Muscular System Review PDF

MUSCULAR SYSTEM  3 types of muscles: Cardiac, Smooth, and Skeletal o Cardiac Muscle o Smooth Muscle o Skeletal Muscle  FUNCTIONS: o Cardiac Muscle - Pumps blood through the circulatory system with rhythmic contractions. o Smooth Muscle - Contr...

MUSCULAR SYSTEM  3 types of muscles: Cardiac, Smooth, and Skeletal o Cardiac Muscle o Smooth Muscle o Skeletal Muscle  FUNCTIONS: o Cardiac Muscle - Pumps blood through the circulatory system with rhythmic contractions. o Smooth Muscle - Controls involuntary movements such as digestion, blood flow, and respiration. o Skeletal Muscle - Facilitates body movement, posture, and heat production.  Role of Blood Supply in Proper Muscle Functioning o Provides oxygen and nutrients essential for ATP production. o Removes metabolic wastes like carbon dioxide and lactic acid. o Increased blood flow during exercise supports higher energy demands.  Regulations of muscle contractions and the chemical (molecules, atoms, enzymes, etc.) Involve o Calcium Ions (Ca²+): Released from the sarcoplasmic reticulum, calcium binds to troponin, allowing myosin to interact with actin filaments, leading to contraction. o Adenosine Triphosphate (ATP): Provides the energy required for muscle contraction and relaxation. o Acetylcholine (ACh): Neurotransmitter that initiates muscle action potential. o Neurotransmitters: Acetylcholine is released at the neuromuscular junction, initiating the contraction process in skeletal muscles. o Enzymes:  Acetylcholinesterase breaks down ACh to terminate contraction.  Myosin ATPase facilitates cross-bridge cycling.  Muscle tonus, muscle tones at rest o Muscle Tonus: Continuous and passive partial contraction of muscles. o Purpose: Maintains posture and readiness for action. o At Rest: Low-level, sustained contraction ensures muscle firmness without fatigue.  Role of sarcoplasmic reticulum o Stores and releases calcium ions during contraction. o Regulates intracellular calcium levels to ensure proper contraction and relaxation cycles.  Muscle strength, how to increase it Muscle strength can be increased through various methods, including: o Resistance Training: Engaging in weightlifting or bodyweight exercises stimulates muscle hypertrophy (growth) and increases strength. o Progressive Overload: Gradually increasing the weight or resistance used in exercises forces muscles to adapt and grow stronger. o Nutrition: Adequate protein intake supports muscle repair and growth, while overall nutrition provides the energy needed for training.   Causes of muscle fatigue o Depletion of Energy Stores: Prolonged activity can deplete ATP and glycogen levels, leading to fatigue. o Accumulation of Metabolic Byproducts: Lactic acid buildup during anaerobic respiration can contribute to the sensation of fatigue. o Neuromuscular Factors: Impaired communication between nerves and muscles can lead to decreased muscle performance. o Psychological Factors: Mental fatigue and lack of motivation can also affect physical performance.  Rules in naming muscles (how muscles are named) o Location: Indicates the muscle's anatomical location (e.g., pectoralis for chest). o Shape: Describes the muscle’s shape (e.g., deltoid for triangular shape). o Size: Relative size of the muscle (e.g., maximus for large, minimus for small). o Direction of Fibers: Orientation of muscle fibers (e.g., rectus for straight). o Number of Origins: Indicates number of tendons (e.g., biceps for two origins). o Action: Describes the muscle’s function (e.g., flexor for bending a joint). o Attachments: Named for their origin and insertion points (e.g., sternocleidomastoid). NERVOUS SYSTEM - Made up of the brain, spinal cord, and nerves. - Controls and coordinate actions by sending electrical signals throughout the body I. CENTRAL NERVOUS SYSTEM o Made up of the brain and spinal cord o The brain controls how we think, learn, move, and feel. o The spinal cord carries messages back and forth between the brain and the nerves that run throughout the body. II. PARTS OF THE BRAIN o Cerebrum – interprets sights, sounds, and touches. It also regulates emotions, reasoning, and learning. o Cerebellum – maintains your balance, posture, coordination and fine motor skills. o Brainstem – connects the cerebrum and cerebellum to the spinal cord. Regulates many automatic body functions. o Limbic System – a group of brain structures located deep within the brain, playing a crucial role in our emotional life, memory, and motivation. It's often referred to as the "emotional brain" because it's involved in processing and experiencing emotions. III. PERIPHERAL NERVOUS SYSTEM (PNS) o Consists of nerves that branch out from the brain and spinal cord. o These nerves form the communication network between the CNS and the body parts. o Further subdivided into the somatic nervous system and the autonomic nervous system.  Somatic Nervous System  Function: Responsible for voluntary movements and the relay of sensory information to the CNS.  Components: Consists of sensory (afferent) nerves that carry information from sensory receptors to the CNS, and motor (efferent) nerves that transmit commands from the CNS to the muscles.  Autonomic Nervous System  Function: Regulates involuntary body functions such as heart rate, digestion, respiratory rate, pupillary response, urination, and sexual arousal. 3 divisions of ANS:  Sympathetic Nervous System – prepares the body for ―fight and flight‖ responses, such as when you’re in danger or stressed. It increases heart rate, blood pressure, and breathing rate, and it diverts blood flow to the muscles.   Parasympathetic Nervous System – responsible for the ―rest-and-digest‖ body processes, helps the body to relax and conserve energy. It slows down heart rate, lowers blood pressure, and stimulate digestion.  Enteric Nervous System – This part of your autonomic nervous system manages how your body digests food. o LOBES OF THE BRAIN  Frontal  Parietal  Occipital  Temporal o Brain  often called the ―command center‖ of the body. It is a very complex and organized body. The brain controls various cognitive, sensory, and motor functions. It processes and interprets information received from the senses. It allows us to perceive and understand the world around us. The brain plays a critical role in memory, learning, decision-making, emotions, and consciousness. o Spinal Cord  a cylindrical structure that extends from the brainstem down the vertebral column. It serves as a conduit for signals between the brain and the rest of the body and is involved in reflex actions IV. NEURONS AND FUNCTIONS  Fundamental building blocks of the nervous system, responsible for transmitting information throughout the body. o STRUCTURE  Cell Body (Soma): Contains the nucleus and maintains the neuron's health.  