BMS 404: Lesson 32-34 Spinal Higher CNS

Definition of Coma

-In medicine, a COMA (from the Greek koma, meaning deep sleep) is: 1) a state of unconsciousness, lasting more than 6 hours in which a person cannot be awakened, fails to respond normally to painful stimuli, light or sound 2)lacks a normal sleep-wake cycle 3)does not initiate voluntary actions.

Brain Death

-Nature and duration of the coma. -Cerebral and brainstem function are absent. -Other criteria (optional): Flat EEG for 30 minutes. Responses absent in vital brainstem structures. Greatly reduced cerebral circulation.

Multiple Neurons and Anatomical Sites are Required

Multisensory modalities contribute to Selective Attention: Brainstem: neurons in the locus coeruleus (responsible for when you awake) improve information processing Cerebral Cortex: association areas in directing attention and improve information processing during directed attention.

Sleep Stage 1

-Alpha waves are present when one begins a state of relaxation. -Stage 1 sleep is when sleep has just begun. =the EEG is dominated by irregular, jagged, low voltage waves. =brain activity begins to decline. =hallmarked by theta waves (4-8 Hz) interspersing alpha waves.

Diseases of Learning and Memory

-Attention Deficit Disorders -Autism -Dyslexia -Brain Injury -Alzheimer's Disease and Related Dementias -Other Neurodegenerative Diseases and Memory Disorders

Other Causes of Senile Dementia

-Cerebrovascular disease -Parkinsonism -Tertiary syphilis -Tumor -Inappropriate medications

Aphasia

-Disturbances in ability to communicate (excluding deafness, impairments to vision, or vocal cord function) -Function is lateralized - on left side in right handed and about right side in left-handed (even in American Sign Language users!)

Supraspinal Control: Corticospinal Tract

-Excitatory -Crosses over in medulla -Voluntary movements -Distal extremities = Fractionated movements (primates only!) -ability to move individual muscles

Local Level: Muscle Sensory Component

Muscle spindles are sensory receptors within the belly of a muscle that primarily detect changes in the length of this muscle. They convey length information to the central nervous system via sensory neurons. There are different types of muscle spindle fibers; they are always sensory receptors

Classification of Nerve Fibers

Sensory and motor: - A alpha- largest diameter; fastest conduction velocity; myelination- example: alpha motor neurons - A gamma- medium diameter; medium conduction velocity; myelination- example: gamma motor neurons to muscle spindles (intrafusal fibers) ------ Sensory ONLY: - Ia- largest diameter; fastest relative conduction velocity; myelination- example: muscle spindle afferent - Ib- largest diameter; fastest relative conduction velocity; myelination- example: golgi tendon organ afferent - II- medium diameter; medium relative conduction velocity; myelination- example: secondary afferent of muscle spindle; touch pressure

Regulatory Inputs to Local Interneurons

Several regulatory inputs: joint, tendon, muscle, skin receptors, and descending pathways from middle neurons KNOW that local interneurons can be either excitatory or inhibitory , but the muscle fibers that are alpha motor neurons are ALL stimulatory

Anatomical Organization of Middle Level Components

Side and cross-sectional views of some of the neural components regulating motor commands. Altered processing abilities in these components can cause motor problems such as Parkinsonism. Know anatomical structures that are associated with the reflex processes Cerebellum functions in: 1) Balance and eye movement; 2) Posture and locomotion; and 3) Skilled movements Basal ganglia functions in motor integration center to create fluid movements. Signals to the premotor area and the primary motor cortex

Co-Operativity of Reflexes: Muscle Spindles and Golgi Tendon Organs Work Together

- Concept of a servomechanism - a system designed to maintain a parameter constant - Spindles are part of a length servo, Golgi tendon organs are part of a tension servo - They work together to regulate muscle stiffness, particularly of postural muscles.

What are Conscious Experiences?

