Biology Final

Cardiovascular System

• functions

  • transport gas, nutrients, hormones and other compounds to cells and tissues

  • Transport waste away from cells and tissues of the body

• Blood

  • special connective tissue

    • plasma 55%

    • Water 90%

    • Gasses 10%

    • Glucose, hormones, waste, and amino acids

• Intracellular fluid

  • in the cytosol within the cell

• Extra cellular fluid

  • surrounds the cells and serves as circulating reservoir

  • Divided into the interstitial fluid which bathes the outside of the cells and intravascular fluid

• Formed elements

  • platelets

    • clothing pieces of cells (blood clotting)

  • Leukocytes

    • nucleated

    • 5 types: granulocytes (neutrophils, eosinophils, and basophils), monocytes and lymphocytes (T cells and B cells)

    • Neutrophils

      • first cells to inflamed areas

      • Phagocytes (eat cells)

    • Lymphocytes

      • B cells

        • produced in bone marrow; form antibodies

      • T cells

        • produced in thymus gland

        • Killer cells (attack viruses)

    • Monocytes

      • killer cells- viral infection

    • Eosinophils

      • limit inflammation

      • Provide protection against parasitic worm infection

    • Basophils

      • help with inflammation response

      • Involve with regulating BV flow

    • Erythrocytes

      • anucleated/mammals (5000000 c/c)

      • Produced in red bone marrow and spleen

      • Contain hemoglobin (200000 hemoglobin molecules per RBC)

        • oxygen binds to hemoglobin (oxygen transport)

      • 120 day life I span

      • Biconcave

• Blood vessels

  • tubes carrying blood

    • lined by epithelium (simple squamous)

    • Arteries and arterioles (away from heart)

    • Veins/venules (towards heart)

• Capillaries

  • smaller diameter

  • Arranged in beds

  • Thin walls, one cell thick (ss)- efficient in secretion and absorption

• Veins/venules

  • carry towards heart

    • thinner smoother tissue

    • Lower pressure vessels

    • Some have valves to prevent back flow

• Gas exchange

  • site between blood and organs; oxygen diffuses out of vessel and CO2 diffuses in

• Mammals 4 chambers

  • 2 atria (left/right) smaller/thinner walls

  • 2 ventricles (left/right) larger/thicker walls “left thickest”

  • Right “pulmonary loop”

  • Left “system loop”

  • Valves

  • Ventricular valve (AV) between atria and ventricles

  • Semilunar valve (SV) pulmonary SV between righ t ventricle and pulmonary artery; aortic SV between left ventricle and aortic trunk

• Pathway of blood flow around heart

  • vena Cavae (deoxygenated blood)- right atrium- AV valve- Right ventricle- pulmonary SV- pulmonary arteries- lungs (oxygenated)- pulmonary veins- left atrium- AV valve- left ventricle- aortic SV- aorta- body

• Evolutionary advances of vertebrate heart

  • increases in the number of chambers (Atrium and ventricle) 2,3,4

  • Increase in size of heart

  • Decrease in pseudo chambers (outside of heart receiving blood)

  • Sinus venusos: outside atrium receives blood from body

  • Conus arteriosus: outside ventricle receives blood from heart

• Fish

  • two pseudo chambers (SV and CA)

  • Two chambers (atrium/ 1 ventricle)

• Amphibians

  • two pseudo chambers (sv and ca)

  • Three chambers (right and left atrium/ 1 ventricle)

• Reptiles

  • sinus venous only

  • Most with three chambers (rigth and left atrium/ 1 ventricle)

  • Crocs with 4 chambers (right and left atrium/ right and left ventricle)

• Birds

  • 4 chambers (right and left atrium/ right and left ventricle)

• Mammal

  • 4 chambers (right and left atrium / right and left ventricle)

  • Most advanced and larges t

• Sinoatrial node

  • remnant of the sinus venous of earlier vertebrates; not a chamber outside of heart but a patch of cells in right atrium

