physiology handout batch 13 2_240905_133617.pdf

Ribaat National University Faculty of health Sciences and technology Program of Clinical and Criminal Psychology Batch 13 Semester: 2 Psychophysiology Course Course I...

Ribaat National University Faculty of health Sciences and technology Program of Clinical and Criminal Psychology Batch 13 Semester: 2 Psychophysiology Course Course Instructor: Dr. Sabry Adam Edrees Assistant Professor Consultant Clinical Psychologist Topics of Course: - Definition and conceptions - History of psychophysiology - Importance of psychophysiology - Correlation of psychophysiology with psychology and neurology - Anatomy of Nervous system - Psychophysiology of senses - Hormones and endocrines - Psychophysiology of sex - Psychophysiology of learning and memorizing - Psychophysiology of sleep - Psychophysiology of psychological disorders - Psychophysiology of nervous system and CBT - Brain imaging and electro encephalogram  Introduction to Psychophysiology Definition: It is the science of studying the biological bases for psychological phenomenon. - What is the difference between soul and psych? - Is the psych metaphysic? A psych is the collection of high brain and nervous system functions. And it is objectively found on synapses and neurons as electrical, chemical, hormonal component and else. If any disturbance happened on those components it will directly lead to disturbances in psych. Psychology and it is correlation to philosophy, and medicine: Psychology studies all types of activities from human being observable and no observable. And the psychology was a part of philosophy but it had it is own identity same of other sciences which was a part of philosophy. One of the most important points of criticism directed at psychology is the importance of transforming it into the field of controlled study and laboratory so that it is considered like other natural sciences The relationship between psychology and medicine and biology: The difference between physiological and psychological behavior is summed up in the meaning. Physiological behavior is confined to carrying out a certain function. As for psychological behavior, it has a human significance and has a meaning that only humans can understand. There are two levels of behavior, the physiological level and the symbolic psychological level. History and development of physiological psychology: The relationship between the soul and the body is a very old relationship, as it was found in papyrus papers from the Pharaonic civilization more than five thousand years ago, indicating interest in studying this relationship Ibograth, the father of medicine, talked about the effect of the body on mood and distinguished between two types of the body corresponding to two types of personality: the subdued model, i.e. the calm one, and the apoptotic model, i.e. prone to heart attack. Galenious divided people into four moods: the bloody, the biliary, the lymphatic, and the phlegmatic. Each mood has a specific character. The bloody is a lot of movement and impulsive, while the bile is quick to anger and capricious, and the phlegmatic is cool and calm, The melancholic tends to be sad and depressed.  The beginnings of modern physiological psychology also go back to the world scientist William Wundt, when he established the first laboratory of psychology in Leipzig in 1879. Among the scientists who contributed to physiological psychology were also Mueller, Helmholtz, Weber, and others. Mueller presented the interpretation of the sensory nerve impulse for the first time. As for Helmholtz, he measured the electrical nerve impulse in 1850. The Soviet scientist Ivan Pavlov 1903, when he conducted reflex experiments on dogs in conditional learning, stated that awareness is the function of the complex part of the body called the brain, and this is considered a major contribution to guiding physiological psychology. The most recent research carried out by Sheldon in 1938 at Harvard University is related to the crucial importance of building the body and its role in the soul, as Sheldon distinguished between the three patterns and their role in behavior, which are: 1- The Viscerotonic or Endomorph type: It is characterized by relaxation, comfort, intercourse, and fun. 2- Somatotonic or mesomorph muscular type, which corresponds to the muscular structure of the body and is characterized by a tendency to demonstrate muscular strength, love of adventure, control, and a tendency to compete and aggression. 