Science: Body Regulation and Nervous System PDF

SCIENCE BODY REGULATION NERVOUS SYSTEM DIVIDED INTRO 3 CLASSES (NEURONS) is the major controlling, regulatory, and 1. Sensory neurons communicating system in the body. get information about what's going on inside the cen...

SCIENCE BODY REGULATION NERVOUS SYSTEM DIVIDED INTRO 3 CLASSES (NEURONS) is the major controlling, regulatory, and 1. Sensory neurons communicating system in the body. get information about what's going on inside the center of all mental activity including and outside of the body and bring that thought, learning, and memory. information into the CNS so it can be Together with the endocrine system, the processed nervous system is responsible for regulating ex: if you picked up a hot coal, sensory neurons and maintaining homeostasis with endings in your fingertips would convey the essential for communication within the body information to your CNS that it was really hot. Stimulus-Respond Coordination 2. Motor Neurons STIMULUS get information from other neurons and > anything that evokes a person’s reaction convey commands to your muscles, organs > every stimuli requires the body to respond and glands ex: if you picked up a hot coal, it motor neurons HOMEOSTASIS innervating the muscles in your fingers would > the body’s ability to maintain constant internal cause your hand to let go. equilibrium by adjusting its physiological process. 3. Interneurons > helps the body maintain a stable internal are found only in the CNS, connect one environment neuron to another. 3 MAIN COMPONENTS: They receive information from other neurons 1. Receptor (either sensory neurons or interneurons) and 2. Control Center transmit information to other neurons 3. Effector (either motor neurons or interneurons). ex: if you picked up a hot coal, the signal from Neurons the sensory neurons in your fingertips would are cells in the brain and nervous system that travel to interneurons in your spinal cord. transmit electrical and chemical signals to other neurons, muscles, and tissues Transmission of Nerve Impulses throughout the body. 3 MAIN PARTS: Synapses 1.Dendrites Neuron-to-neuron connections are > The "arms" of the neuron, which are branch made onto the dendrites and cell bodies of extensions that come out of different parts of the other neurons. neuron. 2 TYPES: 2. Cell body 1. Synapses process > The center of the neuron. Axon splits into multiple branches upon 3. Axon approaching a synapse. > An elongated fiber that extends from the cell These branches terminate into synaptic knob body to the terminal endings and transmits the that is connected to either main parts of the neural signal. neuron. Hormonal secretion enable the propagation of nerve impulses from the synapse. 2. Neurotransmitters are chemical messengers that neurons release to affect other cells across a synapse. The cells that receive the signal are called target cells, and they can be neurons, glands, or muscle cells. examples: > Serotonin: Regulates mood, anxiety, happiness, appetite, sleep, memory, and learning > Acetylcholine: Helps translate intentions to move into actual actions by passing signals from neurons into muscle fibers. > Dopamine: Helps nerve cells send messages to each other > Norepinephrine: Involved in arousal, alertness, memory, and attention, and triggers Central Nervous System (CNS) the "fight-or-flight" response. is made up of the brain and spinal cord. > Endorphins: Stimulates neurons involved in is the body's processing center reducing pain brain controls most of the functions of the body, including awareness, movement, The Reflex thinking, speech, and the 5 senses. is an automatic, involuntary, and rapid response to a stimulus that helps protect the Brain body from harm. The brain is a complex organ that controls occur through neural pathways in the most of the body's activities, including nervous system called reflex arcs. thought and behavior. examples: Spinal Cord > Pulling away from a hot object: When you The spinal cord is a tube-like structure that touch something hot, your hand immediately carries messages between the brain and the pulls away. rest of the body. > Adjusting your eyes to bright light: When It is covered by three thin layers of protective exposed to bright light, your eyes adjust tissue called membranes. automatically. > Withdrawing your hand or leg after MAJOR PARTS OF THE BRAIN being