- Conscious experience: is things we are aware of that include internal or external with sensory awareness (e.g., fatigue, thirst and happiness) being an obvious aspect. - Selective attention: is to avoid a distraction of irrelevant stimuli, while focusing on stimuli that are momentarily important. - Habituation: is a process or procedure that occurs in response to a repeated stimulus. =Process - decrease in an elicited behavior resulting from the repeated presentation of an eliciting stimulus (a simple form of learning). =Procedure - repeated presentation of an eliciting stimulus that may result in the decline of the elicited behavior (the process of habituation), an increase of the elicited behavior (the process of sensitization), or an initial increase followed by a decline of the elicited behavior (a sensitization process followed by a habituation process). habituation -applies to psychological dependency on drugs. four features that characterize drug habituation: 1) "a desire (but not a compulsion) to continue taking the drug for the sense of improved well-being which it engenders" 2) "little or no tendency to increase the dose" 3) "some degree of psychic dependence on the effect of the drug, but absence of physical dependence and hence of an abstinence syndrome" 4)"detrimental effects, if any, primarily on the individual" Substance dependence is the preferred term today when describing drug-related disorders

Distinct Neurological Processes for Selective Attention

- Disengagement (losing/away) from present focus. - Attention is moved to a new focus and is now held to newly acquired focus. - Exhibit an increased arousal that produces a prolonged attention to the newly acquired focus.

Timing of Sleep Stages

- Duration is 90-100 minutes per cycle Note: The pattern is stage 1 -> 2 -> 3-> 4-> REM ->4 ->3->2->1... eventually stage 3 and 4 disappears and only goes from stage 2 -> REM ->stage 2 ->REM.. Etc Also note: that the level of REM lengthen over time Stage 4: when young children wet their bed or when people sleep walk REM: grinding teeth, male penile erection

Supraspinal Control

- Only 1-2% of synaptic inputs to motorneurons are from primary sensory afferents! - The rest are direct from supraspinal centers or indirect via local interneurons.

Reflexes Phasic and Tonic Stretch Reflexes

- Phasic stretch reflex: Stretch sufficient to activate primary afferent fibers (Ia) evokes a brisk, brief myotatic reflex. - Tonic stretch reflex: Sustained muscle stretch also activates type II afferents, modulates muscle tone. - **Postural reflexes: Spindles are more abundant in slow muscles (such as soleus) than in fast muscles (like gastrocnemius). The tonic stretch reflex is more important in proprioception

REM Sleep Stage

- Rapid eye movement sleep (REM) are periods characterized by rapid eye movements during sleep. (Saccade) - Also known as "paradoxical sleep" because it is deep sleep in some ways, but light sleep in other ways. EEG waves are irregular, low-voltage and fast. - Postural muscles of the body are more relaxed than other stages.

Reflexes: Phasic and Tonic Stretch Reflexes

- Stretch sufficient to activate primary afferent fibers (Ia) evokes a brisk, brief myotatic reflex (phasic stretch reflex). - Sustained muscle stretch also activates type II afferents, modulates muscle tone (tonic stretch reflex). -Spindles are more abundant in slow muscles (such as soleus) than in fast muscles (like gastrocnemius). The tonic stretch reflex is more important in postural reflexes. Phasic and tonic stretch reflexes are coordinated by intrafusal fibers (Ia and type II) Extrafusal fibers are all innervated by alpha motor neuron (always stimulatory)

Alternating Neurological Changes

-A model of some of the neurochemical changes across the sleep-wake continuum. -Neural regulation represents a bi-stable switch (flip-flop). -Cause-and-effect relationships are under study.

Patient with right parietal lobe damage does NOT perceive (see) left side of visual world

-Primary motivated behavior is behavior directly related to homeostasis—i.e., the maintenance of a relatively stable internal environment. -Secondary motivation behavior is not directly related to homeostasis, e.g., deciding on what to drink. -Secondary motivations are influenced by habit, learning, intellect, and emotions—what we call incentives (rewards and penalties).

Sleep - Wakefulness Cycles: Circadian Rhythms

-Remains consistent despite lack of environmental cues indicating the time of day -Can differ between people and lead to different patterns of wakefulness and alertness. -Change as a function of age. Example: sleep patterns from childhood to late adulthood. - Results depend upon the amount of light to which subjects are artificially exposed. Rhythms run faster in bright light conditions and subjects have trouble sleeping. In constant darkness, people have difficulty waking.