3- Cerebrotonic or ectomorph type, which is characterized by reservation, caution, avoidance of appearance and social withdrawal, and is characterized by a low surface of the chest and poor development of the muscular and digestive system. - In recent years, scientists have been able to discover some of the causes of psychological and mental illness by studying the different chemical compositions of the body - The possibility of predicting suicide was reached by examining the CSF, and it was proven that depressed patients suffer from a special deficiency in some neurotransmitters, and it was found that schizophrenic patients suffer from a general weakness in some enzymes, which affects neurotransmitters, and then thinking and perception. Subject matter of physiological psychology: So we can say that the subject of physiological psychology is the study of the relationship between the nervous system and behavior. And in a more general and comprehensive way, it is the relationship between all types of behavior, sensations, and bodily activity from all systems and organs, not just the nervous system. Importance of Physiological Psychology: Many physical problems occur as a result of psychological stress. If a person does not complain, his organs will, as it is said. The psychologist who studies and understands a person, his structure and organs, is the most capable of helping him, as he is the most capable of controlling, developing and predicting behavior. Research Methods in Physiological Psychology How did scientists know that when a person gets excited, adrenaline increases? As we mentioned, William Wont was the first to establish a laboratory in psychology, and the number of psychology laboratories in the world increased. The simplest things that a laboratory should include in physiological psychology are:  Signal receptors, sensors, which receive the electrical signal to be recorded  Transducers amplify and transmit the signal  Amplifiers amplify the signal  Signal display and recording devices  A quantization unit which is responsible for converting signals into digital values. How do researchers collect information in psychophysiology?  Note Brain Function: It is done either by removing part of it, cerebral ablation, observing the behavior change, or recording the electroencephalogram, or imaging by injecting air into the ventricles of the brain, pneumograph, and others.  Chemical methods, such as examining hormones, blood, and others  Self-report where we ask the person about what he feels and what is happening in his body  Psychological scales  Nervous system Anatomy and Physiology of the Nervous System The nervous system is the system that controls all body systems to control, adapt and regulate the various vital processes, voluntary and involuntary. It is the communication device between all organs and the brain or central plate. To understand it, it is necessary to understand its anatomical divisions first, bearing in mind that this division and anatomy is relative and from the human condition, as the nervous system works as a single block with the rest of the body, and if an organ complains of it the rest organs will do. - The main component of the nervous system is the nerve cell called the neuron, and the second component is the connective tissue cells Neuroglia, which perform the process of joining the cells together and help heal the wounds of the nervous system. There are more than 100 billion nerve cells in the human body. Neurons in the human body differ from other types of cells in several things, the most important of which are: 1- Its ability to regenerate and heal, as it was previously believed that it does not heal or regenerate. 2- The nerve cell is characterized by the presence of a long appendage that may extend to more than three feet in length, called the axon, in addition to an estimated number of short appendages called dendrites. 3- Neurons transmit impulses from one cell to another, just as impulses are transmitted from the cell through the axon and transmitted to it through dendrites. 4- The nerve cell also consists of the cell body in addition to the appendages. 5- The distance between any two cells is called the synapse, and there are many chemicals in it that exchange impulses with the internal components of the nerve cell. Parts of the nervous system: The nervous system is divided into two main groups: 1- Central Nervous System It is composed of the brain located inside the skull and the spinal cord located inside the vertebral canal. 2- The peripheral nervous system, and this includes all the nerves branching from the central system, namely: - Cranial nerves, numbering (12) pairs, which are the nerves that connect to the brain, including sensory nerves such as (olfactory, visual, and auditory nerves) and other motor nerves such as (hypoglossal nerve), including mixed sensory and motor nerves (such as the facial nerve). - Spinal nerves (31) on each side, and they are the nerves that connect to the spinal cord. All of them are mixed nerves, i.e. they are sensory and motor - Autonomic nerves, which are confined to the thymus and parathyroid systems. And if we examined the brain and spinal cord, it became clear to us that there is a gray squirrel color (Gray Matter) that represents the gathering of original cells, and another color (White Matter) which is the gathering of axons and dendrites that gather to form the pathways. The nervous system has two functions, sensory and motor. Axons are surrounded by a fatty substance called melanin. Firstly: the central nervous system A- Brain: The brain is the largest part of the central nervous system. It occupies a large area of the skull known as the brain box. The weight of the brain varies from one age stage to another and also varies according to the gender (male - female). The brain is surrounded by three membranes called the meninges. 