Chapter 3 Physiological Foundations PDF

Chapter 3: PHYSIOLOGICAL FOUNDATIONS OF BEHAVIOR 3.1 Basic Units of the Nervous system 3.2 Parts of the Nervous system 3.3 The Glandular System 3.4 Interaction between the Endocrine and the Nervous System  THE NERVOUS SYSTEM -The Nervous System is the major instrument of integration...

Chapter 3: PHYSIOLOGICAL FOUNDATIONS OF BEHAVIOR 3.1 Basic Units of the Nervous system 3.2 Parts of the Nervous system 3.3 The Glandular System 3.4 Interaction between the Endocrine and the Nervous System  THE NERVOUS SYSTEM -The Nervous System is the major instrument of integration and coordination of the many activities regarding human behavior through conduction of messages and making connections to ensure the smooth operation of all parts of the body. -Breathing, cognition, emotion, responses and etc.  BASIC FUNCTIONS: Receiving Information or “input” they include the receptors of external stimuli, the sensory systems, which provide information about the environment Integrating it with previous information to generate choices and decisions Guiding Action or “output” through the motor systems, which influence muscles and other organs to respond to the environment in some ways. 4  UNIT 3.1 BASIC UNITS OF THE NERVOUS SYSTEM Objectives: 1. To describe the nature of the basic structural unit of the nervous system in terms of its parts, types, functions, and other properties 2. To discuss the divisions of the nervous system and the structures that form each division BASIC UNITS OF THE NERVOUS SYSTEM Neuron Synapse Nerve  1. Neuron or Nerve Cell Neuron or Nerve Cell is the basic functional unit of the nervous system. -They are responsible for the transmission of nerve impulses through neural circuits within the nervous system. -The human brain is composed of 12 billion or more specialized nerve cells. DENDRITE MYELIN SHEATH AXON TERMINAL AXON CELL BODY/ SOMA 8  STRUCTURE OF THE NEURON CELL BODY- serves as a center for nourishment and a nucleus of the cell - Carries the genetic information that will determine the type of cell and acts to direct the cell's functioning. 9  STRUCTURE OF THE NEURON DENDRITES (Gr. “dendron” meaning “of the tree”) -branches which project from the cell body. -Widely branching structure that receives input from other neurons and carry those signals to the cell body. 10  STRUCTURE OF THE NEURON AXONS - single, long, thin, straight fiber with branches near its tip. -a neuron's extending fiber that conducts impulses away from the cell body and transmits them to other neurons, (output) to where communication occurs with other nerve cells.  STRUCTURE OF THE NEURON AXON TERMINALS - This is an array of small terminal buds at the end of the axon, which will relay information out of the nerve cell to the dendrites of the next neuron.  STRUCTURE OF THE NEURON MYELIN SHEATH- -an axon's protective coating, made of fat and protein. -an insulating sheath that speeds up the transmission of impulses along an axon.  ACTION POTENTIAL Neural information moves along a neuron in the form of neural impulse called an action potential. This is an electrochemical impulse that travels from the cell body down to the end of the axon. Each action potential is the result of the movements by electrically charged molecules known as ions. Movement of ions in-and-out of the cell happens through specific ion gates in the cell membrane. 14  ACTION POTENTIAL At rest, there are more positively charged ions outside the cell membrane and more negatively charged ions inside the neuron, this is called RESTING POTENTIAL When a neuron receives an excitatory input it signals the axon hillock to begin DEPOLARIZATION. Depolarization happens when ion gates open to let positively charged ions outside the cell membrane flow inside the neuron and signals neighboring ion gates to open in a domino fashion until it reaches the end of the axon. 15  ACTION POTENTIAL As the action potential travels down the axon, other ion gates in the cell membrane begin the process of R E P OL A R I Z AT I ON ( p e r i o d o f r e f r ac t i o n) - w h e r e positively charged ions are pumped out of the neuron to achieve a resting state of the neuron. HYPERPOLARIZATION occurs when the membrane potential becomes more negative at a particular spot on the neuron’s membrane. some potassium channels remain open and sodium channels reset. A period of increased potassium permeability results in excessive potassium efflux before the potassium channels close. 16 17 ACTION POTENTIAL 18  2. Synapse The site where transmission of a nerve impulse from one nerve cell to another occurs; it includes the axon terminal, the synaptic cleft, and receptor sites in the membrane of the receiving cell. It triggers the secretion of a chemical called neurotransmitter. 