Ch. 9

which function occurs in the occipital lobe

visual cortex

CN 2: Optic Nerve

visual information from the eyes

Occipital lobe:

visual perception

Reflexive (implicit) memory

which is automatic and does not require conscious processes for either creation or recall, involves the amygdala and the cerebellum. Information stored in reflexive memory is acquired slowly through repetition. *Motor skills fall into this category, as do procedures and rules. Procedural memory*

Simple reflexes in a worm are integrated within a segment rather than in the brain, because

worms have a ganglion at each segment

Cranial Nerve III: Oculomotor

--Function: motor - fibers to the superior, inferior and medial rectus muscles of the eye and to the smooth muscle controlling lens shape. Medial and vertical eye movements; sensory - proprioception of the eye -Testing procedure: pupil sizes are compared for shape and equality, pupillary reflex is tested; visual tracking is tested

Describe the role of the suprachiasmatic nucleus in regulating circadian rhythms.

-A very simple interpretation of how the biological clock works is that clock cycling results from a complex feedback loop in which specific genes turn on and direct protein synthesis. The proteins accumulate, turn off the genes, and then are themselves degraded. As the proteins disappear, the genes turn back on and the cycle begins again -The SCN clock has intrinsic activity that is synchronized with the external environment by sensory information about light cycles received through the eyes -Body temperature, cortisol levels, melatonin release

white matter

-Ascending tracts take sensory information to the brain. They occupy the dorsal and external lateral portions of the spinal cord. -Descending tracts carry mostly efferent (motor) signals from the brain to the cord. They occupy the ventral and interior lateral portions of the white matter. -Propriospinal tracts are those that remain within the cord. In a spinal reflex, sensory information entering the spinal cord is acted on without input from the brain. However, sensory information about the stimulus may be sent to the brain

LIMBIC SYSTEM: links cognitive function and emotional response

-Cingulate gyrus: plays a role in emotion, part of the limbic system -Hippocampus: learning and memory -Amygdala: emotion and memory

medulla oblongata

-Contains somatosensory (going to the brain) and corticospinal tract (going to the spinal) conveying information between cerebrum and spinal cord -Gray matter contains nuclei that control many involuntary functions like breathing, blood pressure, swallowing and vomiting -Contain control centers for many involuntary functions. Tracts (most) cross in the pyramid region. As a result of this crossover, each side of the brain controls the opposite side of the body -Which is NOT housed in the medulla oblongata? Centers for controlling eye movement. Thats in the midbrain

Midbrain

-Controls eye movement -Relays signal for auditory and visual reflexes

gray matter

-Dorsal horn of the grey matter have two nuclei. One for somatic information and one for visceral information -Ventral horns of the grey matter contain cell bodies of motor neurons that carry efferent signals to muscles and glands. The ventral horns are organized into somatic motor and autonomic nuclei.

Cranial Nerve II: Optic

-Function: sensory - carries impulse for vision -Testing procedure: eye chart testing, visual field testing

Distinguish between white matter and gray matter in the CNS.

-Gray matter is unmyelinated nerve cell bodies in the brain and spinal cords called nuclei. -White matter is myelinated axons and very few cell bodies. Also contain tracts that connect the brain with different regions of the

Describe how the reticular activating system influences states of arousal.

-If connections between the reticular formation and the cerebral cortex are disrupted surgically, an animal becomes comatose. -Other evidence for the importance of the reticular formation in states of arousal comes from studies showing that *general anesthetics depress synaptic transmission in that region of the brain* Presumably, blocking ascending pathways between the reticular formation and the cerebral cortex creates a state of unconsciousness.

Explain the role of the corpus callosum.

-It connects the two hemispheres so that they are able to communicate with each other -Information leaving and entering the cerebrum passes through axon tracts through the thalamus

Describe the distinct layering of neurons in the cerebral cortex and cerebral lateralization.

-Neurons of the cerebral cortex are arranged in anatomically distinct vertical columns and horizontal layers. It is within these layers that our higher brain functions arise. -Cerebral lateralization: functional specialization is not symmetrical across the cerebral cortex: each lobe has special functions not shared by the matching lobe on the opposite side.

Explain how emotion and motivation represent a probable overlap of the behavioral state system and the cognitive system.

-Sensory stimuli feeding into the cerebral cortex are constructed in the brain to create a representation (perception) of the world. After information is integrated by the association areas, it is passed on to the limbic system. Feedback from the limbic system to the cerebral cortex creates awareness of the emotion, while descending pathways to the hypothalamus and brain stem initiate voluntary behaviors and unconscious responses mediated by autonomic, endocrine, immune, and somatic motor systems. -Motivation is defined as internal signals that shape voluntary behaviors. Some motivational states are known as drives and generally have three properties in common: (1) they create an increased state of CNS arousal or alertness, (2) they create goal-oriented behavior, and (3) they are capable of coordinating disparate behaviors to achieve that goal.

