Genzoo Reviewer P3 PDF

Lesson 15: Circulatory System Pointers to Review 1. Following are part of the circulatory system. -Heart, Blood ,Blood vessels, Lymph, Lymph Vessels 2. Formed elements of blood a. Erythrocytes are red blood cells (RBC), which carry oxygen and do not play a direct role in immune function. They are s...

Lesson 15: Circulatory System Pointers to Review 1. Following are part of the circulatory system. -Heart, Blood ,Blood vessels, Lymph, Lymph Vessels 2. Formed elements of blood a. Erythrocytes are red blood cells (RBC), which carry oxygen and do not play a direct role in immune function. They are specifically responsible for transporting oxygen throughout the body. RBC's lack nucleus in their mature form to maximize space for hemoglobin, which allows them to efficiently carry oxygen. This also gives them their characteristic biconcave shape, which improves flexibility and gas exchange. Red blood cells (erythrocytes) lose their Nucleus during maturation to maximize space for hemoglobin, which is crucial for oxygen transport. In contrast, white blood cells, heart cells, and lung cells all contain nuclei. b. White blood cells (WBC's)contain a nucleus, as they play a role in the immune response. White blood cells typically refers to leukocytes, which are involved in the immune response. Leukocytes (or white blood cells) include various types such as lymphocytes, and monocytes. Leukocyte, another term for white blood cells. Lymphocyte, a type of white blood cell involved in the immune response. Monocyte, another type of white blood cell that plays a role in fighting infection. Neutrophils are the type of white blood cell responsible for engulfing pathogens during phagocytosis. Neutrophils are a type of granulocyte and play a crucial role in the immune response by ingesting and destroying bacteria and other foreign particles. They are the most common white blood cell. Neutrophils typically make up about 55-70% of the total white blood cell count and are essential for the body's defense against infections, particularly bacterial infections. c. Thrombocytes/platelets- formed elements of the blood responsible in the formation of blood clots. 3. Blood Vessels a. Arteries - While most arteries carry oxygenated blood (except for the pulmonary arteries), the defining characteristic is that arteries transport blood away from the heart to various parts of the body. Arterioles are smaller branches of arteries that lead to capillaries and play a crucial role in regulating blood flow and pressure within the circulatory system. b. Veins Veins are blood vessels that carry blood toward the heart. Veins have thinner walls compared to arteries, as they operate under lower pressure. Their walls consist of three layers: an inner endothelium, a middle muscular layer (which is thinner than that of arteries), and an outer layer of connective tissue. Many veins, especially in the limbs, contain one-way Valves that prevent backflow of blood, ensuring it moves toward the heart, even against gravity. Veins have larger lumens (the interior space of the vessel) than arteries, allowing them to hold a greater volume of blood. c. Capillaries are tiny blood vessels that connect arterioles and venules, facilitating the exchange of oxygen, carbon dioxide, nutrients, and waste products between blood and tissues. Capillaries are tiny blood vessels that interact between arteries and Veins. 4. Heart is classified according to the number of chamber a. A four-chambered heart consists of two atria and two ventricles. This structure is found in mammals and birds, allowing for efficient separation of oxygenated and deoxygenated blood. b. Three-chambered hearts generally consist of two atria and one ventricle. This structure is typical in amphibians and some reptiles, allowing for some mixing of oxygenated and deoxygenated blood. c. A two-chambered heart consists of one atrium and one ventricle. This type of heart is typically found in most fish. - The chamber of the heart that receives blood from the lungs is the Left Atrium. - The outermost layer of the heart wall is known as the Epicardium. The epicardium is a thin layer that also forms part of the pericardium, the protective sac surrounding the heart. - The innermost layer of the heart wall is known as the Endocardium. The endocardium lines the chambers of the heart and covers the heart valves, providing a smooth surface for blood flow. -The heart muscle is known as the Myocardium. The myocardium is the thick, muscular layer of the heart that is responsible for contracting and pumping blood throughout the body. 5. When the heart contracts, it produces a wave of fluid pressure in the Arteries. This is due to the contraction of the ventricles, which pushes blood into the arteries, creating the pulse and pressure wave that travels throughout the arterial system. 