PSYC 2410 Midterm latest updated version with 100% accurate solutions + rationales

What is neuroscience?

the scientific study of the nervous system

What is biopsychology?

the scientific study of the biology of behavior

When did biopsychology originate?

What publications lead to its creation?

20th century (end of the 19th)

"Origin of Behavior" (1949) by D. O. Hebb

What are the 6 subdivisions of biopsychology?

1. Neurophysiology - study of functions and activities of the nervous system

2. Neuropharmacology - study of the effects of drugs on neural activity

3. Neuropathology - study of nervous system disorders

4. Neurochemistry - study of the chemical bases of neural activity

5. Neuroendocrinology - study of interaction b/w the nervous system and the endocrine system

6. Neuroanatomy - study of the structure of the nervous system

What are some advantages and disadvantages of human vs non-human subjects?

1. Humans

- con follow instructions

- can report on subjective experience

- often cheaper

2. Non-humans

- brains & behaviours are simpler - more likely to reveal fundamental brain-behavior interactions

- you can use a comparative approach

- can do experiments considered unethical for humans

What are the 3 types of studies in biopsychology?

1. Experiments

2. Quasi-experimental studies

3. Case studies

What is the difference between pure and applied research?

Pure research is motivated by the curiosity of the researcher, purpose is to acquire knowledge.

Applied research is intended to bring some direct benefit to humankind

what is translational research?

aims to translate the findings of pure research into useful applications

What are the characteristics of research in physiological psychology?

subjects are almost always animals; usually pure research; usually surgical and electrical methods (i.e direct manipulation of the brain)

What are the characteristics of research in psychopharmacology?

most research is applies, used to develop therapeutic drugs; use lab animals and humans when ethical

What are the characteristics of research in neuropsychology?

study effects on brain damage on human subject; most are quasi-experimental studies; cerebral cortex is most likely to be damaged; most applied division; important basis in patient care and counselling

What are the characteristics of research in psychophysiology?

studies relation between physiological activity and psychological processes in humans; non-invasive recording procedure; usually use an EEG; also uses measures such as muscle tension, HR, BP, pupil dilation etc

What are the characteristics of research in cognitive neuroscience?

youngest division; most research involves humans, and is thus noninvasive; major method = functional brain imaging

What are the characteristics of research in comparative psychology?

deals w/ biology of behaviour; compare behaviour of different species to understand evolution, genetics, and adaptiveness; subfields include evolutionary psychology and behavioural genetics

What is the combined approach?

converging operations; made by using different approaches, each compensates for the short-comings of others

Explain the case of Jose and the bull.

Jose Deigado implanted an electrode into caudate nucleus; delivered an electrical stimulation when bull charged; this stoped the charge

his demo provided no support for his conclusion

Explain the case of Becky, Moniz, and prefrontal lobotomy.

Moniz's research was based on the observation of a single chimp in a single situation, there was a lack of appreciation of the diversity of the human brain

What is dichotomous thinking?

When did it originate?

rose following the dark ages in response to a 17th century conflict between since and the roman church;

Descartes argued that one part of the universe belonged to science and the other to the church;

said there were two elements to the universe:

1. physical matter

2. human soul

this is known as Cartesian Dualism

What are the two lines of evidence against Cartesian dualism?

1. Even the most complex psychological changes can be produced by damage or stimulation of the brain

2. nonhuman species (apes) posses some abilities that were once thought to be purely psychological and thus purely human

Why is nature vs nurture problematic?

it has been changed to "genetic factors vs learning"

genetic and experimental factors interact = interactionism

All behaviour is a product of what 3 factors?

1. organisms genetic endowment

2. expereince

3. perception of the current situation

What were the 3 types of evidence for Darwin's theory of evolution?

1. fossil records

2. structural similarities (homologous structures)

3. changes made by selective breeding (e.g. dog breeds)

What is the role of social dominance in evolution?

socially dominant males usually copulate more, therefore passing down more genes

socially dominant females are more likely to produce more and healthier offspring (more access to food and resources)

Summarize the course of human evolution.