20 SYNAPTIC TRANSMISSION 21 22 23  3. Nerve This is a bund l e o f e l o ng a t e d axons belonging to hundreds and thousands or neurons. A single nerve may contain axons from both sensory and motor neurons. Closely interwoven among the neurons are a large number of glial cells (Gr. “glial", meaning “glue”). The glial cells hold the nerves in place and provide them with nutrients. 25  Neurotransmitters Neurotransmitters are chemical substances released from the nerve endings that transmit across synapses to other nerves and across the minute gaps between the nerves and t h e m u s c l e s o f g l a n d s t h a t t h e y s u p p l y. T h e s e neuromessengers (a generic term for neurotransmitters) have either excitatory or inhibitory effects. The nature of the effect depends on the level of the neurotransmitter, its location, and the type of receptor it binds with. Hundreds of substances are known or suspected to be neurotransmitters. 27  Substance: DOPAMINE Functions on Behavior: Involve in the initiation and coordination of movement “Feel-good” hormone Gives you the sense of pleasure Oversupply of dopamine will result to symptoms of schizophrenia. Undersupply will result to mood disorders such as mania and depression Degeneration of dopamine in the post synaptic receptors may cause Parkinson's disease (movement disorder)  Substance: NOREPINEPHRINE (Noradrenaline) Function on Behavior: Hormone and neurotransmitter Responsible for the body’s fight or flight response Undersupply of norepinephrine results to depression, ADHD and etc. Oversupply may result to anxiety and etc.  Substance: SEROTONIN Functions on Behavior: Modulates the transmission of sensory pain input Known to stabilize mood and anxiety Low level of serotonin is associated with depression and anxiety disorders. High level of serotonin causes shivering, muscle rigidity, fever, nervousness, seizures and etc.  Substance: ACETYLCHOLINE Functions on Behavior: Chief neurotransmitter which has an excitatory effect and is associated with mood and sleep disorders Plays a role in memory, learning, attention, arousal and involuntary muscle. Low Level of acetylcholine is associated with memory issues and muscle disorders High Level of acetylcholine can cause muscular paralysis.  Substance: GABA(Gama Amino Butyric Acid) Functions on Behavior: Primary inhibitory neurotransmitter in the brain and spinal cord. Known for producing a calming effect Decreases level of anxiety, decreases activity of the neuron, Sleep inducing Very Low level of GABA leads to anxiety, depression, insomnia and mood disorders High level of GABA- drowsiness and daytime sleepiness  Substance: GLUTAMATE Function on Behavior: The major excitatory neurotransmitter in the brain. Plays a vital role in memory, cognition and mood regulation High levels of glutamate is associated with anxiety, restlessness and symptoms similar to ADHD Low levels of glutamate is associated with learning and memory issues, low conentration, low energy  Substance: HISTAMINE Function on Behavior: It is an important regulator of sleep, maintainance of wakefulness, appetite regulation, cognition and arousal.  UNIT 3.2 PARTS OF THE NERVOUS SYSTEM Objectives: 1. To situate the different parts of the nervous system 2. To clarify functions of the different parts of the nervous system 37  CENTRAL NERVOUS SYSTEM (CNS) I. BRAIN ▪ the center of the system of control in the bodies of man and higher animals ▪ structurally divided into the forebrain (cerebrum and interbrain), the midbrain, and the hind brain (medulla oblongata and cerebellum) ▪ the largest and the most complex of the nervous system, plays the major role in behavior ▪ responsible for all the stimuli and responses that are registered in the central nervous system. ▪ The brain is safely protected by the skull (cranium) and by several layers (meninges) which are: Dura mater (inside the skull) is the outer most layer Arachnoid membrane is the middle layer that secretes a serous fluid Pia mater is the innermost layer that is cellophane- like and rich in blood vessels 40 A. Central Core 1. Brain Stem- Medulla, Pons, & Midbrain 2. Cerebellum A. Limbic System 1. Thalamus 2. Hypothalamus 3. Amygdala 4. Hippocampus A. Cerebrum and Cerebral Cortex 1. Left and Right Hemispheres 2. F-P-O-T Lobes  THREE STRUCTURES OF THE BRAIN A. The Central Core (The “Old Brain”) The central core is the innermost structure of the brain just above the Spinal Cord. It is made up of the Brain Stem and Cerebellum. 