6.The blood group known as the ABO system is based on the presence of Antigens on blood cells. Specifically, the ABO blood group classification is determined by the presence or absence of two types of antigens, A and B, on the surface of red blood cells. Lesson 16: Excretory System Pointers for review 1. The excretory system, also known as the urinary system, includes organs such as the kidneys, ureters, bladder, and urethra, which work together to filter blood, remove waste products, and maintain fluid and electrolyte balance. 2. The kidneys filter blood to remove waste products and excess substances, producing urine, which is then transported to the bladder via the ureters for storage before being excreted through the urethra. 3. Typical Composition of Normal Urine: urine is primarily composed of 96% water. urea is 2%, a major nitrogenous waste product in urine. Urea is secreted into the filtrate in the kidney tubule. 1.5 % salt, this is a general estimate of various salts and electrolytes in urine. Creatinine typically constitutes about 0.1% of urine. 4. The functional and physiological unit of the kidney is the Nephron. Parts of the Nephron: - The renal tubule, composed proximal and distal convoluted tubules, and the loop of Henle. - The renal corpuscles made up of the bowman's capsule and the glomerulus/glomeruli. All of the glomeruli of the kidney are located in the Cortex. 5. The tube that connects the bladder to the kidney is called the Ureter. The ureters transport urine from the kidneys to the urinary bladder for storage before it is excreted through the urethra. 6. The blood vessel that drains blood from the glomerulus after filtration is called the efferent arteriole. The efferent arteriole carries blood away from the glomerulus, while the afferent arteriole brings blood into the glomerulus for filtration. 7. The urinary bladder serves as a reservoir for urine before it is expelled from the body. It is a bi-lobed sac on the ventral surface of the cloaca for the temporary storage of urine. 8. The part of the nephron that performs the majority of the reabsorption of materials from the filtrate is the proximal convoluted tubule. The proximal convoluted tubule is responsible for reabsorbing a significant portion of water, ions, and nutrients (such as glucose and amino acids) back into the bloodstream. Lesson 17: Female Reproductive System 1. A fertilized egg is called a Zygote, which forms when a sperm cell and an egg cell merge during fertilization. The zygote undergoes cell division and develops into an embryo and later into a blastocyst. 2. The EXTERNAL FEMALE REPEODUCTIVE ORGANS are collectively called the VULVA. They include: -MONS PUBIS: A fatty area over the pubic bone. -CLITORIS: A sensitive organ that plays a role in sexual pleasure. -LABIA MAJORA AND LABIA MINORA: Folds of skin that surround the vaginal and urethral openings. -VAGINAL OPENING: The entry to the vagina. -HYMEN (in some cases): A thin membrane partially covering the vaginal opening. Other internal organs, like the OVIDUCTS, ovaries, and uterus are part of the internal reproductive system. 3. The Uterus (or womb) is a hollow, muscular organ in which a fertilized egg implants and develops into a fetus during pregnancy. It provides a nourishing environment for the growing embryo, with the placenta facilitating nutrient and oxygen exchange. The uterus also plays a critical role during labor by contracting to help deliver the baby. 2. The secretory phase occurs during the second half of the menstrual cycle, typically from day 15 to 28, following ovulation. During this phase, the endometrium (uterine lining) thickens and prepares for possible implantation of a fertilized egg, influenced by progesterone from the corpus luteum. If fertilization does not occur, the cycle ends with menstruation. 4. The oviducts (also known as fallopian tube) are two slender, coiled tubes that connect the ovaries to the uterus. They play a crucial role in transporting the egg and are the site where fertilization typically occurs. 5. The ovaries are two small, oval-shaped organs located on either side of the uterus. They are responsible for the formation and release of eggs (oocytes) during ovulation and also produce hormones like estrogen and progesterone. 