1- Cerebral Hemispheres: The cerebral represents the largest part of the brain, and the average weight of the brain is three pounds, i.e. between 1250 and 1350 g, and its weight in women is 6% less than that of men. They cerebral hemispheres occupy most of the cranial cavity, namely the right cerebral hemisphere and the left cerebral hemisphere, and in the middle there is a longitudinal slit that does not completely separate them. The outer surface of the brain is characterized by the presence of several bends and zigzags. & Each of the two hemispheres of the brain is divided into four lobes, all of which have a smooth surface in appearance, but in reality they are deep slits called gyrus furrows, and other slits called gyrus sulcus. In old age, these furrows tend to widen, while the sulkus tend to shrink. Studies revealed that the left hemisphere controls the movement and sensation of the right hemisphere of the body, while the right hemisphere controls the movement and sensation of the left hemisphere. One of them is the dominant cerebral hemisphere. For people who use the right hand, the left cerebral hemisphere is dominant for them, and for people who use the left hand, the right cerebral hemisphere is dominant for them. Since most people use the right hand, the left hemisphere is most likely to be dominant. Therefore, a stroke in the right hemisphere of the brain may cause complete or partial paralysis in the left hemisphere of the body, and this depends on the location and extent of the brain damage. Each hemisphere of the brain is divided into four lobes, namely: - First: Frontal lobe: It is located under the frontal bone and is also known as the “frontal lobe”. It is believed that the frontal lobe is the center of higher mentality (such as judgment, appreciation, inference, logic, management, and marking plans) in addition to that it includes cells of the cerebral cortex responsible for the contraction of skeletal muscles (voluntary), and responsible for controlling emotions and impulses in man and his personality It is also responsible for learning and practicing complex and motor sensory skills. - Second: the parietal lobe: Or what is known as the upper lobe and is located under the parietal bone, and is concerned with the functions of bodily sensations, including the areas of somatosensory interdependence, and is responsible for cerebral sensations. It is also responsible for receiving and operating sensory information, which gives us a good awareness of the world around us, and an awareness of the position of the body in space. It plays a role in cognitive functions such as short-term memory and working memory. - Third: the occipital lobe: Or what is also known as the occipital or posterior lobe, and it is located under the posterior bone. It is responsible for receiving and perceiving nerve and visual impulses, and is also responsible for visual sensory interconnection. - Fourth: Temporal Lobe: Or what is known as the lateral and is located under the temporal bone, which is the primary auditory reception area, and the lateral slit separates it from the frontal lobe. 2- Brain Stem: Or what is known as the "brain stem" is the smallest part of the brain and consists of the midbrain, the pons, and the medulla oblongate. The brainstem is actually a carrier for the brain. The brainstem contains the bodies of motor neurons that control the muscles of the head, and also originates from sympathetic fibers that control smooth muscles and glands in the head as well as organs in the chest and abdomen. Thus, it becomes clear that the stem of the brain is an important and necessary part of life due to the presence of vital centers in it. 3- Cerebellum: It is considered the largest part of the brain after the cerebrum, and it is located in the back of the brain below the temporal lobe, specifically behind the arcade and the medulla oblongata. The cerebellum contains - like the brain - a white matter inside made up of nerve fibers, and a gray matter outside made up of nerve cell bodies called the cerebellar cortex. The cortex wrinkles and its wrinkles stick together more than it does in the cerebral cortex, and its cracks are parallel. The cerebellum performs the following functions: - It plays an important role in organizing voluntary movements, as it coordinates and synergize these movements through its numerous contacts with the frontal lobes, the spinal cord, and the inner ear, which indicate the position of the body and send it to the muscles that, through their contraction, restore the balance of the body. - Contributes to the coordination, order, and timing of muscular contractions according to the directions given by the motor region in the frontal lobe to the muscles. - It is responsible for maintaining normal muscle tension and transmitting nerve impulses that maintain body position. 