Exam 2 Flashcards
A husky having more coats than a lab would be an example of
Variation- INDIVIDUALS WITHIN A SPECIES differ in terms of anatomical physiological and behavioral traits, certain traits are more preferable in certain environments
How do the finches help Darwin’s argument of natural selection
competition for food causes variation in beak size between ground finches (seeds) and tree finches (fruit and insects). those that can’t eat enough don’t survive and don’t pass down disadvantageous traits
How did peacocks hurt the argument of natural selection? What addition to the argument did they make way for?
feathers are in no way advantageous for survival. detrimental most likely- bulky and attention drawing. Made way to argue that the likelihood of passing genes on also depends on traits that make you a more desirable mate- Sexual selection
list of taxonomic (phylogeny) classifications
Kingdom, Phylum, Class, Order, Family, Genus, Species
Kingdom
All living beings divided into five kingdoms (e.g. animalia, plantae, etc.)
Phylum
main subdivision of a kingdom, e.g. vertebrates, invertebrates etc.
Class
subdivision after phyla- Mammals, birds, reptiles
Order
subdivision after class- carnivore, primates
Family
felines, canines, etc
Genus
Dogs, wolves, coyotes, etc
Species
domestic dogs
Homology
Similarities in features due to common evolutionary heritage- same structure may have different function
Are brains typically homologous?
Yes
All vertebrate brains share what basic features?
Develop from dorsal neural tube Bilateral symmetry Segmentation (Hind-mid-forebrain) Hierarchical control (fore>mid>hind) Localization of function (area based functions) Separate PNS and CNS
Why are invertebrates good for studying
less complicated systems. nematodes are translucent
independent evolution of functionally similar characteristics (convergent evolution) bats and butterflies have wings but not same bone structure
analogy
The use or disuse of some structure or behavior causes an increase or decrease in that behavior T or F and name of this theory
Lamarckian evolution. False. this sort of leads to epigenesis
evolution research is restricted to the study of natural history. cannot be studied using contemporary experimental methods T or F
False. William Dallinger and the temperature change experiment proved otherwise
evolution of a mutation can occur without the mutation having an adaptive value t or f
T
Change in the frequency of a trait in a population due to random sampling
Genetic drift
Founder effect
change in the frequency of a gene variant in a population due to random sampling
Vestigiality- giraffe nerve example from class was not an intelligent design but once served a purpose
traits that were adaptive to an ancestral organism which no longer serve any function (ostrich wings) “non adaptive traits” People having blind spots is not adaptive, octopus has no blind spot
do reptiles have an optic tectum? location of optic tectum?
no- superior colliculus in midbrain
maladaptive traits
do not work in favor of a species survival, but were selected for typically for reproductive success (big ass elk antlers) or by chance. pigeons peck at shit they associate with food. not just food
there is now huge variation in humans due to modern medicine, why?
people that normally wouldn’t survive or reproduce in nature have easier lives. this allows them comfort and longevity, more chances to reproduce
difference between human and chimpanzee brain?
chimpanzee brainstem exits toward the back instead of down. chimps do everything humans do, just a little bit worse
thought to be a major contributor to increased cerebral volume throughout evolution (seen in humans and apes)
bipedalism. having more access to hands rather than standing on all fours means increased time to use the hands and learn things with the hands
another physiological component to increased brain size in humans (mutation)
mutation caused overall weaker musculature. weaker jaw muscles means less space and architecture required for mandible, giving brain room to expand
ecological niche
brain develops to efficiently aid organism in survival in its natural habitat. more brain space is dedicated to anatomy/physiology that plays big roles in survival. brains evolve for efficiency, not power. thats why manatees don’t have smart ass fuckin brains- dont need them.
do socialization and mean clique size correlate with an increase or decrease in the evolution of brain size?
increase
food storage is related to what brain structure? why?
birds that store their food have a bigger hippocampus than non-food-storers. the hippocampus forms mental maps and allows animals to keep track of areas where they have hidden food
bigger brains always means better chance of survival true or false
false. brain needs to be efficient. too big of a brain that isn’t necessary may cause unneeded intercranial pressure and kill the organism
encephalization
brain size relative to body size is most important. Brain weight/body weight^.69
second largest encephalization factor in primates? example?
capuchin monkeys exhibit social learning and culture through tool use. Banging rocks on nuts is a learned skill. the monkey will not do it if it is raised in captivity
what has the largest encephalization factor of any invertibrate?
octopus
what factor besides encephalization is important? what separates the reletively equal encephalization factors of the capuchin monkey and the capybara?
neuron count. monkeys have way more
the ratio of what area of the brain compared to other areas is also a predictor of intelligence?