  • Pacemaker: initiates heartbeat

• Nodal tissue

  • specialized cardiac muscle cells (involuntary) capable of spontaneous contraction (impulse)

  • Conus srteriosus no longer a pseudo chamber but beginning of aortic trunk

Respiratory system

• Gas Exchange

  • process of moving CO2 and O2 in opposite directions between the environment, bodily fluids and cells

  • Respiratory system- all structures that contribute to this process

• Physical drops of gasses

  • air

    • 21% oxygen

    • 78% nitrogen

    • Approximately 1% carbon dioxide and other gasses

  • Nitrogen gas is usually ignored because it is not part of the respiratory system

• Solubility of gases

  • gases dissolved in water- whether freshwater, seawater, or bodily fluidas

  • Most gasses dissolve poorly in water

  • Factors influencing solubility in water

    • pressure of the gas- higher pressures will result in more solution, up a limit for each gas at a given temperature

    • Temperature of water- cold water holds more gas than warm water

    • Presence of other solutes- other solutes decrease the amount of gas that dissolves into the solution

  • Ventilation is the process of bringing oxygenated water or air into contact with a gas-exchange organ

• All respiratory organs share common features

  • moist surfaces on which gasses dissolve and diffuse

  • High surface for gas exchange

  • Extensive blood circulation (lots of capillary beds)

  • Thin, delicate structure (simple epithelium)

• Water breathing vs Air breathing

  • different Challenges for gas exchange

  • Aquatic animals

    • less available oxygen

    • When temperatures change in water, oxygen availability also fluctuates

    • Moving dense water over respiratory membranes takes more energy than moving air

      • water also removes heat from gill surface

  • Terrestrial animals

    • deal with desiccation of respiratory membranes (drying out)

• Vertebrate gas exchange types

  • gills: fish, some amphibians, come invertebrates

    • aquatic organisms- difficult due to low oxygen concentration

    • Air- about 21% O2

    • H2O- O2 concentration is less than 1% of air

  • Design must be effective and efficient

• Gills

  • specialized respiratory structures in water breathing animals

    • external gills

      • uncovered extensions from the body surface

      • Found in many invertebrates and larval form of amphibians

      • Vary widely in appearance but all have a large surface area with extensive projections

      • Limitations

        • unprotected and subject to damage

        • Energy is required to wave Gil’s back and forth

        • Appearance and motion may attract predators

    • Internal gills

      • gills of fishes, many with a cover called operculum

      • Gill arches- main support beam/strucuture

        • contain filaments which are composed to lamellae (epithelial sacs of blood)

    • Blood vessels run the entire length of the filaments

      • O2 poor blood travels through afferent vessels

      • O2 rich blood travels through efferent vessel

      • Countercurrent exchange of water and blood flows in different directions and maximizes O2 diffusion into blood

      • H2O flows from the front of the gill region to the back; blood enters the gills at the back and flows to the front. The opposite flow of water and blood maintains the gradient of O2 along the length of the capillaries

• Mechanisms of internal gill ventilation

  • buccal pumping- hydrostatic pressure gradient created by lowering the jaw to suck H2O in and opening the operculum to draw H2O through

    • flap of tissue prevents fish from swallowing h2o

  • Ram ventilation- swimming with mouth open

    • more energy efficient than buccal pumping

  • Many fish use both methods

  • Both are flow-through systems (water moves unidirectionally)

• Countercurrent exchange mechanism

  • oxygen (and co2) diffuse as long as there is a gradient of O2 (and CO2)

  • Diffusion occurs along the entire length of the gill region

  • Highly efficient in water- only energy expended for swimming and/or opening the mouth and operculum

• Cutaneous respiration

  • gas exchange through the integument (skin)

  • Highly efficient

  • Some fish. Some amphibians

  • Both have thin, moist skin, lots of capillaries, no barriers to diffusion (meaning no scales, hair or feathers to stop diffusion)