Motor output can be divided into three major types:

-Skeletal muscle movement, controlled by the somatic motor division -neuroendocrine signals, which are neurohormones secreted into the blood by neurons located primarily in the hypothalamus and adrenal medulla -visceral responses, the actions of smooth and cardiac muscle or endocrine and exocrine glands. Visceral responses are governed by the autonomic division of the nervous system.

Wenicke's area

-at the junction of the parietal, temporal, and occipital lobes. Damage to Wernicke's area results in a person having difficultly understanding language. A person's own speech might be nonsense because they cant understand what they are saying. -People with damage to Wernicke's area do not understand spoken or written communication.

cognitive

-behaviors related to thinking -related to affective -Complex cognitive function is done via the evolution of the forebrain

Hypothalamus

-contains centers for behavioral drives, helps with maintaining homeostasis by controlling endocrine and autonomic functions -considered to be the integrating center for homeostasis -The hypothalamus releases Hypothalamic trophic factors control the release of anterior pituitary hormones. It receives input from multiple sources. The hypothalamus contains various centers for behavioral drives such as hunger and thirst.

medulla oblongata

-contains somatosensory & corticospinal tracts conveying information between cerebrum and spinal cord -contains control centers for many involuntary functions -tracts (most) cross midline in pyramid region

midbrain

-controls eye movement -relays signals for auditory and visual reflexes

vagus nerve

-cranial nerve 10 is a mixed nerve -The mixed cranial nerve that projects to and from internal organs, muscles, and glands is the VAGUS nerve.

Sensitazation learning

-exposure to a noxious or intense stimulus causes an enhanced response upon subsequent exposure. -For example, people who become ill while eating a certain food may find that they lose their desire to eat that food again. You used to love to drink milk when you were a child.Lately, you notice that your stomach hurts and you experience bloating and discomfort when you drink it. It is no longer inviting when you see someone else drinking it.

Broca's area

-in the posterior part of the frontal lobe, close to the motor cortex. -Think Broca = broken speech. -Person can understand simple spoken and written language but cannot speak and write normally. -Usually the person has trouble to physically shape the sound that make up words or unable to coordinate the muscles of their arms and hands to write. -Those with damage to Broca's area understand but are unable to respond appropriately.

brainstem =

-midbrain, pons, and medulla oblongata. -CN II - XII originate here. -Many nuclei associated with reticular formation. -The oldest part of the brain and here is where the CN branch off from.

Declarative (explicit) memory

-requires conscious attention for its recall. Its creation generally depends on the use of higher-level cognitive skills such as inference, comparison, and evaluation. -The neuronal pathways involved in this type of memory are in the temporal lobes. -Declarative memories deal with knowledge about ourselves and the world around us that can be reported or described verbally. -Declarative memories are stored in cortical areas of the temporal lobes.

____ of 12 of the cranial nerves are attached to the brain stem

11

Pons

A brain structure that relays information between the cerebellum and cerebrum to the rest of the brain

motor fibers leave the spinal cord's gray matter via this

ventral root

gray matter

All the unmyelinated cell bodies (nuclei)

7) Diagram the blood- brain barrier and explain both how it is formed and how it controls the movement of substances.

Blood brain barrier: capillary endothelial cells have tight layer of cell to cell junctions, protects the brain from toxic water soluble compounds and pathogens in the blood. Formed by 400 miles of capillaries and its highly selective permeability shelters the brain from toxins, from fluctuations of hormones, ions, and neuroactive substances like neurotransmitters. -Tight junction formation apparently is induced by paracrine signals from adjacent astrocytes whose foot processes surround the capillary. -Hypothalamus and medulla oblongata don't have a blood brain barrier

Which of these does NOT contribute significantly to the protection of the brain? a. The cranium b. subarachniod space c. CSF d. dura mater e. cerebral space

Cerebral space The cranium, subarachniod space, CSF, dura mater all protect the brain

Diagram the secretion and reabsorption of cerebrospinal fluid and describe its purposes and composition (relative to plasma).