450 million years ago - chordates

425 mya - vertebrates (bony fishes came first)

410 mya - first bony fishes left water

300 mya - reptiles

180 mya - mammals

160 mya- birds

6 mya - humans

What are the two advantages of bony fishes leaving the water?

1. could move from stagnant pools to nearby freshwater

2. could eat terrestrial food

What were the advantages to reptilian evolution?

shell covered eggs and dry scales meant they could live far from water - however this also reduced their resilience to water

what are 9 misunderstandings about evolution?

1. it is not a straight line

2. humans have no evolutionary supremacy

3. it is not always slow and gradual

4. very few products of evolution are around today (less than 1%)

5. evolution does no progress to preordained perfection

6. not are existing behaviours/structures are adaptive

7. not all existing adaptive characteristics evolved to perform their current function (exaptations)

8. similarities among species does not necessarily mean common origin

9. considerable evidence that homo sapiens mated with other species

What are the 3 major points about human brain evolution?

1. brain size has increased during evolution

2. most of the increase is in the cerebrum

3. increase in convolutions has greatly increased the SA of the cerebral cortex

Define polygyny and polyandry

polygyny = 1 male forms mating bonds with more than 1 female - this is b/c females make a far larger contribution to raising young, and therefore must be more selective in their mating partners.

polyandry = females form mating binds with more than 1 male - does not happen in mammals - e.g. seahorse

Explain monogamy

enduring mating bond b/w 1 male and 1 female

- 9% of mammals are monogamous

- occurs when females can raise more fit young offspring with undivided help from males

How can we predict mate bonding in humans through evolutionary theory?

1. men value youth and attractiveness (femininity); women value power and earning capacity

2. physical attractiveness best predicts which women will bond with men of high occupational status

3. men are more likely to commit adultery

What 4 factors lead to the rise of epigenetics?

1. genes constitute 1% of human DNA (junk DNA)

2. protein-encoding is a minor function of RNA

3. Mechanisms of gene-experience interactions unknown

4. new research techniques

what were 5 important discoveries of modern epigenetics?

1. non-gene DNA is still active (no longer junk)

2. multiple types of RNA found

3. Advances in understanding gene expression

- DNA methylation

- histone remodelling

4. RNA editing

5. Epigenetic mechanisms are enduring

- transgenerational epigenetics

What is ontogeny vs phylogeny?

ontogeny = development of individuals over their life span

phylogeny = evolutionary development throughout the ages

What were the main findings or the "maze-bright" vs "maze-dull" rat lab experiments?

that genetics play a role in behaviour

Explain phenylketonuria A

lack of phenylalanine hydroxylase; used to convert phenylalanine into tyrosine

- phenylalanine accumulates in the body

- low levels of dopamine due to lack of tyrosine

- results in abnormal brain developments

If infant is place on a phenylalanine-free diet, the effects are reduced

Explain how the development of birdsong demonstrates behavioural development.

birdsong develops in 2 stages:

1. sensory phase - several days after hatching

- form memories of adult song that guides the development of their own song

2. sensorimotor phase - when juvenile begins to tweet subsongs

- rambling vocalizations are usually refined

some species are age-ended while others are open ended learners

Remarkable features :

- lateralized to left hemisphere

- vocal centre is larger in males

- vocal centre doubles in size in spring

- growth of vocal centre is neurogenesis

What was the Minnesota Twin Study?

Adult monozygotic twins were much more similar in every aspect than adult dizygotic twins, regardless of if they were raised together or not

What is a heritability estimate?

numerical estimate of the proportion of

variability that occurred in a particular trait in a particular study as a result of the genetic variation in that study; how much to genes contribute to phenotypic differences

all complex traits have about 40-80 % heritability

What are the two main lines of twin studies?

