Module 2 Exam Review Flashcards
Reductionism
when you look at the pieces to understand the whole
Emergence
the realization that the whole is more than the sum of the pieces
August Krogh principle
for every biological problem there’s an organism in which it can be most conveniently studied
similar geometry
2 animals have the same shape but differ in size
Hydrophobic signalling factors
- cannot cross cell membrane
- can be stored in vesicles and released on demand
- travel easily dissolved in extracellular fluid
Hydrophobic signalling factors (3 pts)
- can cross cell membrane
- can’t be stored so they diffuse upon synthesis
- travel attached to a water-soluble carrier
Water soluble factor
- must initiate a response by binding to a receptor on the cell membrane
- use secondary messengers inside the cell
fat soluble factor
receptor is inside the cell as it can freely cross the cell membrane
- triggers change in gene expression directly
Elements of endocrine signaling pathways(6)
- Synthesis- a hormone is synthesized in an endocrine gland
- Secretion- hormone somehow escapes the tissue(lipid soluble excreted upon synthesis, water soluble by exocytosis)
- transport- travels to target tissue
- reception- binds to a receptor at target tissue
- transduction- connects receptor to effector(uses ATP)
- response- ultimate consequence of the signalling cascade
Antagonistic hormones
a pair of hormones that have opposite effects; they act against each other
tropic hormones
hormones with the main job of regulating other hormones
Acclimation
response to a single environmental factor
Acclimatization
animals remodels itself in response to complex environmental change
endotherms
animals use internal metabolic processes as major heat source
ectotherms
can produce some heat but not enough to elevate temperature
Hypothalamus
gland that controls homeostasis in the body, releases tropic hormones to the pituitary gland
Posterior pituitary
a collection of termini of axons coming from the hypothalamus, axons of the hypothalamus send secretions to the posterior pituitary which then sends them to the rest of the body
Anterior pituitary
hormones travel through a vessel from the hypothalamus to the anterior pituitary where they trigger the release of hormones into circulation
Peptide hormones
- regulated by hypothalamus
- release direct or tropic hormones into blood
direct= act on target tissue (ADH) tropic= stimulate release of other hormones
“puppet”
Poikilotherm
an animals whose body temperature varies with its environment
Homeotherm
has a relatively constant body temperature
Metabolic rate
the sum of all energy used in biochemical reactions over a given time interval
Basal metabolic rate
metabolic rate of a resting, fasting, and non-stressed endotherm at a comfortable temperature
Standard metabolic rate
metabolic rate of a resting, fasting, and non-stressed ectotherm at a particular temperature
torpor
a state of decreased activity and metabolism that enables animals to save energy while avoiding difficult and dangerous conditions
Skeletal muscles/striated muscle
type of muscle responsible for voluntary movements
myofibrils
bundle of muscle cells containing thin filaments of actin and thick filaments of myosin
Cell body
part of the neuron that houses the nucleus and other organelles
dendrites
short, highly branched extensions of a neuron that receives signals from other neurons
axon
extension of a neuron that carries impulses away from the cell body, towards the target cell
synapse
where a neuron communicates with another cell across a narrow gap via a neurotransmitter
neurotransmitter
molecule that diffuses across synaptic terminal to trigger a response
Glial cells
cells of the nervous system that support and regulate neurons
Information processing
- sensory input
- integration
- motor output
Membrane potential
difference in charge across a cell’s plasma membrane due to distribution of ions
Resting membrane potential
membrane potential of a neuron not sending a signal(-70mV)
- expressed relative to the outside of the cell
Equilibrium potential
a cell’s membrane voltage at equilibrium
ion gated channels
open/close in response to concentration change
depolarized
inside of cell becomes less negative relative to outside the cell (sodium opening)
Hyperpolarized
inside of cell becomes more negative relative to outside (potassium opening)
Generation of action potentials
- resting state- gated Na and K channels are closed
- slow depolarization- stimulus opens Na channels, Na inflow depolarizes membrane
- depolarization- once threshold is reached, all voltaged gated Na channels are open, inside is positive
- repolarization- sodium channels close, K gated channels open to permit K outflow, inside of cell is -ve again
- hyperpolarization- K channels close, some Na open, membrane returns to resting potential
refractory period
short time after an action potential where a neuron cannot respond to another stimulus
EPSPs
excitatory post-synaptic potentials
- slight membrane depolarization at excitatory synapses
IPSPs
inhibitory post synaptic potentials
- slight membrane hyper-polarization
summation at axon hillock
combination of IPSP’s and EPSP’s that decide if a cell depolarizes to threshold voltage
plasticity
ability to change synaptic connections and functional properties of neurons
- done by reinforcing or making more connections
myoblasts
immature muscle cells
muscle tissue fibre arrangement
myosin(thick) and actin(thin) -> myofibrils -> muscle fibers ->tissue
myocyte
excitable and contractile cell type
Actin
- the microfilament that mysoin pulls itself along on (actin is train tracks, myosin is train)
- “thin filament”
myosin
- motor protein
- has a contractile head and flexible neck
- force generating
- “thick filament”