4- Brain bed: It is also called the diencephalon, and it is an internal group of neural structures. It is located between the midbrain from below and the brain from above. It consists of two parts: The first: Hypothalamus: Or what is also known as "liberating the visual bed" and consists of the posterior pituitary gland and the peduncle. Although the hypothalamus is one of the smallest parts of the brain, it is one of its most important parts as it performs the following functions: - Regulating hunger, thirst and sleep. -Control and maintain normal body temperature and control. -Controlling the maintenance of body water balance and controlling the function of every cell of the body. - Controlling all the internal organs of a person, such as: controlling heartbeat, narrowing and widening of blood vessels, and contractions of the digestive system, especially the stomach and intestines. The second: the thalamus: It takes the shape of an egg and is located in the third cavity of the brain. It is the last part of the brain that receives physical information before the brain. The thalamus helps the following: -Producing sensations and transmitting them from the various sense organs to the cerebral cortex. -Linking the sensations or emotions that take place in it, as it represents the center of excitement and alarm. Brain function: It can be said that the brain in general performs important functions related to the following: - Emotional feeling. - voluntary movements. - Learning, memory and thinking. B- Spinal Cord: Or what is known as the spinal cord, which is part of the central nervous system that extends inside the spinal canal (a channel located inside the vertebrae along the spine)  The length of the spinal cord is about 45 cm, and it is shorter than the spine by about 25 cm. The spinal cord starts from the medulla oblongata in the brain – the base of the skull – extends to the end of the upper two-thirds of the spine, that is, almost the lower back, and the spinal cord is about the thickness of the pinky of the hand on the face Rounding. The spinal cord is hollow from the inside due to the presence of a narrow channel in it, which sometimes disappears in adults. It is called the “central canal” in which the cerebrospinal fluid flows. To protect the spinal cord, it is surrounded by: the bones of the spine and the meninges. These are the same three membranes that envelop the brain: pea matter, dura matter, and arachnoid matter. The spinal cord has an important role in the conduction of electrical signals to and from the brain, as it conducts electrical signals from the brain to the muscles if a person wants to move his hand, for example, and performs reflex arts if a person touches a hot object, where he issues an order to the muscles to move before they reach the brain The spinal cord consists of two distinct regions: Central gray area: This area consists of the cell bodies that are the starting point for axons and nerve fibers that extend outward from the area. Peripheral white area: The area consists of fibers coming from the body. The fibers in the white matter are a cylindrical axis surrounded only by the myelin sheath. Secondly: the peripheral nervous system: It is the second part of the nervous system and there are two types of peripheral nerves, which can be referred to as follows: - The first type: cranial nerves: Or what is known as the peripheral nerves. The number of these nerves is twelve pairs, half of which feed the right side of the body (brain and viscera) and the other half feed the left side. These nerves come out of the brain stem. These nerves are divided into three groups:  Motor nerves: These include the motor nerve of the eyeball, the trochlear nerve, the abducens nerve, and the spinal nerve.   Sensory nerves: These include the olfactory nerve, the optic nerve, and the auditory nerve.  Mixed nerves (sensomotor): These include the trigeminal nerve, the facial nerve, and the lingual nerve. - The second type: Spinal nerve: Spinal nerves are arranged in regularly alternating pairs on both sides of the spinal cord. There are (31) pairs emerging from the spinal cord. It emerges from between the vertebrae of the spine. 