1. Fraga and colleagues = took tissue samples of twins ranging from ages 3-74; screened DNA for methylation and histone modifications; found that young twins were epigenetically indistinguishable, but differences accumulate as they age; therefore monozygotic twins are NOT genetically identical

2. Wong and colleagues = DNA methylation is due to experiential factors; rates of methylation were the same in dizygotic and monozygotic twins

What did Turkheimer and colleagues find when they assessed the intelligence of twins from different socioeconomic statuses?

One can inherit potential for intelligence in an impoverished environment, but this potential is rarely realized (heritability drops to about 10%)

What 3 things must occur apart from cell multiplication for neurodevelopment?

1. cells must differentiate

2. cells must make their way to appropriate sites

3. cells must establish appropriate functional relations with other cells

define totipotent, pluripotent, multipotent, and unipotent

totipotent = cells has the ability to develop into any class of cell

pluripotent = developing cells that can develop into many, but not all, cell types

multipotent = new cells can develop into different cells of only 1 class (e.g blood cells)

unipotent = can only develop into one type of cell

What are the 5 phases of neurodevelopment?

1. induction of the neural plate

2. neural proliferation

3. migration and aggregation

4. axon growth and synapse formation

5. neuron death and synapse rearrangement

Describe the induction of the neural plate

- 3 weeks after conception, tissue destined to be the nervous system becomes the neural plate

- small patch of ectodermal tissue on the dorsal surface of developing embryo

- development of neural plate is induced by chemical signals from mesoderm

- after induction, lose some totipotentiality - become multipotent

- neural plate develops into neural groove - lips of neural groove fuse to from neural tube - neural tube defects can result from this process

- inside of neural tube eventually becomes the cerebral ventricles and spinal canal

- By 40 days, 3 swelling are visible at the anterior end - become the forebrain, midbrain, and spinal canal

Describe neural proliferation

once neural tube is formed, cells begin to proliferate (increase greatly in number)

does not occur simultaneously or equally across tube

most division is in the ventricular zone

controlled by chemical signals from 2 organizers:

1. floor plate - runs along midline of ventral surface

2. roof plate- runs along midline of dorsal surface

Describe migration

- cells still immature

- 2 types of migration:

1. radial migration - proceeds from ventricular zone in a straight line outward toward outer wall

2. tangential migration - occurs at a right angle to radial migration

- 2 methods of migration:

1. somal translocation - extension grows from developing cell in the direction of migration

2. glia-mediated migration - radial glial cells appear in developing neural tube

- providing a matrix for radial migration was assumed to be the only function of radial glial cells

- now we know many radial glial cells eventually develop into neurons

inside out pattern- each wave or cortical cells migrated through the already formed layer of the cortex

neural crest formed from cells that break off the neural tube - neural crest cells develop into neurons and gilal cells of the PNS

Describe aggregation

the process by which neurons align themselves

mediated by cell-adhesion molecules (CAMs)

- elimination of just one CAM is devastating for brain development

gap junctions are also involved

- bridged by connexins

Describe axon growth

at each growing tip of an axon or dendrite is a growth core - extends and retracts fingerlike structures called filopodia

Sperry suggested chemoaffinity hypothesis

Pioneer growth cones - first cones to travel along a particular route

Fasciculation = tendency of developing axons to grow along the paths established by preceding axons

Topographic-gradient hypothesis = axons growing from one topographic structure (e.g. retina) to another (e.g. optic tectum) are guided to specific targets that are arranged on the terminal surface in the same way as the axons' cell bodies are arranged on the original surface

- guided to their destination by 2 intersecting signal gradients

Describe synapse formation

once axons reach intended sites, they establish a synapse pattern - requires the coordinated activity of two neurons

synaptogenesis = formation of new synapses

- depends on presence of glial cells (astrocytes)