6. The menstrual cycle is divided into 3 phases: the breakdown of the phases in order: -MENSTRUAL CYCLE (Day 1–5): The uterine lining (endometrium) is shed, resulting in menstrual bleeding. - PROLIFERATIVE CYCLE (Day 6–14): The endometrium begins to regenerate and thicken, preparing for potential pregnancy, under the influence of estrogen. Ovulation typically occurs around day 14. -SECRETORY PHASE (Day 15–28): The endometrium becomes more vascularized and glandular, preparing to support a fertilized egg. This phase is regulated by progesterone from the corpus luteum. 7. Typically, the ovaries release an egg (ovulation) once a month as part of the menstrual cycle, which usually lasts about 28 days. Ovulation generally occurs around the Midpoint of the cycle (around day 14), though the exact timing can vary between individuals and cycles. For example, October 10 is the first day of a regular menstrual cycle. The expected date of ovulation is the Mid date of menstrual cycle (day 14) 8. The Menstrual cycle is regulated by a complex interaction of hormones, primarily: -Follicle -stimulating hormone (FSH): Stimulates the growth of ovarian follicles. -Luteinizing hormone (LH) : Triggers ovulation. -Estrogen :Helps rebuild the uterine lining during the proliferative phase. -Progesterone: Maintains the uterine lining during the secretory phase. If fertilization does not occur, Hormone levels drop, leading to the shedding of the uterine lining and the start of menstruation. Lesson 18: Male Reproductive System 1. The external male reproductive organs includes: -Penis : Involved in sexual intercourse and urination. - Testes: Produce sperm and testosterone. -Scrotum: A pouch of skin that houses the testes and regulates their temperature to support sperm production The urethra, prostate gland, and seminal vesicles are internal structures involved in sperm production, storage, and ejaculation. 2. Here’s the correct pathway of sperm: -Seminiferous tubules: Sperm are produced here within the testes. - Epididymis: Sperm mature and are stored here. - Vas deferens: Transports mature sperm from the epididymis - Ejaculatory ducts: Sperm mix with seminal fluid from the seminal vesicles and prostate gland. - Urethra: The final pathway through which semen is expelled from the body during ejaculation. 3. The Penis does not contribute any secretions to semen; it serves as the organ for delivering semen during ejaculation. The components of semen come from: -Testes: Produce sperm cells. - Prostate gland: Adds alkaline fluid to protect sperm from the acidic environment of the vagina. - Seminal vesicles: Provide a sugar-rich fluid (fructose) to nourish sperm and enhance their mobility. These fluids combine to form Semen, which is then ejaculated through the penis. 4. Once sperm are produced in the Seminiferous tubules of the testes, they move into the Epididymis, where they mature and are stored. The epididymis is a coiled tube on the back of each testis, and it plays a key role in the maturation, storage, and transport of sperm. From the epididymis, sperm travel through the vas deferens during ejaculation. Lesson 19:Nervous System Pointers to review 1. The Neuron is the basic unit of the nervous system. Neurons are specialized cells responsible for transmitting information throughout the body via electrical and chemical signals. They play a crucial role in communication within the nervous system, processing sensory input, and controlling motor output. 2. The Central Nervous System (CNS) consists of: - Brain: Controls thoughts, emotions, memory, and bodily functions. -Spinal cord: Relays information between the brain and the rest of the body through the peripheral nerves. The CNS is responsible for processing sensory data and coordinating motor functions. 3. The Peripheral Nervous System (PNS) consists of: - Cranial nerves: 12 pairs originating from the brain, controlling senses and motor functions in the head and neck. - Spinal nerves: 31 pairs connecting the spinal cord with the body, transmitting signals between the CNS and the limbs and organs The PNS includes both the somatic (voluntary control) and autonomic (involuntary control) systems, and it acts as a communication relay between the body and the central nervous system (CNS). 