cortical areas
how can intelligence be maladaptive?
more oxygen required for brain- uses 15-20% of O2, glucose, etc.
long gestational and postnatal developmental periods
more genes needed for brain construction, increasing chances of mutations leading to cognitive and behavioral disorders
weapons of mass destruction
Morphology
Physical shape of things, development of different structures
What influences what? (Behavior, Physiology, Morphology)
Behavior is influenced by morphology and physiology, and can also influence both in return
SIX STAGES OF NEURONAL DEVELOPMENT
Neurogenesis, cell migration, cell differentiation, synaptogenesis, cell death (major part of brain development), synapse rearrangement
Much of neuroplasticity in adults is due to what?
synapse rearrangement
How do neural stem cells migrate
traveling up radial glia
Growth cones and their function
Synaptogenesis. extend from axons and dendrites, attracted to target cells via chemical signals called chemoattractants- can be repelled from other cell groups or locations by other signals called chemorepellents
T or F there is a code within every neuron that determines its future function
False. It is shaped by cells/chemicals around it
Important factor in synaptic connectivity (think behavior)
the human experience! different experiences and uses of neurons increase or inhibit their function and others like them
What prenatal structure is the basis of all brain development?
Neural tube
The ventricular system arises from what structure?
central canal of the neural tube
when does the neural tube present itself?
3 weeks
what part of the neural tube grows way more than every other part?
forebrain
Where is the optic tectum located?
midbrain
T or F- ALL vertebrates have optic tectum
T
control embryonic development of structures like limbs and eyes. regulate expression of networks of other genes by switching them on or off in various parts of the body. its target genes promote cell division, differentiation, cell migration, etc
hox genes
when ultrabithorax gene mutated, what happens?
growth of a second thorax/wings
When antennapedia gene (control of network of genes leading to development of legs) is switched on in the head segment, what happens?
fly grows legs where antenna should be
Olfactory pathway DRAW
Air-{(OLFACTORY EPITHELIUM) olfactory cilia-olfactory receptors-olfactory bulb}-Amygdala, hypothalamus,and prepyriform cortex (primary olfactory cortex)-amygdala and prepyriform cortex also communicate with hypothalamus, and the medial dorsal thalamus-orbital frontal cortices
Olfactory transduction, what system? process?
Secondary messenger. odorant binding to receptor activates g protein with GTP which activates adenyl cyclase releasing cAMP to open ion channes for depolarization
how many functional receptor TYPES do people have? how many receptors altogether? dogs and mice? what causes this difference
350 compared to +1000, 6 million compared to 220 million in dogs. people are less reliant on the sense of smell for survival and communication. DOLPHINS HAVE 0
T or F olfactory neurons cannot regenerate
F. new set every few weeks
Vomeronasal Organ
Animals detect pheromones that cause different behavior through accessory olfactory bulb in cortex. VNO is located superior to hard palate
T or F the Vomeronasal organ connects directly to the thalamus
F. no thalamic connection
Gustatory pathway
Taste buds on papillae-cranial nerves VII, IX, X-Solitary tract in brainstem-thalamus-gustatory cortex
T or F different papillae have specific taste buds according to their location
F. each papilla has buds for each taste, but have diversity of number of buds
Receptors for umami (two identified) respond to what?
MSG- monosodium glutamate. meaning glutamate is probably sufficient
What group is more sensitive to taste and smell, men or women?
women. more taste buds means more taste
when sweet taste receptor hT1R2-hT1R3 is altered to be responsive to acidic pH, what occurs?
The individual can perceive sour tastes as sweet. sour tasting things are acidic
What would happen if you had an nonfunctional T1R2 mutation?
cannot taste sweet things
What taste can whales (cetaceans) experience
salt
function of taste receptors outside of mouth?
signals for toxins that induce sneezing, coughing, vomiting, diarrhea, etc
Fourier analysis
summation of a bunch of general functions to analyze a complicated one
Auditory pathway
tympanic membrane-ossicles-cochlea (basilar membrane)-cochlear nucleus-superior olivary nucleus in brainstem (info from right ear crosses to left side, vice versa)-inferior colliculus-medial geniculate nucleus-auditory cortex
T or F- neurons in the medial geniculate nucleus can be inhibited by certain frequencies
T. this is where and how further sharpening of sound begins, along with neurons along the entire auditory pathway being frequency sensitive- only being stimulated by certain frequencies
Where is the first instance of binaural processing?
Superior olivary nucleus
organ of corti
principle components that convert sound into neural activity- scala vestibuli’s waves of fluid cause basilar membrane to ripple, bending hair cells and opening channels previously closed by tip links
High frequencies displace the basilar membrane at what part of the cochlea?
