APHY 102 module 5-6 flashcards based on study guide questions

what are the functions of the urinary system?

• Filters blood

• Removes metabolic wastes

• Maintains fluid volume, pH, and electrolyte balance

• Produces urine

• Produces erythropoietin and renin

• Activates vitamin D

what are the organs of the urinary system and their functions?

• Kidneys: Filter blood and form urine

• Ureters: Carry urine to the bladder

• Urinary bladder: Stores urine

• Urethra: Carries urine out of the body

where are the kidneys located?

• -Located on either side of the vertebral column on the posterior abdominal wall.

• -The left kidney sits slightly higher than the right.

what does retroperitoneal mean?

behind the parietal peritoneum

what is the renal cortex?

The outer region of the kidney that contains most renal corpuscles and cortical nephrons.

what is the renal medulla?

The inner region of the kidney made up of renal pyramids.

what is a nephron?

The functional unit of the kidney where urine is formed. Each kidney contains about one million nephrons.

identify the major kidney structures.

• Renal cortex

• Renal medulla

• Renal pyramids

• Renal columns

• Renal pelvis

• Major calyces

• Minor calyces

• Renal capsule

• Hilum

• Renal sinus

• Nephrons

what is erythropoietin?

A hormone produced by the kidneys that stimulates red blood cell production.

what is renin?

An enzyme released by the kidneys that helps increase blood pressure through the renin-angiotensin-aldosterone system (RAAS).

what is the blood flow through the kidney?

Renal artery → Segmental arteries → Interlobar arteries → Arcuate arteries → Cortical radiate arteries → Afferent arteriole → Glomerulus → Efferent arteriole → Peritubular capillaries → Cortical radiate vein → Arcuate vein → Interlobar vein → Renal vein

Describe blood flow through the nephron.

Afferent arteriole → Glomerulus (filtration) → Efferent arteriole → Peritubular capillaries (reabsorption and secretion).

what makes up the renal corpuscle?

• -Glomerulus

• -Glomerular (Bowman's) capsule

what structures make up the renal tubule?

Proximal tubule

Loop of Henle (descending and ascending limbs)

Distal tubule

Collecting duct

What is the pathway of urine formation?

Glomerular capsule → Proximal tubule → Loop of Henle → Distal tubule → Collecting duct → Renal papilla → Minor calyx → Major calyx → Renal pelvis → Ureter → Bladder → Urethra

Compare cortical and juxtamedullary nephrons.

Cortical (85%)

• Mostly in cortex

• Short loops

• Corpuscles near surface

Juxtamedullary (15%)

• Long loops

• Extend deep into medulla

• Important for concentrating urine and water balance

What is the function of the juxtaglomerular apparatus (JGA)?

• Monitors blood pressure

• Monitors NaCl concentration

• Regulates renin secretion

• Helps regulate GFR

What are the three processes of urine formation?

1. 1.Glomerular filtration

2. 2.Tubular reabsorption

3. 3.Tubular secretion

What is glomerular filtration rate (GFR)?

The amount of filtrate produced each minute by the kidneys (about 125 mL/min or 180 L/day).

How is GFR regulated?

• -Autoregulation

• -Juxtaglomerular apparatus (tubuloglomerular feedback)

• -Sympathetic nervous system

• -RAAS

• -ANP/BNP hormones

How are sodium and water reabsorbed?

• -Na⁺ is actively transported (mostly in proximal tubule)

• -Water follows Na⁺ by osmosis

• -ADH increases water reabsorption

• -Aldosterone increases Na⁺ reabsorption

Which ion is secreted to regulate pH?

Hydrogen ions (H⁺).

What is the countercurrent mechanism?

A mechanism in juxtamedullary nephrons that creates a hypertonic medulla, allowing water to be reabsorbed and concentrated urine to form.

What does aldosterone do?

Increases sodium reabsorption, causing water retention and increased blood volume.