Hormonal Regulation

-The SCN regulates waking and sleeping by controlling activity levels in other areas of the brain. -The SCN regulates the pineal gland, an endocrine gland located posterior to the thalamus. -The pineal gland secretes melatonin, a hormone that increases sleepiness.

Suprachiasmatic nucleus

-The suprachiasmatic nucleus (SCN) is main part of the hypothalamus and the main control center of the circadian rhythms of sleep and temperature. Located above the optic chiasm. Damage to the SCN results in less consistent body rhythms that are no longer synchronized to environmental patterns of light and dark.

Types of Spinal Cord Motor Neurons

-alpha- (fast, larger neuron) innervate skeletal muscle -gamma- innervate muscle spindle organs and have smaller somas and axons than neurons The alpha and gamma can coordinate and maintain muscle position

Self-assessment

1) describe organizational hierarchy of CNS in motor control 2) identify local control systems as relay points between higher centers and motor neurons 3) define the neuronal pathways for withdrawal reflexes 4) describe the sensorimotor cortex and the areas of the CNS that comprise the sensorimotor cortex. 5) explain the basal nuclei in control of motor function 6) discuss muscle tone and distinguish between hypertonia and hypotonia 7) define and provide examples of diseases of motor function

Questions for lecture 32: Control of body movement

1. What are the characteristics of voluntary action? 2. What are the inputs that can converge on interneurons in local motor control? 3. What are the components of the knee jerk reflex and how does that compare with the withdrawal reflexes? 4. How does alpha-gamma co-activation work? 5. How do the two major types of descending pathways differ in structure and function? 6. What is the role of crossed-extensor reflex in postural stability ?

Three sources of postural sensory information:

=Proprioceptive - the most important -Vestibular system - canal organs (cristae) and maculae -Vision

Criteria for Substance Dependence

Abuse is indicated when >3 of following occur in 12-month periods -Tolerance: increase amount need with decreasing effects. -Withdrawal: symptoms appear upon stopping of use. -Use of substances in larger amounts or for longer periods of time than intended. -Persistent desire for substance. A great deal of time is spent in activities to obtain substance. -Occupational, social, or recreational activities are give up or reduced because of substance use. -Use of substance is continued despite knowledge that of problem that is likely to be exacerbated by the substance.

Stages of wakefulness

Alert Wakefulness: - Behavior: Awake, alter with eyes open. - Beta rhythm (faster than 13 Hz). Relaxed Wakefulness: -Behavior: Awake, relaxed with eyes closed. -Mainly alpha rhythm (8 - 13 Hz) over the parietal and occipital lobes. Changes to beta rhythm in response to internal or external stimuli. Relaxed Drowsiness: -Behavior: Fatigued, tired, or bored; eyelids may narrow and close; momentary lapses of attention and alertness. Sleepy but not asleep. -Decreased in alpha-wave amplitude and frequency.

Rhythms of Waking and Sleep

All animals produce endogenous circadian rhythms, internal mechanisms that operate on an approximately 24 hour cycle. -Regulates the sleep/wake cycle. -Also regulates the frequency of eating and drinking, body temperature, secretion of hormones, volume of urination, and sensitivity to drugs.

Mesolimbic Dopamine Pathway

Alterations in the mesolimbic dopamine pathway (shown here) appear to be a primary mechanism by which psychoactive drugs change behavior.

Locomotion

Basal Nucleus - function - Globus pallidus (basal nucleus) input to thalamus is tonic and inhibitory - acts as a brake on cortical motor programs - Suppl. motor area of the frontal lobe input to striatum is transient - briefly lifts the brake on activated motor program, reinforces the brake on other programs - Substantia nigra (basal nucleus) balances the brake and release Cerebellum contributes to generation of an appropriate error-correcting feedback

Similarities in Neurotransmitters and Psychoactive Drugs

Biogenic amines: serotonin, dopamine, and norephinephrine Psychoactive drugs that affect serotonin- receptors share structural similarities with serotonin. Psychoactive drugs that affect dopamine- receptors share structural similarities with dopamine. Regulate affective states (moods, motivation, and feelings) and in self-awareness, consciousness and personality.