1. The spinal nerves are usually named after the region from which they originate according to the vertebrae in the spine, and the spinal regions are divided as follows: 1) Eight cervical segments 2) Twelve thoracic segments 3) Five lumbar segments 4) Five sacral regions 5) One coccygeal segment Thirdly: Autonomic Nerves It consists of the internal nerves in the body through which the vital functions are controlled and their work is regulated within the human body from the nerves in the circulatory system, the respiratory system and the digestive system, and it is divided into two parts: A - Sympathetic Nervous System: It performs one of the important vital functions, as it specializes in preparing the body for activity, great muscular effort, and the behavior that is required by emergency or urgent situations, or violent movements, such as dilating the pupils, increasing the number of heartbeats, and decreasing the speed of breathing.... Nerve fibers work in This device is in cases of stress and excitement B - Parasympathetic Nervous System: The parasympathetic nervous system works opposite to the sympathetic nervous system, as it controls the internal organs of a person under normal daily conditions. The muscles of the bronchial tubes,.... the nerve fibers in this organ function in states of relaxation.  Basal ganglia It is a group of subcortical nuclei of different origins found in the vertebrate brain. There are many differences in humans and other primates, chiefly in the division of the globus pallidus into an inner and an outer spot, and in the division of the striatum. The basal nuclei are located at the base of the forebrain and the apex of the midbrain. The basal ganglia have close connections with the cerebral cortex, thalamus and brainstem, as well as a number of other brain regions. The basal ganglia are associated with a variety of functions, including control of voluntary movements, procedural learning, habitual learning, conditioned learning, eye movements, and cognition and feeling. The most important diseases that result from its imbalance are Parkinson's disease and Huntington's disease.  Neurotransmission It is the process of passing messages between neurons. - Messages pass CHEMICALLY between neurons, ELECTRICALLY within each neuron. - Neurons cannot touch each other. - Each neuron has thousands of neurotransmitters waiting to cross the synapse. How Neurotransmission & brain signals work - 3D animation.mp4 Neurotransmitters in your body: - Glutamate – excites neurons to fire, involved in memory - GABA – inhibits (stops) other neurons from firing - Serotonin – affects mood - Dopamine – involved with feeling reward, learning, & emotion - Acetylcholine – involved with memory & attention &muscle action - Norepinephrine – involved with alertness What do you predict happens when these are out of balance? Processes Involved in Neurotransmission: - Precursors (getting the raw materials) - Biosynthesis (making the NTs) - Storage (vesicles - Golgi bodies) - Transport (neurofilaments and microtubules) - Docking  - Influx of Ca++ - Vesicle movement - Exocytosis— (fusion and release) - Crossing synaptic gap - Binding postsynaptic receptors - Reuptake mechanisms to recover NTs - Deactivation Categories of NTs: - Amino Acids - Glutamate (Glu) - GABA - Biogenic Amines - Quaternary Amines - Acetylcholine (Ach) - Monoamines - Catecholamines - Dopamine (DA) - Norepinephrine (NE) - Indolamines - Serotonin (5-HT) - Neuropeptides - Opioid Peptides - Enkephalins - Endorphins - Dynorphins - Others (e.g. lipids, nucleosides) Location of neurotransmitters: - Postsynaptic - Presynaptic - Heteroreceptor - Autoreceptor Drugs Associated with Neurotransmitters Why do people have “drugs of choice”? - Dopamine - amphetamines, cocaine, ETOH - Serotonin - LSD, Ethanol Alcohol ETOH - Endorphins - opioids, ETOH - GABA (Gamma-aminobutyric acid)- benzodiazepines, ETOH - Glutamate –ETOH - Acetylcholine - nicotine, ETOH  - Anandamide – Marijuana - Amino Acid NTs The Limbic System: The limbic system is the part of the brain involved in behaviors needed for survival: feeding, reproduction and caring for our young, and fight or flight responses. The limbic system is a set of structures found in the center of the brain. It is a group of structures in the brain that governs emotions, motivation, olfaction (sense of smell), and behavior. The limbic system is also involved in the formation of long- term memory. The structures of the limbic system are found deep inside the brain, immediately below the temporal lobes and buried under the cerebral cortex, just above the brainstem. The limbic system consists of several interconnected components, including the thalamus, hypothalamus, basal ganglia, cingulate gyrus, hippocampus, and amygdala. A dysfunctional limbic system is associated with several conditions and clinical disorders such as epilepsy, dementia, anxiety disorders, and autism. Endocrine System Endocrine system is Composed of glands and cells that secrete hormones. It Helps coordinate functions between cells and it is Critical for maintaining homeostasis It Helps to regulate:  - growth and development - metabolism and water balance - reproduction and stress responses Hormones and Endocrine Glands: Hormones: It is the Chemical messengers