pricked by a pin: You suddenly and involuntarily withdraw your hand or leg. > Coughing or sneezing: When an irritant is present in your trachea or nose, you cough or sneeze to expel it > The brain structure is composed of three main parts: the forebrain, midbrain and hindbrain, each with multiple parts. Peripheral Nervous System (PNS) SNS & PNS a network of nerves that runs throughout the The two systems work together to keep the head, neck, and body. body in balance. carries messages to and from the central The SNS takes the lead when the body needs nervous system (the brain and spinal cord). to get through a period of danger, and then The primary peripheral nervous system the PNS returns things to normal. function is to relay messages back and However, the SNS can strain body systems if forth from the central nervous system it's active for too long (CNS) The muscles, glands, and organs that the PNS transmits signals to from the CNS are known as effectors. 2 main division of PNS 1. Somatic nervous system Controls voluntary muscle movement and includes sensory and motor neurons that send and receive information. 2. Autonomic nervous system Regulates involuntary body functions, such as those of the heart, lungs, and intestines. is further divided into the sympathetic and parasympathetic systems, which have complementary functions that work together to maintain homeostasis Sympathetic nervous system (SNS) Prepares the body for physical and mental activity, such as in times of danger or stress. This system activates the body's "fight-or- flight" response, increasing heart rate, opening airways, and inhibiting digestion. The SNS releases the hormones epinephrine and norepinephrine to accelerate the heart rate. Parasympathetic nervous system (PNS) Responsible for bodily functions when the body is at rest, such as digestion, relaxation, and metabolic processes. This system activates the body's "rest-and- digest" response. The PNS releases the hormone acetylcholine to slow the heart rate.  2. Pituitary Gland (master gland) ENDOCRINE SYSTEM Found at the base of the brain. The endocrine system is a complex Produces hormones that regulate other network of glands and organs. endocrine glands (e.g., thyroid, adrenal It uses hormones to control and coordinate glands). your body's metabolism, energy level, Releases growth hormone, prolactin, and reproduction, growth and development, and oxytocin. response to injury, stress, and mood. a network of glands and organs that produce, store, and secrete hormones, which are chemical messengers that regulate 3. Thyroid Gland various bodily functions. Located in the neck, around the trachea. It works closely with the nervous system to Produces hormones like thyroxine (T4) and maintain homeostasis, control growth, triiodothyronine (T3), which regulate metabolism, and reproduction, and respond metabolism, energy levels, and growth to stress. How the system communicates? > The organs of the endocrine system communicate with each other and the rest of the 4. Parathyroid Gland body using hormones Four small glands behind the thyroid. > Hormones are made and stored in their Regulate calcium levels in the blood and originating organ. The place they are sent is bones via parathyroid hormone (PTH). called the target. > Targets can be anything from all the bones in the body to another endocrine organ. > When the hormones reach their target, they trigger events in that location. Components of the Endocrine System 5. Adrenal Glands Sit atop the kidneys. Produce hormones like cortisol (stress response), adrenaline (fight or flight), and aldosterone (regulates blood pressure). 6. Pancreas Located behind the stomach. Functions as both an endocrine (insulin and 1.Hypothalamus glucagon) and exocrine gland (digestive Located in the brain. enzymes). Regulates the pituitary gland and connects Regulates blood sugar levels. the nervous and endocrine systems. s located inside your abdomen, just behind Controls body temperature, hunger, and your stomach. It's about the size of your thirst. hand. helps your digestive system by making hormones. These are chemical messengers that travel through your blood. Pancreatic hormones include: NEGATIVE FEEDBACK MECHANISM Insulin. This hormone is made in cells of A negative feedback mechanism is a the pancreas known as beta cells. Beta cells biological process in which a system make up about 75% of