4. Parts of the brain. -The Telencephalon is the largest part of the brain and includes the cerebral cortex, which is responsible for higher-order functions such as: Consciousness, Memory, Intelligence, Vision It also contains key structures like the basal ganglia and the limbic system, which play roles in emotion, learning, and voluntary motor control. - The Metencephalon includes the Cerebellum (Regulates balance (equilibrium), coordination of movement, and fine motor skills) and Pons (Helps relay signals between different parts of the brain and assists in controlling breathing.) This region ensures smooth and coordinated movements and is essential for posture and motor learning. The Cerebellum is primarily responsible for regulating balance, posture, and coordination of movement. It helps fine-tune motor activity and ensures smooth and accurate movements. While it plays a role in certain reflexes, it does not control breathing or memory functions. -The Mesencephalon , also known as the Midbrain , plays an essential role in: Visual reflexes (such as tracking moving objects); Auditory reflexes (like the startle response to loud sounds) It contains important structures like the Superior colliculus (involved in visual processing) and the Inferior colliculus (involved in auditory processing). The mesencephalon also helps in controlling eye movements and motor coordination. 5. The Spinal cord extends from the Medulla oblongata at the base of the brain down to the neural canal of the urostyle (or the base of the vertebral column in some animals). It is a vital part of the central nervous system, responsible for transmitting signals between the brain and the rest of the body, as well as coordinating reflexes. 6. The Meninges are the protective linings that surround the brain and spinal cord. They consist of three layers: -Dura mater: The tough outer layer. -Arachnoid mater: The middle layer, which has a web-like structure. -Pia mater: The delicate inner layer that closely adheres to the surface of the brain and spinal cord. The meninges help protect the central nervous system and contain cerebrospinal fluid (CSF), which provides cushioning and support. 7. There are 12 pairs of cranial nerves that emerge from the lateral surfaces of the brain (primarily the brainstem) and extend to various parts of the body. These nerves are responsible for functions such as sensory and motor control, and autonomic functions. Each cranial nerve has specific roles related to senses (like smell and vision) and motor functions (like eye movement and facial expressions). Lesson 20: Endocrine System Pointers for review 1. The Endocrine system produces and releases Hormones —chemical messengers that regulate various physiological processes to maintain Homeostasis. These hormones control functions such as: Metabolism Growth and development Reproduction Stress response Blood sugar regulation The Endocrine system works closely with the nervous system to ensure the body functions smoothly. Unlike electrical signals in the nervous system, the endocrine system relies on chemical communication through hormones. 2. Somatotropin is the growth hormone produced by the Anterior pituitary gland. It plays a crucial role in growth, cell reproduction, and regeneration in humans and other animals. The other hormones listed have different functions: -Prolactin: Primarily responsible for milk production in females. -Luteinizing hormone ( LH):Involved in regulating the menstrual cycle and ovulation in females and testosterone production in males. - Follicle-stimulating hormone ( FSH):Stimulates the growth of ovarian follicles in females and sperm production in males. 3. Thyroid hormones primarily Thyroxine (T4) and Triiodothyronine (T3), regulate the metabolic rate of almost all body cells. They influence various physiological processes, including energy expenditure, protein synthesis, and overall metabolism. 4. The Testes (in males) are responsible for secreting sex hormones, primarily Testosterone. In females, the Ovaries secrete Estrogen and progesterone. 5. The Posterior pituitary gland stores and secretes two important hormones: Oxytocin: Involved in uterine contractions during childbirth and the release of milk during breastfeeding and Antidiuretic hormone (ADH) also known as Vasopressin: Regulates water balance in the body by promoting water reabsorption in the kidneys. 6. Progesterone is a hormone produced primarily by the corpus luteum in the ovaries after ovulation. Its main functions include: Preparing the endometrium (lining of the uterus) for implantation of a fertilized egg. Maintaining the uterine lining during early pregnancy. Preventing contractions of the uterus that could lead to rejection of the embryo. While progesterone does play a role in regulating menstrual cycles and can influence estrogen production, its primary function related to pregnancy is preparing the uterus for implantation and sustaining early pregnancy. 