Exam 2 (Ch. 5-7 & 9) Flashcards
Maturation of the Vertebrate Brain
???
How the brain develops in infant.
What are the five stages in the development of neurons?
Proliferation, Migration, Differentiation, Myelination, and Synaptogenesis
What is proliferation?
Production of new cells/neurons in the brain that primarily occurs early in life.
(Cells tend to divide, but some will remain where they are or become neurons that migrate to other locations)
What is migration?
Movement of newly formed neurons and glia to their eventual locations (chemical trails)
What is differentiation?
Forming of the axon and dendrites that gives the neuron its distinctive shape
What is myelination?
Process by which glia produce the fatty sheath (myelin sheath) that covers the axons of some neurons.
(Myelin speeds up transmission of neural impulses. First occurs in spinal cord, then hindbrain, midbrain, and forebrain. Occurs gradually for decades)
What is synaptogenesis?
Final stage for formation of synapse between neurons
(Occurs throughout life, slows significantly later in lifetime, explains why babies sleep 12-16 hours a day)
The Brain and Experience
The brain doesn’t develop just because of genetics. The brain also develops because of a person’s experience, which is greatly responsible for the growth of brain.
What is the cornea?
Helps the eye to focus light in order to see clearly. Located in the front of the eye.
What is the lens of the eye?
Focuses light rays on the retina. Located in the front of the eye.
What is the pupil?
Controls how much light is let into the eye
What is the iris?
Colored area of eye & controls pupil
What are rods and cones?
Responds to color and bright light. Rods are most abundant in periphery of eye. Cones are most abundant in and around the fovea.
What is the blind spot of the eye?
It has no receptors. Located in the back of eye
What are bipolar cells in the eye?
The only neurons that connect the outer retina to the inner retina
What are ganglion cells of the eye?
They convey info from other retinal neurons to the rest of the brain
What is the optic nerve?
Consists of axons of ganglion cells that band together and exit through the back of the eye (at the blind spot) and travel to the brain
What is the fovea?
Central portion of the retina that allows for acute & detailed vision
How does the eye convert light to electrochemical signals?
First, light passes through the cornea.
Some of this light enters the eye through an opening called the pupil. The iris controls how much light the pupil lets in.
Next, light passes through the lens. The lens works together with the cornea to focus light correctly on the retina.
When light hits the retina, special cells called photoreceptors turn the light into electrical signals.
These electrical signals travel from the retina through the optic nerve to the brain. Then the brain turns the signals into the images you see.
What is color vision?
Visible light is a portion of the electromagnetic spectrum.
Perception of color is dependent upon the wavelength of light, so it is different for each person.
Red & yellow are the easiest colors to see, while blue & violet are the hardest.
What is color blindness? (Also known as color vision deficiency)
Impairment in perceiving color differences (colors not seen are typically red & green).
This happens when at least one cone doesn’t work.
It’s caused by genetics and typically found on the “X” chromosome, so it’s more common in males.
What is the pinna?
Structure of flesh and cartilage attached to each side of head that helps us locate source of sound. A part of the outer ear
What is the auditory canal?
Passageway that leads from the outside of the head to the tympanic membrane (eardrum)
What is the tympanic membrane?
Also known as the eardrum. Vibrates at the same rate when struck by sound waves. Located In the middle ear
What is the hammer of the ear?
Helps in transmission of soundwaves
What is the anvil?
Helps in transmission of soundwaves from the eardrum to the cochlea
What is the stirrup?
Receives sound vibrations from the anvil and hammer
What is the oval window?
Membrane that transmits waves through viscous fluid of inner ear. Located in the inner ear
What is the cochlea?
Filled with fluid that moves in response to vibrations from the oval window
What do hair cells do?
Convert stimuli evoked from sound/head movements into electrical signals that are transmitted into the brain
What is the auditory nerve?
Responsible for sending vibrations to the brain
What is tone deafness?
Also known as amusia. Impaired detection of frequency changes. Tone deaf people have thicker than average auditory cortex but fewer connections from auditory cortex.
What is pitch perfect in people?
Ability to hear a note and identify it. Usually developed from early and extensive musical training.
What is hearing loss?
Prolonged exposure to loud sounds and damage to hair cells.
What are endogenous cycles?
-Some animals generate endogenous circannual rhythms (operate on a yearly cycle)
-ALL animals produce endogenous circadian rhythms (operate on a 24-hour[ish] cycle)
-Cycles can differ between people and lead to different patterns of wakefulness and alertness
-Change as a function of age
Setting and resetting the biological clock
-Setting the biological clock k is important for the purpose of circadian rhythm because it keeps our internal workings in phase with the outside world
-Human circadian clock generates a rhythm slightly longer than 24 hours when there’s no external cue
-Resetting our circadian rhythm is sometimes necessary
What is jet lag?
Disruption of circadian rhythm due to crossing time zones. Mismatch of internal circadian clock and external time.
How does night shift work affect people compared to day shift work?
Night shift disrupts body’s circadian rhythms & can cause person to be more at-risk for certain health problems
Stages of sleep
There are 4 stages and then REM
-When one falls asleep, they go through stages 1-4 in order
-After an hour, they cycle backwards through stages 4, 3, 2 and then REM
-Repeats and each cycle lasts about 90 minutes
Stage 1 of sleep
When sleep has just begun.
EEG is dominated by irregular, jagged, and low-voltage waves
Brain activity begins to decline
Stage 2 of sleep
Sleep spindles (12 to 14 Hz waves during a burst that last at least half a second)
K-complex (sharp high-amplitude negative wave followed by a smaller, slower positive wave)
Stages 3 and 4 of sleep
Slow Wave Sleep (SWS)
EEG recording of slow, large, amplitude wave
Slowing of heart rate, breathing rate, & brain activity
Occurs early in the night
REM sleep (Paradoxical sleep)
Rapid eye movements during sleep.
Deep sleep in some ways, light sleep in others
EEG waves are irregular, low-voltage, and fast, and these waves look the same as brain waves when awake.
Occurs later in the night
What is insomnia?
Persistent inability to fall asleep or stay asleep
What is narcolepsy?
Sleep attacks at inopportune times
(From a lack of the neurotransmitter “orexin”)
What is sleep apnea?
Repeated awakening after breathing stops
What are night terrors?
Episodes of screaming, intense fear and flailing while still asleep.
Does not occur in REM sleep, typically occurs early in sleep, and people don’t remember these.
What is REM sleep behavior disorder?
Play out your dreams because body isn’t paralyzed like it should be during REM sleep
Nightmares
Disturbing/frightening dreams.
Occurs in REM sleep, typically occurs early in the morning, and people do remember these.
The hammer, anvil, and stirrup are found in the…
A) Cochlea
B) Middle ear
C) External auditory canal
D) Auditory cortex
B) Middle ear
The clear protective covering over the eye is…
Cornea
Light from the right half of the world strikes what part of the retina?
A) The left half
B) The right half
C) The whole retina equally
D) It depends on the wavelength
A) The left half
The ability of the brain to change its anatomy over time, within limits, is known as:
A) plasticity
B) regression
C) connectivity
D) reorganization
A) Plasticity
The blind spot is located in the area of the retina:
A) called the fovea
B) that contains rods but no cones
C) where the optic nerve leaves the eye
D) where bipolar cells connect with ganglion cells
C) where the optic nerve leaves the eye
As a rock musician who experienced loud music, Ray is beginning to lose his hearing. Most likely this hearing loss involves the following:
A) auditory canal
B) eardrum
C) tiny bones of the middle ear
D) cochlea
D) cochlea