pancreatic hormone responds to a change by counteracting it, cells. Insulin is the hormone that helps your helping maintain stability or homeostasis. body use sugar for energy. Without enough It is the most common regulatory insulin, your sugar levels rise in your blood mechanism in the body and ensures that and you develop diabetes. variables such as temperature, hormone Glucagon. Alpha cells make up about 20% levels, and blood sugar remain within an of the cells in your pancreas that produce optimal range. hormones. They produce glucagon. If your blood sugar gets too low, glucagon helps raise How It Works: it by sending a message to your liver to Stimulus: A change occurs, such as an increase release stored sugar. or decrease in a physiological variable. Sensor: Receptors detect the change and send 7. Pineal Gland information to a control center. Found in the brain. Control Center: Typically the brain or an Produces melatonin, which influences sleep- endocrine gland, it compares the current state to wake cycles. the desired set point. Effector: A response is initiated to bring the variable back to its set point. Outcome: The original change is diminished or reversed, stabilizing the system. 8. Gonads (Ovaries and Testes) examples: Ovaries (females): Produce estrogen and progesterone, regulating menstrual cycles and pregnancy. Testes (males): Produce testosterone, influencing sperm production and male characteristics 9. Thymus Located in the upper chest. Important during childhood for developing the immune system through T-cell maturation. HUMAN REPRODUCTIVE SYSTEM Male Reproductive System Female Reproductive System The female reproductive system performs the The male reproductive system performs the following functions: following functions: a.Production of the female sex hormones a.Secretion of the male sex hormones b. Production of egg cells b. Production of sperm cells c.Transfer of sperm from the male sex organ c.Release of sperm cells. d.Protection and nourishment of the developing embryo Testes Produce sperm (male gametes) through Ovaries: spermatogenesis. Produce ova (eggs) through oogenesis and Secrete testosterone, a hormone responsible release them during ovulation. Secrete for male secondary sexual characteristics like estrogen and progesterone, hormones that deeper voice, facial hair, and muscle regulate the menstrual cycle and maintain development. pregnancy. Fallopian Tubes: > Epididymis: A coiled tube on the back of each Transport the egg from the ovary to the testis where sperm mature and are stored. uterus. > Vas Deferens: A muscular tube that carries Fertilization typically occurs here if sperm sperm from the epididymis to the urethra during meets the egg. ejaculation. Uterus: > Seminal Vesicles: Add a sugary fluid to A muscular, pear-shaped organ where a sperm, providing energy for movement. fertilized egg implants and grows into a fetus. > Prostate Gland: Produces a fluid that Endometrium: protects sperm and aids its mobility The inner lining of the uterus, which thickens during the menstrual cycle to prepare for Penis and Urethra implantation. The penis delivers sperm into the female Cervix: reproductive tract, and the urethra serves The lower, narrow part of the uterus that as a pathway for both urine and semen (but opens into the vagina. I not simultaneously). it acts as a gateway for sperm to enter and a barrier to pathogens. Testosterone Vagina: Secondary Sexual Characteristics A muscular canal that serves as the At puberty, testosterone drives the passageway for sperm, menstrual flow, and development of traits that distinguish males childbirth. from females, including: ✓Deepening of the voice. Female Sex Hormones ✓Growth of facial, pubic, and body hair. primarily estrogen and progesterone, ✓Increased muscle mass and strength. play critical roles in regulating the ✓Broadening of shoulders. reproductive system, supporting pregnancy, and influencing secondary sexual characteristics. Estrogen: Day 1 to Day 5: Menstruation (period). Development of Secondary Sexual Day 6 to Day 13: Follicles in the ovaries grow, Characteristics and estrogen helps the uterus lining build up. Regulation of the Menstrual Cycle Day 14: Ovulation—egg is released. Bone and Cardiovascular Health Day 15 to Day 28: The uterus prepares for During Pregnancy pregnancy; if the egg isn’t fertilized, the cycle restarts. Progesterone: Preparation