Adolescent Brain Development and Behavior

The male reproductive system's primary function is to produce, store, and deliver sperm as well as secrete testosterone.

The testes are located outside the abdominal cavity within the scrotum. This placement ensures the optimal temperature for sperm production, which is lower than body temperature.

The seminiferous tubules, located within the testes, are the sites of spermatogenesis, or sperm production. Their unique structure enables the complex process of sperm creation.

Leydig cells are found in the interstitial spaces between the seminiferous tubules. They are responsible for the production of testosterone, the primary male sex hormone.

Sertoli cells provide essential support and nourishment to developing sperm cells. They play a crucial role in spermatogenesis, ensuring the proper development of sperm.

The epididymis is a long, coiled duct where sperm mature and gain motility. It is located on the posterior side of the testis and plays a vital role in sperm function.

The vas deferens transports sperm from the epididymis to the ejaculatory ducts. It is a muscular tube that propels sperm through a series of contractions.

The prostate gland produces a fluid that contributes to semen volume and enhances sperm motility. It is located below the bladder and plays a crucial role in ejaculation.

The part of the brain responsible for planning, controlling impulses, and social behavior. It matures later than other brain areas, explaining why adolescents may struggle with impulsivity and decision-making.

A group of brain structures including the amygdala and striatum, which control emotions and reward-seeking. It develops early, making adolescents more sensitive to rewards and prone to sensation-seeking behaviors.

A characteristic of adolescent behavior in which the limbic system's desire for immediate rewards overpowers the prefrontal cortex's ability to plan and consider long-term consequences.

A heightened sensitivity to emotions during adolescence, characterized by strong reactions triggered by the amygdala, and peer approval, which activates the striatum, reinforcing social behaviors.

The disruption of decision-making during adolescence due to the developing stress-response system. Increased cortisol sensitivity creates overreactions in stressful situations.

The use of substances during adolescence can damage the developing reward system, increasing the likelihood of dependency and long-term cognitive issues. Alcohol, cannabis, nicotine, and party drugs all pose significant risks.

Alcohol's impact on the brain, including impaired decision-making, memory loss, and disruptions in synaptic pruning and myelination.

Cannabis's effects on the brain, including memory impairments, disruption in neural plasticity, and possible long-term cognitive problems.

A precancerous cervical lesion characterized by abnormal cell growth, but with a high chance of reverting to normal with treatment or time.

A precancerous lesion with more advanced cell abnormalities, indicating a higher risk of progressing to cervical cancer.

A test that examines cervical cells for abnormal growth, detecting potential precancerous lesions.

A test that identifies the presence of specific high-risk types of HPV, increasing the chances of developing cervical cancer.

A marker that helps distinguish HSIL from other cervical lesions, signifying a higher risk of progressing to cancer.

A type of breast cancer that responds to hormone therapy and is generally less aggressive, making it the most common type.

A type of breast cancer that is intermediate in prognosis, requiring both hormone and targeted therapies.

A challenging type of breast cancer with poor prognosis, limited treatment options, and a higher occurrence in younger women.

These drugs work against cancer cells regardless of their phase of the cell cycle.

Platinum salts like cisplatin and carboplatin create crosslinks in DNA, disrupting its structure and leading to cell death.

Topoisomerase inhibitors like Irinotecan (Top I) and Etoposide (Top II) block enzymes that manage DNA supercoiling, leading to DNA damage and ultimately apoptosis.

Taxanes like Paclitaxel and Docetaxel stabilize microtubules, preventing spindle disassembly and blocking mitosis.

CDK4/6 inhibitors like Palbociclib target cyclin-dependent kinases, halting the G1/S phase transition and preventing cell cycle progression.

HER2, a receptor tyrosine kinase, is often overexpressed in breast cancer. Targeting HER2 can block cell signaling and inhibit growth.

Trastuzumab (Herceptin) is a monoclonal antibody that directly blocks HER2 signaling and also enhances the immune system's attack against HER2-positive cells.

Antibody-drug conjugates, like trastuzumab deruxtecan, deliver chemotherapy directly to HER2-positive cells, maximizing efficacy and minimizing side effects.

Tumor suppressor genes, like RB1 and TP53, are inactive, allowing uncontrolled cell growth.

Cancer cells avoid programmed cell death (apoptosis) by upregulating pro-survival networks, which signals them to keep growing.

Cancer cells activate telomerase, an enzyme that prevents the shortening of telomeres, which normally limits cell division, allowing the cells to keep replicating.

Cancer cells promote the formation of new blood vessels (angiogenesis) through the release of Vascular Endothelial Growth Factor (VEGF), which ensures the supply of nutrients and oxygen to support tumor growth.

Cancer cells undergo EMT (epithelial-to-mesenchymal transition), which increases their mobility and invasiveness.

Cancer cells accumulate genetic mutations due to defects in their DNA repair mechanisms.

Cancer cells increase glycolysis even in the presence of oxygen (Warburg Effect) to generate energy and fuel their growth.

Cancer cells evade the immune system's surveillance by inhibiting T-cell activity, preventing the destruction of cancer cells.

Cancer staging classifies tumors based on their size, spread, and impact on overall health.

The tumor, node, metastasis (TNM) system is the most common method for staging cancers. It assigns a score based on tumor size (T), lymph node involvement (N), and presence of metastasis (M).

Performance status assesses a patient's ability to participate in daily activities. It helps determine treatment plans and predict outcomes.

Chemotherapy uses drugs to target and kill cancer cells. It can be given before surgery (neoadjuvant), after surgery (adjuvant), or to relieve symptoms in advanced stages (palliative).

Immunotherapy uses the body's own immune system to fight cancer by boosting its ability to recognize and destroy cancer cells. It can involve checkpoint inhibitors which block cancer's ability to evade the immune system or CAR-T therapy where engineered T cells target cancer antigens.

Targeted therapy drugs specifically target key molecules or pathways that are important for cancer growth and survival, disrupting those processes. Common examples include EGFR and HER2 inhibitors.

Radiotherapy uses high-energy radiation beams to destroy cancer cells. It can be used for curative, palliative, or preventive purposes. Different types include external beam radiation, brachytherapy, and systemic radioisotopes.

Hormone therapy works by blocking or altering hormones that fuel cancer cell growth, inhibiting their ability to proliferate.