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SCIENCE Reviewer Lesson 1: Brain Exercises Sensory neurons carry impulses from the sense organs, such as the eyes and ears, to Nervous System...

SCIENCE Reviewer Lesson 1: Brain Exercises Sensory neurons carry impulses from the sense organs, such as the eyes and ears, to Nervous System the spinal cord and brain. Functions of the Nervous System Motor neurons carry impulses from the brain and the spinal cord to muscles and glands. 1. Gathers information from both inside and Interneurons process information from outside the body - Sensory Function sensory neurons and then send commands to 2. Transmits information to the processing areas other interneurons or motor neurons. of the brain and spine 3. Processes the information in the brain and spine – Integration Function 4. Sends information to the muscles, glands, and organs so they can respond appropriately – Motor Function Cells of the Nervous System Neurons Basic functional cell of nervous system conducting cells, Neurons receive stimuli and transmit impulses to other neurons or to other body organs such as muscles. Parts of the Neurons Neuroglia Dendrite – receive stimulus and carries it Neuroglia also known as the glial cells, is a impulses toward the cell body supportive cell of the nervous system that forms 40% Cell Body with nucleus – nucleus & most of of the brain’s bulk. cytoplasm Types of Neuroglia Axon – fiber which carries impulses away from cell body Astrocytes supply nutrients to neurons and Schwann Cells – cells which produce myelin or help maintain their ability to transmit fat layer in the Peripheral Nervous System impulses. Myelin sheath – dense lipid layer which Ependymal cells produce the cerebrospinal insulates the axon – makes the axon look gray fluid (a protective cushion) and the bathe Node of Ranvier – gaps or nodes in the myelin brain and the spinal cord. sheath Microglial cells help in removing debris and bacteria from the central nervous system (CNS). Oligodendrocytes in the CNS and Schwann cell in the peripheral nervous system (PNS) produce the protective myelin sheath for the insulation of axons. Types of Neurons * Neurons can be classified into three types according to the direction in which an impulse travels.  SCIENCE Reviewer Parts of the Nervous System Nervous System The nervous system consists of two divisions: the central nervous system containing the brain and spinal cord, and the peripheral nervous system which is a network of nerves and neural tissues branching out throughout the body. Brain The brain is the control center of the human body; it is encased by the bone of the head called the skull. The brain is divided into parts according to position: – forebrain in front, – midbrain in the middle, and Major Division of Nervous System – hindbrain at the back. The CENTRAL NERVOUS SYSTEM, – controls intelligence, sensory, and motor activities involving muscle tone, balance, and coordination. Forebrain The forebrain (prosencephalon) controls body temperature, reproductive functions, eating, sleeping, and the display of emotions. The Central Nervous System The Brain The major areas of the brain—Brain stem – medulla, pons, midbrain; Diencephalon – thalamus & hypothalamus; Cerebellum; Cerebrum Cerebrum – conscious activity including perception, emotion, thought, and planning The Spinal Cord The main communication link between the brain and the rest of the body Meninges Meninges are the three coverings around the brain & spine and help cushion, protect, and nourish the brain and spinal cord. dura mater is the most outer layer, very tough arachnoid mater is the middle layer and adheres to Thalamus – Brain’s switchboard – filters and then the dura mater and has web like attachments to the relays information to various brain regions innermost layer Hypothalamus – involved in regulating activities pia mater is very thin, transparent, but tough, and internal organs, monitoring information from the covers the entire brain, following it into all its crevices autonomic nervous system, controlling the pituitary (sulci) and spinal cord (inner layer) gland and its hormones, and regulating sleep and appetite  SCIENCE Reviewer Cerebrum It consists of two hemispheres divided by a fissure – corpus callosum. It includes the: Cerebral cortex – is the layer of the brain often referred to as gray matter because it has cell bodies and synapses but no myelin Medullary body – is the white matter of the cerebrum and consists of myelinated axons Basal ganglia – masses of gray matter in each hemisphere which are involved in the control of voluntary muscle movements Brainstem Lobes of the Brain acts as a relay center connecting the cerebrum and Frontal – motor area involved in movement and in cerebellum to the spinal cord. planning & coordinating behavior It performs many automatic functions such as Parietal – sensory processing, attention, and breathing, heart rate, body temperature, wake and language sleep cycles, digestion, sneezing, coughing, vomiting, Temporal – auditory perception, speech, and and swallowing. complex