Brain and Behavior Exam 1

Hominid

primate that *walks upright*, has long lower limbs, thumbs that oppose the other four fingers, and a relatively large brain Australopithecus- ("southern" ; "ape") our distant hominid ancestor- gave rise to the genus homo,or human-4 million years ago-brains were 1/3 the size of ours-among the first primates to walk upright Homo habilis- handy human Homo erectus- upright human Homo sapiens

Traumatic Brain Injury (TBI)

wound to the brain that results from a blow to the head

Somatic Nervous System (SNS)

All the spinal and cranial nerves carrying sensory information to the CNS from the muscles, joints, and skin also transmits outgoing motor instructions that produce movement -monitored and controlled by the CNS - the somatic nervous system is bilateral (two sided) ex. Left side controls left side

Chordates

Animal that has both a "true" brain and a spinal cord - from notochord, a flexible rod that runs the length of the back *invertebrate animals- make up majority of animals (97%)

How are traits selected naturally?

Appearance of a new trait Adaptive trait Increases chances of survival Trait passed on to offspring

The Diencephalon

Hypothalamus and thalamus -integrates sensory and motor information on its way to the cerebral cortex -*thalamus- one in each hemisphere—much larger than the hypothalamus- a kind of gateway for channeling sensory information traveling to the cerebral cortex -all sensory systems send inputs to the thalamus for information integration and relay to the appropriate area in the cortex Lateral geniculate nucleus- processes some visual information and then sends it to the visual region of the cortex in each hemisphere-some thalamic regions have motor functions or perform integrative tasks -dorsomedial thalamic nucleus -*hypothalamus- one in each hemisphere-lying bilaterally along the brain's midline -controls the body's production of hormones, which is accomplished by its interactions with the pituitary gland -constitutes only 0.3 percent of the brain's weight - takes part in all aspects of behavior ex. Feeding, sexual behavior, sleeping, temperature regulation, emotional behavior, hormone function, and movement -sex differences

The Macro view

Gray matter-areas of the nervous system predominantly composed of cell bodies and blood vessels - functions either to collect and modify information or to support this activity- collects and processes incoming (afferent) sensory or outgoing (efferent) information White matter- mostly nerve fibers with fatty coverings that produce the white appearance -form the connections between the cells

Annelids to Arthropods (second phyla in cladogram)

Have heads and tails+ Bilateral symmetry-One half of the body is the mirror image of the other+ Segmentation- the body is composed of similarly organized parts - resembles the human spinal cord

fixed action pattern

a sequence of unlearned acts directly linked to a simple stimulus Ex. The graylag goose always retrieves that has been bumped out of her nest in the same manner -she carries this sequence to completion, even if the egg slips away during the process Another Ex. Imprinting- any kind of phase sensitive learning- the bond formed between a new born animal and its caregiver—Konrad Lorenz +ducks *sign stimulus- often a simple cue in the animal's environment—trigger innate, unchangeable FAP's -genetic programming underlying FAPs ensures such activities are performed correctly without practice -yawning in humans

Carotid Arteries

Have very large diameterswhereas the upstream cerebral arteries and capillaries become very small in diameter -debris such as blood clots or plaque deposits, which become dislodged and pass through the carotid artery but block the smaller cerebral arteries or capillaries are common causes of strokes -effect of a stroke is localized

Clinical trial

approved experiment directed toward developing a treatment

Persistent Vegetative State (PVS)

condition in which a person is alive but unable to communicate or to function independently at even the most basic level

Contralateral

Located on opposite side of the body

Ipsilateral

Located on the same side of the body

Behavior

"Patterns in time" -anything that an organism does Involving action and response to sTimulation - patterns can be made up of movements, vocalizations, or changes in appearance -animals with smaller, simpler nervous systems have a narrow range of behaviors dependent on heredity -animals with more complex systems have more behavioral options that depend on learning

Dorsal (opposite of ventral)

"Toward the back" with respect to the central nervous system, in a direction perpendicular to the neuroaxis toward the top of the head or the back -on or toward the back of an animal or,in reference to the human brain nuclei, located above (top)