for Pregnancy Menstruation = shedding of the uterine lining Maintenance of Pregnancy (period). Milk Production Follicular phase = egg growth and estrogen Regulation of the Menstrual Cycle production. Ovulation = egg release from the ovary. Follicle-Stimulating Hormone (FSH) Luteal phase = preparation of the uterus for Stimulates the growth and maturation of pregnancy, or the cycle begins again if no ovarian follicles, each containing an pregnancy occurs immature egg. Works with LH to regulate ovulation. REPRODUCTIVE HEALTH Luteinizing Hormone (LH) Triggers ovulation (the release of a mature STD (Sexually Transmitted Diseases) egg from the ovary). is an infection that is spread primarily Stimulates the formation of the corpus through sexual contact. These diseases are luteum, which produces progesterone. caused by bacteria, viruses, or parasites, and they can affect the genital area, but also the DISORDERS: mouth, throat, or other parts of the body. Polycystic Ovary Syndrome (PCOS) also referred to as STIs (Sexually > A common hormonal disorder in women of Transmitted Infections) because some reproductive age. infections may not cause symptoms but can still be passed to others. Estrogen Deficiency > Low levels of estrogen, often seen in conditions Common Types of STDs like menopause 1. Chlamydia 2. Gonorrhea Premenstrual Syndrome (PMS) and 3. Syphilis Premenstrual Dysphoric Disorder 4. Human Papillomavirus (HPV) (PMDD) 5. Herpes Simplex Virus (HSV) > Hormonal changes during the luteal phase of 6. HIV/AIDS the menstrual cycle 7. Trichomoniasis The Menstrual Cycle How STDs Are Spread? a natural process that prepares the Sexual contact female body for pregnancy each Blood contact month. Mother to child involves changes in the ovaries and the lining of the uterus, and typically lasts about 28 days, though it can range from 21 to 35 days The cycle is regulated by a complex interaction of hormones. Prevention of STDs WHAT IS EVOLUTION? Condoms The process by which species change over Vaccination time through mechanisms like natural Regular testing selection, genetic mutations, and adaptation. Limiting sexual partners Communication JEAN-BAPTISTE LAMARCK AND HIS THEORY OF EVOLUTION Signs and Symptoms of STDs 1. Pain during urination or sex. Jean-baptiste lamarck (1744–1829) was a 2. Unusual discharge from the penis or vagina. french biologist and naturalist who 3. Sores, bumps, or blisters on the genital area, developed one of the earliest theories of mouth, or throat. evolution. 4. Itching or swelling in the genital area. While his ideas were later overshadowed by 5. Flu-like symptoms (fever, chills, sore throat) charles darwin's theory of natural selection, lamarck made significant contributions to Birth Control (Contraception) the study of evolution and biology. refers to methods used to prevent pregnancy. There are many different types, ranging from TWO KEY IDEAS ASSOCIATED WITH JEAN- hormonal methods to physical devices and BAPTISTE LAMARCK'S THEORY OF behavioral strategies. EVOLUTION: Types of Birth Control 1. USE AND DISUSE 1..Hormonal Methods (Birth Control Pills, Lamarck proposed that an organism's body Birth Control Implant) parts develop or shrink based on how much they 2. Barrier Methods (Condoms) are used. 3. Permanent Methods (sterilization) 2. INHERITANCE OF ACQUIRED 4. Natural Methods (Fertility Awareness, CHARACTERISTICS avoiding sex during fertile period) Lamarck believed that traits an organism acquires during its lifetime are passed to its BIODIVERSITY AND offspring. EVOLUTION CONTRIBUTIONS OF LAMARCK’S WORK Charles Darwin & Evolution CONTRIBUTIONS OF LAMARCK’S WORK Classification of Life WHAT IS BIODIVERSITY? Focus on Environmental Influence refers to the variety of life forms on earth. It describes the richness of life in terms of LIMITATIONS OF LAMARCK’S THEORY quantity and variety. 1.Acquired traits are not inherited It is crucial for ecosystem stability, human Inheritance is determined by genes, not by survival, and natural processes like the use or disuse of traits pollination and nutrient cycles. 2.NO EVIDENCE OF "USE AND DISUSE" includes: MECHANISM 1. Genetic diversity: the variety of genes Scientists found no proof that body parts within a species. grow stronger or weaker just because they 2. Species diversity: the number of different are used or unused. species in an area. 3. Ecosystem diversity: the variety of ecosystems, such as forests, grasslands, and oceans. 