bio 224 exam 5

endocrine & reproductive systems

What are the two primary extrinsic regulators? How do they work?

• Nervous system- works by spitting neurotransmitters

• Endocrine system- works by spitting hormones

Function of the Endocrine System

• Extrinsic regulation/control (Maintain homeostasis)

  • ex. hormones to control HR, BP, fluids, immunity, digestion, blood cell formation, etc.

Human endocrine glands (from top to bottom) (9 to list)

• Pineal gland

• hypothalamus

• Anterior & posterior pituitary glands

• Thyroid gland

• Parathyroid glands

• Thymus gland

• Adrenal gland

• Pancreas

• Gonads (testes/ovaries)

How does something qualify as an endocrine gland?

• For something to qualify as an endocrine gland, at least ½ of its function must be endocrine

  • This is why we have many hormone producing organs that aren’t considered as endocrine glands since it isn’t their primary function, such as the heart & kidneys

nervous regulation vs. endocrine regulation

• how quickly does it act & how long does it last? includes what type of modulated signal goes with each (frequency vs. amplitude)

• Nervous regulation

  • Very fast-acting, but short lived

  • Frequency-modulated signal- the use of neurotransmitters to control some distant target. To get more control, must “spit” more on it (more frequently)

• Endocrine regulation

  • slower-acting, but lasts longer

  • Amplitude-modulated signal- the use of hormones to control a target. To get more control, must spit more hormone

Endocrine vs. Exocrine glands (do they have a duct? What do they make/spit out? Where do they spit it out?)

both are multicellular glands

• Endocrine glands

  • no duct

  • spit out hormones directly into blood

• Exocrine glands

  • duct

  • spit out products thru a duct onto a surface

hormones

a chemical messenger. These give a simple (direct, short, & specific) commands to target cells

classes of chemical messengers (4 types)

• Endocrine- secretes hormones that travel thru blood & work on distant cells with the right receptor for the hormone

• Paracrine- secretes chemical to nearby cell

  • ex. prostaglandins & histamine

• Autocrine- cell spits autocrine chemical on itself

  • ex. platelets

• Neurotransmitters (NT)- spit out by neurons. Affect the target cells with receptors for that NT.

Chemical classification of human hormones (2 types)

(include their naming scheme)

• Proteins

  • tend to end in -in, -en, or -ine (often more than 1 word)

• Lipids

  • tend to end in -one (often 1 word long)

Cells & specificity

• A cell can’t respond to a hormone/ligand unless it has a receptor for that specific hormone.

How protein vs. lipid hormones enter & control a cell (know the parts involved (mainly the type of receptor))

• Protein hormones

  • Membrane-bound receptor- a receptor that’s a protein & part of the cell membrane. Receives chemicals that are too large (proteins)

  • 2nd messenger- usually cAMP. Hormone binds to a G prot. & needs a second helper (the 2nd messenger) (cAMP)

    • This is bc. the prot. hormone needs help from something inside the cell

• Lipid hormones

  • These can go thru the cell membrane.

  • Intracellular receptor- a receptor that responds to a hormone (lipid) that can pass thru the CM

  • Direct gene activation- What lipid hormones tend to do. Use intracellular receptor, then go right into the nucleus to turn specific genes on or off

Most human hormones are proteins or lipids?

proteins

What are the 2 things to consider with protein hormones?

• up & down regulation

• signal amplification

Up & down regulation

• Down regulation- reducing the number of receptors when there’s lots of hormone around. Cell is less sensitive to hormone.

• Up regulation- increases the number of receptors when there’s little hormone around. Cell is more sensitive to hormone.

Signal amplification

• Protein hormones make use of intracellular enzymes, and enzymes can catalyze a reaction over & over again

• Signal amplification- huge effect from one hormone due to enzymes

How are endocrine glands controlled? (stimuli) (Meaning how the hormones are controlled) (3 ways)

• includes the definition for tropic hormone

• Neural stimulus- when a neuron/Nervous system is in charge of the endocrine gland. (spits NT)

• Hormonal stimulus- when one endocrine gland is in charge of another endocrine gland

  • Tropic hormone- a hormone whose target is another endocrine gland

• Humoral stimulus- humoral means controlled by something in the blood. Something in the blood is in charge of the endocrine gland.