Cerebrospinal fluid serves two purposes: physical protection and chemical protection.Cerebrospinal fluid exchanges solutes with the interstitial fluid of the CNS and provides a route by which wastes can be removed -It is a salty solution that is continuously secreted by the choroid plexus, a specialized region on the walls of the ventricles that consists of capillaries and a transporting epithelium.The choroid plexus cells selectively pump sodium and other solutes from plasma into the ventricles, creating an osmotic gradient that draws water along with the solutes. -From the ventricles, cerebrospinal fluid flows into the subarachnoid space -The cerebrospinal fluid flows around the neural tissue and is finally absorbed back into the blood by special villi on the arachnoid membrane in the cranium

which of these does not contribute significantly to the protection of the brain? a. cranium b. subarachnoid space c. cerebrospinal fluid d. dura mater e. cerebral space

E. cerebral space

Apply knowledge of nervous system evolution to identify the anatomical similarities humans share with lower order organisms and demonstrate what makes humans unique.

In vertebrate brain evolution, the most dramatic change is seen in the forebrain region, which includes the cerebrum. In humans, the cerebrum is the largest and most distinctive part of the brain, with deep grooves and folds. The other brain structure whose evolution is obvious in vertebrates is the cerebellum, a region of the hindbrain devoted to coordinating movement and balance. Birds and humans both have well-developed cerebellar structures ***Simple reflexes in a worm are integrated within a segment rather than in the brain, because worms have ganglion at each segment

Which statement regarding the hypothalamus is FALSE?

It does not receive sensory fibers from the optic tract, ears, and spinal cord.

Pituitary Gland:

Major hormone gland in the brain

Describe how the behavioral state system modulates motor output.

Many neurons in the behavioral state system are found in regions of the brain outside the cerebral cortex, including parts of the reticular formation in the brain stem, hypothalamus, and the limbic system.

development

Neural tube becomes the spinal tube and brain (CNS) and the neural crest becomes the peripheral nervous system

emotions

One characteristic is that they are difficult to voluntarily turn on or off. Like anger, aggression, sexual feelings, fear, pleasure, happiness, contentment

Arachnoid villus

Projection of space for arachnoid membrane to the venous sinus. Important for circulation of cerebrospinal fluid into the venous blood

Arachnoid villus:

Projection of space for arachnoid membrane to the venous sinus. Important for circulation of cerebrospinal fluid into the venous blood

pons

Relay center for information between cerebellum and cerebrum

Explain why some neuroscientists would propose changing the functional unit of the nervous system from the individual neuron to neural networks.

Signaling within these pathways creates thinking, language, feeling, learning, and memory—the complex behaviors that make us human. Some neuroscientists have proposed that the functional unit of the nervous system be changed from the individual neuron to neural networks because even the most basic functions require circuits of neurons.

RAPID EYE MOVEMENT (REM sleep):

Stage 1→ low amplitude and high frequency waves that look like an awake person

DEEP SLEEP (non-REM sleep):

Stage 4→ high amplitude delta waves, low frequency

Perception

The brain's interpretation of sensory stimuli is called

CSF vs Plasma

The concentration of K+ is lower in the cerebrospinal fluid, and the concentration of H+ is higher than in plasma. The concentration of Na+ in CSF is similar to that in the blood. Cerebrospinal fluid normally contains very little protein and no blood cells

short-term memory

a limited storage area that can hold only about 7 to 12 pieces of informa- tion at a time.

pia mater

a thin membrane that adheres to the surface of the brain and spinal cord (here are the blood vessels that supply blood to the brain)

aphasia

ability to speak or create words

behavioral state system

also resides in the brain and governs sleep-wake cycles and other intrinsic behaviors. Information about the physiological or behavioral responses created by motor output feeds back to the sensory system, which in turn communicates with the cognitive and behavioral state systems

In habituation

an animal shows a decreased response to an irrelevant stimulus that is repeated over and over. For example, a sudden loud noise may startle you, but if the noise is repeated over and over again, your brain begins to ignore it.

moods

are similar to emotions but are longer-lasting, relatively stable subjective feelings related to one's sense of well-being. Studying and treating mood disorders suggests that mood disturbances reflect changes in CNS function, such as abnormal neurotransmitter release or reception in different brain regions.

Temporal lobe:

auditory perception

CN 3: Oculomotor Nerve

eye movement, pupil constriction and lens shape

which functions in the control of movement

basal nuclei

affective

behaviors related to feeling and emotions

ventral root

carries outgoing information from the CNS to muscles and glands.

anterior root

carry MOTOR information

dorsal root

carry SENSORY information

dorsal root

carry incoming sensory information

descending tracts

carry primarily efferent signals from the brain

Which is NOT housed in the medulla oblongata?

centers for control of eye movement

the brain region that is identifiable by its folds and grooves is the

cerebellum & cerebrum

The brain region that is identifiable by its folds and grooves is the ____________ & ______________

cerebellum and the cerebrum

Reasoning arises in the outer layer of neurons of the

cerebral cortex

Map the anatomical divisions of the CNS.

composed of neurons and supportive glial cells. Interneurons are those neurons completely contained within the CNS Brain and spinal cord ***The brain has a HIGH demand for oxygen, and receives about 50% of the total blood volume in circulation. The brain consumes about half of the glucose circulating in the body.