7. Estrogens play several essential roles—such as stimulating bone and muscle growth and maintaining female secondary sex characteristics—the maintenance of the corpus luteum is primarily the function of luteinizing hormone (LH). Estrogens are more involved in regulating the menstrual cycle, promoting the growth of the uterine lining, and supporting the development of secondary sexual traits rather than maintaining the corpus luteum. Lesson 21: Sense Organs Pointers to review Five Senses A. The 5 senses are: -Sight /Vision – Perceives light, color, shapes, and motion through the eyes. 1. The Pupil is the dark circular opening in the center of the eye that adjusts its size to control the amount of light entering the eye. In bright light, the pupil constricts to limit the light. In low light , the pupil dilates to allow more light in. 2. The Iris is the colored part of the eye that surrounds the pupil and controls its size. 3. The Retina is the light-sensitive layer at the back of the eye. -Hearing/ Audition - Detects sound waves through the ears. -Smell/ Olfaction- Identifies odors through the nose. -Taste/ Gustation- Detects flavors through taste buds on the tongue. - Touch/ Somatosensation - Senses pressure, temperature, pain, and texture through skin and other tissues. These senses help humans perceive and interact with the environment. Lesson 22: Prenatal Development Pointers to review 1. A fertilized egg is called a Zygote, which forms when a sperm cell and an egg cell merge during fertilization. The zygote undergoes cell division and develops into an embryo and later into a blastocyst. 2. The EXTERNAL FEMALE REPEODUCTIVE ORGANS are collectively called the VULVA. They include: -MONS PUBIS: A fatty area over the pubic bone. -CLITORIS: A sensitive organ that plays a role in sexual pleasure. -LABIA MAJORA AND LABIA MINORA: Folds of skin that surround the vaginal and urethral openings. -VAGINAL OPENING: The entry to the vagina. -HYMEN (in some cases): A thin membrane partially covering the vaginal opening. Other internal organs, like the OVIDUCTS, ovaries, and uterus are part of the internal reproductive system. 3. The Uterus (or womb) is a hollow, muscular organ in which a fertilized egg implants and develops into a fetus during pregnancy. It provides a nourishing environment for the growing embryo, with the placenta facilitating nutrient and oxygen exchange. The uterus also plays a critical role during labor by contracting to help deliver the baby. 2. The secretory phase occurs during the second half of the menstrual cycle, typically from day 15 to 28, following ovulation. During this phase, the endometrium (uterine lining) thickens and prepares for possible implantation of a fertilized egg, influenced by progesterone from the corpus luteum. If fertilization does not occur, the cycle ends with menstruation. 4. The oviducts (also known as fallopian tube) are two slender, coiled tubes that connect the ovaries to the uterus. They play a crucial role in transporting the egg and are the site where fertilization typically occurs. 5. The ovaries are two small, oval-shaped organs located on either side of the uterus. They are responsible for the formation and release of eggs (oocytes) during ovulation and also produce hormones like estrogen and progesterone. 6. The menstrual cycle is divided into 3 phases: the breakdown of the phases in order: -MENSTRUAL CYCLE (Day 1–5): The uterine lining (endometrium) is shed, resulting in menstrual bleeding. - PROLIFERATIVE CYCLE (Day 6–14): The endometrium begins to regenerate and thicken, preparing for potential pregnancy, under the influence of estrogen. Ovulation typically occurs around day 14. -SECRETORY PHASE (Day 15–28): The endometrium becomes more vascularized and glandular, preparing to support a fertilized egg. This phase is regulated by progesterone from the corpus luteum. 7. Typically, the ovaries release an egg (ovulation) once a month as part of the menstrual cycle, which usually lasts about 28 days. Ovulation generally occurs around the Midpoint of the cycle (around day 14), though the exact timing can vary between individuals and cycles. For example, October 10 is the first day of a regular menstrual cycle. The expected date of ovulation is the Mid date of menstrual cycle (day 14) 8. The Menstrual cycle is regulated by a complex interaction of hormones, primarily: -Follicle -stimulating hormone (FSH): Stimulates the growth of ovarian follicles. -Luteinizing hormone (LH) : Triggers ovulation. -Estrogen :Helps rebuild the uterine lining during the proliferative phase. -Progesterone: Maintains the uterine lining during the secretory phase. If fertilization does not occur, Hormone levels drop, leading to the shedding of the uterine lining and the start of menstruation.