Changes in Body Temperature: Sleep - Wakefulness Cycle

Body temperature changes with the slee—wakefulness cycle Temperature rise when you are awake and drops when you fall asleep and slowly rises so that you are at a basal/base temperature when you wake up Some things people try to fall asleep is to drink a warm glass of milk, taking a hot shower, or exercising rise in temperature and then drops

Characterization of Broca's and Wernicke's Aphasias

Broca's aphasia: - halting speech - tendency to repeat phrases or words (perseveration) - Disordered syntax and grammar - disordered structure of individual words - Comprehension intact Wernicke's aphasia: - fluent speech - little spontaneous repetition - syntax and grammar adequate - contrived or inappropriate words - comprehension not intact

Limbic System Functional Role

Changes in activity of the limbic system underlie some of the primary needs of the organism, including: Learning Motivation Appetite Emotional response Its malfunction is associated with affective disorders.

Major "Motor" Centers of Cerebral Cortex

Extensive neural networks between the major "motor areas" of the cerebral cortex permit fine control of movement, utilizing sensory and intentional signals to activate the appropriate motor neurons at an appropriate level of stimulation.

Activation of Golgi tendon

Compared to when a muscle is contracting, passive stretch of the relaxed muscle produces less stretch of the tendon and fewer action potentials from the Golgi tendon organ.

Neural Pathways for Golgi Tendon Organ

Contraction of the extensor muscle on the thigh tenses the Golgi tendon organ and activates it to fire action potentials. Responses include: A) Inhibition of the motor neurons that innervate this muscle. B) Excitation in the opposing flexor's motor neurons. Note: NMJ = neuromuscular junction

Categories of Memory

Declarative memory is associated with actual events in a person's direct experience. Procedural memory is associated knowledge of the sequence of events and relationships between events. Example of procedural memory is doing math problems (addition, subtraction), or an athlete

EEGs reflect Stages of Sleep

EEG patterns undergo characteristic shifts in a sleeping person, reflecting the NREM four stages of sleep and REM. Duration of the series (NREM REM NREM) is typically ~90 minutes Entire pattern cycles 4 to 8 times per night. 8-12 Hz for alpha wave and 13-30 Hz for beta wave frequencies. In NREM: -stage I- theta waves present. -Stage II- sleep spindles (lasts 1-2 secs; 10-12 Hz) and K complexes (big jump wave followed by alpha waves) -Stage 3 and 4: theta waves and lots of delta waves ; slow wave sleep -REM: similar to beta wave

Epileptic Seizure: Spike-and-wave pattern

EEGs provide diagnostic information about the location of abnormal activity in the brain, such as shown in this record typical of a patient undergoing an epileptic seizure (up to 1000 V). BIG Spikes

Alpha and Beta rhythms in EEGs

EEGs reflect mental state: contrasted here aremental relaxation (a) versus concentration (b). Alpha rhythm: amplitude is higher (more neurons that are synchrony) but the frequency is slower than the beta wave

Corticospinal Pathways

Efferent motor commands from the cerebral cortex are contralateral or crossed (decussation)," meaning that the left cortex controls the muscles on the right side of the body (and vice versa), whereas the brainstem influences Ipsilateral (same side) motor activity.

Higher Cortical Function (Role of CNS)

Electroencephalography: a window on the brain -States of wakefulness and sleep -Limbic system: motivation and reward -Learning and memory -Language -Neurochemistry of drug abuse

Biological Basis for Emotion

Emotion is a relation between an individual and environment based on the individual's evaluation of the environment. 1)Anatomical sites involved in determination of emotional value, such as cerebral cortex, forebrain, limbic system. 2)Emotional behavior: Hormonal, autonomic and outward expression and displays of response. 3)Inner emotions: conscious experience such as feelings of fear, love, anger, joy, anxiety, hope etc.