Afferent

(Incoming) *sensory* information coming into the CNS or one of its parts Ex. Step on a tack, the sensory signals transmitted from the body into the brain are afferent

Efferent

(Outgoing) *motor* refers to information leaving the CNS or one of its parts Ex. Efferent signals from the brain trigger a motor response: you lift your foot

ependymal cells (glial cells)

*- small,ovoid, secrete cerebrospinal fluid-hydrocephalus

The Cortex (forebrain)

*Neocortex-(new bark) tissue visible when we view the brain from the outside -primary function is to create a perceptual world and respond to that world *limbic cortex- more primitive- found in the brains of other chordates in addition to mammals -controls motivational states -both comprise 80% of the human brain overall

Darwin and Materialism

*materialism*- the idea that rational behavior can be fully explained by the workings of the brain and the rest of the nervous system, without any need to refer to an immaterial mind -endorsed by Alfred russel Wallace and Charles Darwin -great diversity in the biological world could have evolved from common ancestry -Darwin formulated the principles of natural selection and evolution, which revolutionized biology - all species of life have descended over time from common ancestry - three factors combine to create new species: variation, inheritance and natural selection

Axon hillock

-*Juncture of soma and axon where action potential begins* *Axon collateral*-branch of an axon Lower tip of an axon may divide into a number of small branches (*teleondendria*, or end branches)-which at the end is a knob called the end foot or *terminal button*

Evolution of Large Brains

-a large brain requires a large skull, and an upright posture limits the size of a woman's birth canal. A newborn baby's head is about as large as it can be - the prenatal period of cell division in the brain is prolonged in humans, which results in a brain weighing an average of 350 g and containing approximately 100 billion neurons -not until late adolescence does the human brain reaches its adult size of approximately 1400g— about four times the weight of a newborn's brain

Cerebrum (forebrain) and cerebellum

-behavioral complexity among chordates is related to the evolution of cerebral hemispheres (forebrain) and cerebellum -the behaviors controlled by these regions include new forms of locomotion on land, complex movements of the mouth and hands for eating, Improved learning ability and highly organized social behavior *Cerebellum*- major structure of the brainstem; involved in coordinating and learning skilled movements *both cerebrum and cerebellum: increases in size led to extensive folding to fit more tissue into the skull*-dolphins and primates -the animals with the largest brains relative to body size-we humans have the largest relative to body size -brain size is not a reliable indicator of number of neurons

Gregor Mendel (1822-1884)

-genetic variation is the biological mechanism of evolution - mendel's pea plant experiments established many of the rules of heredity and the concept of genes -deduced that heritable factors, which we now call genes, are related to the various physical traits displayed by the species

Hindbrain (brainstem)

-has both sensory and motor functions -*especially important in motor functions*-ranging from breathing to balance to fine movements, such as those used in dancing -most distinctive structure is the cerebellum -reticular formation -pons -medulla

Three reasons for linking the study of brain and behavior

1. A growing list of behavioral disorderscan be explained and cured by understanding the brain- more than 2000 disorders may in some way be related to brain abnormalities. 2. The brain is the most complex living organ on earth and is found in many different groups of animals. 3. How the brain produces both behavior and the human consciousness is a major unanswered question.

Oligodendroglia and Shwann Cells (glial cells)

1. Myelinated axons in the brain and spinal cord by sending out large flat branches that enclose and separate adjacent axons-weap tightly to form the myelin Sheath+speeds up electrical signals 2. Myelinated axons in the peripheral nervous system -nodes of ranvier- wraps itself repeatedly around a part of an axon-like bead on a string- Both contribute to a neurons nutrition and function by absorbing chemicals that the neuron releases and releasing chemicals that the neuron absorbs Multiple sclerosis-if myelin (formed by oligodrndroglia) is damaged,a neuron may be unable to send any messages over its axons -functions of neurons it encases are disrupted

Implications for brain and behavior (Darwin and materialism)