Who’s in charge of the endocrine system? How does it make a decision? (includes definition of neuroendocrine structure)

• The hypothalamus is in charge of the endocrine system

  • Pituitary gland has lots of capillaries going thru it

  • Hypothalamus has neurons & is chemically sensitive. Acts like a “tongue” to “taste” & monitor blood. Makes a decision to tell us what to do.

• Hypothalamus makes a decision thru…

  • longer hypothalamus neurons releasing its own hormones into the capillaries (blood) in posterior pituitary gland.

    • Occurs in post. pituitary gland. Doesn’t really act as a gland, more as a “basement” of the hypothalamus

      • ex. ADH is made by hypothalamus but released by post. pituitary gland

    • The hypothalamus is a neuroendocrine structure (a bunch of neurons that spit hormones into bloodstream)

  • shorter hypothalamus neurons spitting their chemicals into a capillary into the anterior pituitary gland

    • Anterior pituitary gland has glandular cells in it & gets told what to do by tropic hormones from the hypothalamus

Hormones produced by the pineal gland (only 1 hormone & 1 special note)

• List the chemical class (prot. or lipid), when its released, its target cells, the effects/results, & any special notes (last one doesn’t apply to all hormones)

Note: pineal gland is a neuroendocrine structure

• Melatonin

  • a protein

  • Targets reticular formation of brain

  • regulates sleep/wake cycle & promotes sleep

  • regulated by light. darker = release more melatonin

Special note for pineal gland

• Seasonal affective disorder (SAD)

  • results from making too much melatonin (too much darkness)

  • a type of seasonal depression. “Cabin fever”

Hormones produced by the hypothalamus (stored in post. pituitary gland) (6 total, 4 are tropic) (1 special note)

• List the chemical class (prot. or lipid), when its released, its target cells, the effects/results, & any special notes (last one doesn’t apply to all hormones)

note: these are ALL PROTEINS

• antidiuretic hormone (ADH)

  • released when blood is too concentrated

  • targets the kidneys

  • inc. water reabsorption & inc. blood volume

  • Special note: hyposecretion of ADH results in diabetes insipidus (very high urine volume since water isn’t being reabsorbed)

    • polyuria- urinating a lot

• oxytocin

  • released when uterus stretches or infant suckling on nipple

  • targets the uterus &/or mammary glands

  • effects: labor pains (strong uterine contractions) (this is bc oxytocin is a powerful smooth musc. constrictor) & milk ejection from breast

• thyrotropin-releasing hormone (TRH)

  • targets & stimulates the thyroid-stimulating hormone (TSH) & prolactin, both in ant. pit. gland

  • a tropic hormone (controls ant. pit. gland)

• corticotropin-releasing hormone (CRH)

  • targets & stimulates the adrenocorticotropic hormone (ACTH) in the ant. pit. gland

  • a tropic hormone (controls ant. pit. gland)

• gonadotropin-releasing hormone (GnRH)

  • targets & stimulates the Luteinizing Hormone (LH) & follicle stimulating hormone (FSH) in the ant. pit. gland

  • a tropic hormone (controls ant. pit. gland)

• growth hormone-releasing hormone (GRHR)

  • targets & stimulates the growth hormone (GH) in the ant. pit. gland

  • a tropic hormone (controls ant. pit. gland)

Hormones produced by the anterior pituitary gland (6 total) (1 special note)

• List the chemical class (prot. or lipid), when its released, its target cells, the effects/results, & any special notes (last one doesn’t apply to all hormones)

note: these are ALL PROTEINS

• thyroid-stimulating hormone (TSH)

  • released due to TRH (thyrotropin-releasing hormone)

  • targets thyroid gland (making it a tropic hormone)

  • effect: produce more thyroid hormones

• adrenocorticotropic hormone (ACTH)

  • released due to corticotropin-releasing hormone (CRH)

  • targets adrenal cortex (making it a tropic hormone)

  • effect: release adrenal steroids

• prolactin (first milk protein)

  • released due to TRH (thyrotropin-releasing hormone)

  • targets mammary gland

  • effect: milk production & activation of mammary glands

• Luteinizing hormone (LH)

  • released due to gonadotropin-releasing hormone (GnRH)

  • targets testes or ovaries

  • effects: testosterone production (in men) or ovulation (in women)

• follicle-stimulating hormone (FSH)

  • released due to gonadotropin-releasing hormone (GnRH)

  • targets testes or ovaries

  • effects: production of sperm cells (in men) or maturing of follicles of the ovary (in women)

• growth hormone (GH)

  • released due to growth hormone-releasing hormone (GHRH)

  • targets most tissues (often muscles & bone)

  • effects: promotes growth & mitosis of cells

  • special notes:

    • pituitary giantism- producing too much (hypersecretion) GH

    • pituitary dwarfism- producing too little (hyposecretion) GH

thyroid microscopy (follicle & parafollicular cells)

• note: these look like “lakes” with the colloid (fluid) being the “water” of the lake.