Motor Control: Middle Level Centers

Function: converts plans received from highest levels to a number if smaller programs, which determine the pattern of neural activation required to perform the movement. Structures: areas involved with memory and emotions, supplementary motor area, and associated cortex. All these structures receive and correlate input from many other brain structures. The programs for movement are broken down into subprograms that determine the movements of individual joints. The programs and subprograms are transmitted through descending pathways to the lowest control level.

Motor Control: Higher Centers Conceptual Motor Control Hierarch for Voluntary Movements.

Function: forms complex plans according to individuals intentions and communicates with the middle level via "command neurons." Structures: areas involved with memory and emotions, supplementary motor area, and associated cortex. All these structures receive and correlate input from many other brain structures.

Motor Control: Local Level

Function: specifies tension of particular muscles and angle of specific joints at specific times necessary to carry out the programs and subprograms transmitted from the middle control levels. Structures: levels of brainstem or spinal cord from which motor neurons exit.

Muscle Spindle Sensory Neurons

Ia nerve fiber: - Type Ia nerve fiber responses are phasic (fast, adapt quickly to maintained stretch) - Type Ia fibers respond to rate of change of muscle length, IIs respond more to length. - Type Ia fibers innervate motorneurons directly (excitatory) or via interneurons (inhibitory) II nerve fiber: - Type II fiber responses are tonic (static) (slower to respond but maintain their response to maintained stretch) - Type II fibers innervate motorneurons only via inhibitory interneurons.

Simultaneous Activation of α and gamma Motor Neurons

In the process of movement both the alpha motor neurons and the spindle intrafusal fibers neurons are both activated.

Structure of Muscle Spindle

Intrafusal Fibers: - Nuclear chain fibers - Nuclear bag fibers Dynamic (Bag 1) Static (Bag 2) Motor neurons: alpha motor neurons Sensory: - Type Ia (primary) - found on central region of all intrafusal fibers - Type II (secondary) - adjacent to the central region of static nuclear bag fibers and nuclear chain fibers. Nuclear chain fibers- set up and give you how muscle is being stretched Nuclear bag fibers- gives magnitude and speed of the stretch response

What is consciousness

Levels of alertness. - awake, drowsy or asleep. - coma, death Conscious experience. -experiences -Changes in thoughts, feelings, perceptions, ideas, dreams, reasoning.

Hierarchical Organization

Motor commands from the brain have been modified by a variety of excitatory and inhibitory control systems, including essential feedback from sensory afferent neurons, along with vision and balance cues

Structure of Muscle Spindle and Golgi Tendon

Local Reflex Circuits: Acting by relaying impulses to the brain, muscle spindles and Golgi tendon organs provide information about muscle position and stretch in order to finely regulate the speed and intensity of muscle contraction.

Summary

Motor Control Hierarchy: - Higher CNS center, sensorimotor cortex, brainstem, fibers - Types of nerve fibers: sensory and motor (α and γ) and sensory only (Ia and Ib) Local Control of Motor Neurons: - Phasic and tonic stretch reflexes and their neuronal components - Role of motor neurons in mechanics of reflexes Cerebral Motor Centers and Descending Pathways: - Somatotopic centers and map of motor cortex - Properties and characteristics of supraspinal systems Postural Reflex and Locomotion: - Sources of postural sensory information and associated receptors - Basal ganglion function and abnormalities

Postural Reflex

Motor activity must be informed about the body's center of gravity in order to make adjustments in the level of stimulation to muscles whose contraction prevents unstable conditions (falling).