Secreted by endocrine glands or tissues into blood, Travel everywhere blood goes, Affect only target cells, cells with receptors. And May affect very distant organs or cells Functions: 1. Controls homeostasis 2. Maintains water balance 3. Controls uterine contractions 4. Controls milk production 5. Regulates ions (calcium, sodium, potassium) 6. Regulates metabolism and growth 7. Regulates heart rate and blood pressure 8. Monitors blood glucose levels 9. Aids the immune system 10. Reproductive functions Comparison of the Nervous and Endocrine Systems: Endocrine System Nervous System - Chemical signals only - Chemical and electrical signals - Slower to respond and stop - Responds and stops quickly - Hormones go everywhere - Targets specific organ - Adapts relatively slowly - Adapts quickly - Sometimes widespread effects - Usually local effects Endocrine glands: secrete their product directly into blood stream Chemical signal: molecules that are released from one location, move to another location, and produce a response. Pheromones: - secreted into env’t and modify behavior and physiology of other individual in same species - Ex. Women and menstrual cycles Hormones and neurohormones: - secreted into blood and bind to receptor sites - Ex. Epinephrine and insulin Hormone is classified into three groups based on structure - Steroid hormones. Lipids synthesized from cholesterol Share structure four organic rings with varied side groups E.g., testosterone and estradiol - Monoamines. Small molecules Synthesized from amino acids tyrosine and tryptophan E.g., thyroxine and epinephrine - Peptide hormones Chains from 3 to more than 200 amino acids Considered proteins if > 50 amino acids Oxytocin, small peptide hormone Insulin, a protein Pituitary Gland the master of glands: Small gland in brain, Controlled by hypothalamus Divided into 2 regions: anterior and posterior Secretes at least 6 hormones A. Growth Hormone: - Target tissues: most - Functions: stimulates growth of bones, muscles, and organs - Abnormalities: Too much GH causes giantism Too little GH causes pituitary dwarfism B. Thyroid-Stimulating Hormone (TSH): - Target tissues: thyroid gland - Functions: regulates thyroid gland secretions - Abnormalities: Too much TSH, thyroid gland enlarges Too little TSH, thyroid gland shrinks C. GONADOTROPINS LH (Luteinizing) for females: - Target tissue: ovaries - Function: promotes ovulation and progesterone production LH for males: - Target tissue: testes - Function: sperm production and testosterone Abnormalities of Thyroid Gland Hypothyroidism: - Decreased metabolism - Weight gain, reduced appetite, fatigue - Low temp. and pulse - Dry, cold skin - Myxedema in adults - Cretinism in infants Hyperthyroidism: - Increased metabolism - Weight loss, increased appetite, nervousness - Higher temp. and pulse - Warm, flushed skin - Graves’ disease (leads to goiter) Adrenal Glands LOCATED On kidneys Has 2 regions medulla and cortex Adrenal Medulla (inner portion): - Epinephrine/Norepinephrine: - Target tissues: heart, blood vessels, liver, fat cells - Functions: released as part of fight or flight response Adrenal Cortex (outer portion): - Aldosterone: Type of mineralocorticoids Target tissues: kidneys Functions: causes Na+ and H2O to be retained and K+ to be secreted, indirectly involved with blood pressure and blood volume Cortisol: - Type of glucocorticoids - Target tissues: most - Functions: increases breakdown of fat and protein for energy uses reduces inflammatory and immune responses Androgens: - Target tissues: most Functions: Males: secondary sexual characteristics Females: sex drive Pituitary gland: Your pituitary gland is a small, pea-sized endocrine gland located at the base of your brain below your hypothalamus. It releases several important hormones and controls the function of many other endocrine system glands What is the function of the pituitary gland? The main function of your pituitary gland is to produce and release several hormones that help carry out important bodily functions, including:  Growth.  Metabolism (how your body transforms and manages the energy from the food you eat).  Reproduction.  Response to stress or trauma.  Lactation.  Water and sodium (salt) balance.  Labor and childbirth. Which hormones does the pituitary gland make? The anterior lobe of your pituitary gland makes and releases the following hormones:  Adrenocorticotropic hormone (ACTH or corticotrophin): ACTH plays a role in how your body responds to stress. It stimulates your adrenal glands to produce cortisol (the “stress hormone”), which has many functions, including regulating metabolism, maintaining blood pressure, regulating blood glucose (blood sugar) levels and reducing inflammation, among others.  Follicle-stimulating hormone (FSH): FSH stimulates sperm production in people assigned male at birth. FSH stimulates the ovaries to produce estrogen and plays a role in egg development in people assigned female at birth. This is known as a gonadotrophic hormone.  