Dendrites: Tree-like extensions that receive signals from other neurons. They act like "antennas" picking up information from neighboring neurons.  Axon: A long, tail-like structure that carries electrical impulses away from the cell body to other neurons, muscles, or  glands. It's like a "cable" transmitting information to its destination.  Axon Hillock – The axon joins the cell body at a specialized junction called the axon hillock. Many axons are insulated with a fatty substance called myelin. Myelin helps axons to conduct an electrical signal.  Neurons usually have one main axon  Myelin Sheath: A fatty substance that insulates the axon, speeding up the transmission of signals. Imagine it as a protective layer around the cable that helps the signal move faster.  Node of Ranvier: Gaps in the myelin sheath that facilitate faster signal propagation.  Synaptic Terminals (Axon Terminals): The end points of the axon where signals are transmitted to other neurons or target cells. These are like the "connectors" at the end of the cable. o FUNCTIONS OF THE NERVOUS SYSTEM:  Signal Reception: Dendrites receive signals (neurotransmitters) from other neurons across synapses.  Signal Integration: The cell body integrates these signals, deciding whether to fire a signal or not.  Signal Transmission: If the signal is strong enough, the cell body generates an electrical impulse (action potential) that travels down the axon.  Signal Release: At the synaptic terminals, neurotransmitters are released into the synaptic cleft (the gap between neurons) to transmit the signal to the next neuron. V. BRAINS ROLE IN BOTH EMOTIONAL AND BAHVIORAL RESPONSES, HEART RATE AND RESPIRATIONS, WHICH PARTS ARE RESPONSIBLE, AUTONOMIC FUNCTIONS o Emotional and Behavioral Responses:  Amygdala: Processes emotions like fear, anger, and pleasure.  Prefrontal Cortex: Regulates decision-making and behavioral responses.  Hippocampus: Links emotions to memories. o Heart Rate and Respirations:  Medulla Oblongata: Controls autonomic functions like heart rate and breathing.  Pons: Works with the medulla to regulate breathing patterns. o Autonomic Functions:  Sympathetic Nervous System (SNS): Increases heart rate, dilates pupils, and reduces digestive activity during "fight or flight."  Parasympathetic Nervous System (PNS): Slows heart rate, constricts pupils, and enhances digestion during "rest and digest." VI. HEARING AND AUDITORY SYSTEM, DISORDERS AND ISSUES o Anatomy of the Auditory System:  Outer Ear: Captures sound waves (pinna, auditory canal).  Middle Ear: Amplifies vibrations (tympanic membrane, ossicles).  Inner Ear: Converts vibrations into electrical signals (cochlea, hair cells). o Auditory Pathway:  Sound signals travel via the auditory nerve to the brainstem, then to the auditory cortex in the temporal lobe for processing. o Common Disorders:   Conductive Hearing Loss: Blockages in the outer or middle ear (e.g., earwax, otitis media).  Sensorineural Hearing Loss: Damage to inner ear or auditory nerve (e.g., noise-induced hearing loss).  Tinnitus: Persistent ringing or buzzing sound. VII. EYE VISION AT DIFFERENT DISTANCES, ACTIONS OF THE PARTS OF THE EYES o Eye Anatomy and Function:  Cornea: Focuses light onto the lens.  Lens: Adjusts shape for focusing on objects at varying distances (accommodation).  Retina: Contains photoreceptors (rods for low light, cones for color and detail). o Vision at Different Distances:  Near Vision: Ciliary muscles contract, lens becomes thicker to focus on close objects.  Distant Vision: Ciliary muscles relax, lens flattens for distant focus. o Common Vision Issues:  Myopia (Nearsightedness): Difficulty seeing distant objects.  Hyperopia (Farsightedness): Difficulty seeing near objects.  Astigmatism: Irregular curvature of the cornea or lens. VIII. SPINAL CORD INJURY AND ITS IMPLICATION TO NEURAL PATHWAYS o Types of Spinal Cord Injuries (SCI):  Complete Injury: Total loss of sensation and motor function below the injury level.  Incomplete Injury: Partial loss of function, with some signals still transmitted. o Implications:  Disruption of neural pathways leads to loss of motor control, sensation, and autonomic functions.  High-level injuries (e.g., cervical spine) can impair breathing and heart rate regulation. o Rehabilitation:  Physical therapy and assistive devices to maximize independence.  Research in neural regeneration and spinal cord repair is ongoing. IX. HYPOTHALAMUS FUNCTIONS AND ITS ROLE IN REGULATING HUNGER AND THIRST o Functions of the Hypothalamus:  Maintains homeostasis by regulating temperature, hunger, thirst, and circadian rhythms.  Controls hormone release via the pituitary gland. o Hunger Regulation:  Arcuate Nucleus: Detects energy levels and signals hunger or satiety.  Hormones:  Ghrelin: Stimulates hunger.  Leptin: Signals satiety to suppress appetite. o Thirst Regulation:  Osmoreceptors: Detect blood osmolarity changes.  Antidiuretic Hormone (ADH): Conserves water by reducing urine output DIGESTIVE SYSTEM I. Functions of the Pancreas and Liver in Relation to Blood Sugar Levels  Insulin: When blood sugar levels rise, such as after eating, the pancreas releases insulin. This hormone facilitates the uptake of glucose by cells, particularly in muscle and fat tissues, and promotes the storage of glucose in the liver as glycogen  Glucagon: Conversely, when blood sugar levels drop, the pancreas secretes glucagon. This hormone signals the liver to release stored glucose into the bloodstream through processes like gluconeogenesis (the production of glucose from non-carbohydrate sources) and glycogenolysis (the breakdown of glycogen into glucose)  II. Functions of the Stomach and Intestines in Digestion, Absorption, and Water Balance Regulation o Four Mains Stages of the Digestive System  Ingestion is the process of taking food and liquids into the body through the mouth.  Digestion involves breaking down food into smaller, absorbable components.  Absorption is the process where nutrients from digested food are absorbed into the bloodstream through the walls of the intestines.  Elimination is the final stage of the digestive process, where indigestible substances and waste products are expelled from the body o Stomach  Mechanical Digestion – churns food to mix with gastric juices.  