BIO 1510: Lecture Exam 2: 44 , 49 & 50
Terms
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- Tonicity
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Tonicity is RELATIVE!
used when comparing osmolality of two solutions - Hypertonic
- solution with greater amount of solute
- Hypotonic
- solution with lesser amount of solute
- Isotonic
- solutions contain equal amounts of solutes
- Nephridia
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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
Annelids - Malpighian tubules
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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
Insects - Kidneys
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specialized organ that filters blood of nitrogenous wastes & regulates osmolality
Vertebrates - Three Different Osmoregulatory Organs
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Nephridia -> Annelids
Malpighian tubules -> Insects
Kidneys -> Vertebrates - Groups and their Waste Products
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Fish -> ammonia
Mammals -> Urea
Reptiles and birds -> Uric acid - Kidney Structure 2 layers
- cortex (outer) & medulla (inner)
- Kidney: Nephrons
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used for filtration & selective reabsorption of blood
2 types: cortical & juxtamedullary
Consist of a long tubule & associated blood vessels - glomerulus
- capillary bed in renal cortex
- Bowman’s capsule
- surrounds glomerulus and collects filtrate
- Proximal convoluted tubule
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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
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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
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located in cortex
Contains dilute filtrate, since NaCl was removed in ascending loop - Collecting duct
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plunges into medulla, which is hypertonic
More H2O diffuses out of tubules & gets re-absorbed into blood - Antidiuretic Hormone (ADH)
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increases collecting duct’s permeability to H2O
Released by pituitary when organism needs to conserve H2O - Asexual reproduction
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offspring identical to parent
TYPES:
Fission (bacteria, protists), Budding (cnidarians) - Sexual reproduction
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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
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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
- protogyny
- male to female
- protandry
- Fertilization
- Joining of sperm & egg
- External Fertilization
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sperm & egg join outside the body
Most aquatic organisms & amphibians
need the H2O to disperse and join - Internal fertilization
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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 - Testes
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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 - Acrosome
- pouch of enzymes used to break down egg cell protective barrier
- Male Accessory Organs
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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 - Ejaculation
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usually about 5mL of semen
Each contains about 300 million sperm (<20 million is considered sterile)
Sperm make up only 1% of semen volume - Ovaries
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contain ovarian follicles which each contain one egg
Also contain granulosa cells, which secrete estrogen - Fallopian tubes
- transports eggs from ovaries to uterus
- Uterus
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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
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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?
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speeds up rate of impulses
protection/insulation - Resting Membrane Potential
- Cytoplasm-side of membrane is negative and extracellular fluid side is positive.
- Three reasons for Potential
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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
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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
- Synapse
- Junction between a neuron and another neuron muscle cell or gland
- Neurotransmitters
- Way in which cells communicate, stored in synaptic vesicles.
- Examples of Neurotransmitters
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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