Growth hormone (GH): In children, growth hormone stimulates growth. In other words, it helps children grow taller. In adults, growth hormone helps maintain healthy muscles and bones and impacts fat distribution. GH also impacts your metabolism (how your body turns the food you eat into energy).  Luteinizing hormone (LH): LH stimulates ovulation in people assigned female at birth and testosterone production in people assigned male at birth.  LH is also known as a gonadotrophic hormone because of the role it plays in controlling the function of the ovaries and testes, known as the gonads.  Prolactin: Prolactin stimulates breast milk production (lactation) after giving birth. It can affect fertility and sexual functions in adults.  Thyroid-stimulating hormone (TSH): TSH stimulates your thyroid to produce thyroid hormones that manage your metabolism, energy levels and your nervous system. The posterior lobe of your pituitary gland stores and releases the following hormones, but your hypothalamus makes them:  Antidiuretic hormone (ADH, or vasopressin): This hormone regulates the water balance and sodium levels in your body.  Oxytocin: Your hypothalamus makes oxytocin, and your pituitary gland stores and releases it. In people assigned female at birth, oxytocin helps labor to progress during childbirth by sending signals to their uterus to contract. It also causes breast milk to flow and influences the bonding between parent and baby. In people assigned male at birth, oxytocin plays a role in moving sperm.  Psychophysiology of sleep Normal sleep is divided into non–rapid eye movement (NREM) and rapid eye movement (REM) sleep. NREM sleep is further divided into progressively deeper stages of sleep: stage N1 (NREM 1), stage N2 (NREM 2), and stage N3 (NREM 3). As NREM stages progress, stronger stimuli are required to result in an awakening. Stage R sleep (REM sleep) is characterized by decreased EEG amplitude, muscle atonia, autonomic variability, and episodic rapid eye movement. REM sleep has tonic and phasic components. The phasic component is a sympathetically driven state with rapid eye movements, distal muscle twitches, cardiorespiratory variability, and middle ear muscle activity. Tonic REM is a parasympathetically driven state with no eye movements, decreased EEG amplitude, and atonia. The REM period length and density of eye movements increase throughout the sleep cycle. Waking usually transitions into light NREM sleep. NREM sleep typically begins in the lighter stages (N1 and N2) and progressively deepens to slow-wave sleep as evidenced by higher-voltage delta waves. When delta waves account for more than 20% of the sleep EEG, the sleep stage is considered to be stage N3. REM sleep follows NREM sleep and occurs 4–5 times during a normal 8- hour sleep period. The REM period becomes progressively longer through the night where the first REM period of the night may be less than 10 minutes in duration, while the last may exceed 60 minutes. The NREM–REM cycles vary in length from 70 to 100 minutes initially to 90 to120 minutes later in the night. Typically, N3 sleep is present more in the first third of the night, whereas REM sleep predominates in the last third of the night. NREM parasomnias such as sleep walking typically occur in the first third of the night with the presence of N3 sleep. This contrasts with REM sleep behavior disorder (RBD), which typically occurs in the last half of the night. Sleep in adults: Stage N1 is considered a transition between wake and sleep. It occurs upon falling asleep and during brief arousal periods within sleep and usually accounts for 2–5% of total sleep time. Stage N2 occurs throughout the sleep period and represents 45–55% of total sleep time. Stage N3 (slow-wave sleep) occurs mostly in the first third of the night and constitutes 10–20% of total sleep time. REM represents 20–25% of total sleep time and occurs in 4–5 episodes throughout the night Circadian Rhythms That Influence Sleep ‫الساعة البيولوجية‬ Circadian sleep rhythm is one of the several intrinsic body rhythms modulated by the hypothalamus. ‫النواة فوق التصالبية‬ The suprachiasmatic nucleus in the anterior hypothalamus sets the body clock to approximately 24.2 hours, with both light exposure and schedule clues entraining to the 24.2-hour cycle. The retinohypothalamic tract allows light cues to directly influence the suprachiasmatic nucleus. Light is called a zeitgeber, a German word meaning time-giver because it sets the suprachiasmatic clock. Examples of other external zeitgebers are exercise, social activities, and mealtimes. ‫المزامنات‬ A practical purpose has been proposed for the circadian rhythm, using the ‫ قياس‬analogy of the brain functioning somewhat like a battery charging during sleep and discharging during the wake period. ‫حضيض‬The nadir of this rhythm is in the early morning. The downswing in circadian rhythm prior