• Buccopharyngeal respiration

  • epithelial lining of the mouth cavity

  • Moist, thin, lots of capillaries

  • Some amphibians

• Lungs

  • a lung is like a “‘vascularized sponge” they are sponge-like sacs that, when squeezed or pressed, shrink to get rid of all air spaces. Constricting forces air out, so when it is released, it expands to let air in

  • With few exceptions, all air breathing terrestrial vertebrates use lungs for gas exchanged

  • Fish-lungfish (simple sacs)

  • Amphibians- simple sacs

  • Reptiles/brids- larger sacs and more lobes= more exchange area

  • Mammal lungs- largest of vertebrates; more exchange area

• Pathway of the mammalian respiratory system

  • nose and mouth

    • air is warmed and moistened

    • Mucus and hairs in the nose cleans the air of dust

  • Pharynx

    • back of the mouth cavity; respiratory and digestive tracts cross

  • Larynx

    • upper part of the trachea (windpipe)

    • Vocal cords- voice box

  • Trachea- opening (glottis)

    • rings of cartilage provide rigidity

    • Lined with cilia and mucus to trap and expel inhaled particles

    • Branched into bronchi (right and left) (helps hold the airway open)

• Bronchi leads to the lungs

  • repeated branching of bronchi eventually form bronchioles

    • contain circular rings of smooth muscle to dilate or constrict passage

  • Bronchioles empty into alveoli (site of gas exchange)

    • alveolus- air sac

  • Exhaled air follows the pathway in reverse

    • bronchioles- bronchi- trachea- larynx- pharynx- nose/mouth

• Diaphragm

  • large muscular organ separating thoracic and abdominal cavities

  • Smooth muscle- involuntary (not consciously controlled)

  • The diaphragm flattens out to expand the chest cavity, allowing air to flow into the lungs due to ventilation. It will push back up to constrict and push air out

    • alternating because of the intercostal muscles

Urinary system

• function

  • waste disposal (ions, urinary wastes)

  • Filtering of blood (cleaning)

  • Water movement

    • redistribution by osmosis

      • if ions are taken out, h2o is also going to leave because at this point it is too high in the concentration gradient. Meaning it will leave to try to maintain the balance

      • Osmosis- diffusion of water across a selectively permeable membrane

  • Osmoregulation

    • regulation of salt/h20 balances of body fluids and cells/tissues of the body

• Excretory system of animals

  • animals make use of one or more organs to remove metabolic wastes, excess h2o, ions and toxins

  • Most excretory organs contain tubular structures lines with epithelial cells that have the capacity to actively transport ions

    • using energy o go from low concentration to high concentration and push against the gradient (active transport)

    • In mammals, there are simple cuboidal epithelial

• Excretory systems

  • critical for removing waste from body fluid and maintaining homeostasis

  • Salt and h2o balance

    • salt- a compound formed from an attraction between positively charged ions and negatively charged ions

      • ionic bonds are broken when dissolved in water

    • Changes in concentration of ions from dissolved salts in extracellular and intracellular fluids can disrupt cellular function

• Principles of homeostasis of internal fluids

  • an animals internal fluids exist in compartments

    • invertebrate: intracellular fluid

    • Vertebrate: intracellular fluid and extracellular fluid

  • h2o is

    • major portion of an animals body mass

    • Solvent for chemical reactions

    • Transport Neville

  • Dehydration occurs when water volume is reduced below the normal range

    • comprises the circulatory system and regulation of body temperature

• Gains of water

  • drinking 48%

  • Free h2o in food 12%

• Losses of water

  • urine 60%

  • Evaporation/sweat 34%

  • Feces 6%

• Nitrogenous wastes

  • produced when proteins and nucleic acids are broken down and metabolized

  • Molecules include nitrogen from amino groups

  • Toxic at high concentrations

    • cannot be eliminated from body through exhalation or diffusion

    • Can be eliminated as urinary waste

• Forms of nitrogenous waste

  • ammonia (NH3) and Ammonium (NH4)