visual perceptions Occipital – visual center – plays a role in processing visual information Midbrain Structures in Brainstem The midbrain or mesencephalon is the forwardmost the gray matter of the midbrain control visual portion of the brainstem and is associated with vision, reflexes and sense of hearing. hearing, motor control, sleep and wakefulness, the white matter of the pons plays a role in arousal (alertness), and temperature regulation. regulating visceral (internal organ) control. the medulla oblongata connects the rest of the brain to the spinal cord. It regulates breathing, swallowing, coughing, sneezing, vomiting, heartbeat, and blood pressure. Cerebellum The cerebellum is the second largest part of the brain. Hindbrain It contains nerve fibers that connect it to every part Hindbrain, also called rhombencephalon, of the central nervous system. region of the developing vertebrate brain that It coordinates voluntary and involuntary patterns of is composed of the medulla oblongata, the movements. pons, and the cerebellum. It also adjusts muscles to automatically maintain The hindbrain coordinates functions that are posture. fundamental to survival, including respiratory rhythm, motor activity, sleep, and wakefulness.  SCIENCE Reviewer Pons Division of Peripheral Nervous System The pons, while involved in the regulation of The SOMATIC NERVOUS SYSTEM – The somatic functions carried out by the cranial nerves it houses, system is the part of the peripheral nervous system works together with the medulla oblongata to serve responsible for carrying sensory and motor an especially critical role in generating the respiratory information to and from the central nervous system. rhythm of breathing. Active functioning of the pons may also be Motor neurons: Also called efferent neurons, fundamental to Rapid Eye Movement (REM) sleep. motor neurons carry information from the brain and spinal cord to muscle fibers Spinal Cord throughout the body. The spinal cord is a long, thin, tubular structure made up of nervous tissue, which extends from the Sensory neurons: Also called afferent medulla oblongata in the brainstem to the lumbar neurons, sensory neurons carry information region of the vertebral column. from the nerves to the central nervous It encloses the central canal of the spinal cord, system. which contains cerebrospinal fluid. The AUTONOMIC NERVOUS SYSTEM – The The spinal cord is a column of nerves that connects autonomic system is the part of the peripheral your brain with the rest of your body, allowing you to nervous system that's responsible for regulating control your movements. involuntary body functions, such as blood flow, heartbeat, digestion, and breathing. Parasympathetic system: This helps maintain normal body functions and conserve physical resources. Sympathetic system: the sympathetic system triggers a response by accelerating heart rate, increasing breathing rate, boosting blood flow to muscles, activating sweat secretion, and dilating the pupils. Lesson 2: Endocrine System Cerebrospinal Fluid The endocrine system is made up of glands and the A colorless fluid produced in the ventricles of the hormones they secrete. Although the endocrine brain. glands are the primary hormone producers, the Protect brain and spinal cord from trauma. brain, heart, lungs, liver, skin, thymus, Supply nutrients to nervous system tissue. gastrointestinal mucosa, and placenta also produce Remove waste products from cerebral metabolism. and release hormones. The primary endocrine glands are the pituitary (the Major Division of Nervous System master gland), pineal, thyroid, parathyroid, islets of The PERIPHERAL NERVOUS SYSTEM – consists of Langerhans, adrenals, ovaries in the female and nerves and supporting cells, – The peripheral system testes in the male. The function of the endocrine allows the brain and spinal cord to receive and send system is the production and regulation of chemical information to other areas of the body, which allows substances called hormones. us to react to stimuli in our environment.  SCIENCE Reviewer Secretion from the ANTERIOR Pituitary Gland Growth Hormone (GH): essential for the growth and development of Hormones bones, muscles, and other organs. It also enhances protein synthesis, decreases the use is a chemical transmitter. It is released in small of glucose, and promotes fat destruction. amounts from glands, and is transported in the bloodstream to target organs or other cells. Hormones are chemical messengers, transferring information and instructions from one set of cells to another. Hormones regulate growth, development, mood, tissue function, metabolism, and sexual function. Hyposecretion or hypersecretion of any hormone can be harmful to the body. Adrenocorticotropin (ACTH): Controlling the production of hormones can essential for the growth of the adrenal cortex. treat many hormonal disorders in the body. Thyroid-Stimulating Hormone (TSH): essential for the growth and development of the thyroid gland. Follicle-Stimulating Hormone (FSH): Nervous System and Endocrine System The endocrine system and nervous system work is a gonadotropic hormone. together to help maintain homeostasis… balance. The hypothalamus is a collection of specialized cells located in the brain, and is the primary link between the two systems. It produces chemicals that either stimulate or suppress hormone secretions of the pituitary gland. It stimulates the growth ovarian follicles in the female and the production of sperm in the male.  