Chemical Digestion – HCl denatures proteins and activates pepsinogen into pepsin for protein breakdown. Gastric lipase begins fat digestion.  Temporary Storage – Holds food and releases it gradually into the small intestine. o Small Intestine  Chemical Digestion – enzymes from the pancreas (e.g., amylase, lipase, proteases) and bile from the liver emulsify and break down macronutrients.  Absorption – villi and microvilli increase surface area for nutrient absorption (e.g., glucose, amino acids, fatty acids). o Large Intestine  Water and Electrolyte Balance – Absorbs water and electrolytes, forming solid feces.  Fermentation – Gut microbiota ferment undigested carbohydrates, producing short-chain fatty acids. III. Process of Emulsifying Fats o Role of Bile  Bile, produced by the liver and stored in the gallbladder, contains bile salts that emulsify fats.  Emulsification breaks large fat globules into smaller droplets, increasing surface area for enzyme action. IV. Roles of HCl, Gastric Juices, and Digestive Enzymes in Digestion o Hydrochloric Acid  Activates pepsinogen into pepsin for protein digestion.  Maintains acidic pH (~2) to denature proteins and kill pathogens. o Gastric Juices  Composed of water, HCl, enzymes (e.g., pepsin), and mucus to lubricate and protect the stomach lining o Digestive Enzymes  Amylase - breaks down carbs and starches  Protease - works on proteins  Lipase - handles fats  Pepsin - breaks proteins into peptides in the stomach. V. Parts and Functions of the Stomach and Small Intestine o Parts of the Stomach  Cardia – entry of food  Fundus and Body – main storage area; secretes gastric juices.  Pylorus – regulates chyme release into the small intestine. o Parts of the Small Intestine  Duodenum – receives chyme, bile, and pancreatic juices. Your duodenum is the place where your small intestine makes the digestive juices and enzymes to break down food.  Jejunum – primary site of nutrient digestion. Its inner lining has folds, villi, and microvilli that increase surface area for maximum nutrient absorption.  Ileum – absorbs vitamin B12and bile salts. o Parts of the Large Intestine  Cecum - receives digested food waste  Colon - largest and longest part of the large intestine, divided into four sections: ascending colon, transverse colon, descending colon, and sigmoid colon. Each section has a specific role in absorbing water, electrolytes, and forming feces.  Rectum and Anus - connects the large intestine to the anus. It acts as a reservoir where stool accumulates before being ready for elimination. The anus marks the exit point for food waste. Muscles, nerves, and mucous membranes work together to facilitate healthy bowel movements that you can control. VI. Diet Implications to Gut Health VII. Chemicals, Molecules, and Hormones Involved in Digestion o Produced by Digestive Organs:  Saliva – contains amylase for starch breakdown.  Gastric secretions – HCl, mucus, and pepsinogen.  Bile – contains bile salts for emulsification.  Pancreatic Juices – contains digestive enzymes and bicarbonate to neutralize chyme. o Key Hormones:  Gastrin – Stimulates HCl secretion.  Cholecystokinin (CCK) – Stimulates bile release and pancreatic enzyme secretion.  Secretin – Promotes bicarbonate release to neutralize acidic chyme.  Motilin – Regulates gastrointestinal motility. ENDOCRINE SYSTEM I. PARTS & FUNCTIONS OF ENDOCRINE SYSTEM o 8 MAIN PARTS OF THE ENDOCRINE SYSTEM: Hypothalamus, Pituitary gland, Pineal gland, Thyroid gland , Parathyroid gland, Adrenal gland, Pancreas, and Gonads (testes and ovaries)  HYPOTHALAMUS: a structure deep in your brain, acts as your body’s smart control coordinating center. Its main function is to maintain homeostasis by influencing the autonomic nervous system or managing hormones. Your hypothalamus helps manage your:  body temperature  satiety  blood pressure  hunger and thirst  sex drive  mood  sleep  PITUITARY GLAND: Often referred to as the "master gland," it regulates other endocrine glands and produces hormones that control growth, metabolism, and reproduction. Your hypothalamus sends signals in the form of releasing hormones to tell the anterior and posterior pituitary when to release (secrete) its hormones. The pituitary gland makes many hormones, such as:  Growth hormone  Prolactin  Thyrotropin  Corticotropin   Antidiuretic  oxytocin  PINEAL GLAND – it is located in the middle of the brain. It secretes melatonin, a hormone that may help regulate when you sleep at night and when you wake in the morning.  Melatonin or sleep hormone regulates night and day cycles or sleep-wake cycles. The pineal gland receives information about the daily light-dark ( cycle from the retinas in your eyes and then produces and releases melatonin accordingly — elevated levels at night and low levels during the day. Melatonin also interacts with biologically female hormones. Research has shown that it helps in regulating menstrual cycles.  Melatonin have low levels of melatonin in your blood during the daylight hours and peak levels of melatonin during the nighttime.  Melatonin has often been referred to as a ―sleep hormone.‖ Pineal Gland secretes:  Melatonin, which is to promote sleepiness and help regulate the biological clock. In animals that breed during specific seasons:  Melatonin apparently alters their capacity for reproduction, but it has not been shown to have a similar effect on humans.  THYROID GLAND – it is located in the front part of the lower neck. It's shaped like a bow tie or butterfly. It makes the thyroid hormones thyroxine and tri-iodothyronine. These hormones control the rate at which cells burn fuels from food to make energy. The more thyroid hormone there is in the bloodstream, the faster chemical reactions happen in the body. HORMONES PRODUCED BY THYROID GLAND:  Thyroxine(T4)  Tri-iodothyronine(T3)  PARATHYROID GLAND – Attached to the thyroid are four tiny glands that work together called the parathyroids (pronounced: par-uh-THY-roydz). They release parathyroid hormone, which controls the level of calcium in the blood with the help of calcitonin (pronounced: kal- suh-TOE-nin), which the thyroid makes. FUNCTIONS Parathyroid gland secrete:  Parathyroid Hormone (PTH, parathormone). Secretion is regulated by blood calcium levels. The main function of Parathyroid hormone:  Is to increase blood calcium levels  keeping your blood calcium levels stable   ADRENAL GLAND - These two triangular adrenal (pronounced: uh-DREE-nul) glands sit on top of each kidney. The adrenal glands have two parts, each of which makes a set of hormones and has a different function:  The outer part is the adrenal cortex. It makes hormones called corticosteroids that help control salt and water balance in the body, the body's response to stress, metabolism, the immune system, and sexual development and function.  