Copus callosum:

connect cerebral hemispheres,

collections of neurons known as diffuse modulatory systems have been shown to influence all of the following except a. attention-motivation b. wakefulness and memory c. motor control d. sexual drive and potency e. metabolic homeostasis

d. sexual drive and potency

FOREBRAIN:

diencephalon and cerebrum

Collections of neurons known as ________ ____________ ________ have been shown to influence all of the following EXCEPT sexual drive and potency.

diffuse modulatory systems They do influence attention -motivation, wakefulness and memory, motor control, metabolic homeostasis

the hormone that is released to enhance the fight or flight response is

epinephrine

The brain consumes about half of the ________ circulating in the body.

glucose

CN 8: Vestibulocochlear Nerve

hearing and equilibrium

Basal ganglia/nuclei:

help control movement

The brain has a ________ (high or low?) demand for oxygen, and receives about ________% of the total blood volume in circulation.

high/15%

which brain area is considered to be the integrating center of homeostasis?

hypothalamus

Diencephalon

hypothalamus and thalamus (also contains the pineal and pituitary glands)

choroid plexus

in the ventricles - makes CSF

Choriod plexus

in the walls of the ventricles - makes CSF

Sleep disorders:

insomnia (inability to sleep), sleep apnea (keeps waking up due to airway muscles relaxing to the point of obstructing airways) somnambulism (sleep walking)

non-associative learning

is a change in behavior that takes place after repeated exposure to a single stimulus. This type of learning includes habituation and sensitization

working memory

is a special form of short-term memory processed in the prefrontal lobes. This region of the cerebral cor- tex is devoted to keeping track of bits of information long enough to put them to use in a task that takes place after the information has been acquired.

long term memory

is a storage area capable of holding vast amounts of information. Information from short term memory is consolidated into the long term memory

which statement regarding the hypothalamus is false

it receives sensory fibers from the optic tract, ears, and spinal cord

The ability of neurons to change their responsiveness or alter their connections with experience is fundamental to the two cognitive processes of _______and ______

learning/ memory

motor fibers

leave the spinal cord's gray matter via this ventral roots.

Arachnoid membrane:

loosely tied to the inner membrane leaving space for the inner membrane space

HINDBRAIN:

medulla oblongata, pons, cerebrum

Memories are stored throughout the cerebral cortex in path- ways known as _______ ______. Some components of memories are stored in the sensory cortices where they are processed. For example, pictures are stored in the visual cortex, and sounds in the auditory cortex. In humans, the __________ seems to be an important struc- ture in both learning and memory.

memory traces/hippocampus

sensory system

monitors the internal and external environments and initiates reflex responses

Frontal lobe:

motor, gustation and olfactory

white matter

myelinated, contains tracts

associative learning

occurs when two stimuli are associated with each other, such as Pavlov's classic experiment in which he simultaneously presented dogs with food and rang a bell. Another form of associative learning occurs when an animal associates a stimulus with a given behavior. An example would be a mouse that gets a shock each time it touches a certain part of its cage. It soon associates that part of the cage with an unpleasant experience and avoids the area.

cerebrum

part of the brain that allows reasoning and cognition. Reasoning arises in the outer layer of neurons of the cerebral cortex.

The brain's interpretation of sensory stimuli is called

perception

receptive aphasia

person is unable to understand sensory input

Cerebellum

processes sensory information, coordinates execution of movement. Equilibrium and balance

Thalamus

relays and modifies sensory and motor information going to and from cerebral cortex

cognitive system

resides in the cerebral cortex and is able to initiate voluntary responses

pineal gland

secretes melatonin

you use to love milk when you were a child, lately you notice discomfort when you drink it. it is no longer inviting when you see someone else drink it, what kind of learning is this?

sensitization

Parietal lobe:

somatosensory perception

declarative memories are stored in cortical areas of the ____ lobes

temporal

Plasticity

the brain's ability to change, especially during childhood, by reorganizing after damage or by building new pathways based on experience

Plasticity

the restructure of the brain networks in response to sensory input and experience.

dura mater

the thickest, associates with veins that drain blood from the brain though vesicles or cavities called sinuses.

CN 8: Vestibulocochlear Nerve

this nerve is responsible for hearing & balance

gray matter

unmyelinated, consists of cell bodies, dendrites, and axon terminals

The mixed cranial nerve that projects to and from internal organs, muscles, and glands is the ________ nerve.

vagus