o Central Nervous system: Brain and Spinal cord
o Peripheral Nervous system: consists of sensory and motor neurons
§ Somatic Nervous system: controls skeletal muscles and is mostly integrated with CNS.
§ Autonomic Nervous system: stimulates smooth and cardiac muscle and also glands. Is not as connected to CNS.
o Cell body--enlarged part containing nucleus
o Axon--single, long extension that conducts impulses away from cell body
o Dendrites--many short extensions that receive stimuli, conducts toward the cell body
o Neuroglia—supporting cells that form a myelin sheath around the axon. Either called oligodendrocytes(CNS) or Schwann cells(PNS). Function: aids transmission of nerve impulse, supplies nutrients, carries away wastes
o Depolarization: Makes the membrane potential more positive, and therefore closer to 0. This is caused by sodium ions flowing in.
o Hyperpolarization: Makes the membrane potential more negative (and therefore farther from 0). This is caused by potassium ions flowing out.
1: The Na+ activation opens allowing a rapid but temporary influx of Na+ that causes the membrane to depolarize.
2a: The Na+ inactivation gate closes which stops this influx of Na+
2b: The K+ channel opens allowing a efflux of K+ ions which repolarizes the membrane.
o Atmosphere: O2: 160 CO2: 0.3
o Lungs: O2: 104.88 CO2: 39.52
o Body Tissues: O2:40 CO2: 46
o It is a protein made of 4 polypeptide chains (2 alpha chains and 2 beta chains.)
o Each chain carries a heme group
o Each heme group has an iron atom that binds O2 (This increases the solubility of O2by 40 times)
o Oxygen diffuses into circulatory system in the lungs because the Po2 is much higher in the lungs. Oxygen diffuses out of the circulatory system in the tissues because the Po2 is much higher in the circulatory system than the tissues.
o The opposite is true of carbon dioxide. CO2 diffuses out of the circulatory system in the lungs and into the circulatory system in the tissues because it wants to flow from high partial pressure to low partial pressure
o Most CO2(72%) is carried in the blood as bicarbonate (HCO3-).The formation of this is catalyzed by carbonic anhydrase.
o 8% is dissolved directly in the blood
o 20% binds to the protein part of hemoglobin
o Xylem: mostly dead tissue that conducts water and minerals. They have a unidirectional flow from roots to shoots.
o Phloem: live tissue that is made of sieve tube cells and conducts dissolved sugars. The phloem had a bidirectional flow and goes from the source to the sink.
Most of the water absorbed by the plant comes in through the root hairs. They greatly increase the surface area for absorption
o Apoplast route—the pathway for movement of water and minerals that leads through cell walls and between cells.
o Symplast route—the pathway for movement of water and minerals within the cell cytoplasm that leads through plasmodesmata that connect cells
o Transmembrane route--the pathway for movement of water and minerals that crosses the cell membrane and also the membrane of vacuoles inside the cell.
o @Source: Sucroseactively transported into the phloem. This lowers psis inside thephloem. Therefore, water passively enters the phloem which causes higher pressure in this part of the phloem.
o @Sink: Sucroseactively transported out of the phloem, which increases psis in thephloem. Therefore, water diffuses out of the phloem which lowers pressurein this part of the phloem.
o This difference in pressure drives the movement down the pressure gradient in the phloem
o Transpiration: pulls water up
o Adhesion: water “clings” to the sides and is therefore able to fight gravity and move up
o Cohesion: water bonds to itself and is therefore able to be “pulled up” by transpiration
o Glomerulus—Mainly responsible for the filtration of theblood.
o Bowman’s Capsule: collects filtrate from glomerulus
o Proximal convoluted tubule (PCT)—Most reabsorptionhappens here, with some secretion happening
o Loop of Henle—A lot of reabsorption happens here
o Distal convoluted tubule—Most of the secretion happenshere
o Collecting duct:reabsorbs water under the control of ADH