- ganglia w/ astrocytes formed 7x more synapses

formation occurs through signals from presynaptic and postsynaptic cells

chemical signalling important

Describe Neuron death

about 50% more neurons are produced than required

initially assumed to be a passive process (necrosis) but is now known to be active (apoptosis)

apoptosis is safer b/c necrosis involves the spillage of cellular contents into the ECM which can cause harmful inflammation

if apoptotic cell pathway is blocked - could result in cancer; if inappropriately activated - could result in neurodegenerative disease

two triggers for apoptosis:

1. some neurons are simply genetically programmed for early death

2. failure to obtain life-preserving chemicals

- grafting extra target structures to embryo before synaptogenesis reduces the death of neurons growing into the area

- destroying some neurons growing into an area before cell death increases the survival rate of remaining neurons

most prominent class of life-preserving chemicals are neurotrophins

- Nerve growth factor (NGF) = first neurotrophin to be isolated

Describe synapse rearrangement

when neurons die, the space they leave is filled by sprouting axons terminals of surviving neurons

thus, cell death results in massive rearrangement of synaptic connections

this process increases the selectivity of transmission

microglia play a role

Why does the human brain grow after birth?

1. synaptogenesis

- burst in visual and auditory cortexes in month 4 w/ max density at month 7 or 8

- much steadier rate in prefrontal cortex, max density at year 2

- greater plasticity

2. myelination of axons

- increases the speed of axonal conduction.

- sensory areas in first few months

- motor areas soon after

- prefrontal cortex continues into adulthood

3. increased branching of dendrites

- even mature dendrites can change their shape in seconds

NOTE: there are also significant regressive changes

What are the 4 functions of the prefrontal cortex?

What are preservative errors?

1. working memory - keeping relevant info accessible for short periods

2. planning and carrying out sequences of actions

3. inhibiting responses that are inappropriate in the current context but not others

4. following rules for social behavior

preservative errors made between 7-12 months but not after

preservation = tendency to continue making a formerly correct response when it is no longer correct

Define permissive experiences vs instructive experiences

permissive experiences = permit info in genetic programs of brain development to be expressed and maintained

instructive experiences = contribute to info in genetic programs and influence course of development

Define critical period vs sensitive period

critical period = when it is absolutely essential for an experience to occur w/in a particular interval to influence development

sensitive period = when an experience has a great effect w/in a particular interval but can still have weak effects outside the interval (most experiential effects)

Explain the effects of deprivation vs enrichment

deprivation (rats in the dark) - fewer synapses and dendritic spindles in visual cortexes - adults had deficits in vision (depth and pattern)

enrichment has beneficial effects - complex vs barren cages - thicker cortexes with more dendritic spines and more synapses

What did we learn from experiments of occular dominance?

depriving on eye of input for a few days early in life has lasting adverse effects - this does not happen is the other eye is also blindfolded

early monocular deprivation changes the pattern of synaptic input into layer IV of the visual cortex

widths of columns of input changes

Name 3 demonstrations of research for the effects of experience of topographic sensory cortex maps.

1. Roe and co. caused auditory complex to be organized retinotopically

2. Knudsen and Brainard; if visual world was shifted 23 degrees right, so was auditory map; objects heard where they were seen to be

3. early musical training expands auditory cortex for complex musical tones

Where does neurogenesis occur in adults?

What is the function of these new cells?

1. olfactory bulbs (not humans) and striatum

- created from adult neural stem cells in certain sites in the sub-ventricular zone of the lateral ventricles

- become interneurons

2. hippocampus

- can show substantial growth

- begins in dendrite gyrus

- becomes granule cells

- can be increased by exposure to enriched environment

unclear function, memory, pattern separation, mood & anxiety, adaptation to complex environments

What are 4 examples of experience reorganizing the adult brain?