1. Brain Stem - looks like a stalk rising out of the spinal cord. It is known as the “reptilian brain” as its structures and functions are so similar with other animals. FUNCTIONS -Breathing -Consciousness -Blood Pressure -Heart Rate -Sleep  The Brainstem is made of the following: a. Medulla - lies just above the spinal cord, the lowest part of the brain stem - connects the spinal cord with the brain and regulates some vital body functions such as heartbeat, blood circulation and respiration - Activities like talking, singing, swallowing, vomiting, sneezing, coughing, chewing, etc. are regulated by the medulla b. Pons - represents the upper part of the hindbrain and lies just above the medulla and in front of the cerebellum. - a “bridge” that connects other parts of the brain and maintains the integration and coordination of the movement between the right and left sides of the body. - Motor impulses that govern chewing, control of eyeball movement, secretion of saliva and tears, contraction of muscles in the face, and impulses related to balance or equilibrium are activities involving the Pons c. Midbrain (Mesencephalon) - lies superior to the Pons and the smallest and least differentiated structure of the brainstem that contains both white and gray matter Reticular Activating System (RAS) - Extending upward from the core of the brain stem The midbrain functions as a relay - A dense network of system, transmitting information neurons found in the necessary for vision and hearing. core of the brain stem: it It also plays an important role in arouses the cortex and motor movement, pain, and the screens incoming sleep/wake cycle. information. 2. Cerebellum (“Lesser brain”) - Standing atop the brain stem and looking toward the back part of the brain is a structure about the size of a small fist - Contributes to a sense of balance and coordinates the muscles so that movement is smooth and precise - Damaged cerebellum may cause exceedingly clumsy and uncoordinated movement. B. The Limbic System (The “Animal Brain”) - Limbic comes from the Latin word for “border” - These structures form a sort of border between the higher and lower parts of the brain - Structures in this region are heavily involved in emotions, such as rage and fear that are shared with other animals (MacLean, 1993) 1. Thalamus – lies deep in the interior of the brain, roughly at its center -The largest subdivision which resembles a two egg- shaped structure located in the uppermost part of the brain stem. -The relay station for sensory impulses (vision, hearing, touch and taste, except smell) and motor sensory signals to the brain, particularly to the cerebrum. 2. Hypothalamus – a structure that sits beneath the thalamus. - it checks the imbalance and maintains the body normal level (homeostasis) - helps manage your body temperature, hunger and thirst, mood, sex drive, blood pressure and sleep - controls emotional and sexual behavior 3. Amygdala – from the ancient Greek word for “almond” - situated within the temporal lobe and implicated in the production of memory, emotions FUNCTION: Major processing center for emotions. It is responsible for perception of anger, fear and sadness as well as the controlling of aggression. It also links your emotions to many other brain abilities, especially memories, learning and your senses. 4. Hippocampus – lies along the temporal cortex which transmits information -regulating learning, memory encoding, memory consolidation, and spatial navigation -storage of long term memories (LTM) -compares sensory information with what the brain has learned to expect about the world -“Gateway to memory” C. Cerebral Hemispheres Cerebrum is a mass of deeply folded, rippled convoluted tissue which represents the largest part of the brain. It is covered by several thin layers of densely packed cells known collectively as the cerebral Cortex. (Cortex is Latin for “bark”or“rind"). Cerebral cortex is a mass of sponge-like gray matter, and its surface is marked by deep wrinkles called fissures. The large fissures (grooves) can be used to mark off parts of the cortex (lobes). 54 Cerebral Hemisphere is a longitudinal fissure that divides the brain into two symmetrical halves Corpus callusom – a bundle of nerve fibers joining the two cerebral hemispheres The right hemisphere is in charge of the left side of the body and the left hemisphere is in charge of the right side of the body. The two hemispheres also have different tasks and talents, a phenomenon known as lateralization.  Right Hemisphere Left Hemisphere This controls the sensory This controls the sensory and motor activities in the motor activities in the right left side of the body, such as side of the body, such as the left hand touch. right hand touch. It is more involved with the I t i s r e f e r r e d t o a s t h e perceptual, visual, spatial, “technical brain” because it artistic, musical and controls certain activities sympathetic cortical activity like skills in math, language, with both perception and science, writing and logic. expression of affective content.  