The inner part is the adrenal medulla. It makes catecholamines, such as epinephrine. Also called adrenaline, epinephrine increases blood pressure and heart rate when the body is under stress.   PANCREAS – The pancreas is located across the back of the abdomen, behind the stomach. It makes insulin (pronounced: IN-suh-lin) and glucagon (pronounced: GLOO-kuh-gawn), which are hormones that control the level of glucose, or sugar, in the blood. Insulin helps keep the body supplied with stores of energy. The body uses this stored energy for exercise and activity, and it also helps organs work as they should.  Exocrine System – enzymes to help with digestion.  Endocrine System – hormones to control the amount of sugar in your bloodstream  GONADS – Produce sex hormones that regulate reproduction and secondary sexual characteristics.  the male reproductive gonad or the testes and the female reproductive gonad or the ovaries  produce gametes and hormones that are involved in reproduction and other functions of the body  testes produce testosterone and inhibin while ovaries produce estrogen and progesterone HORMONES  Testosterone: responsible for male sexual characteristics and regulates sex drive (libido) bone and muscle mass and production of red blood cells and sperms.  Inhibin: inhibits the synthesis and release of follicle stimulating hormone (FSH) in pituitary gland. There are two types of inhibin; inhibin A produce by female, inhibin B produce by male  Estrogen: responsible for developing female sexual characteristics such as breast development and body composition and regulates menstrual cycle.  Progesterone: prepareS the body for pregnancy. It helps thicken the lining of the uterus. II. ROLE OF LOBES OF THE PITUITARY GLANDS IN HORMONE REGULATION The pituitary gland has two main lobes: the anterior and posterior lobes, each with distinct functions:  Anterior Lobe: Produces hormones such as: o Growth Hormone (GH): Stimulates growth and cell reproduction. o Thyroid-Stimulating Hormone (TSH): Stimulates the thyroid gland to produce thyroxine. o Adrenocorticotropic Hormone (ACTH): Stimulates the adrenal glands to produce cortisol o Follicle-Stimulating Hormone (FSH) and Luteinizing Hormone (LH): Regulate reproductive processes  Posterior Lobe: Stores and releases hormones produced by the hypothalamus, including:  o Oxytocin: Stimulates uterine contractions during childbirth and milk ejection during breastfeeding. o Antidiuretic Hormone (ADH): Regulates water balance in the body by controlling kidney function. III. FUNCTION OF THYROXIN Thyroxin (T4) is a hormone produced by the thyroid gland that plays a crucial role in regulating metabolism. It influences how the body uses energy, affects growth and development, and regulates the metabolic rate of cells. Thyroxin increases the rate of oxygen consumption and heat production in tissues, thereby influencing overall energy expenditure. It is released as 80% T4 and 20% T3 (triiodothyronine). T4 is an inactive form of thyroxine that is converted to T3 at the organ level. They function to regulate the body's metabolism. IV. REGULATION OF THE METABOLIC RATE OF THE BODY BY THE THYROID GLAND The thyroid gland regulates the body's metabolic rate through the secretion of thyroxine (T4) and triiodothyronine (T3). These hormones increase the metabolic rate by stimulating the consumption of oxygen and the production of heat. They also influence the metabolism of carbohydrates, fats, and proteins, ensuring that the body has the energy it needs for various functions V. HOW ADRENAL GLAND AND SYMPATHETIC NERVOUS SYSTEM WORK TOGETHER DURING THE FLIGHT AND FIGHT RESPONSE During a stressful situation, the adrenal glands release hormones such as adrenaline (epinephrine) and norepinephrine. These hormones prepare the body for a "fight or flight" response by:  Increasing heart rate and blood pressure.  Dilating airways to improve oxygen intake.  Mobilizing energy stores by increasing glucose availability.  Enhancing blood flow to muscles while redirecting blood from non-essential functions The sympathetic nervous system activates these responses, ensuring a rapid and coordinated reaction to stressors. VI. HOW HYPOTHALAMUS AND PITUITARY GLAND WORK TOGETHER IN REGULATING HORMONES OF THE BODY The hypothalamus and pituitary gland work in tandem to regulate hormone production throughout the body. The hypothalamus produces releasing and inhibiting hormones that control the secretion of hormones from the anterior pituitary. For example:  Thyrotropin-Releasing Hormone (TRH) stimulates the release of TSH from the pituitary, which in turn stimulates the thyroid gland to produce thyroxine.  Corticotropin-Releasing Hormone (CRH) stimulates the release of ACTH, which regulates cortisol production in the adrenal glands. This hypothalamic-pituitary axis is crucial for maintaining homeostasis and responding to physiological changes. VII. HOW PINEAL GLAND IS RESPONSIBLE FOR SLEEP AND WAKE CYCLES The pineal gland produces melatonin, a hormone that regulates sleep-wake cycles. Melatonin secretion is influenced by light exposure; it increases in darkness and decreases in light. This hormone helps signal the body when it is time to sleep, thus playing a vital role in circadian rhythms and overall sleep quality. VIII. ROLE OF PANCREAS IN REGULATING PRODUCTION OF INSULIN   Beta Cells: Produce insulin to lower blood glucose levels in response to elevated blood glucose levels by: o Facilitating glucose uptake by cells. o Promoting glycogen storage in the liver and muscles.  Alpha Cells: Produce glucagon to raise blood glucose levels when blood sugar levels are low by: o Stimulating the liver to release glucose into the bloodstream. IX. HYPOTHYROIDISM AND HYPERTHYROIDISM  Hypothyroidism: A condition where the thyroid gland does not produce enough thyroxine, leading to symptoms such as fatigue, weight gain, cold intolerance, and depression. It can be caused by autoimmune diseases, iodine deficiency, or certain medications.  Hyperthyroidism: A condition characterized by excessive production of thyroid hormones, leading to symptoms such as weight loss, rapid heartbeat, heat intolerance, and anxiety. It is often caused by Graves' disease or thyroid nodules. X. HORMONES PRODUCED DURING CHILDBIRTH During childbirth, several hormones play crucial roles:  Oxytocin: Stimulates uterine contractions during labor and helps with milk ejection during breastfeeding.  