craniometry
Phrenology correlated skull bumps with mental attributes, while craniometry focused on precise measurements.
Who was Barnard Davis and what was his contribution?
A doctor and craniometry enthusiast who built the world’s largest skull collection
He produced numerous books on craniometry and collected 1,540 skulls.
What was Davis’s fundamental ambition regarding race?
To prove that dark-skinned people were created separately from light-skinned people
He believed that intellect and moral qualities were determined by skull shape and race.
What condition did John Langdon Haydon Down describe in 1866?
Down’s syndrome
He referred to it as ‘Mongolism’ and associated it with an inferior ethnic regression.
What did Cesare Lombroso theorize about the physical appearance of criminals?
Criminals had anatomical features indicating evolutionary throwbacks
Features included the slope of the forehead and ear shapes.
What significant discovery did Pierre Paul Broca make?
The brain’s speech center in the frontal lobe
This discovery linked a specific brain area to the function of speech.
What did Charles Darwin’s 1872 work focus on?
Expressions of emotions in humans and animals
He argued that certain expressions are common across all peoples.
How many facial expressions can humans make according to estimates?
Estimates range from 4,100 to 10,000
More than forty muscles are involved in facial expressions.
What did Paul Ekman conclude about facial expressions?
Six expressions are universal: fear, anger, surprise, pleasure, disgust, and sorrow
A smile is the most universal expression.
What are ‘microexpressions’?
Flashes of emotion lasting no more than a quarter of a second
They reveal true inner feelings regardless of controlled expressions.
What anthropological feature is unique to humans?
The chin
Its purpose is not clearly understood.
What is notable about human noses compared to other mammals?
Humans have round, projecting noses instead of snouts
This adaptation has helped with breathing efficiency and thermoregulation.
What is the function of eyebrows in humans?
To convey feelings and keep sweat out of the eyes
Eyebrows send various messages through their movements.
What did the experiment with digitally doctored photographs reveal about eyebrows?
Subjects found it harder to identify celebrities without eyebrows than without eyes
This highlights the importance of eyebrows in facial recognition.
What is the primary function of human facial features?
To help us interpret the world through our senses
Humans have more than five senses, including balance and proprioception.
What is unique about the human chin?
It is unique to humans, and its purpose is not clearly understood
The chin may be perceived as aesthetically pleasing.
How many systems do humans have that help them understand their environment?
As many as thirty-three systems
This includes senses beyond the traditional five.
What percentage of the cerebral cortex is engaged with vision?
About one-third
Vision is a complex and critical sense for humans.
What is the technical name for the phenomenon of seeing white sparks in a blue sky?
Scheerer’s blue field entoptic phenomena
This phenomenon is caused by white blood cells in capillaries.
What are floaters in the eye caused by?
Clumps of microscopic fibers in the vitreous humor
Floaters are generally harmless but can indicate retinal issues.
What does the cornea do?
Protects the eye and does two-thirds of the eyeball’s focusing
The lens only does about one-third of the focusing.
What are the three varieties of tears?
- Basal tears
- Reflex tears
- Emotional tears
Emotional tears are unique to humans.
What gives the eye its color?
The iris
The iris is made of muscles that adjust the pupil’s opening.
What is the sclera?
The white of the eye
Scleras allow for precise monitoring of gazes.
What are the two types of photoreceptors in the eye?
- Rods
- Cones
Rods help in dim light, while cones enable color vision.
What is the range of colors the human eye can distinguish?
Between 2 million and 7.5 million colors
This varies according to different calculations.
What is a blind spot in the human eye?
A portion of the visual field where no photoreceptors are present
The brain fills in this gap through perceptual interpolation.
What are the three parts of the ear?
- Outer ear
- Middle ear
- Inner ear
Each part plays a crucial role in the auditory process.
What are the tiny bones in the middle ear called?
Ossicles
The ossicles consist of the malleus, incus, and stapes.
What does the cochlea do?
Transforms sound waves into signals for the brain
It contains delicate hair-like filaments called stereocilia.
What is the tympanic membrane commonly known as?
The eardrum
It marks the boundary between the outer ear and middle ear.
What is the evolutionary significance of the ossicles?
They were jawbones in ancient ancestors that migrated to the inner ear
This demonstrates the adaptability of evolution.
Fill in the blank: The eye is filled with a gel-like material called _______.
vitreous humor
Humor refers to any fluid or semifluid in the body.
How do the structures of the outer ear contribute to hearing?
They capture sounds and help locate their source
This feature is essential for survival, having evolved from prey ancestors.
What is the pressure wave that activates the ossicles and reaches the brain as sound?
A pressure wave that moves the eardrum by less than the width of an atom
This demonstrates the sensitivity of human hearing.
What is the range of sound from the quietest detectable sound to the loudest?
About a million million times of amplitude.
What is the purpose of the acoustic reflex?
To protect us from damage caused by really loud noises.
How long does it take for the muscle involved in the acoustic reflex to contract?
About a third of a second.
What happens to stereocilia as we age?
They tend to wear out and do not regenerate.
Who coined the term ‘decibel’?
Colonel Sir Thomas Fortune Purves.
What does the decibel scale measure?
The power, intensity, and loudness of different sounds.
What is the pain threshold for noise in decibels?
About 120 decibels.
What is the vestibular system responsible for?
Keeping you balanced.
What effect is felt when changing heights rapidly, such as during airplane landing?
The Valsalva effect.
What is the Valsalva maneuver?
Making your ears pop by blowing out while keeping your mouth and nose closed.
What is the largest research institution dedicated to taste and smell?
The Monell Chemical Senses Center.
How many types of odor receptors do humans have?
Approximately 350 to 400 types.
What is anosmia?
Total smell loss.
What is hyposmia?
Partial loss of smell.
What is cacosmia?
A condition where everything smells like feces.
Which part of the brain does smell information go to?
The olfactory cortex.
What is the relationship between smell and memory?
Smell is thought to evoke powerful memories.
What is the main cause of smell loss?
Infectious diseases like flu and sinusitis.
What percentage of people who lose smell through head injury never regain it?
Ninety percent.
What is the significance of smell in interpreting the world?
It is crucial for getting pleasure from experiences, especially food.
Fill in the blank: The sum of two 10-decibel sounds is not 20 decibels but _______.
13 decibels.
True or False: Humans can discriminate about ten thousand different smells.
False.
What did researchers find about the number of smells humans can detect?
At least a trillion, possibly more.
What happens to the gel inside the vestibular system as we age?
It thickens and doesn’t slosh around as well.
