Biol 242 Exam 3 Review

Connective Tissue: ​Holds tissues and organs together, stores fat, involved in gas exchange, and can be mineralized into bone. Ex. RBC

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Muscle Tissue: ​Contractile Filaments; Voluntary movement & Involuntary organ movement. Ex. heart beat

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Nervous Tissue: ​Reciept, Process and transmit information. Ex. Nuerons & Glial cells (support cells for neurons)

Explanation​

​If over time a population of white fish turns red:

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-The population is evolving to be red

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-Natural selection is acting on individuals (red fish survive and reproduce more)​

Adaptation: A heritable, genetic trait that confers a benefit to survival or reproduction; does not change during an organism’s lifetime

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Acclimation: ​A physiological change during an organism’s lifetime to aid its survival or reproduction; may or may not be temporary/reversible

Negative Feedback loop: The output of a system inhibits its own production. Ex. Thermoregulation.

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Positive Feedback​ Loop: Output of a system promotes its own production

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-Unicellular organisms access gases and nutrients by diffusion

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-​In animals, circulatory systems enhance access of cells to oxygen and nutrients:

​1.Gastrovascular cavities

2.Open circulatory systems

3.Closed circulatory systems

​Explanation

Atria: Collect blood coming into the heart from veins

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Ventricles: Pump blood out of the heart through arteries

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Right Side: Receives deoxygenated blood from the body

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Left Side: Receives oxygenated blood from ​ the lungs

-Veins collect blood from capillaries and bring it back to the heart:

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*could be oxygenated OR deoxygenated​

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Ex: Oxygenated blood travel through veins from the lungs to the heart​ (pulmonary veins)

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-Lady Bugs Are Insects -> Open Circulatory Systems:

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-Use​ hemolymph (blood and interstitial fluid to bath organs directly in nutrients

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-Low cost/energy system

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-No real red blood cells, use free O2 binding protein (hemocyanin) in plasma​

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​-Higher surface area = Diffusion occurs more quickly

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-The thinner the tissue/membrane (less distance) = diffusion is quicker

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-All respiratory systems have relatively high surface area (alveoli), thin-walled (capillary coat), and are easy to keep moist​ (gasses need to be dissolved to cross cell membranes)

Positive Pressure Ventilation: ​Forcing air into the lungs (usually by contraction)

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Negative Pressure Ventilation: ​Inhalation driven by lowering pressure compared to the outside (gas wants to flow from high pressure to low)

-Gasses diffuse from areas of high pressure to low pressure

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-Body wants oxygen from alveolar sacs (lungs) to move into pulmonary capillaries in order to transport it to the heart.

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-The pressure in the alveolar sacs must be higher​

​-Cooperativity is responsible for hemoglobins ability to change in oxygen affinity

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-deoxygenated hemoglobin​ has low affinity for oxygen

-Oxygenated hemoglobin has high affinity for hemoglobin

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-If oxygen binds to one of hemoglobins subunits, other subunits more likely to take up oxygen​

Polysaccharides (complex carbs) -> monosaccharides (simple sugars)

Polypeptides (proteins) -> Amino Acids

Lipids (fats) -> Fatty Acids​

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-Protein digestion begins in the stomach when pepsin is introduced

-Fat digestion begins in the small intestine when bile salts (from liver) are introduced ​

-Amylase breaks down polysaccharides and disaccharides​ (complex carbs such as sugar in fruits)

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-Pepsin is used to breakdown proteins

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-Lipase is used to breakdown fats

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-​Nuclease is used to breakdown nucleotides

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​-When blood glucose level is low: pancreas secreates glucagon which promotes liver to breakdown glycogen

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-​When blood glucose level is high pancreas produces insulin which signals liver to store glucose as glycogen

-Damaged skin cells trigger the release of histamines and other chemical signals from mast cells (Which recruit other immune cells)

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-Histamines cause blood vessels to dilate (and become more permeable to leukocytes

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-​ Neutrophils are from blood, Macrophages are from tissue, both destroy pathogens.​

-Macrophages​ can aslo release cytokines which attract more nucleophiles

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-​B cells: mature in bone marrow

-T cells: mature in thymus

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B cells: ​produce antigen receptors and antibodies that detect diverse antigens

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T cells: ​produce receptors that can recognize pathogen fragments displayed by MHC molecules on other cells

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Helper T Cells: ​Bind to pathogen (or B cell) by MHC, release cytokines which attract other B cells and cloning

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Cytotoxic T cells: Recognize MHC of infected cell (stimulated by helper T cells), and secretes perforin which lyse infected cell

-Water flows from areas with lower solute concentration to areas with higher concentration (salt is solute and the fish has less salt than the water)

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-​Hyperosmotic: Solution with higher solute concentration

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-Hypoosmotic: Solution with lower solute concentration​

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-When dehydrated, your body wants to hold onto as much water as possible.

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-​ADH (antidiuretic hormone), released by hypothalamus creates aquaporins in the collecting ducts

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-Aquaporins (channels ​for water in epithelial cells) allow water to leave the collecting duct and return to the body (raising urine concentration)

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