Zusammenfassung der Ressource
Principles of Biology:
Exam 1
- Overview/Homestasis
- Vertebrates
- Chordates
Anmerkungen:
- Amniotic vs Anamniotic
Amniotic: Reptiles, Mammals, Avians
Anamniotic: Amphibians, Osteichtyes (bony fishes), Agnatha (lampreys), Chondrichthyes (cartliginous fish)
- Invertebrates
- Anthropods
- Sponges
- Cnidarians
- Roundworms
- Flatworms
Anmerkungen:
- lack a circulatory system and rely on diffusion for gas exchange
*hence why they re flat, to reduce L, diffusion distance
- Annelids
- Echinoderms
- Mollusks
- Thermoregulations
- Endotherms
(Homeotherm)
Anmerkungen:
- internally generate heat to maintain body temp, temp stays steady regardless of environment
Higher metabolic rates
- Birds and Mammals
- Ectotherms
(Pakelotherm)
Anmerkungen:
- depend on external heat sources, body temp changes w/ temp of environment
lower metabolic rates
*However, most ectotherms regulate body temp to some degree, most use behavioral methods, however, some use physiological methods
- Reptiles, Fish, Amphibians
- Tunas (bony fish)
Anmerkungen:
- Elevate body temp by retaining metabolic rates with a COUNTERCURRENT heat exchanger
- Pelagic Sharks
(cartilaginous fish)
Anmerkungen:
- Elevate body temp by retainig metabolic rates with a COUNTERCURRENT heat exchanger
- Effect of Environmental Temp on
Body T and Metabolism
- Homeostasis
Anmerkungen:
- the ability to maintain a constant internal environment in response to environmental changes
- Feedback Loops
Anmerkungen:
- Positive Feedback Loops: a self-amplifying cycle where a physiological change leads to even greater change in the same direction
Negative Feedback Loop: a process in which the body senses a change, and activates mechanisms to reverse that change
- Sensors
- Control Center
(integrator,
summator)
- Effectors
- Hypothalamus
Anmerkungen:
- Most important sensor found in mammals (thermostat)
When the hypothalamus is cooled, metabolism increases and body temp increases
When the hypothalamus is heated, metabolism decreases and body temp decreases
- Regulating
Temperature
Anmerkungen:
- 1. Insulation
2. Circulatory rerouting
3. Evaporative cooling
*** dH/dt= C(TA-TB)
C= conductance
(TA-TB)= driving force
- Heat Production
Anmerkungen:
- 1. metabolism of nutrients (50% efficiency
2.muscle activity
3.shivering thermogenesis
4.non-shivering thermogensis (Brown Fat)
- Brown Fat
Anmerkungen:
- In brown fat the inner mitochondrial membrane is made leaky to H+ so energy is not used to make a ATP but rather is released as heat
- Countercurrent
Exchange
- Evaporative
Cooling
Anmerkungen:
- -sweating
-respiratory surfaces ( i.e. panting)
-gular flutter (avians)
- Gular Flutter
Anmerkungen:
- Form of evaporative cooling used by avians
Disadvantage: Loss of water
- Heterotherms
Anmerkungen:
- animals (mammals and birds) whose body temp varies at different times
*Conserves energy by lowering body T set point
- Torpor
Anmerkungen:
- Period of time when body temperature changes (hibernation)
Ex; squirrels, bears, bats
*Only one bird- hummingbirds
- Respiration, Gas Transport,
and Hemoglobin
- Fick's Law of
Diffusion
Anmerkungen:
- Q=DA((P1-P2)/L)
Q= rate of diffusion
D= diffusion coefficient
A= surface area for exchange
P1-P2= pressure difference
L= diffusion distance
- Gas exhange by
diffusion
Anmerkungen:
- Ex: flatworms and insects
insects take in air to the tissues via tracheae (air ducts), vunerable to dehydration
- Ventilatory systems of
a terrestrial
vertebrate
Anmerkungen:
- Terrestrial vertebrates breathe using internal lungs a circulatory system for transport (not very efficient)
TIDAL VENTILATION (2 Way)
- Surface
tension
Anmerkungen:
- Causes the lungs the lungs to expand
Collapsed lungs are a result of loss of surface tension
- Surfactant
(detergent)
Anmerkungen:
- Substance produced by the lungs of humans
Important for preventing collapse of alveoli
- Anatomical Dead Space/
Residual Volume
Anmerkungen:
- Dead Volume: large amount of air in bronchi never reach the lungs
Residual Volume: not all air is removed from lungs when exhaling (fresh air diluted by stale air)
- Atmosphere Air/ Air
in Lungs
Anmerkungen:
- Atmosphere: 21% O2, .03% CO2, 78% N2
Po2 in lungs= 114 mmHg (15%)
- Myoglobin &
Hemoglobin
Anmerkungen:
- subunits of protein (globin) + heme (iron ring)
- Hemoglobin (4)
Anmerkungen:
- Myoglobin (1)
- Cooperativity
vs Affintity
Anmerkungen:
- Cooperativity- sigmoidal shape of hemoglobin's oxygen-dissociation curve results from cooperative binding