Base. (outer ring)
Low frequencies displace the basilar membrane at what part of the cochlea?
Apex (center point)
what hair cells are in charge of hearing? inner or outer?
Inner. they possess 95% of the afferent neurons in the basilar membrane. 16-20 per cell
Purpose of outer hair cells?
fine tuning cochlea for accurate discrimination between frequencies. lengthens and stiffens membrane to sharpen tones
where do afferent neurons connected to hair cells go to?
cochlear nucleus in brain stem
where do efferent neurons connected to inner hair cells come from?
lateral superior olivary nucleus
where do efferent neurons connected to outer hair cells come from?
medial superior olivary nucleus
how do cochlear implants work?
line a tube through the scala tympani and send wave functions to specific high or low frequency areas. just like basilar membrane
T or F it is better to receive an auditory brainstem implant at a young age rather than old
T. due to brain plasticity
is the sound shadow effect greater at higher or lower freq? why?
higher. low freq have larger waves that are more effective at quickly reaching the ear further from the auditory stimulus
two key components in spatial discrimination of auditory stimuli (think binaural processing)
interaural intensity difference (one ear pointed more directly at sound source) and Latency/time difference. differences in the onset of cochlear vibration
What structure detects interaural time differences?
Medial superior olive. sound location is encoded by the relative activity of the entire left MSO compared to the entire right MSO. bigger the difference, further away the sound
What structure detects interaural intensity differences
Lateral Superior Olive
selectivity of pinna’s ridges and valleys to reinforce certain frequencies, sending information about vertical position of sound to inferior colliculus (in which it ends up converging with binaural cues to completely localize sound)
spectral filtration
Pitch discrimination- place theory
encoding of a sound frequency as a function of the location on the basilar membrane that is most stimulated by that sound
pitch discrimination- volley theory
neurons fire in synchrony with tone frequencies- a 100 Hz tone elicits a neuronal response of 100 action potentials per second
pitch discrimination- phase locking
for very high frequencies in which one neuron cannot fire enough to match- multiple neurons fire to a represent the tone frequency. a summation of all of the neurons firing
why do humans have such a wide hearing range
survival. we have a lot of things we need to be afraid of so we need to be able to hear a lot of things and communicate
Where is the primary auditory cortex (A1) located
upper surface of temporal lobes. speech perception moves forward through left temporal lobe (Phonemes, words, phrases)
targeted expression of Pax-6 gene in thoracic segment of fruit fly produces what what
ectopic fruit fly eye. Pax-6 gene in mice- which causes eye growth- is homologous to the Eyeless gene in fruit flies
temperature-dependent sex determination in reptiles is a result of what?
a combination of the fact that there is no gene that codes for sex in reptiles, and the effect of the environment on the expression of the reptilian genome
T or F instincts are inherent in the genome, they require no experience prior to expression
F duck call example, righting reflex in antigravity example. you are born with the reflexes, but you have to learn them
what did we learn from the selective breeding mean mice example
you can be born mean but if you are raised in an environment that contradicts that phenotype, you wont learn to be mean. you will learn to be good, because everyone else is being good, and keeps you in line
Thalidomide
teratogen prescribed in the 50s to treat morning sickness. interferes with genes controlling limb and organ development
why might a dog that you cloned from your original dog look different?
Epigenetics. You used the same genes, but did not provide the same exact environment. different experience influences differences in the expressions of the genome
epigenetics
changes in gene expression that do not depend on underlying sequence, and do not change DNA itself- drugs, development, environmental chemicals, diet, aging
methylation
expression of genes can be modified by chemical marks on the DNA and on histones that DNA wraps around. Methylation attaches directly to DNA , but methyl groups and more can attach to histones and either loosen or tighten wrapping of DNA during histone modification
best example of epigenesis
the face. skin, eyes, teeth, and hair all look different. but they contain exactly the same genetic information
what does all the work, the genome or the epigenome?
genome. epigenome tells genome what to do
T or F epigenetics are inherited and passed down
T
Pathway of light stimulus to secondary vision centers
RETINA(rods and cones-bipolar neurons-ganglion cells)-optic nerve-optic tract-Lateral Geniculate Nucleus and superior colliculus on side-(From LGN) optic radiations-primary visual cortex V1-secondary visual cortex (dorsal stream and ventral stream)
function of cornea outside of protection from foreign objects
filters out UV light, bends light
function of horizontal and amacrine cells
allow neighboring cells to influence each other. lateral communication
list cells in eye able to produce action potentials? graded/local potentials? photoreceptor cells, horizontal and amacrine cells, ganglion cells, bipolar cells
ACTION- Ganglion cells only
LOCAL- all others
Type of photoreceptor cells concentrated in and around the fovea
cones
type of photoreceptor cells that predominate in the periphery
rods
“blind spot”?
optic disc
T or F. light hyperpolarizes the rod cell by closing cGMP gated sodium ion channels. brighter light further hyperpolarizes the cell by unbinding more cGMP through a cascade event
T. it is a long chain. In the dark, retinal cells are constantly releasing glutamate
What is faster, auditory or visual transduction?