What does ADH do?

Makes the distal tubules and collecting ducts permeable to water, increasing water reabsorption and producing concentrated urine.

Describe urea, uric acid, creatinine, and normal urine.

• -Urea: Protein metabolism waste

• -Uric acid: Nucleic acid metabolism waste

• -Creatinine: Muscle metabolism waste

• -Normal urine is about 95% water and contains urea, uric acid, creatinine, electrolytes, and small amounts of amino acids.

How is urine stored and eliminated?

Urine flows from collecting ducts → renal papilla → minor calyx → major calyx → renal pelvis → ureter → bladder → urethra.

What smooth muscle is found in the urinary bladder?

The detrusor muscle.

What is micturition?

The process of urination, involving contraction of the detrusor muscle and relaxation of the urethral sphincters.

What are electrolytes?

Charged ions dissolved in water, including Na⁺, K⁺, Ca²⁺, H⁺, OH⁻, Cl⁻, and Mg²⁺.

What are intracellular fluid (ICF) and extracellular fluid (ECF)?

• ICF: Fluid inside cells

• ECF: Fluid outside cells

Define interstitial fluid, blood plasma, lymph, and transcellular fluid.

• Interstitial fluid: Between tissue cells

• Blood plasma: Fluid in blood vessels

• Lymph: Fluid in lymphatic vessels

• Transcellular fluid: CSF, synovial fluid, eye fluids, serous fluid

Which ions are most abundant in extracellular fluid?

• Sodium (Na⁺)

• Chloride (Cl⁻)

• Calcium (Ca²⁺)

• Bicarbonate (HCO₃⁻)

Which ions are most abundant in intracellular fluid?

• Potassium (K⁺)

• Magnesium (Mg²⁺)

• Phosphate (PO₄³⁻)

• Sulfate (SO₄²⁻)

What controls water intake and water output?

• Water intake is controlled by the thirst center in the hypothalamus.

• Water output is controlled by the kidneys through ADH.

How does ADH respond to dehydration and excess water?

• Dehydration: ADH increases → more water reabsorbed → less, concentrated urine.

• Excess water: ADH decreases → less water reabsorbed → more dilute urine.

What are dehydration and water intoxication?

• Dehydration: Loss of more water than is taken in, causing increased osmotic pressure and increased ADH.

• Water intoxication: Excess water intake dilutes body fluids, decreases ADH, and increases urine output.

What is electrolyte balance?

Electrolyte balance is maintaining equal amounts of electrolytes entering and leaving the body so homeostasis is preserved.

What are the male and female gonads, and what are their main functions?

Testes (male gonads) produce sperm and male sex hormones. Ovaries (female gonads) produce oocytes (ova) and female sex hormones.

How many chromosomes do sex cells have? How many do other body cells have?

Sex cells are haploid and have 23 chromosomes (1 set). Other body cells are diploid and have 46 chromosomes (2 sets).

What is meiosis?

Meiosis is a special type of cell division that produces sex cells (gametes) and reduces the chromosome number from 46 to 23.

What are the similarities and differences between meiosis and mitosis?

Both: begin after DNA replication and use spindle fibers. Mitosis: one division → 2 identical diploid cells. Meiosis: two divisions (I and II) → 4 genetically different haploid cells. Meiosis includes synapsis and crossing over; mitosis does not.

What are the major steps of meiosis, and when does crossing over occur?

Meiosis I: Prophase I (synapsis + crossing over), Metaphase I, Anaphase I, Telophase I. Meiosis II: Prophase II, Metaphase II, Anaphase II, Telophase II. Crossing over occurs during Prophase I between homologous chromosomes to exchange genetic material and increase genetic variation.

What are the primary sex organs of the male reproductive system?

The two testes are the primary sex organs. They produce sperm cells (spermatozoa) and male sex hormones.

What are the secondary sex organs of the male reproductive system?