• Follicle= the “shoreline” of the lake

• parafollicular cells= cells next to the follicle cells but have no colloid in them

Hormones produced by the thyroid gland (2 total) (1 special note)

• List the chemical class (prot. or lipid), when its released, its target cells, the effects/results, & any special notes (last one doesn’t apply to all hormones)

• Calcitonin (bone builder hormone)

  • protein

  • made by parafollicular cells

  • released when there’s high blood calcium concentration

  • targets osteoclasts (bone destroyers)

  • effect: inhibits osteoclast activity (inc. bone density, dec. blood calciuim)

• Thyroid hormone (T₃ & T₄)

  • Protein, but acts like a lipid!!! (the only exception to this rule)

  • made by follicle cells

  • released due to TSH from ant. pit.

  • targets nearly every cell in the body

  • effects: sets basal metabolic rate, thermoregulation, & growth

• Special notes:

  • T₃ & T₄ require iodine ions

  • take iodine out of blood & put in colloid to make T₃ & T₄

    • If low or no iodine in blood, T₃ & T₄ can’t be made. Follicle cells get hit with TSH, so they make protein sections while waiting for iodine, which will then swell up & cause a goiter (enlarged thyroid gland)

      • treatment: give limited iodine. Too much iodine will cause thyroid storm, causing death

Hormones produced by the parathyroid gland (only 1)

• List the chemical class (prot. or lipid), when its released, its target cells, the effects/results, & any special notes (last one doesn’t apply to all hormones)

• Parathyroid hormone (PTH) (bone breaker hormone)

  • protein

  • released due to low blood calcium concentration

  • targets osteoclasts

  • effects: increases osteoclast activity (dec. bone density, inc. blood calcium)

Hormones produced by the thymus gland (only 1)

• List the chemical class (prot. or lipid), when its released, its target cells, the effects/results, & any special notes (last one doesn’t apply to all hormones)

• Thymosin

  • protein

  • released/regulated by age

  • targets T lymphocytes

  • effects: promotes T lymphocyte maturation

microscopic anatomy of adrenal gland

• Cortex- outer layer. Made of 3 layers with each producing a different hormone: (outer to inner)

  • zona glomerulosa

  • zona fasciculata

  • zona reticularis

• Medulla- inner layer. has many blood vessels.

  • It’s another neuroendocrine structure

Hormones produced by the adrenal gland (4 total) (separated by adrenocortical (3) & adrenal medullary (1))

• List the chemical class (prot. or lipid), when its released, its target cells, the effects/results, & any special notes (last one doesn’t apply to all hormones)

Adrenocortical hormones (ALL LIPIDS)

• Aldosterone (mineralocorticoids)

  • made in glomerulosa

  • released due to angiotensin-II or ACTH to save more sodium

  • targets DCT/CD

  • effects: inc. sodium reabsorption

• Cortisol (glucocorticoid) “glucose sparing hormone”

  • made in fasciculata

  • released due to ACTH

  • targets many, but not all tissues in body

  • effects: increases gluconeogenesis, prot. & lipid metabolism, & inhibits inflammation

• Androgens (androgenic steroids) (testosterone)

  • made in reticularis

  • released due to ACTH

  • targets many tissues, including brain, bone, & reproductive

  • effects: inc. pubic hair & libido (sex drive)

Adrenal medullary hormones

• Epinephrine (80% epi, 20% norepinephrine)

  • protein

  • released due to stimulation from preganglionic sympathetic neurons (sympathetic div. of ANS)

  • targets most cells of the body

  • effects: inc. heart rate, dilate bronchioles & dilate pupils

Hormones produced by the pancreas (only 2) (1 special note)

• List the chemical class (prot. or lipid), when its released, its target cells, the effects/results, & any special notes (last one doesn’t apply to all hormones)