LOBES OF THE CORTEX LOBES OF THE CORTEX Source: http://www.deryckthake.com  LOBES OF THE CORTEX FRONTAL LOBE Located toward the front of the brain, just under the skull in the area of the forehead. Broca's area handles speech production During short-term memory task, areas in the frontal lobes are especially active (Goldman- Rakie, 1996). The frontal lobes are also involved in emotion, and in the ability to make plans, think creatively, and take initiative.  LOBES OF THE CORTEX PARIETAL LOBE from the Latin for “pertaining to the walls” top of the brain that contains the somatosensory c o r t e x , w h i c h r e c e i ve s i n f o r m a t i o n a b o u t pressure, pain, touch, and temperature from all over the body Parts of the parietal lobes are also involved in attention and various mental processes  LOBES OF THE CORTEX OCCIPITAL LOBE from the Latin for “in the back of the head” Located at the back part of the brain they contain the visual cortex, visual signals are processed. Damage to the visual cortex can cause impaired visual recognition or blindness.  LOBES OF THE CORTEX TEMPORAL LOBE Located near the temples of the head. Memory, perception, emotion, hearing, language, comprehension Damage to the Wernicke's area of the temporal lobe results to Wernicke's aphasia (difficulty in understanding spoken or written words and a difficulty in putting words into meaningful sentences.)  STRUCTURES OF THE BRAIN (Tabular Summary) Structure Functions on Behavior A. CENTRAL Controls vital reflexes such as respiration, CORE heart rate and blood pressure 1. Brain Stem Suppression of the function of medulla 1.1 Medulla through large amounts of alcohol/depressant (myencephalon) drugs may cause death by stopped breathing. 1.2 Pons Functional problems of the pons may cause (Metencephalon) serious sleep disorder  STRUCTURES OF THE BRAIN Structure Functions on Behavior 1.3 Midbrain Involves in visual and auditory reflexes, such (Mesencephalon) automatic turning of the head towards a noise. 2. Cerebellum Involves in coordinating movement but not in initiating voluntary movements Involves in learning to perform timed motor responses such as those required in playing sports or games  STRUCTURES OF THE BRAIN Structure Functions on Behavior B. LIMBIC Relay of impulses from higher centers to SYSTEM the spinal cord, and of the incoming 1. Diencephalon sensory information (except for olfactory 1.1 Thalamus sensations) to other brain centers Malfunctions in the thalamus may result to difficulty in learning to read (which is one sign of dyslexia) especially when the processing of auditory information slows down.  STRUCTURES OF THE BRAIN Structure Functions on Behavior 1.2 Master control for many emotional Hypothalamus responses, such as arousing the body when fighting or fleeing Regulates many motivational behaviors i.e. eating, drinking, and sexual responses. Regulates the secretion of hormones during puberty  STRUCTURES OF THE BRAIN Structure Functions on Behavior 2. Amygdala Involves in forming, recognizing and remembering emotional experiences and facial expressions Involves in recognizing dangerous situations Damage to amygdala results to difficulty in recognizing personal facial expressions  STRUCTURES OF THE BRAIN Structure Functions on Behavior 3. Hippocampus Involves in saving many kinds of fleeting memories by putting them into permanent storage in various parts of the brain. Damage to hippocampus results to difficulty in remembering new facts, places, faces, or conversations because these new events cannot be placed in permanent storage Functions like the "save“ command in the computer.  STRUCTURES OF THE BRAIN Structure Functions on Behavior C. CEREBRAL HEMISPHERES 1. Cerebral Cortex Involves in the formation and storage of “Gray Matter” short-term memories. Damage to the cerebral cortex results to prevention of storing long-term memories. Involves in the formation of long-term memory  STRUCTURES OF THE BRAIN Structure Functions on Behavior 2. Lobes a. Frontal Lobe - Movement, short-term memory, planning, Expressive - Center setting goals, creative thinking, initiative, and Motor Area of social judgment, rational decision making, the Brain speech production. Damage to frontal lobe results to problems in paying attention, remembering things, making good decisions, planning and organizing events, and carrying out a sequence of behavior.  STRUCTURES OF THE BRAIN Structure Functions on Behavior 2. Lobes b. Parietal Lobe Processing of pressure, pain, touch and - Somatosensory temperature Area of the Brain Damage at the back of parietal lobe results to inability to recognize common objects by touch or feel, e.g., agraphia or dysgraphia, acquired inability to write  STRUCTURES OF THE BRAIN Structure Functions on Behavior 2. Lobes c. Temporal Memory, perception, emotion, hearing, Lobe - Auditory, language, comprehension Olfactory, and Damage to the Wernicke's area of the Gustatory Centers temporal lobe results to Wernicke's aphasia of the Brain (difficulty in understanding spoken or written words and a difficulty in putting words into meaningful sentences.)  