Prostaglandins: Help soften the cervix and stimulate contractions.  Relaxin: Prepares the pelvis for delivery by relaxing ligaments and joints. These hormones work together to facilitate the birthing process and support maternal and neonatal health. XI. HORMONES  Hormones are chemical messengers carried by cell tissues that regulate various functions in your body. They travel through your bloodstream to organs, skin, muscles, and other tissues, signaling them on what actions to perform and when. There are over 50 hormones produced and found inside of the human body which serves different functions. Hormones and most of the tissues (mainly glands) that create and release them make up your endocrine system.  Hormones can have a very powerful effect, even when present in very low concentrations. The specific cells which are affected by a hormone are called target cells.  Hormones influence their target cell by binding to protein or glycoprotein in the cell membrane called receptors. FUNCTION: Hormones perform essential functions in the body, including:  Control the chemical composition and quantity of the internal environment (extracellular fluid).  Help regulate metabolism and energy balance  Help maintain hormoestasis  Help regulate contraction of smooth and cardiac muscle fibers and secretion by glands  Integration of growth and development  Contribute to the basic process of reproduction  HORMONES: TARGET CELLS Most hormones circulate in blood, coming into contact with essentially all cells. However, a given hormone usually affects only a limited number of cells, which are called target cells. A target cell responds to a hormone because it bears receptors for the hormone. HORMONES: CELL SIGNALING Hormones were once thought to act only on distant cells through the blood, but research shows they can also affect nearby cells or the ones that release them. These effects are categorized as:  Endocrine action: the hormone is distributed in blood and binds to distant target cells.  Paracrine action: the hormone acts locally by diffusing from its source to target cells in the neighborhood.  Autocrine action: the hormone acts on the same cell that produced it. HORMONES: CATEGORIES Although there are many different hormones in the human body, they can be divided into three classes based on their chemical structure:  Peptides (Protein hormones)- are short chains of amino acids which are also the building blocks of proteins that regulate processes like growth, metabolism, and immune response. Water-soluble which means they cannot pass through cell membranes easily and typically act on receptors on the cell surface. Ex: Insulin (regulates blood sugar levels)  Steroids hormones- are a class of lipids that are derived from cholesterol, involved with the regulation of metabolism, immune function, salt balance, and reproductive processes. Lipid-soluble they can pass through cell membranes and bind to intracellular receptors. Ex: Cortisol (regulates stress response, metabolism, and immune function)  Amines (Amino Acid Derivatives)- are derived from amino acids, which are the basic building blocks of proteins. Amino acid-derived hormones help regulate metabolism, stress, and the sleep-wake cycle. Can be either water-soluble (like catecholamines) or lipid-soluble (like thyroid hormones). Ex: Thyroid hormones (e.g., thyroxine, T3) (regulate metabolism) HORMONES: FEEDBACK MECHANISM The hormonal feedback mechanism is a regulatory process that helps maintain balance in hormone levels within the body.  Negative Feedback - The common feedback mechanism, reduces hormone release once effects reach a certain level, maintaining balance and preventing excess.  Positive Feedback - Less common, Positive feedback amplifies hormone release to strengthen responses, supporting processes like labor or blood clotting. CARDIOVASCULAR SYSTEM I. IMPLICATIONS TO BLOOD PRESSURE IF CHAMBERS OF THE HEART FAIL TO PUMP BLOOD If the chambers of the heart fail to pump blood effectively, it can lead to heart failure, which significantly impacts blood pressure. The heart's inability to pump blood can result in:  Decreased Cardiac Output: This leads to lower blood pressure, as less blood is being circulated throughout the body.   Compensatory Mechanisms: The body may attempt to compensate by increasing heart rate or constricting blood vessels, which can initially maintain blood pressure but may lead to further complications over time.  Fluid Accumulation: Poor pumping can cause fluid to back up in the lungs (pulmonary congestion) or other parts of the body (edema), exacerbating the situation and potentially leading to hypertension in other areas due to increased vascular resistance II. BLOOD TRANSFUSION COMPATIBILITY Blood transfusion compatibility is crucial to prevent adverse reactions. The main factors to consider include:  Blood Types: The ABO and Rh blood group systems determine compatibility. For example, type O is a universal donor, while type AB is a universal recipient. o Type O: Universal donor (no A or B antigens). o Type AB: Universal recipient (no anti-A or anti-B antibodies). o Type A: Can receive A and O blood. o Type B: Can receive B and O blood.  Rh o Rh-positive individuals can receive Rh-negative or Rh-positive blood. o Rh-negative individuals can only receive Rh-negative blood.  Crossmatching: Before a transfusion, blood samples from the donor and recipient are mixed to check for reactions, ensuring compatibility and minimizing the risk of hemolytic reactions. III. ORDER OF ACTIONS OF THE WHITE BLOOD CELLS IN DEALING WITH BACTERIAL INFECTION What are the types of white blood cells? There are five types of white blood cells:  Neutrophils: Help protect your body from infections by killing bacteria, fungi and foreign debris.  Lymphocytes: Consist of T cells, natural killer cells and B cells to protect against viral infections and produce proteins to help you fight infection (antibodies).  Eosinophils: Identify and destroy parasites, cancer cells and assists basophils with your allergic response.  Basophils: Produce an allergic response like coughing, sneezing or a runny nose.  Monocytes: Defend against infection by cleaning up damaged cells. When the body encounters a bacterial infection, white blood cells (WBCs) respond in a coordinated manner:  Neutrophils: The first responders that quickly migrate to the site of infection, engulfing and destroying bacteria through phagocytosis.  