    • most toxic of nitrogenous wastes

    • Animals that excrete wastes in this form typically live in water

    • Easily diffuse in water

    • Aquatic animals can excrete it as soon as it forms

    • Chief advantage is that energy is not required for conversion to a less toxic product

  • Urea

    • all mammals, most amphibians, some marine fishes, some reptiles, some terrestrial invertebrates

    • Produced by metabolic conversion of ammonia

    • Less toxic

    • Does not need as large a volume of h2o for excretion

    • Can tolerate some urea accumulation

    • Drawback is conversion of ammonium to urea requires atp and time

  • Uric acid

    • birds, insects, and most reptiles

    • Less toxic than ammonia

    • More energetically costly to make from ammonia than urea and more time

      • balance against h2o conserved by excreting semisolid, partly dried precipitate

      • The white part of “bird poop” is uric acid. The black part is feces

• Kidney

  • major organ in the urinary system

  • Vertebrates- kidneys are paired

  • Fishes/amphibians- kidneys are simple sacs

  • Mammals/birds/reptiles - metanephric kidnets

    • most advanced kidneys; drained by a ureter; lots of nephrons; filter at much higher pressures

      • best design for terrestrial lifestyle- mammals

• Organs of the urinary system

  • kidney

    • forms urine from the blood

    • Urine forming structure: nephrons (structural/functional unit of the kidney)

  • Ureter

    • transports urine from kidney to urinary bladder

  • Urinary bladder

    • stores urine until it is voided from the body

  • Urethra- conducts urine from bladder during urination

• Nephron

  • functional unit of the kidney

  • 18 liters filtered per day

  • Total blood volume: 5L

  • Composed of

    • renal corpuscle

    • Renal tubule (surrounded by simple epithelium)

    • Renal- kidney related

• Nephron structure

  • blood that goes to glomerulus. It is intense enough to force material into the tubule. It enters the proximal tube- lower tube-distal tube. It exits through the collecting duct

• 3 stages of urine formation

  • filtration

    • cleaning/filtering blood

    • Glomerulus- bowman’s capsule

  • Reabsorption

    • proximal tubule

  • Secretion

    • pushing material into the distal tube

• Renal corpuscle

  • glomerulus

    • capillary network

    • Blood filtered here

    • Filtered material

      • glomerular filtrate (GF): stuff pushed out due to pressure (can’t call it waste because goodies are still inside)

  • Bowman’s capsule

    • blind-ended pouch

    • Receives glomerular filtrate (GF) from glomerulus

• Renal tubule

  • proximal tubule

  • Lower loop

  • Distal tube

  • Collecting duct

• Proximal tubule

  • receives GF from bowman’s capsule

  • Primary site of tubular reabsorption

    • approx 60% of GF volume and nearly all glucose, amino acids, and vitamins are reabsorbed here (removing goodies from tubule)

  • Tubular reabsorption

    • movement of GF out of renal tubule back into blood

    • Occurs along length of the renal tubule

  • Most reabsorption of solutes is by active transport

    • ATP expenditure (low concentration to high concentration)

  • Water follows passively by osmosis

    • now GF is less water, less goodies but higher percentage of waste ions

  • For most substances (except glucose )

    • upper limit reabsorption

• Lower loop

  • most enhanced with metanephric kidneys (mammals, birds, reptiles)

  • Best in mammals

• Distal tubule

  • primary site of tubular secretion

    • movement of substances out of blood into renal tubule

      • push material into tubule (ATP expenditure; low-high)

• Collecting duct

  • waste (mostly)

  • Filtrate that has reached this point should mostly be waste material; h2o reabsorption in collecting duct to be just enough water to release waste from the body

  • Urine- renal pelvis of kidney- released out of ureter- urinary bladder (temporary storage)- urethra to outside

• Vertebrates nephron differences

  • freshwater fish

    • concentration environmental ions < concentration body ions

    • Concentration environmental water > concentration body water

      • constantly taking in water; doesn’t drink water because they already take it in