1. Environmental enrichment

2. sensory and motor cortical maps

3. adaptation improved

4. brain damage

Explain Autism Spectrum Disorder

2 core symptoms:

1. reduced capacity for social interaction and communication

2. restricted and repetitive patterns of behaviour, interests or activities

75% male

may suffer from intellectual or learning disabilities

more likely to suffer from epilepsy

most prevalent neurodevelopment disorder

heterogeneous = impaired in some respects but superior in others

ASD savants have exceptional abilities in a certain area (10-30% of individuals with ASD)

genetic factors

potential neural mechanisms:

1. Associated with brain damage in the cerebellum, amygdala, and frontal cortex

2. abnormal reaction to faces associate with fusiform area

Explain Williams Syndrome

Intellectual disability with heterogenous pattern of ability and disability

1/7500 births

social, empathetic, talkative

language is remarkable for a low IQ

near perfect pitch

sense of rhythm

remarkable facial recognition

attentional problems

poor spatial ability

difficulty drawing objects

heart problems due to mutation of chromosome 7 (elastin)

thinning of cortex and white matter

- greatest in boundary of the parietal and occipital lobes and in orbitofrontal cortex

thicknening of the cortex in the superior temporal

gyrus, which includes primary and secondary auditory cortex

What are the major divisions of the nervous system?

central and peripheral nervous systems

CNS = brain and spinal cord

PNS = somatic and autonomic systems

SNS = interacts with external environment

ANS = regulates internal environment

(both have both afferent and efferent nerves)

ANS = parasympathetic and sympathetic nerves

what is the difference between afferent and efferent nerves?

in SNS - afferent nerves carry sensory signals from skin to brain; efferent nerves carry motor signals from CNS to muscles

in ANS - efferent nerves are sympathetic or parasympathetic

1. sympathetic nerves - motor nerves that project from CNS in lumbar and thoracic regions

2. parasympathetic nerves - motor nerves that project form brain and sacral region

What are some important distinctions between the sympathetic and parasympathetic nervous systems?

they are all two-stage neural pathways: they must synapse to other neurons to reach target

- parasympathetic neurons are much closer to their target organs (very short second-stage neurons)

sympathetic nerves stimulate, organize, and mobilize energy resources in threatening situations; parasympathetic act to conserve energy

each autonomic target organ receives opposing sympathetic and parasympathetic input, and its activity is thus controlled by relative levels of parasympathetic activity

sympathetic changes are indicative of psychological arousal, whereas parasympathetic changes are indicative of psychological relaxation

What are some important notes about the nerves of the PNS?

most project from spinal cord

12 pairs of exceptions (cranial nerves; project from brain)

includes purely sensory nerves such as olfactory (I) and optic nerves (III)

most contain both sensory and motor fibres

longest are vagus nerves (X)

disruptions of cranial nerves provide clues about location and extent of tumours

What are the 3 meninges? What is their purpose?

dura mater, fine arachnoid membrane, pia mater (adheres to surface of CNS)

encase brain and spinal cord for protection

Between fine arachnoid membrane and pia mater is subarachnoid space which contains large blood vessels and cerebrospinal fluid

What is the central canal?

small central channel that runs the length of the spinal cord

What are the cerebral ventricles?

4 large internal chambers of the brain: 2 lateral ventricles, the third, and the fourth

How does cerebrospinal fluid circulate?

subarachnoid space, central canal, and cerebral ventricles are all connected; a single reservoir

CSF cushions brain; people w/ fluid drained have raging headaches and stabbing pain

Where is CSF produced?

choroid plexus (network of capillaries) & excess CSF is continuously absorbed into large blood-filled spaces (dural sinuses) that run through dura mater & drain into jugular veins

What is hydrocephalus?

when the flow of CSF is blocked, for example by a tumour, causing walls of ventricles (& thus of entire brain) to expand

must drain excess fluid and remove obstruction

What is the blood brain barrier (BBB)?

it impedes the passage of toxic substances from blood to brain; the cells of blood vessels are tightly packed (unlike the rest of the body)

the degree to which therapeutic & recreational drugs work is based on the ease with which they cross the BBB

some large molecules (e.g. glucose) are actively transported across the BBB

many CNS disorders are associated with the impairment of the BBB

What is the neuron cell membrane?

lipid bilayer within which channel proteins and signal proteins are embedded

Name the 9 external structures of a neuron.