Accessory organs include the epididymis, ductus (vas) deferens, ejaculatory ducts, seminal vesicles, prostate gland, bulbourethral glands, urethra, penis, and scrotum. They transport, nourish, and help deliver sperm outside the body.

What is the role of the gubernaculum in testicular descent?

the gubernaculum is a fibrous cord that guides the testes through the inguinal canal into the scrotum, usually 1–2 months before birth under the influence of testosterone.

What are the functions of the seminiferous tubules and interstitial cells?

Seminiferous tubules: site of sperm production. Interstitial (Leydig) cells: produce and secrete testosterone and other androgens.

What is the function of the epididymis?

The epididymis promotes sperm maturation, stores sperm, and transports sperm from the testis to the ductus deferens.

What is the location and function of the ductus (vas) deferens?

It is a 45-cm muscular tube that is part of the spermatic cord and extends from the epididymis to the ejaculatory duct. Its function is to convey sperm to the ejaculatory duct.

What are the functions of the seminal vesicles?

They secrete an alkaline fluid containing fructose and prostaglandins, help regulate pH in the reproductive tracts, and contribute most of the volume of semen. PowerPoint

What are the functions of the prostate gland?

The prostate surrounds the proximal urethra and secretes a thin, milky, alkaline fluid (including citrate) that enhances sperm motility and contributes to semen volume.

What are the functions of the bulbourethral glands?

They secrete a mucus-like fluid into the urethra during sexual stimulation that lubricates the end of the penis.

Which male reproductive structures are paired and which are unpaired?

Paired: testes, epididymides, ductus deferentia, seminal vesicles, bulbourethral glands. Unpaired: prostate gland, urethra, penis, scrotum. PowerPoint

What is semen composed of?

Semen contains sperm from the testes plus secretions from the seminal vesicles, prostate gland, and bulbourethral glands. It is slightly alkaline (pH ≈ 7.5) and contains nutrients and prostaglandins

What are the male external reproductive organs?

the scrotum and the penis

Describe erection, orgasm, emission, and ejaculation.

Erection: parasympathetic stimulation → nitric oxide → arterial dilation → blood fills erectile tissue.

Orgasm: culmination of sexual stimulation.

Emission: movement of semen into the urethra.

Ejaculation: movement of semen out of the urethra; both depend on sympathetic impulses.

What are the characteristics and actions of testosterone?

Testosterone is the principal androgen produced by Leydig cells. It causes development of male reproductive organs, testicular descent, enlargement of testes and accessory organs, body hair growth, deeper voice, increased muscle and bone growth, thicker skin, increased red blood cell production, and increased cellular metabolism.

Define spermiogenesis and spermatogenesis.

Spermiogenesis: development of spermatids into sperm.

Spermatogenesis: the combined processes of meiosis + spermiogenesis that produce sperm cells.

How many sperm cells are produced from one primary spermatocyte?

Four sperm cells are produced from the meiosis of one primary spermatocyte.

What is the function of sustentacular (Sertoli) cells?

They support, house, and nourish developing spermatogenic cells throughout spermatogenesis.

What are the main parts of a sperm cell and their functions?

Head: nucleus (23 chromosomes) + acrosome (enzymes for penetrating the oocyte).

Midpiece: mitochondria that produce ATP.

Tail/flagellum: propels the sperm toward the egg.

What are the functions of GnRH, LH, and FSH in the male?

GnRH: stimulates the anterior pituitary to release LH and FSH. LH (ICSH): stimulates Leydig cells to produce testosterone. FSH: stimulates Sertoli cells, which—together with testosterone—promote spermatogenesis.

What are the primary and secondary female sex organs?

Primary: ovaries.

Secondary (accessory): uterine tubes, uterus, vagina, and the external genitalia (vulva).

How are oocytes produced, and what are the stages of follicle development?

