تجربة 1 Flashcards
What is the name of the phase where the uterine lining becomes thicker in preparation for possible pregnancy?
Proliferative phase or follicular phase.
What hormone exerts negative feedback on LH and FSH production during the follicular phase?
Estrogen and inhibin.
What triggers the mature follicle to rupture and release the egg into the fallopian tube?
Peak levels of LH around day 14.
What structure does the follicle develop into after ovulation?
Corpus luteum.
What hormone does the corpus luteum predominantly produce after ovulation?
Progesterone.
What is the phase of the uterine cycle where the uterine lining thickens and becomes more vascular due to progesterone?
Secretory phase or luteal phase.
What event marks the end of the follicular phase and the beginning of the luteal phase?
Ovulation.
What causes the uterine lining to break down leading to menstrual bleeding if fertilization doesn’t occur?
Sudden decline in progesterone and estrogen levels.
What do elevated levels of circulating estrogen, progesterone, and inhibin inhibit during the menstrual cycle?
Secretion of GNRH, FSH, and LH.
What are the two types of hormonal contraceptives?
Combined method (estrogen and progesterone) and progestin-only method (progestin).
Which form of hormonal contraceptives is most widely used?
Oral tablet or birth control pill.
What is the term for birth control pills that deliver synthetic forms of both estrogen and progesterone?
Combination or combined birth control pills.
What is the term for birth control pills that contain synthetic progestin, a version of progesterone?
Progestin-only birth control pills.
What phase of the uterine cycle is known for secreting fluids necessary for embryo nutrition and closing off the uterine opening?
Secretory or luteal phase.
What is the major sterol found in fungal plasma membrane?
Ergosterol
What is the function of ergosterol in fungal cells?
Maintain membrane integrity
What enzymes are responsible for fungal cell wall construction in the plasma membrane?
Multi-subunit enzymes
How do antifungal drugs targeting ergosterol work?
By binding to cholesterol in ergosterol and forming pores
What is the major adverse effect of antifungal drugs causing membrane permeability?
Rapid leakage of intracellular ions
Which antifungal drug is used only for severe systemic infections that require a rapid response?
Amphotericin B
Why is Nystatin not used systematically like Amphotericin B?
It is more toxic
What is the target of Ergosterol Biosynthesis Enzymes Inhibitors Antifungal Drugs?
Squalene epoxidase and P450 enzyme
How do squalene epoxidase and P450 enzyme inhibitors cause fungal cell death?
By depleting cell membrane ergosterol
What is the main advantage of Echinocandins antifungal drugs relative to others?
Low potential for toxicity or serious drug interaction
What is cancer characterized by uncontrolled cell division and ability to invade other tissues?
Carcinoma
What is the term for the spread of cancer cells to other parts of the body?
Metastasis
Which cancer type is related to tissues that line or cover internal organs?
Carcinoma
Which cancer type affects bone, cartilage, muscle, etc.?
Sarcoma
What type of cells are affected by Leukemia?
White blood cells
What is the essential component of thyroid hormones?
Iodine (59% and 65%)
Which protein primarily binds to circulating thyroid hormones?
Thyroxin-binding globulin (TBG)
Which thyroid hormone is more potent in activity, T4, or T3?
T3 (T3 is four times more potent in activity)
Where is T4 converted into T3 in the body?
In the tissues, especially in the liver
Which part of the gastrointestinal tract absorbs T4 best?
Duodenum and ileum
What factor can modify the absorption of T4?
Intraluminal factors such as food, drugs, gastric acidity, and intestinal flora
How much of T3 is almost completely absorbed?
95%
What happens to metabolic clearances of T4 and T3 in hyperthyroidism?
They are increased, and the half-lives are decreased
What effects do thyroid hormones have on growth and development?
Critical for developing nervous, skeletal, and reproductive tissues
How do thyroid hormones affect the metabolism of carbohydrates, fats, and proteins?
They produce a general increase in metabolism
Which organs are unresponsive to the calorigenic effects of thyroid hormone?