3. EVOLUTION DOESN’T STRIVE FOR BIOCHEMICAL EVIDENCE PERFECTION The nitrogen base sequences in the genetic Lamarck believed organisms aim to become code are the same in almost every organism. better or more complex, but evolution depends on survival and reproduction, not COMPARATIVE MORPHOLOGY AND perfection. ANATOMY It is seen mainly in the biological structure WHO WAS CHARLES DARWIN? of animals. Most have similar structures but > Born in 1809 in England. have different functions. > Naturalist and geologist. > Famous for his work on the theory of OBSERVABLE EVENTS evolution. Changes have been observed in species over > Published On the Origin of Species in 1859. time. These observable changes show that evolution is an ongoing process DARWIN’S JOURNEY Date: 1831–1836 NATURAL SELECTION Explored south America, the Galapagos islands, A PROCESS THAT CAUSES SPECIES TO and other regions. CHANGE OVER TIME BY FAVORING THE Observations: SURVIVAL AND REPRODUCTION OF Fossils of extinct animals. ORGANISMS THAT ARE BEST ADAPTED Unique species on islands (e.g., Galápagos TO THEIR ENVIRONMENT. IT'S A finches). FUNDAMENTAL MECHANISM OF Differences in species related to their EVOLUTION environment DEFINED AS A PROCESS BY WHICH SPECIES OF ANIMALS AND PLANTS THAT DARWIN’S ROLE ON THE VOYAGE ARE BEST ADAPTED TO THEIR Darwin’s job was to collect and document plant ENVIRONMENT SURVIVE AND and animal specimens, observe geological REPRODUCE, WHILE THOSE THAT ARE formations, and record his findings in detail. His LESS WELL ADAPTED DIE OUT. work focused on: Fossils of extinct animals that resembled ARTIFICIAL SELECTION modern species. Also known as selective breeding, is a Unique adaptations in plants and animals on process where humans intentionally breed the galápagos islands. plants or animals to produce specific traits. Geological evidence supporting gradual change Unlike natural selection, where over time, such as uplifted sea beds. environmental pressures determine which traits are advantageous, artificial selection is EVIDENCE OF EVOLUTION guided by human preferences. FOSSIL RECORDS usually found in the sedimentary layers. This means that the more the layers, the more evidence there is of different organisms BIOCHEMICAL EVIDENCE DARWIN'S FINCHES The nitrogen base sequences in the genetic also known as galapagos finches) code are the same in almost every organism. A GROUP OF ABOUT 18 SPECIES OF PASSERINE BIRDS COMPARATIVE MORPHOLOGY AND WELL KNOWN FOR BEING A CLASSIC ANATOMY EXAMPLE OF ADAPTIVE RADIATION It is seen mainly in the biological structure of animals. Most have similar structures but TYPES OF SPECIATION have different functions. 1.ALLOPATRIC SPECIATION OBSERVABLE EVENTS Occurs when a population is geographically Changes have been observed in species over separated time. These observable changes show that Is a process that occurs when a species splits evolution is an ongoing process into two or more groups that are isolated from each other and develop into new NATURAL SELECTION species. A PROCESS THAT CAUSES SPECIES TO It's also known as geographic CHANGE OVER TIME BY FAVORING THE speciation SURVIVAL AND REPRODUCTION OF ORGANISMS THAT ARE BEST ADAPTED 2. SYMPATRIC SPECIATION TO THEIR ENVIRONMENT. IT'S A Happens without geographic FUNDAMENTAL MECHANISM OF separation. EVOLUTION Can occur due to ecological differences DEFINED AS A PROCESS BY WHICH a type of evolution where a new species SPECIES OF ANIMALS AND PLANTS THAT develops from an existing species while both ARE BEST ADAPTED TO THEIR species continue to live in the same area ENVIRONMENT SURVIVE AND sympatric = same place (greek word) REPRODUCE, WHILE THOSE THAT ARE LESS WELL ADAPTED DIE OUT. 3. PERIPATRIC SPECIATION type of allopatric speciation that occurs ARTIFICIAL SELECTION when a small group from a larger Also known as selective breeding, is a population becomes geographically process where humans intentionally breed isolated at the edges of the range plants or animals to produce specific traits. This isolated group may experience rapid Unlike natural selection, where evolutionary changes due to its small size and environmental pressures determine which the unique selective pressures of its traits are advantageous, artificial selection is environment. guided by human preferences. Is similar to allopatric speciation, but the new species is formed from a much smaller SPECIATION group. Speciation is the evolutionary process by ex: Polar bears and brown bears which populations of a single species diverge to form new, distinct species. 