Monocytes: These cells differentiate into macrophages and dendritic cells, which continue to phagocytose pathogens and present antigens to T cells.  Lymphocytes: o T cells: Help regulate the immune response and directly kill infected cells. o B cells: Produce antibodies that target specific bacteria for destruction  IV. RED BLOOD CELL COUNTS AND THEIR IMPLICATIONS FOR THE OVERALL HEALTH OF THE INDIVIDUAL  RBC = 40-45% o Adult females: 4.2 to 5.4 million/mcL o Adult males: 4.7 to 6.1 million/mcL o Children: 4.0 to 5.5 million/mcL  Low RBC Count (Anemia): Can lead to fatigue, weakness, and pallor. Causes may include nutritional deficiencies (iron, vitamin B12), chronic diseases, or bone marrow disorders.  High RBC Count (Polycythemia): May indicate dehydration, heart disease, or lung disease, leading to increased blood viscosity and potential complications such as thrombosis. V. SYSTOLE AND DIASTOLE FUNCTIONS AND THEIR PROPER COORDINATION IN BLOOD CIRCULATION  Systole: The phase when the heart muscles contract, pumping blood out of the chambers. The ventricles contract to send blood to the lungs (right ventricle) and the rest of the body (left ventricle).  Diastole: The phase when the heart muscles relax, allowing the chambers to fill with blood. During this phase, the atria fill with blood returning from the body and lungs. VI. SA AND AV NODES ELECTRICAL CONDUCTION SYSTEM OF THE HEART AND HOW THESE IMPACT HEARTBEAT  Sinoatrial node  Sometimes called your heart’s natural pacemaker. It sends the electrical impulses that start the heartbeat.  The SA node is in the upper part of your heart’s right atrium. It is at the edge of your atrium near your superior vena cava (vein that brings oxygen-poor blood from your body to your heart).  Your autonomic nervous system controls how fast or slowly your SA node sends electrical signals. This part of the nervous system directs hormones that control your heart rate based on what you are doing.  Atreoventicular node  Delays the SA node’s electrical signal. It delays the signal by a consistent amount of time (a fraction of a second) each time. The delay ensures that your atria are empty of blood before the contraction stops. The atria are the heart’s upper chambers. They receive blood from your body and empty it into the ventricles. Your AV node is located in an area known as the triangle of Koch (located between the septal leaflet of the tricuspid valve, the coronary sinus and the membranous portion of the interatrial septum). This is near the central area of the heart. VII. BLOOD COMPOSITION AND FUNCTIONS 4 main components of blood:  Red blood cells (RBC) / Erythrocytes  It contains hemoglobin (the red iron-rich protein that carries O2 - a molecule specially designed to hold oxygen and carry it to cells that need it.)   Mainly involved in transporting oxygen, nutrients, and other substances to various parts of the body. These blood cells also remove waste from the body.  White blood cells (WBC) / Leukocytes  Have many different types and all contain a big nucleus.  The two main ones are the lymphocytes and the macrophages o Macrophages 'eat' and digest microorganisms. o Some lymphocytes fight disease by making antibodies to destroy invaders by dissolving them. Other lymphocytes make antitoxins to break down poisons.  Platelets  small, disc-shaped cell fragments  gather at the site of injury and help the clotting process  Platelets produce tiny fibrinogen fibers to form a net. This net traps other blood cells to form a blood clot for you to stop bleeding and heal wounds.  Plasma  A straw-colored liquid that carries the cells and the platelets that help blood clot.  It also contains things like; o carbon dioxide o glucose o amino acids o proteins o minerals o vitamins o hormones o waste materials like urea. VIII. MANAGING HYPERTENSIONS Hypertension, or high blood pressure, can lead to serious health issues, including heart disease and stroke. Management strategies include:  Lifestyle Changes: Adopting a healthy diet (e.g., DASH diet), regular physical activity, maintaining a healthy weight, and reducing sodium intake.  Medications: Various classes of antihypertensive drugs, such as diuretics, ACE inhibitors, and beta- blockers, may be prescribed to help lower blood pressure. IX. HEART RATE AND CARDIAC CYCLE  Heart Rate (HR) - The number of heartbeats per minute.  Cardiac Cycle - the sequence of events that occur in the heart during a single heartbeat. It's a series of pressure changes that cause blood to flow through the heart's chambers and the body LYMPHATIC SYSTEM I. PARTS AND PRIMARY FUNCTIONS OF LYMPHATIC SYSTEM Key components of lymphatic system  Lymph - tissue fluid that has entered the lymphatic vessels. Transports proteins and other molecules to the bloodstream  lymphatic vessels - collect lymph, filter out waste products and abnormal cells, and return the remaining fluid to the bloodstream   lymphoid ducts - empty lymph fluid into the bloodstream, which helps maintain  fluid levels in the body and filters out waste products and abnormal cells. Lymphatic Organs and Tissues Two Types of Lymphoid Organ 1. Primary Lymphoid Organ- (thymus & red bone marrow) 2. Secondary Lymphoid Organ- (Lymph nodes, Spleen, and Tonsils)  Spleen - The spleen filters blood, removing old or damaged red blood cells and pathogens. It also serves as a reservoir for blood and helps produce lymphocytes.  Thymus - Located in the chest, the thymus is where T-cells mature and become functional in the immune response.  Tonsils - Protect against pathogens entering through the mouth and nose.  Red bone marrow - Produces lymphocytes (a type of white blood cell). II. LYMPH NODES AND INFECTION Lymph nodes play a critical role in the immune response to infections. When pathogens enter the body, they are often transported through lymphatic vessels to the nearest lymph nodes. Here’s how lymph nodes respond to infection:  Filtration: Lymph nodes filter lymph fluid, trapping bacteria, viruses, and other foreign substances.  Immune Activation: Within the lymph nodes, T-cells and B-cells are activated. B-cells can differentiate into plasma cells that produce antibodies specific to the pathogens, while T-cells can directly attack infected cells or help coordinate the immune response  Swelling: During an infection, lymph nodes may become swollen and tender due to increased lymphocyte production and activity, indicating an active immune response III. ROLE OF SPLEEN IN LYMPHATIC SYSTEM  Blood Filtration: The spleen filters blood, removing old or damaged red blood cells and recycling iron for future use.  