Brain, gonads, and spleen
How is hypothyroidism diagnosed?
By elevated thyroid-stimulating hormone (TSH)
What is the treatment for hypothyroidism?
Administering thyroid hormones as replacement therapy
What is used to treat drug-induced hypothyroidism?
Simply removing the depressant agent
Name two thyroid preparations used in replacement therapy.
Levothyroxine (T4) and Liothyronine (T3)
What adverse effects are associated with chronic overtreatment with T4?
Increased risk of atrial fibrillation and accelerated osteoporosis
What are the primary drugs used to decrease thyroid hormone production?
Thionamides
What is the goal of treatment in inhibiting thyroid hormone synthesis?
Inhibit hormone synthesis and block its release from the follicle
How do thionamides affect thyroid hormone synthesis?
They inhibit organification of iodine and coupling of iodotyrosines
What is a potential adverse effect of thionamides?
Agranulocytosis (rare)
What category of drugs are primarily used to decrease thyroid hormone production?
Thionamides
How should tetracycline be taken in relation to antacids, calcium supplements, and magnesium-containing laxatives?
One hour before or two hours after.
What is the role of folate in DNA and RNA synthesis?
Folate is required for the synthesis of DNA and RNA precursors.
How do sulfonamides inhibit folic acid metabolism?
Sulfonamides act as competitive inhibitors by mimicking PABA.
What is the target enzyme of sulfonamides in folic acid synthesis?
Dihydropteroate synthase.
What is the host range of a virus?
The spectrum of host cells in which a virus can multiply.
Explain the attachment and penetration stage in the virus life cycle.
Virus attaches to a host cell and injects genetic material.
What happens during the replication stage of the virus life cycle?
Viral DNA or RNA incorporates into the host cell’s genetic material.
Describe the release stage in the virus life cycle.
Host cell releases newly created viruses.
How do anti-viral drugs differ from most antibiotics?
Anti-viral drugs inhibit virus development, not destroy pathogens.
What makes designing safe and effective anti-viral drugs difficult?
Viruses use host cells to replicate.
Name some categories of anti-viral drugs.
Anti-Influenza, Anti-HIV, Anti-Hepatitis, Anti-Herpes.
What viral proteins are translated from pregenomic RNAs in hepatitis B virus?
Core and polymerase proteins.
How is the negative DNA strand of the viral genome generated in hepatitis B virus?
Through reverse transcription using RNA as a template.
What are the functions of nucleoside and nucleotide analogues in hepatitis B virus treatment?
Inhibit multiple functions of the virus polymerase by competing with natural substrates.
How does hepatitis C virus enter hepatocytes?
Via receptor-mediated endocytosis.
What viral RNA is used as a template for polyprotein synthesis in hepatitis C virus?
Positive single-stranded viral RNA.
What enzymes process the viral polyprotein to generate mature proteins in hepatitis C virus?
Proteases like NS3-4A serine protease.
What role does NS5A play in hepatitis C viral replication?
Regulates the replication of viral RNA.
What does the RNA-dependent RNA polymerase NS5B do in hepatitis C virus?
Produces negative-sense RNA intermediates for replication.
How is the newly replicated viral RNA released from infected cells in hepatitis C virus?
Released by exocytosis after being encased between membranes.
What is the mechanism of action of anti-Herpes drugs on DNA polymerase?
Compete with natural nucleotides or lead to chain termination.
Name two types of deep/systemic fungal infections affecting internal organs.
Blastomyces and Coccidiodes.
What are the components of the fungal cell wall that act as a protective barrier?
Mannoproteins and complex polysaccharides like glucans and chitin.
What is the main action of Folic acid analogues?
Interfere with thymidylate synthesis essential for DNA synthesis and cell division.
How does Methotrexate work in the body?
Prevents the formation of tetrahydrofolate (FH4), essential for purine synthesis.
What is the mechanism of action of Alkylating Agents in chemotherapy?
They covalently bind to nucleophilic substances, impeding DNA and RNA replication.
What are the characteristics of cancer cells?