Oogonia → primary oocytes (formed before birth and arrested in meiosis I) → secondary oocyte + first polar body at ovulation → meiosis II completes only if fertilization occurs. Follicles mature as primordial → primary → pre-antral → antral → mature (Graafian) follicles.

Where are the ovaries, uterine tubes, uterus, and vagina located, and what do they do?

Ovaries: lateral pelvic cavity; produce oocytes and hormones.

Uterine tubes: connect ovaries to uterus; transport the oocyte and embryo.

Uterus: hollow muscular organ that receives and sustains the embryo.

Vagina: fibromuscular tube between uterus and exterior; receives the penis, conveys secretions, and serves as the birth canal.

Where does fertilization occur?

Fertilization occurs in the uterine (fallopian) tube, usually near the ampulla.

What are the layers of the uterine wall?

Endometrium (mucosa), Myometrium (smooth muscle), and Perimetrium (serosa).

Define cervix, vulva, labia majora, labia minora, clitoris, and vestibule.

Cervix: lower third (neck) of the uterus extending into the vagina.

Vulva: all external female genitalia.

Labia majora: fatty protective folds.

Labia minora: inner vascular folds that protect the openings.

Clitoris: erectile organ rich in sensory nerves.

Vestibule: space between the labia minora containing the urethral and vaginal openings.

A surge of which hormone triggers ovulation?

A surge of LH (luteinizing hormone) triggers ovulation. PowerPoint

What are the functions of GnRH, LH, and FSH in the female?

GnRH: stimulates pituitary release of FSH and LH. FSH: stimulates follicle maturation and estrogen production by granulosa cells. LH: stimulates ovarian cells and triggers ovulation and corpus luteum formation.

What are the functions of estrogens and progesterone?

Estrogens: enlarge accessory reproductive organs, thicken the endometrium, and maintain female secondary sex characteristics (breast development, fat distribution, increased skin vascularization).

Progesterone: stimulates uterine changes during the menstrual cycle, makes the endometrium more glandular and vascular, affects mammary glands, and helps regulate gonadotropin secretion

Explain the menstrual cycle and ovulation.

Ovarian phases: Follicular (FSH → follicle matures) →

Ovulation (LH surge releases secondary oocyte) → Luteal (corpus luteum secretes estrogen, progesterone, and inhibin).

Uterine phases: Proliferative (estrogen thickens endometrium) → Secretory (progesterone makes it glandular/vascular) → Menstrual (lining sloughs off when the corpus luteum degenerates).

What is endometriosis?

Endometriosis is the growth of endometrial tissue in the abdominal cavity, which can cause fibrosis, encase the ovary, or obstruct the uterine tubes.

What is menopause?

Menopause is the cessation of menstrual cycles for 1 year, usually in the late 40s or early 50s. Ovarian estrogen and progesterone production decreases, some secondary sex characteristics may diminish, osteoporosis risk increases, and many women experience hot

What are the characteristics of the mammary glands?

They are accessory reproductive organs located in the subcutaneous tissue of the breasts. Each gland has 15–20 lobes containing alveolar glands → alveolar ducts → lactiferous ducts → nipple. The nipple is surrounded by the areola, and suspensory ligaments support the breast. Ovarian hormones stimulate their development at puberty.

How do the major types of birth control work?

Withdrawal: prevents sperm entry (low effectiveness).

Rhythm: avoids intercourse around ovulation.

Barrier methods (condoms): physically block sperm.

Spermicides: chemically kill sperm.

Combined hormonal contraceptives: provide estrogen/progestin, suppress FSH and LH, prevent follicle maturation and ovulation, and thicken cervical mucus.

Medroxyprogesterone injection: prevents ovulation.

IUD: creates a uterine environment toxic to sperm and oocytes and prevents pregnancy.

Emergency contraception: temporarily stops ovulation if taken within 3–5 days.

Vasectomy: cuts the ductus deferens.

Tubal ligation: cuts the uterine tubes.