Note: BOTH PROTEINS

• Insulin

  • made by beta cells in pancreatic islets

  • released due to lots of blood glucose

  • targets most cells, often on skeletal muscle

  • effects: stimulates glucose uptake (makes glucose move into cells). Decreases blood glucose

• Glucagon

  • made by alpha cells in pancreatic islets

  • released due to low blood glucose. release when “gluca is gone”

  • targets mostly liver & adipose

  • effects: gluconeogenesis (make new glucose), glycogenolysis (break apart glycogen), & break apart fat & protein. increases blood glucose

• Special note: diabetes mellitus

  • Glucose/insulin-related diabetes

  • Two types:

    • Type I (juvenile onset) (born with) (insulin-dependent)

      • 5-10% of cases

      • Could be…

        • autoimmune destruction of islets

        • genetic nonfunctioning insulin or insulin receptors

      • without insulin, blood glucose gets high

    • Type II (adult onset) (usually shows up when 45 or older) (non-insulin dependent)

      • 90% of cases

      • Is usually…

        • gradual reduction in tissue response to insulin

        • some adipose cells produce a chem. that reduces g uptake

      • not responding to insulin make blood glucose levels high

      • Type II can become insulin dependent if islets atrophy

not enough insulin vs. too much insulin

• Not enough insulin

  • cells get starved for glucose

  • fat & prot. metabolism makes too many ketones. ketoacidosis

  • problem for type I mostly

• Too much insulin

  • blood glucose falls too fast

  • hypoglycemia

  • N.S. problems

  • “insulin shock”

GLP-1 drugs

• these drugs activate glucagon receptors on alpha cells of pancreas

• Makes the pancreas “think” there’s plenty of glucagon around so less is released (less hunger). Often, more insulin released & blood sugar goes down

diabetes insipidus vs. diabetes mellitus

• Diabetes insipidus- related to hyposecretion of ADH (urinating a lot)

• Diabetes mellitus- glucose/insulin-related diabetes.

prostaglandins

a group of chemicals (lipids) that trigger inflammation & ramp up effects of histamine to make capillaries more leaky. also causes motility of sperm cells

infundibulum

the stalk that connects the pituitary gland to the hypothalamus

hypophysis

another name for the pituitary gland

neurohypophysis

refers to the posterior pituitary gland. neuro- refers to it being made up of nervous tissue

adenohypophysis

refers to the anterior pituitary gland. adeno- refers to how the anterior pit. gland is a true gland made of hormone-secreting epithelium unlike the post. pit. gland, which is more like a basement to the hypothalamus

anabolic steroids

drugs that mimic the effects of testosterone, often abused to enhance athletic performance & increase muscle mass

androgen, EPO, & GHB abuse

• androgen- mimics the effects of testosterone & abused for body & performance enhancement. Can increase mortality

• EPO- used to increased red blood cell mass, allowing the body to transport more oxygen & increase stamina, but can result in clotting

• GHB- a drug abused for building muscles, weight loss, libido (sex drive), & for its calming, euphoric effect. Overdose can result in coma or death

meiosis

• production of sex cells (gametes). (sperm cells & egg cells)

• DNA replicates once & divides twice

  • results in haploid cells (cells have ½ the normal chromosome number)

    • Normal chromosome number: 46 chromosomes

    • Haploid chromosome number: 23 chromosomes

oogenesis vs. spermatogenesis

• oogenesis- meiosis in the ovaries, making egg cells

• spermatogenesis- meiosis in the testes, making sperm cells

functions of the reproductive system (3 to list)

• produce & deliver gametes (sex cells produced by meiosis)

• Produce sex hormones (testosterone, estrogens, & progesterone)

• fertilization (joining of 2 sex cells) / gestation (where it occurs)

major reproductive hormones in males (5 to list)

• list the source, what it targets, & effects.

• includes definition for secondary sex characteristics

• gonadotropin-releasing hormone

  • from hypothalamus

  • targets ant. pit to make LH & FSH

• follicle-stimulating hormone (FSH)

  • from ant. pit

  • targets testes (nurse cells) to start spermatogenesis (making sperm cells)

• luteinizing hormone (LH)

  • from ant. pit.