Persistent cell proliferation, invasive growth, metastases.
Define Benign tumors in cancer.
Noncancerous, not an immediate threat to life, may require treatment eventually.
Explain the toxicity of Antineoplastic Drugs in the short-term.
Includes common side reactions in rapid proliferating tissues like marrow, GI tract, and alopecia.
Name 3 types of central nervous system cancers.
Cancers that begin in the tissues of the brain and spinal cord.
What is the difference between Benign and Malignant tumors?
Benign is noncancerous, while Malignant tends to worsen, invade, and metastasize.
What is the main function of Myeloma cells in the body?
B-cells producing antibodies and spreads through the lymphatic system.
How do most antineoplastic drugs act on cancer cells?
By targeting the proliferating cycle of cells through various mechanisms.
Explain the long-term toxicity of Antineoplastic Drugs.
May lead to carcinogenesis, teratogenesis, and sterility in patients.
What is danazol primarily used for?
To treat certain types of breast cancer, dysfunctional uterine bleeding, and endometriosis.
What are the adverse effects of danazol?
Edema, hypertension, acne, increased oiliness of skin and hair, increased libido in males, deepening of voice, and menstrual irregularities in females.
How do antiandrogens work?
By antagonizing the androgen receptor and inhibiting the secretion of LH, FSH, and testosterone.
What are the clinical uses of estrogen replacement therapy?
Postmenopausal syndrome, hypogonadism, menstrual disorders, contraceptive, and advanced prostate cancer.
What is the role of estrogen in the body?
Responsible for the development of female genital tract, secondary sex characteristics, uterine endometrium, ovulation, and other functions.
What does progesterone do in the body?
Converts the uterine epithelium from proliferative to secretory phase, induces thermoregulation, and antagonizes aldosterone.
What are the clinical uses of synthetic progestin?
Treating menstrual disorders, cancers like endometrial and prostatic cancer, and as a contraceptive.
Describe the menstrual cycle feedback system.
Involves the hypothalamus, pituitary, ovary, and uterus in a complex feedback system regulating ovulation and menstrual cycle.
What is the normal length of the average menstrual cycle?
28 days, but it can vary between individuals and from one cycle to the next.
Explain the events that occur in the first week of the menstrual cycle.
Elevated levels of FSH and LH, followed by rising estrogen levels.
What does estrogen primarily do in the early stages of the menstrual cycle?
Causes the proliferation of the uterine lining (endometrium).
What is the role of viral neuraminidase in influenza virus replication?
It cleaves and removes sialic acid receptors from the cell surface for virus release.
How do approved drugs for influenza virus target viral gene transcription?
They selectively inhibit cap-dependent endonuclease, preventing viral mRNA synthesis.
Describe the composition of Human Immunodeficiency Virus (HIV).
It consists of an envelope, viral matrix, and core encasing RNA, reverse transcription, and integrase enzymes.
How does HIV infection initiate in CD4+ T lymphocytes?
It starts with binding of gp120 to CD4 receptor followed by binding to human co-receptor CCR5 or CXCR4.
What is the role of reverse transcriptase in HIV replication?
It converts the virus RNA into double-stranded DNA in the host cell cytoplasm.
Explain the function of HIV integrase in the replication process.
It transports viral DNA into the nucleus and inserts it into the host cell’s DNA.
How are new HIV viruses formed within the host cell?
Structural proteins and replication enzymes assemble with viral genomic RNA, then bud off the host cell.
How do Nucleoside reverse transcriptase inhibitors work against HIV?
They competitively inhibit reverse transcription by acting as structural analogues of nucleic acids.
Describe the mechanism of action of HIV protease inhibitors.
They prevent cleavage of viral polyproteins, necessary for assembling new viral particles.
How do Non-Nucleoside reverse transcriptase inhibitors act against HIV?
They bind and denature reverse transcriptase enzyme, preventing competitive inhibition.
Which receptor does Hepatitis B virus bind to on hepatocytes?
It binds to the receptor named Na taurocholate co-transporting polypeptide (NTCP).