    • Large glomerulus to filter blood

    • Short tubule doesn’t reabsorb or keep water

    • Dilute waste- ammonia (getting rid of lots of water)

  • Marine fish (seawater)

    • opposite of freshwater

    • Concentration environmental ions > concentration body ions

    • Concentration environmental water < concentration body water

      • constant loss of water; drinks water to compensate

    • Small glomerulus

    • Long tubule to reabsorb ions/h2o

    • Stores ions in tissue (urea) to slow osmotic ions of h2o

    • Produce concentrated waste (urea)

      • some urea is stored in tissue to increase ion balance

• Mammalian nephron

  • loop of henle- lower loop is greatly constricted (narrow tube); slows down GF

  • By slowing it down, more water reabsorption occurs

  • Allows more goodies reabsorption

  • Allow more concentration (secretion) os wastes 20% more concentration

  • Plan-concentrated wastes, minimal goodies, minimal h2o- waste product of urea

  • Loop of henle is the reason mammal kidneys are better

Endocrine System

• pituitary gland and hypothalamus

  • anterior pituitary- secretes hormones that regulate or act upon other endocrine glands

  • Thyrotropic hormones- acts on thyroid gland

  • Adrenocorticotropin- acts on adrenal gland

  • Gondatropins- acts on gonads (LH- luteinizing hormons and FSH follicle stimulating hormone)

  • Prolactin- stimulates mammary glands for milk production

  • Growth hormone- stimulates cell division

  • Melanophore stimulating hormone- pigment dispersion

  • Hypothalamus- produces releasing hormones that regulate pituitary hormones

  • LH-RH- luteinizing hormones/ releasing hormones

  • FSH-RH- follicle stimulating hormone/ releasing hormone

  • Posterior pituitary- also regulated by hypothalamus

  • Vasopressin- acts on kidney to reduce urine flow

  • Oxytocin- stimulates contraction of uterus during birth and the release of milk by mammary glands

• Metabolic hormones and associated glands- alter enzyme activity

  • thyroid gland

    • thyroxine- promotes normal development of nervous system

  • Adrenal glands

    • cortisol- anit-inflammatory hormone

    • Aldosterone- promotes tubular reabsorption of NaC by nephron

    • Epinephrine (adrenaline)-

    • Norepinephrine (noradrenaline)-

• Digestive hormone

  • gastrin- stimulates secretion of HCl in stomach

  • Cholecystokinin- stimulates gallbladder contraction to increase flow bile into duodenum and stimulates pancreas to secrete enzymatic juices

Animal Reproduction and Development

• overview of asexual reproduction and sexual reproduction

  • asexual reproduction

    • offspring are produced from a single parent and are clones of the part

    • Three parts of asexual reproduction

      • budding- portion of parent pinched off to form a completely new individual

      • Regeneration/fragmentation - complete organism formed from a fragment of parents body

      • Fission- parent divides mitotically into 2 nearly equal parts

    • Same genes, no genetic variation

  • Sexual reproduction

    • requires meiosis followed by cytokinesis reduction division

    • 2 haploid gametes fuse to produce a new individual

      • offspring are genetically different from both parents

        • genetics variation/ new gene combo

      • Most animal species reproduce sexually

      • Energetically expensive, especially on female side

        • requires time for sexual maturity, sex organs, and sex cells

      • Fertilization is the union of a haploid egg and haploid sperm to produce a diploid zygote

      • Development of the zygote forms the embryo

      • 1n egg + 1n sperm 2N zygote- cell division- 2N multicellular embryo

• Advantages and disadvantages

  • asexual reproduction

    • one parent; no gametes; no reproductive organs

    • Simple way to produce many copies of an individual

    • Result of mitosis/cytokinesis

    • Can reproduce even if isolated alone

    • Can reproduce rapidly and at any time

    • Energetically cheap

    • Genetically the same

    • More prevalent in species from stable environments with lots of resources and little selection pressure for genetic diversity

