Science 2Q PDF

**[Nervous system]** **3 basic components:** **Central Nervous system (CNS)** **Peripheral Nervous System (PNS)** **Neurons (***Nerve Cells)* *All types of neurons have 2 common features:* [The cell body and its neural processes] **3 Functional neurons:** **3 Structural classifications of neu...

**[Nervous system]** **3 basic components:** **Central Nervous system (CNS)** **Peripheral Nervous System (PNS)** **Neurons (***Nerve Cells)* *All types of neurons have 2 common features:* [The cell body and its neural processes] **3 Functional neurons:** **3 Structural classifications of neurons:** **[Central Nervous System]** **Brain** **Four Major Regions of the Brain** - - **Spinal Cord** **Peripheral Nervous System (PNS)** **Cranial nerves** **Spinal nerves** *Their names correspond to the muscles or organs they control.* **Divisions of the Peripheral Nervous System:** **Four major states of Nerve Impulse** ***Neurons communicate with other neurons through the extracellular gaps between them which is the synapse.*** **Reflex** -- A rapid, instantaneous, and involuntary response of the body to stimuli that do not undergo integration in the brain. It occurs in the reflex arc. **Endocrine System** - **Key Components of the Endocrine System** 1.Pituitary Gland: \- Often referred to as the \"master gland,\" it is a pea-sized gland located at the base of the brain. \- Controls the function of most other glands and secretes various hormones, including: \- Growth Hormone: Regulates bone and muscle growth. \- Thyroid Stimulating Hormone: Stimulates the thyroid gland. 2\. Hypothalamus: \- A small region of the brain that controls the pituitary gland. 3.Thyroid Gland: \- Located in the neck, it secretes thyroid hormones that regulate metabolism, influencing vital functions such as heart rate. 4.Pancreas: \- Plays a crucial role in controlling blood glucose levels by secreting insulin, which helps move glucose from the blood into cells. \- Diabetes occurs when there is insufficient insulin production to manage blood sugar levels. 5.Adrenal Glands: \- Two glands located on top of each kidney. \- Secrete hormones such as: -Epinephrine (Adrenaline): Involved in stress response. -Aldosterone: Helps regulate blood pressure and fluid balance. \- Cortisol: Plays a role in metabolism and response to stress. 6\. Gonads (Testes and Ovaries): \- Under control of the pituitary gland, they produce sex hormones and reproductive cells. \- Testes produce testosterone and sperm, while ovaries produce estrogen and eggs. **Cells of the Anterior Pituitary Gland** **Somatotrophs** **Thyrotrophs** **Gonadotrophs** **Lactotrophs** **Corticotrophs** **Cells of the Posterior Pituitary Gland** **Oxytocin** **Vasopressin** **Negative and Positive Feedback Mechanism** **Parts and Functions of the Reproductive System** **[Male RS]**  **Testes** -- produces sperm and testosterone. **Epididymis** -- stores sperm and allows them to mature. **Vas Deferens** -- transports sperm from the epididymis to the urethra. **Urethra** -- carries urine and semen out of the body. **Prostate gland** -- Secretes prostate fluid which neutralizes the acidic conditions of the vagina. **Erectile tissue** -- This allows the penis to be erected when it is filled with blood. **Scrotum** -- Protects the testes by helping with the thermoregulation of testicles. **Penis** -- It contains the urethra which allows it to pass the urine and semen out of the body. **Bladder** -- Stores urine until it is released through the urethra. **Seminal vesicle** -- produces the fluids that will turn into semen. **[Female RS]** **Ovary** -- Produces eggs (ova) and female sex hormones (estrogen and progesterone) **Uterus** -- houses and nourishes the developed fetus. **Fimbriae** -- Finger-like projections that help guide the egg from the ovary into the fallopian tube. **Endometrium** -- The inner lining of the uterus where a fertilized egg implants. **Fallopian tube** -- Connects the ovaries to the uterus **Myometrium** -- Responsible for uterine contractions **Cervical Canal** -- Allows blood from the menstrual period and a fetus to pass from the womb into the vagina. **Cervix** -- Hold the fetus during pregnancy. **Vagina** -- Passes blood during menstruation. The passageway of the baby during delivery. To receive penis and sperm during sexual intercourse. **Female** **Male** **Sex Characteristics** **Purpose of Puberty** **Feedback System**  **Menstrual Cycle** **Hormones**: Adrenaline: Secreted by the adrenal gland; increases blood pressure, heart rate, and metabolism in reaction to stress. Aldosterone: Secreted by the adrenal gland; controls the body's salt and water balance. Cortisol: Secreted by the adrenal gland; plays a role in stress response. Dehydroepiandrosterone (DHEA): Secreted by the adrenal gland; aids in the production of body odor and growth of body hair during puberty. Estrogen: Secreted by the ovary; regulates the menstrual cycle, maintains pregnancy, and develops female sex characteristics; also aids in sperm production. Follicle Stimulating Hormone (FSH): Secreted by the pituitary gland; controls the production of eggs and sperm. Glucagon: Secreted by the pancreas; helps to increase blood glucose levels Insulin: Secreted by the pancreas; helps to reduce blood glucose levels. Luteinizing Hormone (LH): Secreted by the pituitary gland; controls estrogen and testosterone production as well as ovulation. Melatonin: Secreted by the pineal gland; controls sleep and wake cycles. Oxytocin: Secreted by the pituitary gland; helps with lactation, childbirth, and mother-child bonding. Parathyroid Hormone: Secreted by the parathyroid gland; controls calcium levels in bones and blood. Progesterone: Secreted by the ovary; helps to prepare the body for pregnancy when an egg is fertilized. Prolactin: Secreted by the pituitary gland; promotes breast milk production. Testosterone: Secreted by the ovary, testes, and adrenal gland; contributes to sex drive, body density in males and females, and development of male sex characteristics. Thyroid Hormone: Secreted by the thyroid gland; controls several body functions, including metabolism and energy levels.