SCIENCE Reviewer Luteinizing Hormone (LH): Melatonin: is a gonadotropic hormone stimulating the communicates information about development of corpus luteum in the female environmental lighting to various parts of the ovarian follicles and the production of body. Has some effect on sleep/awake cycles testosterone in the male. The yellow corpus and other biological events connected to luteum remains after ovulation; it produces them, such as a lower production of gastric estrogen and progesterone. secretions at night. Prolactin (PRL): stimulates the development and growth of the mammary glands and milk production during pregnancy. The sucking motion of the baby stimulates prolactin secretion. Serotonin: Melanocyte-stimulating hormone (MSH): a neurotransmitter that regulates intestinal movements and affects appetite, mood, sleep, regulates skin pigmentation and promotes the anger, and metabolism. deposit of melanin in the skin after exposure to sunlight Secretion from the Thyroid Gland The thyroid gland plays a vital role in metabolism and Secretion from the Posterior Lobe of the Pituitary regulates the body’s metabolic processes. Gland Calcitonin: Antidiuretic Hormone (ADH): influences bone and calcium metabolism; stimulates the reabsorption of water by the maintains a homeostasis of calcium in the renal tubules. Hyposecretion of this hormone blood plasma can result in diabetes insipidus. Secretion from the Parathyroid Gland The two pairs of parathyroid glands are located on the dorsal or back side of the thyroid gland. They secrete parathyroid (PTH) which plays a role in the metabolism of phosphorus. Too little results in cramping; too much results in osteoporosis or kidney stones. Oxytocin: stimulates the uterus to contract during labor, delivery, and parturition. A synthetic version of this hormone, used to induce labor, is called Pitocin. It also stimulates the mammary glands to release milk. Secretion from the Pineal Gland The pineal gland is pine-cone-shaped and only about 1 cm in diameter.  SCIENCE Reviewer The Islets of Langerhans Corticosterone: - The islets of Langerhans are small clusters of cells like cortisol, it is a steroid; influences located in the pancreas. potassium and sodium metabolism Aldosterone: essential in regulating electrolyte and water balance by promoting sodium and chloride retention and potassium excretion. Androgens: Secretion from the Islets of Langerhans several hormones including testosterone; they Alpha cells facilitate the breakdown of glycogen to promote the development of secondary sex glucose. This elevates the blood sugar. characteristics in the male. Beta cells secrete the hormone insulin, which is Secretion from the Adrenal Medulla essential for the maintenance of normal blood sugar Dopamine levels. Inadequate levels result in diabetes mellitus. Delta cells suppress the release of glucagon and is used to treat shock. It dilates the arteries, insulin. elevates systolic blood pressure, increases cardiac output, and increases urinary output. Epinephrine is also called adrenalin. It elevates systolic blood pressure, increases heart rate and cardiac output, speeds up the release of glucose from the liver… giving a spurt of energy, dilates the bronchial tubes and relaxes airways, and dilates the pupils to see more clearly. It is often used to counteract an The Adrenal Glands allergic reaction. The triangular-shaped adrenal glands are located on the top of each kidney. The inside is called the Norepinephrine medulla and the outside layer is called the cortex. like epinephrine, is released when the body is under stress. It creates the underlying influence in the fight or flight response. As a drug, however, it actually triggers a drop-in heart rate. Secretion from the Ovaries - The ovaries produce several estrogen hormones and progesterone. These Secretion from the Adrenal Cortex hormones prepare the uterus for pregnancy, Cortisol: promote the development of regulates carbohydrate, protein, and fat mammary glands, play metabolism; has an anti-inflammatory effect; a role in sex drive, and helps the body cope during times of stress develop secondary sex Hyposecretion results in Addison’s disease; characteristics in the hypersecretion results in Cushing’s disease. female. - Estrogen is essential for the growth, development, and maintenance of female sex organs.  