    • If the selection pressure increases, it would wipe out the population due to the lack of genetic variation (genetic variation allows for survival of the fittest so if there’s no variation then the whole population will be on the same level)

  • Sexual reproduction

    • 2 types of gametes must be made

    • Male and female requires specialized body parts and must find each other to mate

    • Allows for greater genetic variation due to genetic recombination

      • may allow rapid adaptation to environment changes

• Types of sexual reproduction

  • hermaphroditism

    • individuals have both male and female reproductive organs- each individual usually capable of producing offspring

    • Monoecious- condition where both types of sex organs in same individual

      • most examples exhibit cross-fertilization (2 individuals); self fertilization uncommon

      • Sex reversal on occasion (fish)

  • Parthenogenesis:

    • development of an embryo from an unfertilized egg

    • Sperm may or may no be involved with initiation of development

      • this means sperm does not fuse with egg but it does trigger certain hormonal developments to help drop the egg

      • Amniotic- no meiosis and egg forms by mitosis/cytokenisis

      • Meiotic- egg forms by meiosis (haploid) an develops without fusing sperm

      • Has been described in vertebrate animals (all groups but mammals)

    • Biparental reproduction

      • 2 genetically different individuals

      • 2 types of sex organs producing 2 types of gametes (sex cells)

      • Dioecious- condition of separate sexed individuals

      • Fusion of egg and sperm

• Reproductive modes (vertebrates)

  • oviparous

    • condition of egg-laying outside of the body

    • Fertilization may be external or internal

    • Eggs may be abandoned

    • Fish, amphibians, reptiles, birds, mammals (3 species)

    • Simple (but wouldn’t call it primitive)

  • Ovoviviparous

    • condition of eggs (within some form of shell-like structure) retained in female’s body

    • Fertilization must be internal

    • All nourishment derived from yolk of egg

    • No maternal connection

    • Offspring are both “live” (but enclosed)

      • enclosed in sac but emerges quickly after “birthing”

    • Fish, amphibians, reptiles

  • Viviparous

    • condition of live-bearing with a maternal connection

    • Placenta- connecting structure with uterus

    • Requires internal fertilization

    • Nourishment and gas exchange with placenta

    • Live-bearing is highest degree of parental care

    • Fish, reptiles, mammas

• Why sexual reproduction of asexual reproduction

  • vertebrates

    • much more common

    • Energetically costly, takes time, complex structures and sex cells

    • Advantage: results in genetic variation (most important)

• Gametogenesis and fertilization

  • gametes (sex cells) are formed in gonads

    • testes in males, ovaries in females

  • Gametogenesis begins with germ cells that multiply by mitosis to produce spermatogonia (diploid) or oogonia (diploid)

  • Primordial germ cells arise from yolk sac and migrate to primitive gonad

  • Vertebrate gonads arise from pair of genital ridges along the dorsal body wall and migrate lower trunk region

  • Some spermatogonia and oogonia multiply again by mitosis to produce primary spermatocytes and primary oocytes

  • These undergo meiosis to form haploid gametes (sperm and egg) eventually

• Spermatogenesis

  • primary spermatocytes undergo mitosis I to produce 2 haploid secondary spermatocytes

  • Eventually develops into sperm

  • One diploid cell becomes 4 gametes (haploid)

  • Spermatogonia 2n- primary spermatocytes 2n- secondary spermatocytes 1n- spermatids 1n- mature sperm cells 1n

• Oocytes

  • 1 gamete produced from each primary oocyte

  • Meiosis 1 produces 1 large secondary oocyte plus a smaller polar body which eventually degenerates

  • 1 or many ova can develop at a time

  • Oocytes develop within follicles in the ovaries and are released during ovulation (rupturing of the follicles)

  • Timing is longer on females and there’s dormancy at a certain period

• Mammalian oogenesis

  • begins in the fetus before birth

    • cohort of germ cells enter meiosis 1 and arrest- will not resume development until pubert