What is the primary difference between Hepatitis B and Hepatitis C viruses?
Hepatitis B virus uncoats at the nuclear membrane releasing circular DNA, whereas Hepatitis C virus’s details are not described.
Name two examples of Gram-negative bacteria.
E. coli, Salmonella
Name two examples of Gram-positive bacteria.
Staphylococci, Listeria
What are the features of antibacterial drugs related to host toxicity?
Highly selective toxicity, low toxicity to host, high therapeutic index
What is the advantage of using bactericidal drugs?
Useful when host defenses can’t control the pathogen
What is the difference between bacteriostatic and bactericidal drugs?
Bacteriostatic drugs rely on host immunity; bactericidal kill bacteria.
What is the spectrum of activity for narrow-spectrum antibacterial drugs?
Work on Gram-positive or Gram-negative only
Why is the use of broad-spectrum antibacterial drugs disadvantageous?
Disruption of normal flora
List two mechanisms of action for antibacterial drugs.
Inhibition of cell wall synthesis, inhibition of DNA/RNA synthesis
What is the action of b-lactam drugs like penicillins and cephalosporins?
Inhibit enzymes involved in final steps of Gram-positive cell wall synthesis
What enzymes does fluoroquinolones inhibit for DNA synthesis?
Enzymes maintaining supercoiling of closed circular DNA
Which drug class reversibly binds to 30S subunit for protein synthesis inhibition?
Tetracyclines
Why are tetracyclines regarded as bacteriostatic?
Effective against certain Gram-positive and negative bacteria but not bactericidal
What is the active ingredient of Castor oil?
Ricinoleic acid
What type of laxative acts as a large bowel irritant?
Anthraquinones
Which antidiarrheal drug has a selective action only on the GI tract?
Loperamide
What is the main cause of death in children due to diarrhea?
Excessive loss of water and minerals
What type of drugs are categorized as diuretics?
Most used to increase urine excretion
What is the main action of Thiazides and related diuretics?
Reduce the circulating fluid volume
In which condition are bladder anti-spasmodics like Oxytrol used?
Overactive bladder (OAB)
What is the purpose of using Phenazopyridine as a urinary analgesic?
To reduce burning, pain, discomfort, and urgency associated with cystitis
How do uricosuric agents like Probenecid act in the treatment of gout?
By blocking reabsorption in the kidneys
What is the first-line therapy for treating benign prostatic hyperplasia?
Alpha-Blockers like Tamsulosin
What is the main role of FH4 in the cell?
FH4 transfers methyl groups essential for DNA synthesis, RNA, and proteins.
How is antitumor antibiotic Doxorubicin’s mechanism of action described?
Inserts between base pairs to block DNA and RNA synthesis; inhibits topoisomerase II.
What are the common adverse effects of Doxorubicin?
Irreversible heart problems, myelosuppression, hypersensitivity, nausea, red urine.
Explain the role of Gonadotropins in the body.
Stimulate gonads to secrete sex hormones, induce ovulation and sperm production.
What are the main categories of hormones that regulate the reproductive system?
Gonadotropins, Androgens, Estrogens, Progestins.
How is testosterone absorption affected in the body?
Testosterone is absorbed poorly from the GI tract and extensively metabolized in the liver.
What is the clinical use of synthetic androgens like testosterone?
Replacement therapy for insufficient endogenous production, available in parenteral and transdermal forms.
What type of feedback loop is more common in regulating the endocrine system?
Negative feedback loops are more common.
How are hormones transported in the endocrine system?
Hormones are transported in the blood.
What are the two types of feedback loops involved in regulating the endocrine system?
Negative feedback loops and positive feedback loops.
What glands secrete chemical messengers called hormones into the blood?
Ductless glands secrete hormones.
What controls the endocrine system through a feedback mechanism?
The hypothalamus, pituitary gland, and other endocrine glands.
What is the purpose of negative feedback loops in the endocrine system?
Negative feedback reverses changes in the controlled condition.
When do positive feedback loops occur in the endocrine system?