STRUCTURES OF THE BRAIN Structure Functions on Behavior 2. Lobes d. Occipital Lobe Visual processing - Visual Center of Damage to the visual association area of the Brain the occipital lobe results to visual agnosia (failure to recognize some objects, person, or color, yet has the ability to see and even describe pieces or parts of some visual stimulus)  II. SPINAL CORD This is a remarkably compact organ, barely the diameter of your small finger, where most of the nerve fibers connecting various parts of the body to the brain are gathered.  Functions It receives signal from peripheral senses (ascending tract), such as touch, and relays them upward to the brain. Its neurons also carry signals downward (back portion) to cause muscles to contract and move the body (descending tract). Reflexes are simple behaviors which are organized completely in the spinal cord.  PERIPHERAL NERVOUS SYSTEM (PNS) The PNS consists of nerve fibers going to and from the CNS. It lies outside the bony case of the skull and the spinal cord. I. AUTONOMIC NERVOUS SYSTEM (ANS) This system is composed of the nerves that are not under voluntary control.. The activities it controls are autonomous, self regulating, and continue even when a person is asleep or unconscious.  Functions: ▪ It carries messages back and forth between the CNS and the internal organs like the heart, lungs, blood vessels, and the glands. ▪ This system has control of emotional behavior in terms of regulating the secretion of bodily hormones. ▪ This system maintains body homeostasis or balance of functions, the normal state of the body somewhere between extreme excitement and vegetative placidity  Subdivisions: a. SYMPATHETIC NERVOUS SYSTEM (SNS) energizes the internal organs during the states of emotional excitation or violent activity uses up our bodily resources to activate glands and secretion of hormone to increase levels of arousal acts on the body as a unit, affecting different organs simultaneously during episodes of excited activity b. PARASYMPATHETIC NERVOUS SYSTEM (PNS) dominant during quiescence, rest, relaxation, or sleep maintains normal functioning and it conserves, stores, and protects bodily resources affects and effects relaxation of excited organs one at a time Parts of Autonomic Nervous System and their Functions Source: http://www.drstandley.com  Parasympathetic Actions Sympathetic Actions constricts pupil of eye dilates pupil of eye stimulates flow of saliva inhibits flow of saliva slows heart rate accelerates heart rate constricts bronchi of lungs dilates bronchi of lungs stimulates digestion (stomach stimulates stomach peristalsis peristalsis and secretion) and secretion stimulates release of bile from stimulates conversion of bile liver to glycogen contracts Urinarybladder inhibits bladder contraction II. SOMATIC NERVOUS SYSTEM Functions: ▪ organizes the voluntary movements of the body. ▪ transmits information from the senses to the CNS and carries signal from the CNS to the muscle that move the skeleton. ▪ involved in making the body aware of stimuli outside the body Subdivisions: a. Sensory or Afferent (“coming toward”) neurons These fast-acting neurons provide information about the environment through the senses, which include hearing, vision, taste, smell, and touch. b. Interneurons or Association neurons These come between the sensory and motor neurons, specifically within connections in the spinal cord and the brain. c. Motor or Efferent (“going away”) neurons These carry messages that prompt immediate protective actions in the appropriate muscles, bones and other organs to respond to the environment. Voluntary movements, as well as involuntary adjustments in posture and balance are controlled by these nerves.  Central Core Brain Limbic System Central Nervous System Spinal Cerebral Cord Hemispheres NERVOUS SYSTEM Somatic Peripheral System Sympathetic Nervous Autonomic NS System System Parasympathetic NS UNIT 3.3 THE GLANDULAR SYSTEM Objectives: 1. To identify the different glands 2. To relate the functions and effects of different glands to human behavior  TWO KINDS OF GLANDS: 1. THE EXOCRINE GLANDS (Duct Glands) They eliminate their secretions on to the body surface through a duct or a tube as for instance the tear, sweat, and salivary glands. 2. THE ENDOCRINE GLANDS (Ductless Glands) They discharge their secretions directly into the blood stream that affect the specialized cells in the various organs of the body.  