SCIENCE Reviewer Secretion from the Testes Secretion from the Thymus - The testes produce the male sex hormone called - The thymus gland has two lobes, and is part of the testosterone. It is essential for normal growth and lymphatic system. It is a ductless gland, and secretes development of the male sex organs. Testosterone is thymosin. This is necessary for the Thymus’ normal responsible for the erection of the penis. production of T cells for the immune system. Some common Hormones Secretion from the Placenta Adrenaline - During pregnancy, the placenta serves as an Where it comes from: adrenal gland endocrine gland. Where it acts: heart, blood vessels, eyes - It produces chorionic gonadotropin hormone, What it does: stimulates heart rate, increases blood estrogen, and progesterone. pressure, dilates pupils Causes "adrenaline rush” A 'fight and flight' hormone. It is released in high stress conditions or in excitement or fear. Loud noise, high temperature etc. May also trigger its release since these are also high stress situations. Progesterone Where it comes from: ovary (where an egg was Secretion from the Gastrointestinal Mucosa released) - The mucosa of the pyloric area of the stomach Where it acts: uterus secretes the hormone gastrin, which stimulates the What it does: controls menstruation in women and production of gastric acid for digestion. plays a role in pregnancy. One of the components of birth control pills Thyroxine Where it comes from: thyroid gland Where it acts: most cells of the body What it does: controls the rate of metabolic processes (how energy is used) in the body and influences physical development People may not produce enough of this hormone and get a condition known as hypothyroidism. They can take thyroxine to treat this condition. - The mucosa of the duodenum and jejunum secretes Testosterone the hormone secretin, which stimulates pancreatic Where it comes from: testicles juice, bile, and Where it acts: body-hair cells, muscle, reproductive intestinal structures secretion. What it does: stimulates development of male sexual characteristics Testosterone is a steroid and has been administered to athletes in order to improve performance. This is considered to be a form of doping in most sports and is a very dangerous practice.  SCIENCE Reviewer Females also produce small amounts of testosterone After conception, the uterus provides a safe in their ovaries that affect muscle development and environment for a baby to develop before it is time for other body functions. it to make its way into the outside world. Estrogen If fertilization does not take place, the system is Where it comes from: ovary designed to menstruate. Where it acts: breast tissue, reproductive structures In addition, the female reproductive system in female produces female sex hormones that maintain the What it does: stimulates development of female reproductive cycle. sexual characteristics Estrogen levels may be related somehow to migraine headaches in women. Cortisol Where it comes from: outer part of adrenal gland Where it acts: multiple tissues What it does: mental stimulation, breaks down fat and protein to glucose, anti-inflammation The External Female Reproductive Structures It is usually referred to as the "stress hormone" as it is involved in response to stress and anxiety. The function of the external female Insulin reproductive structures Where it comes from: insulin is produced in the (the genitals) is twofold: pancreas To enable sperm to Where it acts: liver, muscle, and fat tissue enter the body and What it does: insulin causes cells to take up glucose To protect the internal (sugar) from the blood, storing it in the liver and genital organs from muscle, and stopping use of fat as an energy source. infectious organisms. Problems with insulin production or use in the body can lead to diabetes Labia Majora Lesson 3.3.1: Female Reproductive System The labia majora enclose and protect the other external reproductive organs. Where is this body system located? Literally translated as "large lips," the labia majora are relatively large and fleshy, and are comparable to the scrotum in males. The labia majora contain sweat and oil-secreting glands. After puberty, the labia majora are covered with hair. The human female has a reproductive system located entirely in the pelvis. The external part of the female reproductive organs is called the vulva which is located between the legs. A female's internal reproductive organs are the Labia Minora vagina, uterus, fallopian tubes, and ovaries. Literally translated as "small Role/Performance lips," the labia minora can be The female reproductive system is designed to carry very small or up to 2 inches wide. out several functions. It produces the female egg cells They lie just inside the labia necessary for reproduction. The system is designed to majora, and surround the transport the ova to the site of fertilization. openings to the vagina and Conception, the fertilization of an egg by a sperm, urethra. normally occurs in the fallopian tubes.  