1. cell membrane

2. dendrites - short processes emanating from cell body that receive synaptic contact from other neurons

3. Axon hillock -cone shaped regions at the junction b/w axon and cell body

4. cell body - metabolic centre of the neuron (AKA soma)

5. Axon - long narrow process that extends from cell body

6. Myelin - fatty insulation around axons

7. Nodes of Ranvier - gaps b/w myelin

8. Buttons - buttonlike endings of axon branches, which release chemicals into synapses

9. synapses - gaps b/w adjacent neurons

Name the 9 internal structures of a neuron (7 in cell body, 2 in axon buttons)

1. Endoplasmic reticulum - system of folded membranes in cell body; RER plays a role in protein synthesis, SER plays a role in fat synthesis

2. Cytoplasm - clear internal fluid of cell

3. Ribosomes - proteins synthesis; located on ER

4. Golgi complex - packages molecules into vesicles

5. Nucleus - DNA - containing structure of cell body

6. Mitochondria - sites of aerobic energy release

7. Microtubules - responsible for the rapid transport of material throughout neurons

8. Synaptic vesicles - spherical membrane packages that store neurotransmitters

9. neurotransmitters - molecules that are related from active neurons and influence the activity of other cells

What are the 4 classes of neuron?

1. Multipolar neuron = more than 2 processes extending from cell body (most neurons)

2. unipolar neuron = one process extending from cell body

3. Bipolar neuron - two processes

4. interneuron - short (or no) axon, they serve to integrate neural activity w/in a single brain structure, not to conduct signals

What are the names of clusters of cell bodies in CNS and PNS?

What about bundles of axons?

CNS = nuclei; PNS = ganglia

CNS = tracts; PNS= nerves

What is the name of glia found in the CNS? What is its purpose?

What about in the PNS?

How are they different?

oligodendrocytes; extensions are rich in myelin and they form a myelin sheath

Schwann cells

each Schwann cell constitutes one myelin segment, each oligodendrocyte provides several myelin segments, often on more than 1 axon

Schwann cells can guide axonal regeneration (restricted to PNS)

What are microglia?

Class of glia that respond to injury or disease by multiplying, engulfing cellular debris or even entire cells, and triggering inflammatory response

smaller than other glial cells

What are astrocytes?

Largest glial cells; star-shaped

extensions cover the outer surfaces of blood vessels in the brain

play a role in the passage of chemicals from blood into CNS neurons & blocking other chemicals

How does a Golgi stain work?

potassium dichromate and silver nitrate react to form silver chromate; this invades neurons and stains them entirely black

How does the Nissl stain work?

use cresyl violet dye to bind to structures in neuron cell bodies; thus, you can estimate the amount of neurons in an area by counting dots

How does electron microscopy work?

coat thin slices of neural tissue w/ electron absorbing substance that is taken up by different parts of neurons to different degrees

then pass a beam of electrons through the tissue onto photographic film

a scanning electron micrograph captures images in 3D

What are the 2 types of neuroanatomical tracing techniques?

1. anterograde (forwards)

- used to trace paths of axons projecting away from cell bodies

- inject chemicals into the area

- after a few days, brain is removed & sliced, slices are treated to determine locations of the chemical

2. retrograde (backwards)

- trace paths of axons projecting into a particular area

- inject chemicals that are taken up by terminal buttons and transported backwards along axons to cell bodies

- brain sliced and treated

Explain the composition of the spinal cord

gray matter composed of cell bodies and unmyelinated interneurons

white matter is most myelinated axons

two dorsal arms of spinal gray matter = dorsal horn; two ventral arms = ventral horns

31 pairs of spinal nerves joined to cord via dorsal or ventral roots

- all dorsal root axons are sensory (afferent) unipolar neurons with cell bodies grouped together just outside cord to from dorsal root ganglia

What is the purpose of the myelencephalon?