  • targets testes (interstitial cells) for secretion of testosterone

• testosterone

  • from testes (interstitial cells)

  • primarily targets other body tissues to stimulate the development of reproductive organs & secondary sex characteristics

    • secondary sex characteristics- things attributed to “maleness” like facial hair, deeper voice, more skeletal muscle. NOT the gonads/sex chromosomes

• inhibin

  • from testes (nurse cells)

  • targets ant. pit. to inhibit FSH

male reproductive organs & accessory organs (this is basically what was covered in lab)

• testes

• scrotum

• penis

• seminal vesicle

• prostate gland

• bulbourethral gland

• ejaculatory duct

• vas deferens

• urethra

• epididymis

testes

• What temperature is necessary for max. sperm cell production? List the 5 anatomical features associated with this

• Where sperm is made

• require 2-5 degrees Fahrenheit below normal body temp. for max sperm cell production

Anatomical features associated with testes:

• scrotum- sac of skin seen externally that holds the testes

• raphe- a seam on the scrotum that indicates where the scrotal septum is (divides the 2 testicular chambers from each other). This is where the dartos muscle anchors itself

• dartos muscle- layer of smooth muscle inside the scrotum. Pulls testes to each other (contract) or farther apart from one another (relax) for temperature regulation

  • If it’s too cold, testes get closer to conserve heat, & vice versa.

• cremaster muscle- mostly skeletal muscle with some smooth muscle. fibers run up to pull a testes up (contracts) or let the testes hang low (relax) for temperature regulation

• spermatic cord (includes testicular artery & vein)- anterior to pubic bone. Blood vessels have countercurrent heat exchanger.

  • artery carries hotter blood down, veins carry cooler blood back. Artery loses heat to the vein on the way down, which makes testicular blood cooler

Internal structures of testes & epididymis (3 structures & 2 types of cells)

• seminiferous tubule- where sperm cells are made (spermatogenesis). Target of FSH. also makes inhibin.

  • Interstitial cells- tend to clump in triangular arrangements. Targets of LH to make testosterone

  • Nurse cells- cells in the wall of seminiferous tubule. These protect & guide developing sperm cells. These are the ones that are the target of FSH & make inhibin

    • Developing sperm cells are between nurse cells rather than inside them

  • 300-400 million sperm cells formed per day in the two testes. Not all of them are good, though!

• epididymis- where spermiogenesis (maturing of sperm cells) occurs. Tube is 20ft long & 20 days for sperm cells to develop.

  • Sperm cell will be fully mature by the time it reaches the tail of epididymis

  • Sperm is released from the tail at ejaculation

• vas deferens- a tube that carries semen from the epididymis to the ejaculatory duct (going into urethra). Done thru peristalsis

germ cell

• a cell that can only become one thing, it just isn’t that thing yet.

  • ex. spermatogonium will become a sperm cell, but it isn’t one yet.

spermatogenesis (4 parts)

• This is meiosis that makes sperm cells

• spermatogonium- a germ cell that’ll become a sperm cell

  • undergoes understood mitosis. One goes into meiosis, the other stays behind so you don’t run out.

• Becomes a primary spermatocyte- goes into meiosis I.

• Meiosis I produces secondary spermatocytes- goes into meiosis II, producing gametes (in testes, 4 haploid spermatids)

spermatid

immature sperm cell. “spermakid.” Created after spermatogenesis to go into spermiogenesis

spermatozoa

sperm cell

spermiogenesis

• Occurs in the epididymis. The maturing of sperm cells, going from a spermatid to a sperm cell (spermatozoa)

• Grows a tail, develop nucleus, get mitochondria, & make an acrosome

• Takes about 20 days to develop.

sperm cell parts (list the 3 regions & 3 structures)

• acrosome- in the nose of the sperm cell. Has hydrolase enzymes to digest its way into the oocyte for fertilization.

• head- where the nucleus is. Where the 23 chromosomes would be

• neck/midpiece- below the head. has mitochondria in it

• The only human cell with flagella (tail)

What happens when sperm cells aren’t released?

They’ll get torn up by macrophages & recycle/reuse parts that can be used.

vasectomy

• Reproductive surgery.

• Cut the vas deferens & tie the two ends off, leaving the sperm cells nowhere to go.

semen

a milky white, somewhat sticky mixture of sperm cells (5% of total volume) & fluids from accessory glands (95% of total volume)

accessory glands (3 to list)

• List the percentages for semen volume & the function of each gland

These accessory glands produce most of semen

• 2 seminal vesicles- makes 60% of semen’s volume.