1.because all species are related, so too must be their brains-studying simpler animals to understand humans 2.because all species are related-so must their behavior 3. Both the brain and behavior changed bit by bit in animals that evolved to greater complexity, as humans obviously did

cerebrospinal fluid (CSF)

A colorless solution of sodium chloride and other salts -cushions the brain so it can move or expand slightly without pressing on the skull -in cases where the CsF cannot protect the brain from forced contact with the skull case, causing hemorrhaging, brain damage, and sometimes death -prevention of brain ischemia *- made by decreasing the amount of CSF in the limited space inside the skull-decreases total intracranial pressure and facilitates blood perfusion

gyrus (gyri)

A fold or ridge in the cortex-the "flatter" part on top- small protrusion or bump from day by the folding of the cerebral cortex - these surface convolutions appear during fetal development and continue to mature after birth through the process of gyrification

Common ancestor

A forebearer from which two or more lineages or family groups arise Ex. Humans and apes are thought to share a common ancestor Can trace our lineage by comparing the genes, brains and behaviors of different animals

Sulcus (sulci)

A groove or vally in the surface of the cerebral hemisphere - the majority of the cerebral cortex is not visible from the outside, but buried in the sulci

Nuclei

A group of cells forming a cluster that can be identified with special stains to form a functional grouping

reticular formation (part of the hindbrain)

A netlike mixture of neurons (gray matter) and nerve fibers (white matter) that gives this structure the mottled appearance from which its name derives -nuclei are localized along its length into small patches, each with a special function in stimulating the forebrain, such as in awakening from sleep and behavioral arousal

Fissure

A very deep sulcus

Glial cells

Aid and modulate the neuron's activities-bind neurons together and providing support,nutrients,and protection p,among other functions -constantly replacing themselves Ex. Insulating neurons -myelin -tumors grow from glial cells Outnumber neurons 10:1

Peripheral Nervous System (PNS)

All the neurons in the body located outside the brain and spinal cord; provides sensory motor connections to and from the central nervous system - consists of heroes and ganglia outside of the brain and spinal cord Somatic: neurons connect to receptors on the body's surface and on its muscles to gather sensory info for the cNs+ convey info from the CNS to move muscles of the face, body, and limbs Autonomic: enables the CNS to govern the workings of your body's internal organs ex. Beating of your heart

autonomic nervous system (ANS)

Balances the body's internal organs to "rest and digest" through the *parasympathetic* (calming nerves) or to "fight or flee" (ex. Slowing the heartbeat and Inhibiting digestion when we exert ourselves) engage in vigorous activity through the *sympathetic* (arousing) nerves -interacts with the rest of the nervous system -activation of the *sympathetic division starts in the thoracic and lumbar spinal cord regions - spinal nerves do not directly control the target organs - connect to autonomic control centers or collections of cells called ganglia*-minibrain *sympathetic ganglia are located near the spinal cord, forming a chain that runs parallel to the cord *parasympathetic division is also connected to the spinal cord-specifically the sacral region - greater part derives from three cranial nerves:the vagus nerve, which calms the internal organs, and the facial and oculomotor nerves, which control salivation and pupil dilation *in contrast with the sympathetic division, the parasympathetic division connects with ganglia the are near the target organs

Aristotle and Mentalism

Believed the brain cooled the blood: no role in producing behavior - our actions are controlled by an immaterial soul or Psyche- was responsible for human thoughts, perceptions, and emotions and for such processes as imagination, opinion, desire, pleasure, pain, memory, and reason -housed in the heart -while known as a philosopher his work also had a long lasting impact on science and ethology *mentalism*- "of the mind" the philosophical position that a person's mind or psyche is responsible for behavior

Central Nervous System (CNS)

Brain and spinal cord - encased in bone, the brain by the skull and the spinal cord by the vertebrae -considered to be the core because it's physically located to be the core of the nervous system + it is the core structure mediating behavior

Nerves

Bundles of neuronal fibers located outside CNS structures are typically referred to simply as ...