The chemical substances secreted by the endocrine glands are called hormones (chemicals that circulate throughout the blood and affect the functioning and growth of the parts of the body). These hormones are secreted in normal quantities as needed by the body. Over secretion or under secretion of these hormones disrupts normal functioning, thus affecting behavior. The Endocrine glands: a. PITUITARY GLAND ( hypophysis or the “master gland”) b. THYROID GLAND c. PARATHYROID GLAND d. ADRENAL GLANDS e. PANCREAS (Inlets of Langerhans) f. SEX GLANDS (Gonads)  PITUITARY GLAND ⮚ Located at the base of the brain, near the hypothalamus ⮚ "master gland" for it secretes a number of PITUITARY GLAND hormones that stimulate or inhibit the secretion of other glands. Hormone Secreted: Growth hormone (GH) Function: ⮚ Promotes and controls normal increase in size of the body; as well as in bones and muscles ⮚ Somatotropic hormone regulates the growth of the skeletal system ⮚ Overproduction (hyperpituitarism) of this hormone during growth years/childhood results to gigantism ⮚ Oversecretion after the growth years in life causes acromegaly (occurs in adults) which is characterized by the development of abnormally large hand, feet, and jaw ⮚ Underproduction (hypopituitarism) causes dwarfism  Anterior Lobe (andrenohypophysis) Hormone Secreted: Adrenocorticotropic hormone(ACTH) Function: ⮚ It controls the development of the adrenal and maintains the normal structure and function of the adrenal cortex Hormone Secreted: Thyroid-stimulating hormone(TSH) Function: ⮚ It stimulates the release of the thyroid hormone in the thyroid gland Hormone Secreted: Luteinizing hormone(LH) Function: ⮚ It is a sex hormone in males which stimulates the Leydig cells in the testes to manufacture testosterone and estrogen on females ⮚ It serves as a trigger for ovulation (release of and egg from the ovary) which stimulates conversion of follicles into corpus luteum Hormone Secreted: Prolactin releasing/inhibiting hormone Function: ⮚ Stimulates milk production in the breast of nursing mothers ⮚ excessive secretion is known as galactorrhea  Posterior Lobe (neuro-hypophysis) Hormone Secreted: Antidiuretic hormone(ADH) Function: ⮚ Retains sufficient water for the body by controlling the secretion of water in the kidney and its reabsorption ⮚ Deficiency in the secretion of this hormone results in diabetes insipidus where big volume of urine discharge/ output as much as 18-20 liters per day in dehydration, thus causing extreme weakness and sometimes disorientation Hormone Secreted: Oxytocin Function: ⮚ Helps deliver milk from the glands of the breast to the nipple during sucking; stimulates contraction of the muscles of the uterus that help in the delivery of the baby THYROID GLAND and PARATHYROID GLAND  THYROID GLAND located in the tissue of the neck around the windpipe Hormone Secreted: Thyroxin (T4) Function: ⮚ controls and stimulates basal or oxidative metabolism ⮚ Oversecretion of this hormone leads to GRAVE'S DISEASE, characterized by the speeding up of metabolism and over stimulation, over activity, and irritability, easily exhausted and prone to weight loss. Symptoms are protrusion (eye bulging abnormally) of the eyeball, high blood pressure nervous tension, etc. ⮚ Undersecretion results in cretinism, wherein physical and mental development is arrested during childhood. Myxedema is a disease characterized by slowing of motor activity, increase of weight, slowing of speech, sluggish mentality in adulthood ⮚ Hypothyroidism is often accompanied by Goiter, which is the swelling of the thyroid gland, brought about by the overworking of the gland because of the inability to secrete enough hormones.  PARATHYROID GLAND These are two pairs of small glands in the posterior portion of the thyroids Hormone Secreted: Parathormone (Pth) Function: ⮚ Responsible in keeping the supply of calcium in the blood high and that of phosphorus relatively low ⮚ Deficiency results in extremely low calcium content level in the blood or tetany and characterized by chronic muscle spasms, muscle cramps, stiffening of hand and fingers, and irritability. ⮚ Excess of this hormone results in a desensitized nervous system and poor physical coordination results. This also results in the thinning and weakening of bones and the deposition of calcium salts and kidney stones ADRENAL GLANDS These are glands found at the back of the body above each kidney  Adrenal Medulla (internal part) Hormone Secreted: Adrenalin and Noradrenaline or Epinephrine and Norepinephrine Function: ⮚ Adjusts the body to sudden stress caused by the extra energy they give during emergencies (“fight/flight”) and prolonged stress. ⮚ Undersecretion of ADRENALINE makes the organism incapable of coping with stress and reduction of body resistance to diseases  Adrenal Cortex (external part) Hormone Secreted: Cortin Function: ⮚ This plays a major role in maintaining masculine characteristics, such as