  • Secretes slightly alkaline (basic) fluid with nutrients (fructose), prostaglandins (cause motility of sperm cells, so flagella don’t work til this point), & coagulating/clotting factors (helps semen hold together. Gets “clotty" & the longer it holds together, the greater the chance for pregnancy)

• 1 prostate gland- makes 30% of semen’s volume.

  • Releases slightly alkaline fluid. Small anticoagulant (so we don’t clot too hard) & has immunological function (antibiotic called seminal plasmin)

    • PSA- one of the anticoagulant enzymes. If amount is abnormally high, can indicate prostate cancer

• 2 bulbourethral glands- makes 5% of semen’s volume

  • secretes mucus that lubricates glans (head of penis) & neutralize acidic urine in urethra. (lower pH can kill sperm cells). This fluid is called pre-ejaculatory fluid

average ejaculate (semen released)

2.75 ml of semen with 182 million+ sperm cells (this is a lower amount compared to before & there are lower birth rates now)

emission

the movement of sperm cells & fluid (semen) into urethra by peristalsis in the ducts (vas deferens & urethra) (spinal reflex) (sympathetic)

ejaculation

another sympathetic spinal reflex causing MORE peristalsis & contractions of a few skeletal muscles (bulbospongiosus & ischiocavernosus). propel the semen out of the body

Fertile (3 qualifications) (includes definitions for infertile & sterile)

• must be at least 20 million sperm cells/ml

• 60% must be “normal shape”

• 40% must be “good swimmers”

All qualification must be met to be considered fertile

• infertile means not likely to cause pregnancy (but not impossible)

• sterile means no chance for pregnancy (become sterile after vasectomy)

capacitation (2 parts to it)

Sperm cell must be capacitated prior to fertilizing anything or else they won’t do anything. This is a two-step process.

1. Motility- sperm needs to begin moving their flagella. Happens in a male system after seminal vesicles add their fluid. occurs in MALE

2. Weakening of acrosomal membrane- this happens in the acidic female reproductive tract. occurs in FEMALE

process of erection (List the tissues involved & how they work)

• 3 erectile bodies: 2 corpora cavernosa & 1 corpus spongiosum

  • Corpus Spongiosum (CS)- forms head of penis & surrounds urethra

    • Males have one spongiosum, women have two (under the labia)

    • stays soft during erection

  • Corpora cavernosa (CC)- two bodies of erectile tissue that are on the top of the penis

    • Men have two corpora cavernosa, women have one (the clitoris)

    • becomes rigid during erection

• Erectile tissues: highly vascular, many chambers, smooth musc., fibers.

  • CS has extra elastin in it (allows it to stay soft & squishy, even during erection)

  • erection gets more blood into these tissues

    • Need to dilate smooth musc. to allow more blood into these tissues.

    • Erection: The idea here is to cause relaxation of smooth musc. cells in the arterioles that lead into the erectile tissues. These are parasympathetic reflexes

      • cGmP causes relaxation

        • PDE-5- an enzyme that breaks apart smooth musc. relaxer (cGmP) & ends erection

          • Sildenafil (Viagra) blocks PDE to prolong vasodilation & lower BP

      • dilated arterioles will push against corresponding veins & slow venous return

perineum

diamond-shaped area between the thighs bordered by pubic symphysis anteriorly, ischial tuberosities laterally, & coccyx posteriorly.

inguinal hernia

abdominal contents protruding thru the inguinal canal

cryptorchidism

a disorder where the testes don’t descend into the scrotum, causing sperm cells to not be produced

oligospermia

a condition where there are fewer sperm cells in semen than normal

circumcision

the prepuce (foreskin, the loose skin covering the penis & forming a circular fold) getting removed shortly after birth

orgasm

the time period when the greatest feelings of pleasure are experienced during sexual stimulation. In males, this coincides with ejaculation

how the scrotum & descent of testes aid in sperm cell formation

• Scrotum- aids thru temperature regulation (controlled thru testicular artery & vein and by adjusting proximity to the body cavity

• Descent of testes- testes must descend into the scrotum, bringing them to a cooler temperature necessary for maximum sperm production. Otherwise, sperm cells won’t be produced

Timeline of oogenesis (when does it start & end?)

• Oogenesis begins before birth & ends during menopause (when menstruation ends)

  • notice how this is different from men where they start making sperm during puberty & continue until death

What happens to the primary oocytes at birth?

