BIO183 Exam 4 Pt. 2

• Anti-Diuretic Hormone (ADH) is a hormone that regulates the amount of water in the body by controlling the amount of urine produced by the kidneys. When the body is dehydrated, ADH is released to reduce the amount of urine produced, which helps to conserve water. Alcohol inhibits the release of ADH, causing an increase in urinary water loss and increasing chance of dehydration. The consumption of a very large amount of water in a short period of time, coupled with an absence of solute intake, can reduce sodium levels in the blood below tolerable levels.
• Negative feedback involving ADH and dehydration:

  1. When the body is dehydrated, ADH is released to reduce the amount of urine produced by the kidneys.
  2. Alcohol inhibits the release of ADH, causing an increase in urinary water loss and increasing the chance of dehydration.
  3. Drinking a large amount of water in a short period of time, coupled with an absence of solute intake, can lead to hyponatremia, which is a condition where sodium levels in the blood are reduced below tolerable levels.
• Pros of Sexual Reproduction

  • Sexual reproduction produces offspring with varied genotypes, which can enhance the reproductive success of parents when environmental factors change rapidly.
  • The shuffling of genes during sexual reproduction can allow a population to rid itself of sets of harmful genes more readily.
  • Sexual reproduction generates most of the genetic variation that makes evolutionary adaptation possible.

  Cons of Sexual Reproduction

  • Sexual reproduction takes longer to occur.
• Pros of Asexual Reproduction

  • Asexual reproduction allows things to pass on all its genetic legacy intact to its progeny.
  • Asexual reproduction can be advantageous in stable, favorable environments because it can perpetuate successful genotypes precisely.
  • Asexual reproduction enables successful things to proliferate quickly.

  Cons of Asexual Reproduction

  • Asexual reproduction does not generate genetic variation, which can limit the ability of a population to adapt to changing environmental conditions.
• Define oviparity.

  Fertilized eggs that are deposited outside the mothers body to complete their development. (lays eggs)
• Define ovoviviparity

  Fertilized eggs that are kept within the mother to complete development. Young obtain food from egg yolk.
• Define viviparity

  Young develop within the mother and obtain nourishment from her blood.
• Synapses are the junctions between neurons that allow for the transmission of information from one neuron to another. There are two types of synapses: electrical and chemical. Electrical synapses contain gap junctions that allow electrical current to flow directly from one neuron to another. Chemical synapses rely on the release of a chemical neurotransmitter by the presynaptic neuron to transfer information to the target cell.
• When an action potential arrives at a chemical synapse, it depolarizes the plasma membrane at the synaptic terminal, opening voltage-gated channels that allow Ca2+ to diffuse in. The Ca2+ concentration in the terminal rises, causing synaptic vesicles to fuse with the terminal membrane and release the neurotransmitter. Neurotransmitter released from the synaptic terminus diffuses across the synaptic cleft, the gap that separates the presynaptic neuron from the postsynaptic cell.
• What is the name of the unit that actually shortens during muscle contractions?

  Sacromere
• Name the 2 major divisions of the human autonomic nervous system.

  Parasympathetic (relax) and sympathetic (fight or flight)
• In humans, urine leaves the bladder to the outside of the body through the _?

  Urethra
• In humans, the process of an ova(egg) being released from an ovary is called _?

  Ovulation
• What is the functional unit of the nervous system?

  Neuron
• What is the functional unit of the human kidney?

  Nephron
• Define neurons.

  Nerve cells that transfer information within the body and are the functional units of the nervous system.
• The central nervous system is composed of the _ and _?

  Brain and spinal cord
• The peripheral nervous system is composed of _ and _?

  Motor system and sensory system
• What is the Central Nervous System composed of?

  Brain and spinal cord
• What are the 2 main divisions of motor pathways?

  Somatic (voluntary) and autonomic (involuntary) nervous system