Brain

Complex organ with many components -work together to maintain basic life processes, like breathing, body temp and blood pressure, as well as higher functions like creative thought and emotions -comprises two major sets of structures - forebrain and the brainstem

Minimally Conscious State (MCS)

Condition in which a person can display some rudimentary behaviors, such as smiling or uttering a few words, but is otherwise not conscious.

Cerebellum (part of the hindbrain)

Controls complex movements and has a role in a variety of cognitive functions, as well Size of cerebellum increases with the physical speed and motor skill of a species

Frontal lobe

Cortex anterior (in front of ) the central sulcus and beneath the frontal bone of the skull. "Executive functions, such as decision making , planning and execution of movements

occipital lobe

Cortex at the back of the brain and beneath the occipital bone of the skull. -visual processing

Temporal lobe

Cortex lying below the lateral fissure, beneath the temporal bone at the side of the skull -functions in connection with hearing and language and musical abilities- auditory processing and memories

Parietal Lobe

Cortex posterior to the central sulcus, beneath the temporal bone at the top of the skull. Involved In information processing and goal directed movement such as grasping an object.

Coronal section

Cut in a vertical plane, from the crown of the head down, yielding a frontal view of the brain's internal structures

Brain-body orientation

Describes brain structure location from the frame of reference of the face

Spatial orientation

Describes brain-structure location in relation to other body parts.

Anatomical orientation

Describes the direction of a cut, or section, through the brain from the perspective of a viewer.

Right Brain vs. Left Brain

Dr. Micheal Gazzaniga and Joe, an epileptic who had his corpus callosum severed to stop daily seizures from joe's right hemisphere to his left-prevented the two hemispheres fro communicating with each other -split brain research paradigm -cause and effect- left hemisphere property- "don't leave home without your left hemisphere." -archinbaldo-fruit faces- right hemisphere can see faces- left hemisphere can't -language on left, spatial functions are usually on the right

Cerebral cortex

Entire outer layer of the forebrain consists of a heavily, folded layer of nerve tissue - consisting of gray matter, which contains neuronsl cell bodies - brains folds are not random but rather demarcate its functional zones -largest region of the cerebrumin the mammalian brain and plays a key role in memory, attention, perception, cognition, awareness, thought, language, and consciousness -in large animals, the cerebral cortex is usually folded, providing a greater surface area in the confined volume of the cranium- allows for the addition and evolution of a greater diversity of functional areas ex. Gyrus and sulcus

The evolution of the human brain and nervous system

Evolution of nervous system Not essential for life- only the animalia kingdom have it - fairly recent development -vertebrates or chordates= animals with spinal columns and centralized brains Evolution of the human brain - outstanding feature of modern humans is brain size -accompanied by many different functions first evolved in the ancestors of birds and mammals -brain evolution occurred relatively quickly

Hemispheres

Forebrain has two symmetrical halves- one on the left and one on the right Divides the cerebral cortex by the longitudinal fissure

Why the Hominid Brain Enlarged

Hypotheses: 1. The primate lifestyle favors an increasingly complex nervous system. *(foraging activities can be complex or simple-eating grass or vegetation is simple ergo they do not have big brains=fruit eaters have larger brains-foraging for fruit is a more complex behavior than grazing-color vision "good sensory skills are necessary +good motor skills to reach and manipulate it+ good memory) (spider monkey has a larger brain than a howler monkey) 2. Links brain growth to brain cooling.-*radiator hypothesis* - the more active the brain is, the more heat it generates-homo species skulls had more widely dispersed blood flow, which allowed for increased brain size Increased blood circulation—- Improved Brain cooling—-enables size of hominid brains to increase 3. A slowed rate of maturation favors large brains.- neotany ( slowing of maturation) - juvenile stages of predecessors become the adult features of descendants- a small face, a vaulted cranium, an un rotated big toe, an upright posture, a primary distribution of hair on the head, armpits, and pubic areas -slowing down human maturation would have allowed more time for brain cells to be produced-due to abundant resources- or non-abundant resources