SCIENCE Reviewer Bartholin’s Gland The corpus can easily expand to hold a developing These glands are located beside the vaginal opening baby. and produce a fluid (mucus) secretion. A channel through the cervix allows sperm to enter and menstrual blood to exit. Clitoris The two labia minora meet at the clitoris, a small, Structures in the Uterus (womb) sensitive protrusion that is comparable to the penis in The endometrium is the inner layer that lines the males. uterus. It is made up of glandular cells that make The clitoris is covered by a fold of skin, called the secretions. prepuce, which is similar to the foreskin at the end of The myometrium is the middle and thickest layer of the penis. Like the penis, the clitoris is very sensitive the uterus wall. It is made up mostly of smooth to stimulation and can become erect. muscle. *The myometrium and the endometrium, are all important in preparing the uterus to carry out its functions of protection, nutritional support and waste removal for the developing fetus. The perimetrium is the outer serous layer of the uterus. It helps keep everything in place. Perineum - The perineum is the area located between the vaginal opening and the anus. It is a muscular sheet that can be torn during childbirth. - Some doctors avoid uncontrolled tearing of the perineum by making a surgical incision called an episiotomy. The Internal Female Reproductive Structures Vagina Function of the Uterus (womb) The vagina is a canal that joins the cervix (the lower The uterus has 3 functions: part of uterus) to the outside of the body. 1. The endometrium sheds the lining of the uterus It also is known as the birth canal. every 21 to 40 days by menstruation 2. It provides a place for the protection and nourishment of the fetus during pregnancy 3. It contracts during labor to expel the fetus Fallopian Tube These are narrow tubes that are attached to the upper part of the uterus and serve as tunnels for the ova (egg cells) Uterus(womb) to travel from the ovaries to The uterus is a hollow, pear-shaped organ that is the the uterus. (4-6 inches long) home to a developing fetus. Conception, the fertilization The uterus is divided into two parts: of an egg by a sperm, normally occurs in the fallopian – the cervix, which is the lower part that opens into tubes. The fertilized egg then moves to the uterus, the vagina, and where it implants into the lining of the uterine wall. – the main body of the uterus, called the corpus.  SCIENCE Reviewer Structures in Fallopian Tube Structure in Breast The dark-colored circle at the tip of the breast is called the areola. It contains sebaceous glands to keep the skin conditioned. In the center is the nipple, where ducts from the lobules open. The first secretion from the breast is not a true milk, but a thin yellowish substance called colostrum. Ovaries Colostrum contains nutrients and the mother’s The two ovaries are attached to each side of the immunities that can protect baby. uterus by a ligament. They are oval-shaped, about the size of a large olive, and lie close to the fimbria at the end of the fallopian tubes. *Each ovary is filled, already at birth, with egg- containing sacs called follicles. Each egg is called an ovum. What Happens During Menstrual Cycle? Ovarian Cycle The ovarian cycle refers to the series of changes in the ovary during which the follicle matures, the ovum Once every 21 days, one follicle in one ovary ripens. is shed, and the corpus luteum develops. This mature follicle is a graafian follicle. Phases of Ovarian Cycle The follicle ruptures in response to hormones from Follicular Phase the pituitary gland, releasing the ovum/egg, a process This phase typically takes place from days 6 to 14. called ovulation. During this time, the level of the hormone estrogen *After the follicle ruptures, it becomes a mass of rises, which causes the lining of the uterus (called the yellow cells called the corpus luteum. This is a endometrium) to grow and thicken. temporary, progesterone-producing structure. In addition, another hormone—follicle-stimulating Breast hormone—causes follicles in the ovaries to grow. The breasts are the mammary glands, varying in size During days 10 to 14, one of the developing follicles according to age, heredity, and the amount of fatty will form a fully mature egg (ovum). tissue present. Ovulatory Phase Each breast has 15-20 glandular lobes separated by The ovulatory phase, or ovulation, starts about 14 connective tissue. days after the follicular phase started. After childbirth, the pituitary gland stimulates these The ovulatory phase is the midpoint of the lobules with the hormone prolactin and they produce menstrual cycle, with the next menstrual period milk starting about two weeks later. Ovulatory Phase (Events) The rise in estrogen from the dominant follicle triggers a surge in the amount of luteinizing hormone that is produced by the brain. This causes the dominant follicle to release its egg from the ovary. As the egg is released (a process called ovulation), it is captured by finger-like projections on the end of the fallopian tubes (fimbriae). The fimbriae sweep the egg into the tube. Also, during this phase, there is an increase in the amount and thickness of mucus produced by the cervix (lower part of the uterus). If a woman were to have intercourse during this time, the thick mucus captures the man's sperm, nourishes it, and helps it to move towards the egg for fertilization.