Immune Response: It contains lymphocytes that respond to blood-borne pathogens. The spleen can mount an immune response by producing antibodies and activating T-cells when it detects infections  Blood Reservoir: The spleen acts as a reservoir for blood, storing platelets and white blood cells that can be released into circulation when needed, such as during physical exertion or in response to blood loss IV. ISSUES OF LYMPHATIC SYSTEM  Lymphedema: A condition characterized by swelling due to the accumulation of lymph fluid, often resulting from damage to lymphatic vessels or nodes, commonly seen after surgery or radiation therapy for cancer  Lymphoma: A type of cancer that originates in the lymphatic system, affecting lymphocytes. It can lead to swollen lymph nodes, fever, weight loss, and night sweats  Infections: The lymphatic system can be affected by infections such as lymphangitis (inflammation of lymphatic vessels) or lymphadenitis (inflammation of lymph nodes), which can cause pain, swelling, and fever  Autoimmune Disorders: Conditions like lupus or rheumatoid arthritis can affect the lymphatic system, leading to abnormal immune responses and inflammation. RESPIRATORY SYSTEM I. DIFFERENCES BETWEEN UPPER AND LOWER RESPIRATORY TRACT o Upper Respiratory Tract:  Components: Includes the nose, nasal cavity, paranasal sinuses, pharynx, and larynx.  Function: Primarily involved in filtering, warming, and humidifying the air before it enters the lungs. It also plays a role in olfaction (sense of smell) and phonation (voice production). o Lower Respiratory Tract:  Components: Comprises the trachea, bronchi, bronchioles, and alveoli.  Function: Responsible for the conduction of air to the lungs and the site of gas exchange. The lower tract is where oxygen enters the bloodstream and carbon dioxide is expelled. II. ASTHMA AND ITS CONSEQUENCES SPECIFICALLY THE CONSTRICTION OF THE BRONCHIOLES Asthma is a chronic inflammatory disorder characterized by hyperresponsiveness of the airways, leading to episodic bronchoconstriction. During an asthma attack, the bronchioles constrict, resulting in: o Symptoms: Wheezing, shortness of breath, chest tightness, and coughing. o Consequences: Reduced airflow can lead to hypoxemia (low oxygen levels in the blood) and increased work of breathing. Chronic asthma can result in airway remodeling, leading to permanent changes in the structure of the airways and further exacerbation of symptoms III. ROLE OF ALVEOLAR MEMBRANE IN GAS EXCHANGE AND ITS CONSEQUENCES The alveolar membrane is crucial for efficient gas exchange. It consists of a thin layer of epithelial cells and a capillary endothelium, forming the respiratory membrane. Key points include: o Gas Exchange: Oxygen diffuses from the alveoli into the blood, while carbon dioxide diffuses from the blood into the alveoli to be exhaled. o Consequences of Dysfunction: Conditions such as pulmonary edema or fibrosis can thicken the alveolar membrane, impairing gas exchange and leading to respiratory distress IV. EXCHANGE OF OXYGEN AND CARBON DIOXIDE Gas exchange occurs via diffusion, driven by differences in partial pressures: o Oxygen: Higher partial pressure in the alveoli compared to the blood allows oxygen to move into the bloodstream. o Carbon Dioxide: Higher partial pressure in the blood compared to the alveoli facilitates the diffusion of carbon dioxide out of the blood V. OLFACTORY RECEPTORS LOCATION AND FUNCTION Olfactory receptors are specialized sensory neurons located in the olfactory epithelium, found in the upper part of the nasal cavity. Their functions include:  o Detection of Odors: Olfactory receptors bind to odorant molecules, initiating a signal transduction pathway that sends information to the brain. o Role in Taste and Smell: These receptors contribute to the sense of smell, which is closely linked to taste and overall flavor perception. Inside the top part of your nose, there are special cells called olfactory receptors. When you breathe in, air passes over these receptors, and they pick up different scent. These receptors then send signals to the brain, which processes the information and helps you recognize and identify different smells. VI. TISSUES OF RESPIRATORY TRACT The respiratory tract is lined with various types of tissues, including: o Ciliated Epithelium: Lines the trachea and bronchi, helping to trap and expel particles and pathogens through ciliary action. o Goblet Cells: Produce mucus to trap debris and pathogens, keeping the airways moist and clean. o Smooth Muscle: Surrounds the bronchi and bronchioles, allowing for regulation of airflow through bronchoconstriction and bronchodilation. VII. PARTIAL PRESSURES OF OXYGEN IN BLOOD AND ALVEOLI The partial pressure of gases is a critical factor in gas exchange: o In the Alveoli: The partial pressure of oxygen (PaO2) is typically around 100 mmHg, while carbon dioxide (PaCO2) is about 40 mmHg. o In the Blood: Oxygen is transported in two forms: dissolved in plasma and bound to hemoglobin. The partial pressure of oxygen in arterial blood is influenced by the alveolar pressure and the efficiency of gas exchange VIII. SPECIFIC ROLE OF ALVEOLI o Function:  Site of gas exchange between air and blood. o Adaptations:  Large surface area, thin walls, and rich capillary network. URINARY SYSTEM I. PARTS AND FUNCTIONS OF THE US (KIDNEY, ETC.) Key organs: Kidneys, Ureters, Bladder, Urethra.  KIDNEYS: o remove waste and extra fluid from the blood to make urine. o located just below the rib cage, one on each side of your spine.  URETERS o transport urine from the kidneys to the bladder.  BLADDER o stores urine until it is expelled from the body.  URETHRA o The tube through which urine is expelled from the bladder to the outside of the body. II. PROCESSES OCCURRING IN THE LOOP OF HENLE Henle’s loop has a descending and an ascending limb. Being parts of the same loop, both the descending and ascending limbs show different permeability. The descending limb is permeable to water but impermeable to  an electrolyte, while the ascending limb is permeable to electrolytes but impermeable to water. Since the electrolytes get reabsorbed at the ascending loop of Henle, the filtrate gets diluted as it moves towards the ascending limb. But reabsorption is limited in this segment.  Descending Limb: o Permeable to water, allowing reabsorption into the surrounding medulla. o Concentrates the filtrate.  