Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

51 Cards in this Set

  • Front
  • Back
Tonicity is RELATIVE!

used when comparing osmolality of two solutions
solution with greater amount of solute
solution with lesser amount of solute
solutions contain equal amounts of solutes
tubules open to inside & outside of body

Fluids filtered (by size) into tubules; NaCl removed via active transport

Urine is more dilute than body fluids

Malpighian tubules
extensions of digestive tract

Waste & K+ secreted into tubules via active transport, causing water to enter as well

Water & K+ then reabsorbed, leaving only wastes

specialized organ that filters blood of nitrogenous wastes & regulates osmolality

Three Different Osmoregulatory Organs
Nephridia -> Annelids

Malpighian tubules -> Insects

Kidneys -> Vertebrates
Groups and their Waste Products
Fish -> ammonia

Mammals -> Urea

Reptiles and birds -> Uric acid
Kidney Structure 2 layers
cortex (outer) & medulla (inner)
Kidney: Nephrons
used for filtration & selective reabsorption of blood

2 types: cortical & juxtamedullary

Consist of a long tubule & associated blood vessels
capillary bed in renal cortex
Bowman’s capsule
surrounds glomerulus and collects filtrate
Proximal convoluted tubule
located in cortex

Immediately re-absorbs 2/3 of the NaCl & H2O from Bowman’s capsule

Na+ moved by active transport; Cl- & H2O follow
Loop of Henle
loops into medulla

Descending limb: permeable to H2O

H2O moves into hypertonic medulla via osmosis

Ascending limb: not permeable to H2O

Na+ moved into medulla via active transport; Cl- follows
Distal tubule
located in cortex

Contains dilute filtrate, since NaCl was removed in ascending loop
Collecting duct
plunges into medulla, which is hypertonic

More H2O diffuses out of tubules & gets re-absorbed into blood
Antidiuretic Hormone (ADH)
increases collecting duct’s permeability to H2O

Released by pituitary when organism needs to conserve H2O
Asexual reproduction
offspring identical to parent

Fission (bacteria, protists), Budding (cnidarians)
Sexual reproduction
unique offspring

Alternation of generations (haploid / diploid)

Meiosis creates gametes (sperm & egg)
Definition of Sex
fusion of haploid sperm and haploid egg to create a diploid zygote
Other Reproductive Strategies
Parthenogenesis - development of an egg without fertilization
Aphids, bees, ants, lizards

Hermaphroditism – organism has both male and female functional reproductive organs
Tapeworms, earthworms

Sequential hermaphroditism - deep-sea fish that can change from female to male (protogyny) and from male to female (protandry)
female to male
male to female
Joining of sperm & egg
External Fertilization
sperm & egg join outside the body
Most aquatic organisms & amphibians

need the H2O to disperse and join
Internal fertilization
sperm & egg join inside the body
Most terrestrial organisms (reptiles, birds, mammals)

because they are land animals they do not have H2O as a medium
composed of highly convoluted seminiferous tubules (site of spermatogenesis)

Between tubules are Leydig cells : secrete testosterone

Formed in abdomen & descend into scrotum before birth

Must be kept at 34°C for sperm production (normal body temp is 37°C)

Sperm then enter the epididymis –must remain there for 18 hours to become motile

Then the vas deferens, which goes into the abdomen
pouch of enzymes used to break down egg cell protective barrier
Male Accessory Organs
Seminal vesicles: produce a fructose-rich fluid

Prostate gland: secretes 60% of the fluid in semen

Bulbo-urethral gland: secretes fluid that lines & protects the urethra
usually about 5mL of semen
Each contains about 300 million sperm (<20 million is considered sterile)

Sperm make up only 1% of semen volume
contain ovarian follicles which each contain one egg

Also contain granulosa cells, which secrete estrogen
Fallopian tubes
transports eggs from ovaries to uterus
muscular organ that narrows into a cervix

Lined with an epithelium called an endometrium, which is shed monthly during menstruation
Follicle-stimulating hormone (FSH) MALE
Stimulates spermatogenesis
Luteinizing hormone (LH) MALE
Stimulates secretion of testosterone by Leydig cells.
Testosterone MALE
Stimulates development and maintenance of male secondary sexual characteristics, accessory sex organs and spermatogenesis
Follicle-stimulating hormone (FSH) FEMALE
Stimulates growth of ovarian follicles and secretion of estradiol
Luteinizing hormone (LH) FEMALE
Stimulates ovulation, conversion of ovarian follicles into corpus luteum, and secreation of setradiol and progesterone by corpus luteum
Estradiol FEMALE
Stimulates development and maintenance of female secondary sexual characteristics; prompts monthly preparation of uterus for pregnancy
Progesterone FEMALE
Completes preparation of uterus for pregnancy; helps maintain female secondadry sexual characterisitics
Oxytocin FEMALE
Stimulates contraction of uterus and milk-ejection reflex
Prolactin FEMALE
Stimulates milk production
What are the two functions of the myelin sheath?
speeds up rate of impulses

Resting Membrane Potential
Cytoplasm-side of membrane is negative and extracellular fluid side is positive.
Three reasons for Potential
1. Large negative charged particles inside (proteins, nucleic acids)

2. Na+/K+ pump moves 2 K+ in for every 3Na+ out

3. Ion channels allow more K+ to diffuse out that Na+ to diffuse in
Action Potential
A transient, all or none reversal of the electric potential across a membranes.

Na+ channels open allowing Na+ to flow in.

Action Potential is propogated down axon.
Example of Action Potential
nerve impulse
Junction between a neuron and another neuron muscle cell or gland
Way in which cells communicate, stored in synaptic vesicles.
Examples of Neurotransmitters
Acetylcholine: between neurons & muscle cells

Dopamine: between brain neurons
Too little=Parkinson’s; too much=schizophrenia

Norepinephrine: brain neurons; autonomic system

Serotonin: brain neurons; sleep, emotion, depression