Defect in Perception of Visual World

Neural damage in the right parietal lobe of this patient results in the unilateral visual neglect seen in this drawing task. Although patient is not impaired visually, patient does not perceive part (left) of visual world. Patient with right parietal lobe damage does NOT perceive (see) left side of visual world

Brain Structures in Sleep-Wakefulness Cycles

Neuronal changes in these CNS structures appear to be essential participants in sleep-wake transitions and in biological rhythms. -Locus coerulus - norepinephrine; Raphe nuclei - serotonin -Pineal gland - melatonin -RAS = raphe nuclei (median column), magnocellular nuclei (medial column), parvocellular nuclei (lateral column)

Physiological Basis of Memory

Not in genes, but transcription is involved Possibly related to strength of synaptic connections (Long Term Potentiation - LTP) Hebbian rules - repeated stimulation of a pathway increases the synaptic strength of that pathway Mechanisms of learning include: -changes in neural parameters (threshold, time constants) -creation of new synapses -elimination of synapses -changes in the synaptic weights or connection strengths

Photoreceptors in Signaling Circadian Light Changes

Photoreceptors by the eyes allows for neural connection with the pineal gland (endocrine gland) that controls melatonin production. Melatonin levels are extremely high during 2AM - 5AM in the young males and females vs. elderly

Sleep Centers of Hypothalamus

Posterior Hypothalamus (tuberomammillary region) - alertness promoting - histamine as neurotransmitter - orexin (controls alertness and appetite) Anterior Preoptic & Basal Forebrain of Meynert - suprachiasmatic nucleus (circadian rhythm) - sleep promoting (prostaglandins) - inhibits tuberomammillary region Orexin, also called hypocretin, is a neurotransmitter that regulates arousal, wakefulness, and appetite.

Contraction of Extrafusal fibers

Regardless of the reason for a change in length, the stretched spindle in scenario the shortened spindle produces fewer action potentials from the spindle.

Passive Stretch of Muscle Activates Stretch Receptors

Regardless of the reason for a change in length, the stretched spindle in this scenario generates a burst of action potentials as the muscle is lengthened.

Supraspinal Control: Descending spinal influences, direct and via inhibitory interneurons

Six separate systems: - Corticospinal tract pathway from motor cortex to lower motor neuron fine voluntary motor control of limbs and controls voluntary body posture adjustments - Corticobulbar tract pathway from motor cortex to nuclei in pons and medulla oblongata controls facial and jaw musculature, swallowing and tongue movements - Rubrospinal tract red nuclei in brain stem (basal ganglia) involuntary adjustment of arm position in response to balance information; support of body -Vestibulospinal tract pathway from vestibular nuclei that process stimuli from semicircular canals adjustment of posture to maintain balance -Reticulospinal tract from reticular formation regulates various involuntary motor activities and assists in balance -Midbrain systems locus coeruleus and Raphe nuclei involved in responses to stress and panic alertness and sleep

Why is Sleep Important?

Sleep is a specialized state that serves a variety of important functions including: - conservation of energy. - repair and restoration. - learning and memory consolidation.

Simple Model of Aphasia

Speech Function Axis: -Wernicke's area (auditory image of speech) sensory or fluent aphasia; primary and secondary associated auditory areas -Broca's area (speech articulation), and arcuate fasciculus interconnecting them. Motor, non-fluent or expressive aphasia Other cortical areas are involved. Speech also involves cortical areas in Comprehension and Articulation, especially voluntary speech

Sleep Stage 2

Stage 2 sleep is characterized by the presence of: -Sleep spindles - 12- to 14-Hz waves during a burst that lasts at least half a second. -K-complexes - a sharp high-amplitude negative wave followed by a smaller, slower positive wave.

Sleep Stages 3 and 4

Stage 3 and stage 4 together constitute slow wave sleep (SWS) and is characterized by: -EEG recording of slow, large amplitude wave. -Slowing of heart rate, breathing rate, and brain activity. -Highly synchronized neuronal activity. -Stage 3: 20-50% delta activity; mixture of theta and delta waves -Stage 4: >50% delta activity

Consciousness, Brain, and Behavior

States of wakefulness and sleep Limbic system: motivation and reward Learning and memory Language Neurochemistry of drug abuse

Mechanisms for Tolerance and Withdrawal

Substance dependence: -Tolerance: to a substance occurs when increasing doses of the substance are required to achieve effects that initially occurred in response to a smaller dose. -Withdrawal: is a spectrum of unpleasant physiological symptoms that occurs with cessation of use of a drug to which one has become tolerant. Both can be explained by mechanisms by which the drug decreases the secretion of the endogenous ligand (the neurotransmitter for which the drug is an agonist), increases its degradation by enzymes, or down-regulates its receptors. Effects of the endogenous messenger would become lessened with time, and more and more drug would be required to have the desired effect. When a tolerant person stops using the drug, there is an abnormally small amount of activity in the neurotransmitter-receptor pathway, bringing on the symptoms of withdrawal.