• At birth, there are about 400,000-500,000 primary oocytes frozen at Prophase I (an early stage in meiosis).

• Stays frozen until FSH (which starts puberty) stimulates follicles (in ovary)

oogenesis (in simpler steps, based on the first document)

• meiosis that occurs in the ovaries to produce egg cells (ovum)

• oogonium- the germ cell that undergoes understood mitosis

• oogonium becomes the primary oocyte- goes into meiosis I

• Becomes a secondary oocyte- goes into meiosis II

• Produces a gamete (only one ovum) (ONLY after fertilization)

oogenesis (more detailed, based on the second document)

• Discuss what occurs with the primary follicles, the maturing follicle, the first polar body, & what a Graafian follicle is

• begins with primary follicles with primary oocyte frozen in prophase I. Target cells of FSH to begin developing.

  • The follicle cells (cells surrounding oocyte) have receptors for FSH & LH & make inhibin

  • Typically, only a few respond to FSH. otherwise, all the follicles would be stimulated at once & only have 1 chance to become pregnant. Usually less than 10 follicles respond to FSH per menstrual cycle.

  • Follicles that don’t respond to FSH will produce estrogens & inhibin

  • only one makes it all the way thru maturity, so the rest will be broken by macrophages thru phagocytosis

• Maturing follicle will grow larger & release more estrogens. Estrogens build up endometrium & completes meiosis I

  • Makes a secondary oocyte that’s still in the follicle. This carries the “cellular machinery” (mitochondria, lysosome, centrioles, etc.)

  • also makes the first polar body (“garbage bag” of chromosomes to reduce the number of chromosomes. Macrophage destroys it)

• Graafian follicle- a mature follicle with a secondary oocyte frozen at Metaphase II. Target of LH (triggers ovulation)

major reproductive hormones in females (6 to list)

• list the source, what it targets, & effects.

• Gonadotropin-Releasing Hormone (GnRH)

  • protein

  • from hypothalamus

  • targets ant. pituitary to stimulate secretion of FSH & LH

• Follicle-stimulating Hormone (FSH)

  • protein

  • from ant. pituitary

  • targets ovarian follicles to begin development & start production of estrogens

• Luteinizing Hormone (LH)

  • protein

  • from ant. pituitary

  • targets ovarian follicles to cause ovulation

• Estrogens

  • lipid

  • from ovarian follicle

  • targets…

    • mammary glands to stimulate them

    • other body tissues for secondary sex characteristics (ex. breast development, changes in size of pelvis)

    • uterus to stimulate proliferation of endometrial cells (AKA build up endometrium)

• Progesterone

  • lipid

  • from ovaries (corpus luteum)

  • targets uterus to maintain endometrium

• Inhibin

  • protein

  • from ovaries

  • targets ant. pituitary to inhibit FSH

Internal structures in the Female Reproductive System (11 structures)

• Ovary- gonad. where follicles are. Suspended by ligaments

  • Notice how this is internal compared to the testes since it doesn’t need a reduced temperature. Goes for one large, quality gamete rather than multiple gametes in the male reproductive system.

• fallopian tube- 2 total, one on each side. not physically connected or continuous with ovary. sits on top of it. this is WHERE FERTILIZATION OCCURS

  • fimbriae- finger-like end of fallopian tube. creates a current to pull oocyte into fallopian tube.

  • ciliated cells- draws in oocyte

• vagina- reproductive tube. posterior to urethra. 3-3.5 inches long & has rugae. Provides passageway for sperm, menstrual flow, & infant during birth

• uterus- mostly muscle

  • endometrium- inner layer of uterine wall. Where implantation of an embryo would occur. inc. thickness by 10x (0.5mm-5mm) every menstrual cycle

  • myometrium- smooth muscle. makes up 90% of the organ. Target of oxytocin

  • perimetrium- the serosa layer of the uterus on the outside

• Labia (major & minor)- corpus spongiosum under the labia

• Clitoris- corpora cavernosa, located above labia. functions in sexual stimulation

Accessory glands of female reproductive system & what they do (3 accessory glands)

All of these provide vaginal lubrication & tend to be slightly acidic for the 2nd step of capacitation (weaken acrosomal membrane of sperm cell)

• Cervical glands

• Vestibular glands

• Leaky capillaries (in wall of vagina)

ovulation

“let go” or release the oocyte

Ovarian cycle (List the hormones involved & the stages of the follicles)

• FSH gets the follicle to mature (until it becomes a mature follicle), & it releases estrogens & inhibin

• LH targets mature follicle makes ovulation occur. The secondary oocyte gets released along with…

  • Corona radiata- 1-2 layers of follicle cells attached to secondary oocyte

  • Zona pellucida- extracellular proteinaceous gel

• Corpus Luteum- the follicle (in ovary) after secondary oocyte is ovulated. Begins to make progesterone to maintain endometrium

Estrogen vs. Progesterone (what are they made by? When do they dominate in relation to ovulation? what do they do to endometrium?)