Embodied consciousness

Hypothesis that the movements that we make and those that we perceive in others are essential features of our conscious behavior Ex. Overt gestures and body language CNS needs ongoing sensory stimulation from the world and from its own body's movement if it is to maintain its intelligent activity

Sagittal section

Is cut lengthways (along the hemispheres) from front to back of the skull-viewsbrain from the side as if Brain was oriented as an arrow

Encephalization Quotient (EQ)

Jerison's quantitative measure of brain size obtained from the ratio of actual brain size to expected brain size, according to the principle of proper mass, for an animal of a particular body size *the ratio of brain volume to body size*

Synapse

Junction between one neuron and another neuron, usually between an end foot (terminal button) of the axon of one neuron and a dendritic spine of the other neuron

corpus callosum

Long band of white matter (largest white matter structure) that runs the length of the cerebral hemispheres -contains 200 million nerve fibers that reach out to every major Cortex in the brain and join the two hemispheres and allow communication between them-*most prominent connecting cable *transferring motor, sensory, and cognitive information-integration of cognitive activities, body movements and sensory information Musical training increases plasticity -damage to this area may result in coma or vegetative state, mutism, memory impairment -reductions in volume have been associated with schizophrenia and onset of psychotic episodes -abnormalities viewed in Alzheimer's patients and children with adhd

Neurons

Nerve cells that compose the nervous system that engage in information processing -communicate with one another, with sensory receptors on the body, with muscles and with internal organs

deep brain stimulation (DBS)

Neurosurgery in which electrodes implanted in the brain stimulate a targeted area with a low-voltage electrical current to facilitate behavior.

Founding father of modern Ethology (Nobel prize 1973)

Nikolaas Tinbergen-stimulus response Konrad Lorenz-fixed action pattern+imprinting Karl Ritter von Frisch-bee dance

Nerve net (first phyla in cladogram)

No structure that resembles a brain or spinal cord but consists entirely of neurons that receive sensory information and connect directly to other neurons that move muscles -diffuse mesh of nerve cells that take part in simple reflex pathways -nerve cells interact with sensory and contractile cells Ex. The nerve net of sea anemones is one of the simplest type of nervous system producing behavior

The study of the human brain

Not just the study of the structure of a body organ but how that organ acquires cultural skills— how the human brain fosters behavior in today's world *what is true for evolutionary comparisons across different species may not be true for comparisons within a single species* *brain size and intelligence not particularly related* *humans development of culture have surpassed other species* -primary function is to produce behavior, or movement

Medulla (part of the hindbrain)

Nuclei control such vital functions as regulating breathing and the cardiovascular system (heart rasate)

Pons (part of the hindbrain)

Nuclei within the pons receive inputs from the cerebellum and actually form a bridge from it to the rest of the brain *controls important movements of the body*

ventral (opposite of dorsal)

On or toward the belly or the side of the animal where the belly is located; in reference to brain nuclei -bottom of the skull or the front surface of the body (bottom)

Microglia (glial cells)

Originate in the blood as an offshoot of the *immune system* - monitor the health of brain tissue Phagocytosis- engulf and remove foreign matter and debris

Spinal cord

Part of the central nervous system encased it hi the vertebrae (spinal column) that provides most of the connections between the brain and the rest of the body

The spinal cord

Produces most body movements, usually following instructions from the brain but at times acting independently - is not a single structure but rather a set of segmented "switching stations" -each segment receives info from a discrete part of the body and sends out commands to that area - spinal nerves ,part of the somatic system carry sensory information to the cord from the skin, muscles, and related structures and ,in turn, send motor instructions to control each muscle Ex. Hitting your patella-spinal reflex

Forebrain

Prominent in birds and mammals with big brains, including ourselves -enfolds the brainstem and is responsible for most our* conscious behaviors* -comprises of three parts: neocortex, basal ganglia, and limbic system - holds ultimate control over movement