  • Meiosis 1 is completed in some primary oocytes to produce haploid secondary oocytes

  • Meiosis in

  • Fusion of the 1n egg muscles with a haploid sperm nucleus produces a 2N zygote (fertilized egg)

  • Oogonia 2n- primary oocytes 2n- secondary oocyte 1n- secondary polar body 1n degenerates and haploid egg 1n (diploid zygote once the egg and sperm nuclei fuse)

• Fertilization

  • haploid egg and sperm unite to form a 2n zygote

  • Sperm swims toward egg

  • Sperm uses proteolytic enzymes in acrosome (protective cap) to digest the plasma membrane of egg

• Mammalian reproductive structure and function

  • male genitalia

    • consists of penis and scrotum

    • Scrotum holds tests where sperm develops at 2 degrees Celsius lower than core body temp

  • Each testis is composed of seminiferous tubules (site of spermatogenesis) and leydig cells (endocrine cells that secrete testosterone)

    • spermatogenesis begins at puberty and continues throughout life

    • Sertoli cells provide nutrients and protection to developing sperm

• Sperm

  • sperm are released into lime of seminiferous tubules

  • Move into epidiymis to complete their differentiation by become in motile and capable of fertilization

  • Then to vas deferents leading to ejactulatory ducts and urethra

  • Semen constrains fluid and sperm

    • sperm abt 50% of volume

    • Fluid from seminal vesicles (fructose), bulbourethral glands (fluid) and prostate gland (fluid)

• Hormonal control of male reproductive system

  • hypothalamus (secretes LH and FSH)- bloodstream- pituitary glans (secretes LH and FSH) - bloodstream- gonads (male=testes)

  • FSH (follicle stimulating hormone)- initiates sperm production in seminiferous tubules

  • LH (luteinizing hormone)- stimulates leydig cells to secrete testosterone

• Testosterone

  • actions of testosterone

    • stimulates growth of male reproductive reach and genitalia during development and puberty

    • Stimulates development of male secondary sexual characteristics- facial hair in humans, horns in bulls, bright feather in peacocks

• Ovary (female gonad)

  • production of ovum (egg)

  • Hormone secretion- estrogen and progesterone

  • Primordial cells producing oogonia form during embryonic development

  • Much more time and energy required than with male

• Female reproductive tissue

  • female genitalia differentiate from the same embryonic tissue as male genitalia

    • labia majora- same tissue as scrotum

    • Labia minora- same tissue as urethral primordial tissue

    • Clitoris- same erectile tissue as penis

  • Urthera is not part of the reproductive tract in females

  • Opening of reproductive tract and urethra are separate

  • External opening of the reproductive tract leads to vagina, cervix, and into uterus

  • Uterus has inner glandular lining (endometrium)

    • endometrium builds up for implantation

• Oocytes

  • develop in 1 orf 2 ovaries

  • Typically, 1 secondary oocyte released and is quickly drawn to oviduct (uterine tube/ fallopian tube)

    • moves down oviduct by cilia

  • Fertilization usually in oviduct (upper 40%)

    • zygote develops into blastocyst (a ball o f32-150 cells) and entera the uterus

• Fertilization

  • uterus is the implantation site

    • many cell division to become blastocytes

  • Endometrium builds up with vessels and epithelial tissue

  • If fertilization happens and implantation occurs endometrium continues to develop and is maintained by hormonal activity

    • connection in the placenta

  • If fertilization/implantation does not occur- endometrium sloughs off and is discharged

• Hormonal control of female reproductive system

  • hypothalamus (secretes LH and FSH)- bloodstream- pituitary gland (secretes LH and FSH)- bloodstream- gonads (female=ovaries)

  • FSH- stimulates development of ovarian follicles and estrogen (and progesterone) by follicle

  • LHH- stimulates secretion of progesterone (and estrogen) by corpus luterum (remnant of follicle after ovulation-release oocyte)