Body Systems 1
Because its cells are dense with energy-generating mitochondria, which of your muscles never tires?
A. heart
B. triceps
C. tongue
The heart is a muscle made of cardiomyocytes, cells that have 10 times the density of mitochondria (commonly known as “the powerhouse of the cell”). This allows the heart to keep pumping without getting fatigued.
Which of these body parts has the most bones?
A. rib cage
B. foot
C. hand
The hand has 14 phalanges, or finger bones, 5 metacarpal bones that make up the middle hand, and 8 carpal bones in the wrist for a total of 27 bones, the most of any body part.
True or false: Human embryos have a tail for several weeks during gestation.
TRUE! About the fifth or sixth week of development, human embryos develop a lengthy tail—about 10–12 vertebrae long. The tail usually gets absorbed by the rest of the body, becoming the coccyx (tailbone).
Which of these is true about the outer part of the eye called the cornea?
A. it stays the same size from birth
B. it changes color based on your mood
C. it gets oxygen straight from the air, rather than from blood
The cornea does not contain blood vessels, since the opaque fluid would obscure vision. It needs to absorb oxygen from other places, such as tears and directly from the atmosphere.
The part of the brain primarily responsible for production of speech is the ____.
A. Broca area
B. thalamus
C. basal ganglia
The Broca area, or Broca’s area, is responsible for speech and speech function. It is located in the left hemisphere of the brain, and it is crucial to the development of articulate speech.
Beriberi, meaning “extreme weakness,” is the name of a disorder caused by a lack of which vitamin?
A. vitamin D
B. vitamin A
C. vitamin B1
Beriberi is a nutritional disorder caused by a deficiency of vitamin B1 (thiamin) and characterized by impairment of the nerves and heart. The term beriberi is derived from a Sinhalese word meaning “extreme weakness.”
Which of these bodily responses is a holdover from animal ancestors dealing with cold?
A. pupil dilation
B. goosebumps
C. increased saliva production
Goosebumps happen when tiny muscles in the skin’s hair follicles pull hair upright. For animals with thick fur, this offers greater insulation. Unfortunately, human body hair is too short to trap heat this way.
True or false: Stress can cause hair to turn gray.
TRUE! Norepinephrine, also known as noradrenaline, is a neurotransmitter that conveys the body's fight-or-flight response; it’s been shown to cause graying when injected into otherwise unstressed lab mice.
Where are red blood cells created?
A. spleen
B. bones
C. brain
Bone marrow, the soft gelatinous tissue that fills the cavity of your bones, produces all of your red blood cells as well as all of your platelets and most of your white blood cells.
Which of these is NOT a component of a neuron?
A. hydrocephalus
B. terminal buttons
C. myelin sheath
A. hydrocephalus. A neuron is made up of dendrites, axons, myelin sheaths, Schwann’s cells, nodes of ranvier, and terminal buttons.
We use only 80 percent of our brains.
TRUE OR FALSE!
Human brains are very efficient, and nearly 100 percent are in full use most of the time. Doctors thus take special care when operating on the brain to make sure no function is damaged.
Prosopagnosia is also known as ____.
A. sensory deprivation
B. touch sensitivity
C. face blindness
C. face blindness
Prosopagnosia is an impairment in the ability to recognize faces—hence, the colloquial name face blindness.
The paper-thin tympanic membrane can be found in what body part?
A. lung
B. colon
C. ear
Derived from the Latin for “drum” (also where timpani comes from), the tympanic membrane is the eardrum. When sound waves hit this membrane, it vibrates, sending signals to the inner ear and eventually to the brain.
If a frozen drink gives you “brain freeze,” which of these tactics helps ease the pain?
A. pressing your thumb against the roof of your mouth
B. holding your breath
C. blinking your eyes rapidly
When eating cold things too fast, the body tries to offset the lower temperature by quickly expanding blood vessels in the head. By pressing your tongue or thumb against the roof of your mouth, you help return your mouth’s temperature to normal.
Lunulae are small whitish half circles visible on what body part?
A. fingernails
B. kneecaps
C. nose
Lunulae are the half-moon circles that appear on the base of fingernails, most noticeably on thumbs. They sometimes provide clues to medical conditions; for example, their absence may be an indication of a vitamin B12 deficiency.
Which of these is a kind of flu?
A. H2O
B. HOV
C. H1N1
C. H1N1
H1N1, also called the swine flu, is an influenza virus.
The spleen is part of the lymphatic system.
TRUE OR FASE
TRUE!
The spleen is part of the lymphatic system. Located behind the stomach, it produces lymphocytes, which help our bodies fight infection.
Viruses can fight cancer.
TRUE OR FALSE
TRUE!
Viruses can be used to fight cancers of various kinds. Most treatments of this type are experimental.
True or false: Veins look blue because the unoxygenated blood in them is blue.
FALSE!
Red portions of the visible light spectrum easily penetrate skin and become absorbed by hemoglobin in the blood. Blue light scatters when it hits skin and gets reflected back to your eye, causing veins to appear blue.
Which of these body parts continues to get bigger with age?
A. ear
B. spine
C. thumb
Ears, as well as noses, get longer as people age, but they aren’t growing. Instead, they are being pulled by gravity, causing them to stretch about a 10th of an inch every 10 years.
True or false: Logical thinkers are left-brain dominant, while artistic people are right-brain dominant.
FALSE! Brain imaging technology has found that there is no such thing as dominance when it comes to the brain’s hemispheres. While both halves tend to handle separate tasks, they work together in complex ways and are not linked to specific personality traits.
Which of these is another name for growth hormone?
A. insulin
B. epinephrine
C. somatotropin
C. Somatotropin, or human growth hormone, is a peptide hormone secreted by the anterior lobe of the pituitary gland. It stimulates growth of bone and essentially all tissues of the body by stimulating protein synthesis and breaking down fat to provide energy.
A zygote is a ____________
A. an egg cell inside the ovary
B. a fertilized egg cell
C. male reproductive cell
B. a fertilized egg cell?
"Which of these is NOT a part of the brainstem?
A. cerebellum
B. medulla oblongata
C. pons
A. cerebellum
The brainstem is responsible for automatic functions of the body. It includes the medulla oblongata, the pons, and the midbrain. The cerebellum is located on the back of the brainstem but is not considered part of it.
The diaphragm moves this way when we inhale
UP OR DOWN
“The funny bone” is actually what type of anatomical part?
A. nerve
B. organ
C. bone
For much of its path from spine to finger, the ulnar nerve is protected by layers of bone and muscle. However, there is a four-millimeter-wide spot at the elbow where the nerve is vulnerable. Hitting this spot, called “the funny bone,” results in a tingling sensation.
Which of these fluids is cleared out of the body on an “escalator” of tiny hairlike cilia?
A. mucus
B. urine
C. bile
A. mucus. Often maligned as a gross side effect of being sick, mucus is constantly made by the body to line parts of the lung, where it catches harmful particles before they go too deep.
The visible spectrum that humans can see is vast.
TRUE OR FALSE
FALSE!
Humans can see a fairly narrow portion of the spectrum of visible light. This spans from 380 to 750 nanometers in wavelength.
Hair helps us hear.
TRUE OR FALSE
TRUE! Tiny hair cells in the cochlea of the ear, called the organ of Corti, serve as receptors for sound waves and help us hear.
Which of these is not a form of colour blindness?
A. myopia
B. protanopia
C. tritanopia
A. myopia
Myopia is nearsightedness, not a form of colour blindness. Colour-blind persons may be blind to one, two, or all of the colours red, green, and blue. Blindness to red is called protanopia; to green, deuteranopia; and to blue, tritanopia.