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a cell that has a distinct nucleus and other membrane-enclosed organelles
protists that are the closest living relatives to animals
heterotrophs that ingest their food multicellular have true tissues: differentiated cells (including nervous and muscletissue) lack cell walls have structural proteins like collagen 95% animals are invertebrates (lack backbone)
blastula development stage
hollow sphere of cells formed during an early stage of embryonic development inanimals [1]. The blastula is created when the zygoteundergoes the cell division process known as cleavage.[2] The blastula is preceded by the morulaand is followed by the gastrula in the developmental sequence
In which type of embryos does the endoderm originate from te mouth end, and if cells are removed, development is arrested
the anus forms first humans are deuterostomes
Reproduction and Embryonic development in animals
-Most animals reproduce sexually -Diploid stage dominates the lifecycle -After sperm fertilizes the egg, a diploid zygote is formed -Zygote undergoes cleavage (early micotic cell division) -A mulitcellular blastula is formed -Blastula undergoes gastrulation which results in the forma…
Sets of DNA sequences that regulate the expression of other genes Hox genes in many animals 
Body plans
1. Spherical symmetry 2. Radial Symmetry 3. Biradial Symmetry 4. Bilateral Symmetry
Body plans: Radial vs. Bilateral Symmetry:
Radial Symmetry- can be cut into four symmetrical parts. Bilateral Symmetry-  can only be cut into two symmetrical parts, down the center.
back of body 
Bottom of animal
situated in the front
back or facing behind/backwards.
the concentration of sensory neurons and interneurons in a head
Germ Layers
Ectoderm Endoderm Mesoderm
body cavity, fluid filled space seperatign the digestive tract from the outer body wall cushions organs, hydrostatic skeleton, organs independent
Maintenance of a relatively stable internal environment despite continuous outside changes. A dynamic state of equilibrium.
negative feedback/feedback inhibition
one of the products downstream in a reaction series comes back and inhibits enzymatic activity in an earlier reaction
In negative feedback loop,
The response of the effector always results in decreasing the sensor aspect of the pathway and it counteracts the effectiveness of that pathway
maintenance of internal temperature within a range that allows cells to function efficiently
Emission of electromagnetic waves by all objects warmer than absolute zero. Radiation can transfer heat between objects that are not in direct contact. 
Removal of heat from the surface of a liquid that is losing some of its molecules as gas. 
Transfer of heat by the movement of air or liquid past a surface
Direct transfer of thermal motion (heat) between molecules of objects in direct contact with each other
insulation and sweating (adaptation- thermoregulation)
epidrmis- outer skin covering dermis- sweat gland, nerves, muscles adipose- layer of fat for insulaiton
nerve net
A network of continuously interconnected nerve fibers (as contrasted with neural networks, in which fibers are connected by synapses)
Nerve ring
Nerves radiating evenly around the body.
Central Nervous System (nervous system)
Acts as control center for nervous system, issues orders to muscles glands and organs (BRAIN & SPINAL CORD) 
The nervous system: Peripheral nervous system
The sensory and motor neurons that connect the central nervous system to the rest of the body. (brings info into CNS and carry out of the CNS) - sensory receptors, muscles, and glands Lie outside the brain and spinal chord 2 parts somatic - voluntary muscles automatic - involuntary (…
Parts of the Neuron
Nucleus, cell body, dendrites, glial cells, axon, axon terminals, myelin sheath, nodes of ranvier, synaptic vesicles, neurotransmitters
Cytoplasmic extensions that receive information and transmit it towards the cell body.  
long appendages where an action potential travels
Myelin sheath
A fatty material, made up of glial cells, that insulates the axon and allows for the rapid movement of electrical sheath. Where action potentials are transmitted. 
nodes of Ranvier
increase efficiency of signal transmission
membrane potential
The electrical potential difference across a cell's plasma membrane. In membrane biophysics it is sometimes used interchangeably with cell potential, but is applicable to any lipid bilayer or membrane. Hence every organelle and every membranous compartment has a transmembrane potential.
Resting potential
why is the resting potential -70mV
there is an unequal distribution of ions membrane is more permeable to K+ ions than Na+
Equilibrium Potential 
When the electrical gradient opposes the concentration gradient Calculated using the Nernst Equation Depends on the concentration gradient E(k+)= -90mV and E(Na+)= +60mV
2 factors influence membrane potential
1)concentration gradient of ions 2)permeability of membrane(gated channels)
1. a change in a cell's membrane potential that makes it more negative 2. After action potential membrane overshoots resting value (-70 mV) 3. As inside becomes more positive with accumulation of K + , the membrane becomes more negative than at resting potential and only gradually retur…
a shift in transmembrane potential toward 0mV. Involves sodium channels.
