All topics and their key points listed below must be discussed in your essayTopic 1: Reproduction (10 marks total)A simple pregnancy test using Elastigirl’s urine helped to confirm...

Topic 1: Reproduction    1
Topic 2: Respiratory system    2
Topic 3: Digestion and Metabolism    3
Topic 4: Pharmacology    4
Reference    6
Topic 1: Reproduction
A typical home pregnancy test detects the presence of human chorionic gonadotropin (hCG) hormone in the urine. hCG is produced by the cells that form the placenta, which nourishes the developing embryo after it implants in the uterus.
When a fertilised egg implants in the uterus, it begins to release hCG, which can be detected in a woman's urine a few days after implantation. Home pregnancy tests use antibodies that bind to hCG to produce a positive or negative result. If hCG is present in the urine sample, it binds to the antibodies on the test strip, causing a visible line or symbol to appear on the test.
In pregnancy, hCG plays a vital role in maintaining the function of the corpus luteum, which is the structure that forms from the follicle after ovulation and produces progesterone. Progesterone is necessary to maintain the thickness of the endometrium and prevent menstruation, which would otherwise cause the embryo to be expelled from the uterus. hCG also helps stimulate the placenta's growth, which provides oxygen and nutrients to the developing fetus.
In addition to its role in pregnancy, hCG can also be produced by some tumours, such as certain types of testicular and ovarian cancer. Therefore, a healthcare provider should always confirm a positive pregnancy test result to rule out other potential causes of elevated hCG levels.
As for the future role of oxytocin during childbirth, it is a hormone produced by the hypothalamus and released by the pituitary gland. Its primary function is to stimulate uterine contractions during labour and delivery. As the baby moves through the birth canal, the pressure on the cervix triggers the release of oxytocin, which causes the uterine muscles to contract and push the baby out. Oxytocin also plays a role in the milk ejection reflex during breastfeeding. Overall, oxytocin is vital in childbirth and bonding between the mother and baby.
Topic 2: Respiratory system
Elastigirl's inhalation involves a complex interplay of muscular and mechanical actions that result in changes in the volume and pressure of her chest cavity (Cheng & Jin,2021).
During inhalation, Elastigirl's diaphragm and external intercostal muscles contract, causing the volume of her chest cavity to increase. This increase in volume decreases the pressure within the chest cavity, which causes air to rush into her lungs from the surrounding environment. The expansion of the chest cavity is due to the diaphragm's contraction and the ribcage's lifting, which increases the space available for the lungs to fill with air (López-Cortés et al.,2023).
As air enters Elastigirl's lungs, the pressure inside the lungs gradually equalises with the pressure outside the body, resulting in a state of equilibrium. This equilibrium allows for smooth and efficient airflow into the lungs, providing the necessary oxygen for respiration.
The changes in volume and pressure in Elastigirl's chest cavity during inhalation are necessary for respiration. Elastigirl could not breathe the essential oxygen to...