to the nadir is thought to assist the brain to remain asleep overnight for full restoration by preventing premature awakening. The morning upswing then facilitates awakening and through the day acts as a counterbalance to the progressive discharge of wake neuronal activity. After the circadian apex in the early evening, the downswing aids sleep initiation. This model explains the relatively steady cognitive function throughout wakefulness. Body temperature cycles are also under hypothalamic control. An increase in body temperature is seen during the course of the day and a decrease is observed during the night. The temperature peaks and troughs are thought to mirror the sleep rhythm. People who are alert late in the evening (ie, evening types) have body temperature peaks late in the evening, while those who find themselves most alert early in the morning (ie, morning types) have body temperature peaks early in the evening. Melatonin has been implicated as a modulator of light entrainment. It is secreted maximally during the night by the pineal gland. Prolactin, testosterone, parathyroid hormone, and growth hormone also demonstrate circadian rhythms, with maximal secretion during the night. Psychophysiology of memory: Research has shown that short-term memory involves chemical modifications that strengthen existing connections, called synapses, between neurons. stored in the cerebral cortex of the brain. We have now learned that long-term memories are stored in multiple regions throughout the nervous system. Psychophysiology of sex: Sex is a multifactorial phenomena, affects by many factors, biological, cultural, social, environmental, religious, etc. but the physiological study of sex behavior is more simple. Physiology divide sexual behavior to identified four successive (hence, linear) stages: (1) excitement, (2) plateau, (3) orgasm, and (4) resolution. The first phase, excitement, refers to the initial physiological sexual arousal response as characterized by increased heart rate, respiration, and blood pressure Phase 1: Desire General characteristics of this phase, which can last from a few minutes to several hours, may include any of the following:  Muscle tension increases.  Heart rate quickens and breathing gets faster.  Skin may become flushed (blotches may appear on your chest and back).  Nipples become hardened or erect.  Blood flow to your genitals increases, which causes swelling of the clitoris (in people AFAB) and an erection (in people AMAB).  A person AFAB may feel their vagina get “wet” or see their breasts become fuller.  A person AMAB may see their testicles swell or their scrotum (sac that holds testicles) tighten, and they may begin secreting a lubricating liquid from the tip of their penis. It’s important to note that everyone’s sexual experience is different. You may not consistently experience any changes when you enter the desire phase. You may experience it during certain sexual encounters only. Sometimes the desire phase may come after arousal. Phase 2: Arousal The arousal phase lasts until just before orgasm. It takes you to the brink of sexual pleasure and could include:  The changes in the desire phase get even more intense.  The vagina continues to swell from increased blood flow, and the vaginal walls turn a darker color.  The clitoris becomes highly sensitive (may even be painful to touch).  The testicles withdraw up into the scrotum.  Breathing, heart rate and blood pressure continue to increase.  Muscle tension continues to increase.  Muscle spasms may begin in the feet, face and hands. You might experience arousal at the same time as desire or shortly before. Phase 3: Orgasm This phase is the climax of the sexual response cycle. It’s the shortest of the phases and generally lasts only a few seconds. The orgasm phase can include:  Involuntary muscle contractions or twitching.  Blood pressure, heart rate and breathing are at their highest rates.  There’s a sudden, forceful release of sexual tension.  Contraction of vaginal muscles.  Ejaculation (releasing semen from your penis).  A rash or “sex flush” may appear over your entire body. Phase 4: Resolution During this phase, your body slowly returns to its normal level of functioning. Any swollen or erect body parts return to their previous size or position. People may feel a sense of satisfaction, and often, fatigue. Some people AFAB can go back to the orgasm phase with further sexual stimulation and may experience additional orgasms. People AMAB typically need recovery time after orgasm, called a refractory period, during which they can’t reach orgasm again. The duration of the refractory period varies among people and changes with age. The hypothalamus, progesterone, estrogens, testosterone, play important role in this phenomena. NB: - Psychophysiology of psychological disorders will study in other courses - Psychophysiology of psychological psychotherapy will study in other courses too. The End