muscle formation in males and sexual potency. ⮚ Over secretion of CORTIN has a musculining effect, inhibiting female functions. Females will develop a “buffalo torso”, stocky muscles and grow a mustache (Cushing's Disease). On the other hand, the concentration of adrenaline in the blood stream is increased to as much as 20  PANCREAS Islets of Langerhans PANCREAS The Islets of Langerhans (endocrine) is located in the posterior part of the stomach and attached by a duct to the intestinal tract, secrete insulin and glucagons INSULIN stimulates Lipogenesis, which enable glucose to move out of the blood into the cells of the muscles and other tissues. When insulin is present in normal levels in the blood, it ensures that various tissues get enough glucose which serves as their fuel for what they do. The nervous system, especially the brain consumes glucose almost exclusively for its activities, insulin is important in the nervous functions. GLUCAGON stimulates Gluconeogenesis, which is the release of glucose into the bloodstream from the glycogen stored in the liver. When the sugar level in the blood drops, Glucagon releases sugar from the liver in the form of glucose to supply the body's energy needs. Male Gonads Female Gonads (Testes) (Ovaries) SEX GLANDS (GONADS) MALE GONADS OR TESTES These are found in the scrotal sac of male groin. They secrete the male hormones (ANDROGENS) of which the most familiar is TESTOSTERONE. These are released under the influence of the GONADOTROPIC hormones from the pituitary during puberty. This determines and regulates the development of: Primary Sex Characteristics. The tissues of the sex organ mature and the production of spermatozoa. Secondary Sex Characteristics. The external appearance that the body has reached sexual maturity. ⮚ Oversecretion (Hypergonadism) leads to precocious sexual development. If over secretion occurs after puberty, it does not lead to any referable complaint. ⮚ Undersecretion (Hypogonadism) before puberty results to sexual neutrality with the absence of secondary sex characteristics. There is a persistence of childish characteristics with a feminine appearance. FEMALE GONADS OR OVARIES This pair of ovoid organs is located in the lateral (side) walls of the lower abdominal cavity. ESTROGEN is responsible for feminine behavior. It has the task of producing female gametes (primary sex characteristics) and of secondary hormones to regulate the secondary sex characteristics such as ovulation and the onset of menstruation, development of the breast, widening of hips and growth of pubic and armpit hair. PROGESTERONE stimulates the thickening of the uterine lining in preparation for pregnancy. ⮚ Over secretion of estrogen leads to precocious sexual development and makes women highly erotic with tendency of nymphomania. ⮚ Under secretion of estrogen at puberty makes the secondary sex characteristics never to attain their mature condition. Under secretion after puberty causes prompt regression of these secondary sex characteristics. UNIT 3.4 INTERACTION BETWEEN THE ENDOCRINE AND NERVOUS SYSTEM Objectives: 1. To compare both systems in terms of their roles in affecting behavior 2. To identify the interaction between the endocrine and nervous systems  BASIC UNITS Nervous System Endocrine System Neurons communicate Glands have specific effects with one another to affect on other glands or behavior and mental particular organs and body processes. tissues.  RELAY STATIONS Nervous System Endocrine System Neurons transmit chemical Glands secrete chemicals Neurotransmitters in the called hormones (Gr. SYNAPSES to relay Hormein meaning information. “activators”) directly into the bloodstream.  BREADTH OF COMMUNICATION SYSTEM Nervous System Endocrine System Receptors receive stimuli Target organs can as information from simultaneously receive outside the body forming a information from the neural communication to glands through different specific points in the body. hormones released.  SPEED OF COMMUNICATION Nervous System Endocrine System A nerve impulse can Several seconds, or even travel through the minutes, may be required for organism in a few the Endocrine gland to produce hundredths of a second. an effect. The process is very fast. The hormone, once released, must travel to its target site through the bloodstream-a much slower process.  INTERACTION (Fight-Flight Syndrome) Nervous System Endocrine System When the brain interprets a The Pituitary gland secretes situation as threatening, it hormones which in turn causes the hypothalamus to stimulate other glands to release hormones into the secrete their hormones. bloodstream activating the These hormones act on cells in other glands like the Pituitary the body, as well as feedback gland to respond to the to the brain and pituitary. emergency situation.