Ascending Limb: o Impermeable to water but allows active reabsorption of sodium and chloride. o Dilutes the filtrate. III. ALDOSTERONE DEFICIENCY IN RENAL FUNCTION Aldosterone is a hormone produced by the adrenal glands that plays a key role in regulating sodium and potassium levels in the body. It acts primarily on the distal nephron, promoting sodium reabsorption and potassium excretion. Aldosterone deficiency can lead to several issues:  Hyponatremia: Low sodium levels due to decreased reabsorption, which can result in symptoms such as fatigue, confusion, and muscle weakness.  Hyperkalemia: Elevated potassium levels due to reduced excretion, which can lead to dangerous cardiac arrhythmias.  Volume Depletion: Reduced sodium reabsorption can lead to decreased blood volume and hypotension, potentially causing dizziness and fainting. IV. DEHYDRATION RESPONSE V. CONSEQUENCES OF THE KIDNEY’S INABILITY TO REGULATE SODIUM IN DISTAL NEPHRON REPRODUCTIVE SYSTEM I. PARTS AND FUNCTIONS OF THE REPRODUCTIVE SYSTEM Male Reproductive System External Structures  Testes: Produce sperm and testosterone, the primary male sex hormone.  Scrotum: Regulates temperature to optimize sperm production (lower than body temperature).  Penis: Delivers sperm to the female reproductive tract during intercourse. Internal Structures  Epididymis: Stores and matures sperm.  Vas deferens: Transports sperm from the epididymis to the ejaculatory duct during ejaculation.  Prostate Gland: Produces seminal fluid that nourishes and helps transport sperm.  Urethra: transports semen and urine outside the body.  Seminal Vesicles: produce seminal fluid rich in fructose to nourish sperm.  Bulbourethral Glands (Cowper’s Glands): secrete a pre-ejaculate fluid that neutralize acidity in the urethra and lubricates the tip of the penis.  Female Reproductive System External Genitalia  Labia Majora - outer folds of skin that protect the more sensitive internal structures  Labia Minora - inner folds of skin that surround the vaginal opening and urethra  Clitors - small, sensitive organ composed of nerves, blood vessels, and erectile tissue  Vaginal Opening - External opening of the vagina  Urehtral Opening - External opening of the urethra Internal Genitalia  Ovaries: Produce eggs (ova) and hormones such as estrogen and progesterone.  Fallopian Tubes: Transport eggs from the ovaries to the uterus; fertilization typically occurs here.  Uterus: Houses and nourishes the developing fetus during pregnancy.  Cervix: The lower part of the uterus that opens into the vagina; it allows the passage of sperm and menstrual fluid.  Vagina: The canal that connects the external genitals to the uterus; it serves as the birth canal and receives the penis during intercourse. II. FERTILIZATION PROCESSES, LOCATIONS AND PATHWAYS Fertilization occurs when a sperm cell successfully penetrates an egg cell, resulting in the formation of a zygote. The process involves several key steps:  Ovulation: An egg is released from the ovary and enters the fallopian tube.  Sperm Transport: During ejaculation, sperm are deposited in the vagina and must swim through the cervix and uterus to reach the fallopian tubes.  Fertilization Location: Fertilization typically occurs in the ampulla of the fallopian tube, where the sperm meets the egg.  Zygote Formation: Once a sperm penetrates the egg, the genetic material combines to form a zygote, which begins to divide and develop as it moves toward the uterus for implantation III. ROLE OF PROSTATE GLAND The prostate gland plays a crucial role in male reproductive health by producing a significant portion of seminal fluid. Its functions include:  Secretion of Prostatic Fluid: This fluid nourishes sperm and helps protect them from the acidic environment of the female reproductive tract.  Facilitating Sperm Motility: The fluid contains enzymes and substances that enhance sperm mobility and viability.  Contributing to Semen Volume: The prostate contributes to the overall volume of semen, which is essential for effective sperm delivery during ejaculation IV. FUNCTION OF THE PLACENTA AND CONSEQUENCES OF UNDERDEVELOPED PLACENTA The placenta is a vital organ that develops during pregnancy, serving several essential functions: 1. Nutrient and Gas Exchange: The placenta facilitates the transfer of oxygen and nutrients from the mother to the fetus while removing waste products like carbon dioxide. 2. Hormone Production: It produces hormones such as human chorionic gonadotropin (hCG), progesterone, and estrogen, which are crucial for maintaining pregnancy. 3. Immune Protection: The placenta acts as a barrier, protecting the fetus from certain infections while allowing maternal antibodies to pass through. An underdeveloped placenta can lead to complications such as:  Intrauterine Growth Restriction (IUGR): The fetus may not receive adequate nutrients and oxygen, leading to poor growth and development.   Preterm Birth: Insufficient placental function can increase the risk of premature labor.  Pregnancy Complications: Conditions like preeclampsia may arise, affecting both maternal and fetal health. V. LOW LEVELS OF HORMONES DURING PREGNANCY AND WHAT ARE THE INTERVENTIONS TO BE DONE Hormonal balance is critical during pregnancy. Low levels of certain hormones can lead to complications:  Progesterone: Essential for maintaining the uterine lining and preventing miscarriage. Low levels may require supplementation.  Estrogen: Important for fetal development and preparing the body for labor. Insufficient levels can affect pregnancy progression. Interventions may include:  Hormone Replacement Therapy: Administering progesterone or estrogen supplements as needed.  Monitoring: Regular check-ups to assess hormone levels and fetal development.  Lifestyle Modifications: Encouraging a healthy diet and stress management to support hormonal balance VI. HORMONES Several hormones play critical roles in the reproductive system:  Gonadotropin-Releasing Hormone (GnRH): Produced by the hypothalamus, it stimulates the pituitary gland to release FSH and LH, which regulate the reproductive cycle.  Follicle-Stimulating Hormone (FSH): Stimulates the growth of ovarian follicles in females and sperm production in males.  Luteinizing Hormone (LH): Triggers ovulation in females and testosterone production in males.  Estrogen: Regulates the menstrual cycle and promotes the development of female secondary sexual characteristics.  Progesterone: Prepares the uterus for implantation and maintains pregnancy.  Testosterone: Responsible for the development of male secondary sexual characteristics and sperm production. These hormones work in concert to regulate reproductive functions, support pregnancy, and influence sexual characteristics