Positive feedback loops occur when hormone levels continue to rise in response to stimuli.
What are the potential consequences of disorders in the endocrine system and metabolism if left untreated?
Serious effects, and in some cases may be fatal.
How can drug treatments help individuals with disorders related to the endocrine system?
Control symptoms and restore normal health.
What hormone is involved in the improvement of cardiovascular functions during septic shock?
Adrenal corticosteroids.
What are the main drugs for diabetes mellitus?
Insulin and anti-diabetic drugs
How are insulin injections administered?
Parenterally, because insulin is destroyed in the GI tract
What is the role of insulin in the body?
Insulin helps regulate blood glucose levels
What is lipohypertrophy?
Localized fat accumulation due to insulin injections
What is the onset time of rapid-acting insulin?
Within 15 minutes
What is the peak action time of short-acting insulin?
2 to 3 hours
What are the side effects of long-acting insulin?
Hypoglycemia, swelling in arms and legs, ocular disturbance
What is the mechanism of action of sulfonylureas?
Stimulate insulin release from pancreatic beta cells
What are the side effects of biguanides like metformin?
Gastrointestinal symptoms, lactic acidosis
How do thiazolidinediones (Glitazones) work?
Enhance insulin sensitivity in peripheral tissues
What is the mechanism of action of a-glucosidase inhibitors?
Delay carbohydrate absorption in the gut
What do DPP-4 inhibitors (Gliptins) do?
Enhance incretin hormones, increase insulin release
How do GLT2 inhibitors work in diabetes treatment?
Block renal glucose reabsorption, increase urinary glucose excretion
What is the purpose of the last 7 days of placebo pills in combination birth control?
To allow estrogen and progestin levels to fall, triggering withdrawal bleeding.
How do multiphasic birth control pills differ from monophasic pills?
Multiphasic pills deliver varying hormone levels to mimic natural fluctuations.
What is the mechanism of action of progestin-only birth control pills?
They thicken cervical mucus and cause endometrial atrophy.
How can extended-cycle contraceptive regimens eliminate menstrual periods?
By continuously taking combined estrogen-progestin pills beyond the initial 3 weeks.
Why are progestin-only pills beneficial for women with contraindications to estrogen?
They provide contraception without the use of exogenous estrogen.
What is the role of LH and FSH suppression in combined estrogen-progestin birth control?
Suppressing LH and FSH inhibits ovulation.
How do anti-estrogens like tamoxifen function in the body?
They decrease estrogen levels or block estrogen receptors.
What is the primary clinical use of anti-progesterone medications?
They are used for labor induction, emergency contraception, and Cushing syndrome.
What is the mechanism of action of Clomid (clomiphene) in fertility treatment?
It inhibits estrogen feedback, stimulating FSH and LH release for ovulation.
What are the adverse effects associated with the use of Oxytocin for labor?
Adverse effects include postpartum hemorrhage and fetal hypoxia.
What are the typical side effects of antacids containing magnesium hydroxide?
Diarrhea
Which drug category irreversibly inhibits the H+/K+-ATPase in gastric parietal cells?
Proton pump inhibitors
How do antacids work in the stomach?
Neutralize acid, raising gastric pH
What is the function of mucus production in the gastrointestinal tract?
Creates a protective barrier maintaining pH balance
Which drug class is used for symptomatic relief in peptic ulcers?
Antacids
What is the role of histamine H2 receptor blockers in the treatment of peptic ulcers?
Inhibit acid production
How do proton pump inhibitors affect acid production in the stomach?
Irreversibly inhibit acid pumps
What is the primary effect of bulk laxatives in the intestine?
Increase bowel content volume
Which laxative class triggers peristalsis by causing reflex contractions?
Bulk laxatives
Which drug category is used to prevent and treat stomach ulcers by stimulating mucus and bicarbonate production?
Mucosal protective agents
What are the uses of PGF2a analogue?
Induction of labor and Abortion (combined with anti-progestrone)
List some adverse effects of PGF2a analogue.
Nausea, vomiting, abdominal pain, bronchospasm, hypotension