Descartes and dualism

Proposed that the brain played an important role in behavior Dualism- both a nonmaterial mind and the material body contribute to behavior - the immaterial mind acts through the material brain to produce language and rational behavior , whereas the brain alone is responsible for the "Lower" kinds of actions that we have In common with other animal species Mind body problem- quandary of explaining a nonmaterial mind in command of a material body - and how a nonmaterial mind and physical brain might interact -suggested that the mind resides in a small structure in the center of the brain, the pineal body(now called the pineal gland) (is unitary) which is located besides fluid filled (cerebrospinal fluid) cavities called ventricles -the pineal body directs fluid from the ventricles through the nerves and into muscles-when the fluid expands those muscles,the body moves -*pineal gland is involved in biological rhythms, not in intelligence or behavioral control -*fluid is not pumped from the ventricles to control movement -proposed language and action tests to determine if an organism possesses a mind-justified the cruel treatment

Dendritic spine

Protrusion from dendrite that greatly increases the dendrite's surface area and is the usual point of dendritic contact with the axons of other cells

Tracts

Refers to collections of nerve fibers found within the brain and spinal cord

Cladogram

Show relations among organisms- evolutionarily -among the various animal phyla (groups of animals) the nervous system has evolved considerably

Homology

Similarity in characteristics resulting from a shared ancestry.-Richard Owen Ex. throughout the process of natural selection, these forelimb bones have been adapted to suit many different functions

Where we stand now?

Simple nature / nurture or instinctive/learned dichotomies have been abandoned -all behavior depends on both genes (gene expression) and environmental factors *epigenetics*-study of differences in gene expression related to environment and experience -do not change your gene, but they do influence how your genes express the traits you have inherited from your parents -interested in how genetic and environmental factors interact

Horizontal section

So-called because the view or the cut falls along the horizon, is usually viewed looking down on the brain from above- a dorsal view

Brainstem

Source of behavior in simpler animals such as fish, amphibians, and reptiles -responsible for most of our unconscious behavior Begins where the spinal cord enters the skull Produces movement and creates a sensory world -include hindbrain- medulla, pons (head/face CN), cerebellum midbrain: Eye movement- (sup. Col) vision and Auditory (inf col) processing Diencephalon: thalamus, and hypothalamus

Ganglia (third phyla)

Such as clams, snails and octopuses Have clusters of neurons called ganglia- represent primitive brains and function somewhat like command centers -encephalization-"in the head" -insects have ganglia in the head that are sufficient to merit the term brain

The Midbrain

Tectum- (roof) is located dorsally - *first brain region to receive sensory inputs* receives a massive amount of sensory information from the eyes and ears - the optic nerve sends a large bundle of nerve fibers to the superior colliculus whereas the inferior colliculus receives much of its input from auditory pathways - colliculi function not only to process sensory information but also to produce orienting movements related to sensory inputs ex. Turning your head to see the source of a sound Tegmentum (floor) is ventral-composed of many nuclei, largely with movement related functions - several of its nuclei control eye movements — the *red nucleus controls limb movements +*substantia nigra is connected to the forebrain + periaqueductal gray matter contains circuits controlling species typical behaviors (ex. Female sexual behavior)

Features common to primates

The human relationship to apes and monkeys places us in the primate order, a subcategory of mammals that includes not only apes and monkeys but lemurs, tarsiers, and marmosets as -1 of about 275 species of the primate order 1. Excellent color Vision 2.eyes in front of face: enhance depth perception. 3. Females: usually only one Infant per pregnancy ; infants need more care 4. Large brains for skilled movements and social behavior -members of the great ape family, orangutans, gorillas, and chimpanzee -apes are arboreal *-among apes, we are most closely related to the chimpanzee*- having had a common ancestor between 5 million and 10 million years ago

Neuroplasticity

The nervous system's potential for physical or chemical change that enhances its adaptability to environmental change and its ability to compensate for injury

Meninges

Three layers of protective tissue under the skull-dura mater (tough double layer of fibrous tissue that encloses the brain and spinal cord in a loose sack) , arachnoid,(a very thin sheet of delicate connective tissue that follows the brain's contours) and pia mater(moderately tough membrane of connective tissue that cling to the brain's surface) -that encase the brain and spinal cord Between arachnoid and pia mater flows cerebrospinal fluid