Affinity- how easily the oxygen molecules bind to the molecule
Fetus- needs stronger affinity for O2 to go thru the placenta
Oxygen is not very soluble in blood plasma
- Respiration
- Medulla (respiratory
control center)
Anmerkungen:
- more soluble than O2
in solution (5%)
bound as Hb (20%)
as bicarbonate ions (70%)
buffers plasma
- CO2
Anmerkungen:
- converted to HCO3- & H+
- CO2 transport in
blood
Anmerkungen:
- more soluble than O2
in solution (5%)
bound to Hb (20%)
ss bicarbonate ions (70%)
*buffers plasma
- Avian Respiratory
Anmerkungen:
- Avians have both air sacs and lungs (sacs act as bellows)
- Accessory sacs
Anmerkungen:
- Air sacs that at as bellows pushing air thru in one direction, and not for gas exhange surfaces
- Breathing is more costly
in water than air
Anmerkungen:
- Problems:
1. Less air content in water
2. Oxygen diffuses thru water slower than air
3.Viscosity/ density of water
- Countercurrent
Exchange (One Way)
Anmerkungen:
- Gills have lamellae structures allowing for countercurrent exchange
- One-Way Flow
Anmerkungen:
- freshwater moves continuously thru the gills during inhalation and exhalation
- Circulatory Systems: Pumps,
Plumbing & Capillaries
- Capillaries
Anmerkungen:
- Capillaries are permeable to CO2, H2O, small proteins, and O2, but not large molecules such as large proteins and blood cells
Blood cells flow single filePermeability regulated by pH, temp, and histamine
- Osmotic Pressure/
Hydrostatic Presssure
Anmerkungen:
- net movement of fluid IN and OUT of the capillaries is determined by osmotic pressure (roughly the same) and hydrostatic pressure
- Precapillary
Sphinctors
Anmerkungen:
- Location of capillary exchange processes (found in capillary beds)
1. diffusion
2.bulk flow--osmotic pressure (inward)--blood pressure (outward)
- Influence of pH/ Temp
Anmerkungen:
- pH and temperature influence blood flow
decreased pH opes capillary vents
decreased temp constricts capilary
- The Peripheral
Vasculature
Anmerkungen:
- Vasculature Effectors:
-Local factors
-Autonomic N.S.
-Hormonal
- Autonomic
Nervous System
Anmerkungen:
- Sympathetic & Parasympathetic
Fight or Flight (Sympathetic)
- Blood Flow;
Pressure &
Velocity
Anmerkungen:
- As blood flows thru capillaries heat, O2, and waste are exchanged/ blood pressure drops
- Different ways to
pump blood
- Peristalsis
Anmerkungen:
- Present in many invertebrates
Muscular, and can contract and prevent blood flow from moving backwards
- Chambered Heart
Valves
Anmerkungen:
- Present in vertebrates
Valves prevent blood flow from going backwards
- Skeletal muscles &
valves
Anmerkungen:
- Present in vertebrate veins
Venous system in which blood moves thru veins using gravity or muscular contraction
- Seperate Pulmonary/
Systemic Circulatory
Systems (birds &
Mammals)
Anmerkungen:
- Advantages:
control volume and blood pressure seperately
-different velocity
-different pressure
- Blood Pressure
Anmerkungen:
- Cardiac Output x Total Resistance
Pressure pushes fluid thru the body, therefore low pressure would leave fluid in the lungs
Blood Pressure= CO x Peripheral Resistance
- Cardiac Output
Anmerkungen:
- How much blood is being pumped in a given time
Heart Rate & Stroke Volume (HR x SV)
- Regulation of Water & Ion
Balance: Kidney I
- Kidney
Anmerkungen:
- Takes in H2O w/ ions
Removes urine and eliminates wastes (thru sweating/ respiratory evaporation)
- Function: Bulk Filtration and
Selective Reabsorption
Anmerkungen:
- 1. Filters the blood
2. Maintains plasma osmolarity & ions3. Eliminates waste
- Waste Elimination
Anmerkungen:
- nitrogenous waste- proteins, nucleic acids, nutrients
ammonia (NH4OH)- toxic, highly solubleuric acid (C5H4N4O5)- not toxic, insolubleurea (CO(NH2)2)-non toxic, soluble*primary waste for humans
- Filtration
Anmerkungen:
- -happens at the glomerulus
-large volume of plasma goes thru the the capillaries
- Movement
Anmerkungen:
- Blood pressure and osmotic pressure move water
Urine produced can be more concentrated than blood
- Selective Reuptake
Anmerkungen:
- -happens in the proximal convoluted tubule
-active transport
-reuptake of ions, water, and glucose
- Active Transport
Anmerkungen:
- 1. Movement of molecules against concentration gradient
2. Requires ATP (energy)
3. Specific protein transporter (none for water)
- Nephron
(subunit)
- Osmoregulation in
other animals
Anmerkungen:
- birds, fish, lizards all have other osmoregulators
- Kidney II; Comparative
Physiology of Osmoregulation