AKA medulla

most posterior part of brain - composed largely of tracts carrying signals b/w brain and body

has a reticular formation

- complex network of ~100 tiny nuclei that occupy the central core of the brain stem

- named b/c of its netlike appearance

- involved in a variety of functions: sleep, attention, movement

What is the job of the metencephalon?

houses many ascending and descending tracts and part of the reticular formation

- these structures create a bulge = the pons

the other major division is the cerebellum

- important sensorimotor structure; damage makes it difficult to control movement

- however damage also causes other cognitive defect and so it therefore must have other purposes

What are the parts of the mesencephalon?

2 divisions:

1. Tectum (roof) = dorsal surface; in mammals composed to 2 pars of bumps, the colliculi

- posterior pair = inferior colliculi, auditory function

- anterior pair - superior colliculi, visual-motor function (directs body's orientation)

2. Tegmentum = ventral to tectum

- contains reticular formation, tracts of passage & 3 extra structures:

a) periaqueductal gray = gray matter situated around cerebral aqueduct (duct containing third and fourth ventricles); has a role in mediating analgesic effects of opioid drugs

b) substatia nigra

c) red nucleus; both b and c are important components of the sensorimotor system

What is the structure of the diencephalon?

1. Thalamus

- large, 2 lobed structure that constitutes the top of the brain stem

- one lobe on each side of the third ventricle - joined by massa intermedia

- most well-understood thalamic nulcei are sensory relay nuclei

- e.g. lateral geniculate nuclei (visual), medial geniculate nuclei (auditory), and ventral posterior nuclei (somatosensory system)

- most thalamic nuclei receive input from areas of the cortex and project it to other areas

2. Hypothalamus

- located just below anterior thalamus

- plays important role in motivated behaviour

- exerts effects by regulating release of hormones from the pituitary gland

- mammillary bodies are sometimes considered a part of the hypothalamus; they are a pair of spherical nuclei

What is the optic chiasm?

How is it formed?

the X-shaped structure formed at the point below the brain where the two optic nerves cross over each other.

some axons of optic nerves decussate (cross over to the other side of the brain) via optic chiasm

- decussating fibers (contralateral) vs nondecussating fibers (ipsilateral)

What is the telencephalon?

the largest division of the brain; where the most growth occurs

What is the cerebral cortex?

What is it made of?

outer layer of the cerebrum

small, unmyelinated neurons, therefore is gray and is sometimes called gray matter

- layer beneath the cortex is highly myelinated (white matter)

Why does the cerebral cortex have so many folds?

What are they called?

To increase the amount of cortex without increasing brain volume

- most mammals are lissencephatic (smooth brained) but most large mammals have convoluted cortexes

large furrows = fissures

small furrows = sulci

ridges b/w fissures and sulci = gyri

How are the cerebral hemispheres connected?

How are they divided?

a few tracts called cerebral commissures - largest is corpus callosum

longitudinal fissure (the largest fissure)

How are the four lobes of the brain separated? What are the four lobes?

what are the names of the large gyri that reside there?

central fissure and lateral fissure

frontal, parietal, temporal, occipital

precentral gyri (frontal), postcentral gyri (parietal), and superior temporal gyri (temporal lobe)

What is the functional area of the occipital lobe?

occipital cortex that analyzes visual input to guide behaviour

What is the functional area of the parietal lobe?

postcentral gyrus analyzes touch sensations; remaining cortex plays a role in perceiving locations of object and our bodies and then directing our attention

What is the functional area of the temporal lobe?

1. superior temporal gyrus - hearing and language

2. inferior temporal cortex - identifies visual patterns

3. medial portion of temporal cortex - memory