Major cerebral arteries

Three major arteries that send blood to the cerebrum -the anterior, middle, and posterior cerebral arteries -emerge from the neck to wrap around the outside of the brainstem, cerebrum, and cerebellum -brain is very sensitive to loss of blood, a blockage or break in a cerebral artery -likely to lead to death of the affected region, or *stroke* -disrupt different brain functions, depending on the artery affected -sudden appearance of neurological symptoms

Medial

Toward the middle of the body, away from the side, specifically the body's midline; in reference to brain sections, a side view of central structures

Lateral

Toward the side of the body, away from the middle (front facing)

The cortical lobes (the cortex) (the forebrain)

Two nearly symmetrical hemispheres (left and right) which are separated by the longitudinal fissure -frontal, temporal, parietal, and occipital-arbitrary Occipital- vision Parietal-tactile functions Temporal-visual, auditory, and gustatory functions Friontal- motor and executive functions -integrates motor and sensory functions and formulates a plan of action Fissures and sulci establish the boundaries of cortical lobes

Ventricles

Two wing shaped cavities that contain cerebrospinal fluid -brain contains four ventricles -cells that line the ventricles (choroid plexus) make the cerebrospinal fluid that fills them *maintains brain metabolism- may allow certain compounds access to the brain+ helps brain excrete metabolic wastes* - CSF flows throughout the Inner ventricular system and is absorbed back isn't the bloodstream (foramena) Rinsing the metabolic waste from the central nervous system through the blood brain Barrier ventricles are connected; so the CSF flows from the two lateral ventricles to the third and fourth ventricles that lie on the brain's midline and into the cerebral aqueduct - a canal that runs the length of the spinal cord

Bee Dance

Upon returning to the hive, the bee enacts a complex pattern of movements that tells the other bees how to go directly to the food. Though they learn the route from the worker bee's dance, the other bees rely on their genetic predisposition to such learning. Thus, instincts play an important role in developing unique or creative behavioral responses to the environment. First learned by Aristotle and continued by Karl von Frisch

Additional info about chordates

Wide variation exists in the nervous system of chordates, but the basic pattern is segmented, bilaterally symmetrical and has a spinal cord and brain encased in brain or cartilage - as chordates evolved limbs and new forms of locomotion, their brains became larger ex.- all chordates have a brainstem, but only birds and mammals have a large forebrain Two other features distinguish the chordates: 1.the nervous system is crossed 2. The chordate spinal cord lies behind the heart and the gut.

anterior (opposite of posterior)

With respect to the central nervous system, located near or toward the head (front)

posterior (opposite of anterior)

With respect to the central nervous system, located near or toward the tail (at the back)

Neuroaxis

an imaginary line that runs the length of the spinal cord up to the front of the brain

Astroglia (glial cells)

astrocytes- star shaped,symmetrical: nutritive and support function-attach to blood vessels and brain's lining and create scaffolding that holds neurons in place -also secrete chemicals that keeps neurons healthy and help them heal if injured—contribute to the blood brain barrier=attach to blood vessel cells causing them to bind tightly together-doesn't permit useful drugs —enhance brain activity-trigger the blood vessels to dilute allowing greater oxygen -convey signals from neurons to blood vessels causing them to expand +provide more fuel —heal damaged brain tissue-form a scar-acts as a barrier to the regrowing of damaged nerves -involves in establishing synapses or dendritic spines

Neurons

nerve cells; that carry out the brain's major functions -have plasticity (even in fully grown neurons, the cells genetic blueprints can be reopened to produce new proteins and allow the neuron to alter its structure) and longevity (neurons lost are not replaced and functional recovery is poor) -three basic subdivisions: core region, or cell body or *soma* (integrating info)—- *dendrites*, or neuron's branching extensions (collect info from other cells) —*axon*- main root-only one(sending info)