Alzheimer's Disease

Symptoms: Dementia : memory loss in otherwise alert patient; Impairment in at least one other area - language, problem solving, attention, perception, etc. If you think you have Alzheimer's, you don't (because if you actually DO have Alzheimer's you wont remember what is wrong with you and deny that you have it) Clinical Features: -Neurofibrillary tangles in cells - normal in aging -Later, large pathological extracellular amyloid plaques -Loss of cholinergic neurons in forebrain

Mechanics of Knee Jerk Reflex

Tapping the patellar tendon lengthens the stretch receptor in the associated extensor muscle in the thigh; responses include: -compensatory contraction in that muscle (A and C), - relaxation in the opposing flexor (B), and - sensory afferent delivery to the brain (D). Note: NMJ = neuromuscular junction

Physiological Changes during Sleep

The EEG pattern was analyzed to produce this graph of a full night's sequence of sleep stages; also shown are cyclic patterns in the periphery. -Eye movement becomes rapid [Saccade (rapid eye movement)] -Neck muscle movement increases at beginning and end of REM sleep -Heart rate increases -Respiration rate increases

Electroencephalogram

The ElectroEncephaloGraphy (EEG) is the printout of an electronic device that uses scalp electrodes to monitor the internal neural activity in the brain. Recorded in Wave-like pattern. -Below shows a record from the parietal or occipital lobes of an awake person (beta wave) - Location of probes (~19) for EEG: frontal, parietal, occipital, & temporal lobes and central leads. - Amplitude is 20 microV, frequency 0.5 to 40 Hz (hertz) - Amplitude: how many of the neurons can go through a synchronized pattern - Frequency measured in hertz (how many cycles per sec)

Mechanisms of Circadian Rhythms

The Suprachiasmatic nucleus. Genes that produce certain proteins. Hormone levels (Melatonin from pineal).

Duration of sleep

The average hours of sleep for a person is ~7 hrs As you age, the amount of sleep decreases

Posture - Proprioception

The fastest source of postural change information Types of receptors : -Muscle stretch receptors -Golgi tendon organs -Joint position receptors

Somatotopic Map of Body Areas Found in Motor Cortex

The location and relative size of the cartoon body-shapes represent the location and relative number of motor-related neurons in the cerebral cortex.

Pain-withdrawal Reflex

The neural components of the pain-withdrawal reflex in this example proceed as follows: 1) Pain sensory afferents detect pain in foot and send action potentials via dorsal horn of spinal cord. 2) Interneurons in the cord activate extensor muscles on the "pained" side the body and flexor muscles on the opposite side of the body. 3) Muscles move body away from painful stimulus.

Regions Associated with Speech

The primary loci underlying the comprehension of speech are in Wernicke's area The primary loci for the production of speech are located in Broca's area.

Frequency of Substance Abuse and Dependence

Tobacco and alcohol use are the highest.. Marijuana rate is increasing due to several states allowing use of marijuana for recreational and medical purposes

Gene Regulation

Two types of genes are responsible for generating the circadian rhythm. 1) Period - produce proteins called Per. 2) Timeless - produce proteins called Tim. -PER and TIM (Cry1/2) proteins increase the activity of certain kinds of neurons in the SCN that regulate sleep and waking. -Mutations in the Per gene result in odd circadian rhythms. Cry1/2 - cryptochrome circadian clock genes.

Light Regulation

Zeitgebers: External Cues Help Set Circadian Rhythms "Zeit" means time in German. "Gebers" means givers. -Internal clocks interact with zeitgebers. -Light is an important human zeitgeber. -Human "free-running" cycle is about 25 hours. -Blind individuals and sailors serving on submarines may experience sleep problems.