4. PARAPATRIC SPECIATION It occurs when groups within a species Occurs in populations that are adjacent but become reproductively isolated, preventing not fully geographically isolated. gene flow between them. Over time, genetic differences accumulate, leading to the development of new species MICROEVOLUTION Autotrophs - organisms that use light energy Is the process of small changes in the from the sun to produce food; also called frequency of genes in a population over time. producers These changes can occur in a short period of Examples: plants, blue-green algae, some time and may not be obvious to the casual prokaryotes. observer. Heterotrophs - organisms that obtain energy ADAPTIVE RADIATION from the foods they consume; also called Is the process by which a single ancestral consumers species rapidly evolves into multiple distinct Examples: animals, fungus, some prokaryotes species, each adapted to different ecological and protists. niches TROPHIC LEVELS DIVERSITY AND STABILITY A trophic level is defined as a position in the food chain where organisms are grouped what is ecosystem? based on their feeding relationships. A community of living organisms and their physical environment that interact with each trophic levels other. 1 - grass (producer) 2 - mouse (primary producer) Components of Ecosystem 3 - snake (secondary consumer) Biotic factors:Living organisms, such as 4 - hawk (tertiary consumer) plants, animals, and microorganisms Abiotic factors: Nonliving factors, such as SYMBIOTIC RELATIONSHIP climate, temperature, humidity, and nutrient concentration SYMBIOSIS A close and long-term interaction between two different species living together, where at least one of them benefits. take several forms, depending on how the species interact and benefit from each other main types: 1.MUTUALISM In mutualism, both the involved organisms FOOD CHAIN benefit from each other. A linear sequence of organisms through ex: bees and flowers, clownfish & sea anemones which nutrients and energy pass as one 2.COMMENSALISM organism eats another. In commensalism, only one organism benefits, while the other is neither benefited FOOD WEB nor harmed. A food web is the natural interconnection of ex: barnacles on whales, remora fish & sharks food chains and a graphical representation of 3.PARASITISM what-eatswhat in an ecological community In parasitism, one organism is benefited while the other organism is harmed. Producers - make their own food ex: mosquitoes & humans, head lice & humans Consumers - Eat other organisms Decomposers - Break down dead material other interactions: How Carrying Capacity Affects Population 1. Competition Definition: Both species Growth? compete for the same limited resources (e.g., food, space), which harms both to some degree. When a population size is below carrying Example: Lions and hyenas compete for prey in capacity, growth can occur. the same habitat. When the population size reaches carrying 2. Predation Definition: One species capacity, growth slows or stops. (predator) hunts and kills another species (prey) If a population exceeds carrying capacity for food. Example: A lion hunts and eats a zebra. (overshoot), resources are depleted, leading 3. Herbivory Definition: An animal feeds on to a population crash or decline until balance plants, which can harm or sometimes benefit the is restored plant. Example: A caterpillar eating leaves of a plant. POPULATION GROWTH refers to the change in the size of a population over time. It can occur in two main patterns: 1. Exponential Growth Population grows rapidly as resources are abundant, and conditions are ideal. Example: Bacteria in a nutrient-rich environment can multiply rapidly without constraints 2. Logistic Growth Population growth slows as it approaches the carrying capacity due to limited resources. Shape of the Growth Curve: S-shaped (sigmoid curve) Example: A deer population in a forest slows its growth as food becomes scarce CARRYING CAPACITY (K) The maximum number of individuals of a species that an environment can sustain indefinitely based on available resources. Factors Influencing Carrying Capacity: ▪Food availability ▪Water supply ▪Space and shelter ▪Competition and predation