Auditory
this bipolar cell is depolarized by decreased glutamate released by a photoreceptor cell in response to a light stimulus (the glutamate typically inhibits the bipolar cell)
on-center or off-center bipolar cell?
on-center. this increases the release of glutamate in the bipolar cell to the on-center ganglion cell which causes it to fire
which is used for night vision rods or cones? day vision?
Rods for night, cones for day
how many different types of cones respond to different wavelengths of light
3 a mixture of all of them are firing at different rates to sum up and tell the individual what wavelength they are seeing
cortical areas for color vision (V#)
V1, V2, V4
trichromatic vision? dichromatic vision?
3 cone types (people and primates)
2 cone types (cats have weak dichromatic, dogs have strong red vs. blue)
why does night vision need rods? why do people move their heads side to side when walking around at night?
they are more light sensitive than cones. they move their heads to access the rods, which are in the periphery
lateral geniculate nucleus dorsal layers (3-6) receive input from rods or cones? parvocellular or magnocellular?
Cones. Parvocellular. color vision
lateral geniculate nucleus ventral layers (1&2) receive input from rods or cones? parvocellular or magnocellular?
rods. magnocellular (larger so less acuity) light vision
what part of the visual field needs a lot of brain for representation?
fovea
Nasal retinal ganglion cells receive input from the inside or outside of the visual field? do they send axons across midline or to the same side of the brain?
Outside. cross the midline.
what retinal ganglion cells (temporal or nasal) send information to the same side of the brain as the eye receiving the information? do animals of prey show more or less of this same side input?
Temporal. sees the inside of the visual field. animals of prey show less because they focus on more of the outside of the visual field, the eyes do not really share much of the field, input mostly comes from one or the other and more axons cross the midline (nasal ganglion cells)
vision neurons excited by very fine detail (high frequency) or by big picture stuff (low frequency) shows what?
spatial frequency selectivity
“where” pathway
dorsal stream. vision for movement and location
“what” pathway
ventral stream. vision for recognition of objects and faces.
area V5 or MT (middle temporal) function PART OF DORSAL STREAM
Detection of motion MT can stand for MOTION. if you didn’t have this, you would be seeing the world through a strobe light. over stimulation causes reports of moving things that aren’t moving
Area V4 and IT (inferior temporal) function PART OF VENTRAL STREAM
sensitive to color and line orientation. but not to location. V4 is basic processing. more complex shapes are processed in IT. IT is also activated by biological stimuli
this area of the brain is selective to expertise when processing images. things that look very similar are distinguished between each other here (faces, sheep, cars, etc)
Right fusiform gyrus
face blindness is a result of damage to what structure? (cant detect differences between faces)
fusiform gyrus
the magnocellular system would relate to what visual stream in the brain? (what do magnocellular receptive areas process?)
dorsal. MOVEMENT!
the parvocellular system would relate to what visual stream in the brain? (what do parvocellular receptive areas process?)
ventral. colors, shapes WHAT
dorsal stream. how is vision related to audition here?
identifies where the sound is coming from
Ventral stream. how is vision related to audition here?
determines what is being heard. processes and analyzes the sound
superior colliculus function
shared in all vertebrates. projects to dorsal stream directs behavioral responses toward motion and spatial locations. depth perception, location of sounds and stimuli (thermal sensing in snakes allows them to sense and locate prey)
If you have lesion/don’t have V1, you still have 5% of optic tract going to this structure. it allows you to still react to motion but you don’t consciously perceive things “blindsight”
superior colliculus
If you have lesion/don’t have V1, you still have 5% of optic tract going to this structure. it allows you to still react to motion but you don’t consciously perceive things. “blindsight”
superior colliculus
how many neurons are muscle fibers innervated by? how many fibers can one neuron innervate?
one. can innervate very many “divergence”
what neurotransmitter causes muscular contraction? what receptors receive the NT
Ach. nicotinic ach receptors
actin and myosin. what surrounds what? what causes them to bind together for contraction?