• Estrogen

  • made by maturing follicles.

  • Dominates before ovulation

  • builds up endometrium

• Progesterone-

  • made by corpus luteum.

  • Dominates after ovulation

  • maintains endometrium

Menstrual cycle

• The first half of the menstrual cycle is where variation occurs (roughly 14 days)

  • Variation comes from how many follicle's we’re making & how quickly they’re making estrogens

• Period (2nd half of menstrual cycle) begins 14 days after ovulation.

  • This is how long the corpus luteum stays for & then stops making progesterone

    • When progesterone gets too low, spiral arterioles constrict & the period begins & sheds endometrium

    • Cutting of progesterone triggers the start of the period

birth control pills

• provide estrogens, then progesterone to trick the hypothalamus into thinking ovulation occurred. Often used to regulate menstrual cycle rather than controlling birth. prevents ovulation

“Morning After Pill’/Plan B

High dosage of progesterone to prevent ovulation if it hasn’t already happened. Then you cut off drug & endometrium sheds

RU486/Mifepristone

a progesterone blocker (blocks the receptors), causing the immediate shedding of endometrium. The “abortion pill”

Fertilization window

• 4 days

  • 3 days before ovulation to 1 day after

    • This is bc sperm cells can stay viable for up to 3 days

    • Oocyte stays fertilizable for one day after ovulation

Fertilization (Know what happens with sperm cells & meiosis)

• Sperm cells need to go in the right direction for fertilization

  • Most will go in the right direction, but some can go in the wrong direction, swim in circles, get stuck in the fornix, etc.

• If, and ONLY IF fertilization happens will the oocyte complete meiosis

  • If no fertilization, the oocyte is destroyed by macrophage

  • The number of times meiosis II is finished is the same as the number of times they get pregnant

Fast Block to Polyspermy

• When the first sperm cell attaches to receptors on oocyte, CM depolarizes, making all other sperm cells detach

• Polyspermy- fertilization by more than 1 sperm cell (we don’t want this bc then there’d be too many chromosomes

Slow Block to Polyspermy

• zona pellucida hardens, swells, & detaches itself, carrying the corona radiata with it, shoving sperm away

Stages when fertilization happens (zygote, morula, & blastula/blastocyst) (embryonic phases)

• zygote- single, fertilized cell

• morula- solid ball of cells (made after zygote does mitosis)

• blastula/blastocyst- hollow ball of cells. Implants at day 6.

Fetus

• occurs at 8 weeks

• fetus- term used during the embryonic stage where you can recognize what species it is

embryo

• stage between blastocyst & fetus

• Still can’t tell what species it is at this point

Human Chorionic Gonadotropin (hCG)

• Hormone that keeps Corpus luteum Going (continue making progesterone to maintain endometrium)

• Made by embryo

episiotomy

a straight cut between the vagina & anus during childbirth. Done if a tear is likely. (Straight cuts heal faster than jagged tears)

mammary glands

• Exocrine glands within breasts to produce milk to nourish infant

menarche

• 1st episode of menstrual bleeding. A person’s first period

tubal ligation

closing off uterine tubes. A form of birth control

laparoscopy

a surgical procedure used to examine organs in the abdomen

ovarian cyst

a sac of fluid developed on an ovary. Usually don’t cause symptoms & go away on their own

uterine prolapse

uterus falls/sags into vagina bc muscles & tissues can’t hold it in place. Usually affects those in menopause after 1+ vaginal deliveries

hysterectomy

removal of uterus

PCOS

• a condition with abnormal periods (can be too few, irregular, or last too long)

• Often caused by having too much androgen (a male hormone)

endometriosis

a condition where tissue similar to the endometrium grows outside the uterus

blastocele/blastocyst cavity

a fluid-filled cavity in the blastula/blastocyst of the developing embryo