actin surrounds myosin. ach opens sodium channels for depolarization
Main muscular receptor (innervated by primary and secondary afferent fibers)
muscle spindle. gives feedback to CNS when muscle is stretched- tell about velocity of stretch (primary afferent fiber) and the muscle length (secondary afferent fiber)
Golgi tendon organ
monitors force of muscle contractions. providing info for precisely controlling movement. activated during heavy muscle contractions. detect overloads that threaten muscle tears
brain system associated with motorizing learned habits and regulating motor activity initiated in other brain areas
Basal ganglia mediates memory-guided motor patterns. prevents unwanted, unnecessary info
cerebellum and three sections of cerebellum
involved in coordination and fine motor control/balance. spino- cerebro- vestibulocerebellum
T or F. in precentral gyrus there aren’t really hand or foot specific neurons, rather there are areas related to certain behaviors
T.
What secondary motor cortex is in charge of planning and initiation Supplementary motor area or premotor cortex
Supplementary motor area SMA
premotor cortex
movements in response to external cues (defensive behavior, flailing to get away from bees)
neurons in premotor cortex that help in planning, initiating, organizing behaviors and motions to be carried out by M1, spinal cord, and cerebellum. copying motions in head
mirror neurons
huntingtons disease is the absence of what structure
basal ganglia. causes loss of motor control, primarily inhibition of motor control
autoimmune disorder in which antibodies destroy ACh receptor proteins. your body is killing your neurons
Myasthenia gravis
what sensory input is not relayed through the thalamus?
olfaction
chemical sensations
taste, smell
touch, pain, audition, muscle tension, joint position and movement, balance are all ______ sensory systems
mechanical
platypuses experience _____ through their bills (sensory info)
Mechanoreception and electroreception. electroreception allows platypus to sense very small environmental changes
area of brain that will only respond maximally when two types of stimuli are paired together (such as visual and auditory)
Polymodal
where does multisensory integration tend to occur?
around borders of specified brain areas “overlapping”
synesthesia (color)
leters, words, combinations of letters evoke color perceptions. Synesthesia- activation of some neurons automatically activate other groups of neurons in other brain location
Certain neurons sense different types of touch and only fire when those certain types stimulate it. all action potentials are still similar. the brain can just tell where they are coming from. What is this physiological phenomenon called
Labelled lines
Top-down processing (somatosensation)
non primary sensory areas tell thalamus to not give a certain signal or to increase a certain signal. like selective attention. don’t need to feel non essential sensations (shoes on your feet
Labelled lines pathway-
peripheral sensory receptors insert to the dorsal roots of spinal cord-brainstem (where cranial nerves insert)- thalamus- primary sensory cortical areas (post central gyrus)- secondary (nonprimary) sensory cortical areas. thalamus, postcentral gyrus, nonprimary sensory areas all intercommunicate communicate with each other
receptors that detect pain and temperature
free nerve endings
touch receptor that is fast adapting to measure change (start and end of sensation)
meissners corpuscle
touch receptors that are slow adapting and provides input of ongoing duration
merkels discs
Vibratory receptors that are fast adapting, having large vague borders of sensation
pacinian corpuscle
stretch receptors that are slow adapting with large vague borders to identify stretch of skin
ruffini’s ending
name of receptors that respond to noxous (painful) stimuli
nocireceptors
Prostaglandins, Serotonin, K+, and leukotrienes are all related how?
all chemicals involved in action potential generation for pain transmission. dorsal root ganglion pain fibers ultimately release glutamate
SCN9A function
promotes reception of pain
TRPV1 function
reception of dull pain, heat
CMR1 function
cool temperatures
TRP2 function
sensation of sharp sudden pain/high temperature causing reflexive drawback
pain modulation
top down regulation telling spinal cord how much of the pain you should be receiving. constant pain begins to be ignored
cingulate cortex activated during pain perception
sensory emotional and cognitive components to pain
how does the periaqueductal grey modulate pain perception?
interrupts ascending pathway and inhibits pain by stimulating medulla to spinal cord with spinal cord releasing opioids, PREVENTING any INCOMING pain signal from getting through
this technique activates the nucleus accumbens, an area rich in opioid receptors and neurotransmitters by causing a person to believe that they are receiving treatment to stop pain. so the body does the work for them
use of placebos. you need opiods in your system for this to work!
technique releases endogenous opioids by inducing a small amount of pain
acupuncture
what could cause phantom limb pain?
brain sees that you are missing your arm and freaks out because its not supposed to be like that
T or F analgesics (pain inhibitors like Tylenol) alleviate emotional distress
T. social rejection activates the same area as pain (anterior cingulate cortex)