The action potential generated at the axon 
hillock propagates as a wave along the axon.[59] The currents flowing inwards at a point on the axon during an action potential spread out along the axon, and depolarize the adjacent sections of its membrane. If sufficiently strong, this depolarization provokes a similar action potential …
the refractory period of the axon is due to what?
Na inactivation and K activation which hyperpolarizes the inside of the cell. Keeps the signal moving forward in the axon and doesn't allow it to move backward. 
Action Potential Propagation- Myelination
myelinated axons transmit faster than unmyelinated axons. If depolarization shifts the membrane potential sufficiently, the result is a massive change in membrane voltage. 
Signal transmission between neurons
neurons can receive more than one signal at a time; some are excitatory (depolarizing) [EPSP] and some are inhibitory (hyperpolarize) [IPSP]
What are the 5 groups of neurotransmitters?
-acytlcholine -biogenic amines -amino acids -neuropeptides -gases
Muscle stimulation, memory formation, learning
Amino Acids
long-term memory
Biogenic Amines
sleep, mood, attention, learning. Used for nervous system disorders and treatments
pain reception 
Nictric Oxide (local regulators) Carbon Monoxide- hypothalmic hormone release; intestine smooth muscle plasma membrane hyper polarization)
Post-Synaptic Responses
Excitatory Post-Synaptic Potential (EPSP) and Inhibitory Post-Synaptic Potential (IPSP)
Disorders of the nervous system
Schizophrenia, depression, Alzheimer's disease, and Parkinson's disease Genetic and environmental factors contribute to the diseases of the nervous system
simple aquatic animals that lack tissues, feed as suspension feeders, with skeletons of organic matter or calcium carbonate or silica secreted in the form of spicules, dating back to the Cambrian Period
Animals with back bones Linnaen classification, they are bilateral deuterostomes that belong to the kingdom animalia. (Deuterostomes are animals whose mouth develops after the ass) Major sub-phylum of the phylum Cordata Mobile organisims with sensory organs in a head bilateral symmetry…
-Marine suspension feeders -Intermediate b/w vertebrates & invertebrates: notochord acts as endoskeleton in adults -Feed by burrowing tail first in sediment; take in water through mouth and trap food on gill slits with the help of cilia
Interstitial fluid
fluid that surrounds body cells
collections of specialized cells and cell products that perform a relatively limited number of functions are called what?
a group of several different kinds of tissues arranged so they can act together as a unit to perform a special function
internal mechanisms to control internal change in the face of external fluctuation 
animal uses for environmental variable if it allows its internal condition to change in accordance with external changes in the variable.
set point 
maintaining a variable at or near this particular value
Environmental feature that provokes a response from an organism
mechanisms of homeostasis
- for a given variable, fluctuation above or below a set point serves as a stimulus - detected by a sensor and triggers a response response returns the variable to set point e.g. THERMOSTAT MODEL moderate changes in the internal enviroment
negative feedback
a control mechanism that reduces or "damps" the stimulus
positive feedback
control mechanism that amplifies rather than reduces the stimulus. 
positive feedback loop
do not play a major role in homeostasis, but instead help drive process to completion 
describes chemical reactions that absorb heat energy from the surroundings
body heated by environment
In negative feedback loop,
a process whereby a change in an initial condition triggers a response that counteracts the initial change. 
integumentary system
protective membrane, temperature regulator, and sensory receptor-- humans = convering of the body- skin, hair and nails 
countercurrent heat exchange 
transfer of heat between fluids that are flowing in opposite directions. arteries and veins are adjacent to each other
the concentration of sensory neurons and interneurons in a head
sensory neurons 
transmit information from eyes and other sensors that detect external stimuli
vast majority of neurons in brain. Form local circuits connecting neurons in the brain.
Motor Neurons
transmit signals to muscle cells and cause them to contract. 
tiny fluid filled gap between axon terminal of 1 neuron and the dendrite of another
chemical that causes activity in the neuron
Glial Cells
- supportive cells w/in the nervous tissue
ion channels 
pores formed by clusters of specialized proteins that span the membrane. Allow diffusion 
Equalibrium potential 
the magnitude of the membrane voltage at equilibrium for a particular ion. When electrical gradient opposes the concentration gradient 
electrical force
negative on the inside of the cell and positive on the outside.
2 factors that influence membrane potential?
1) the concentration gradient of different ions 2) the permeability of the membrane of those ions
cambrain explosion
-first radiation of animals with skeletons -every animal phyla that exists now suddenly sppear 542 Ma -first appearance of animals with hard parts -defines base of phanerozoic
germ layer covering surface of embryo. Gives rise to outer layer covering of animal and central nervous system
-innermost layer -forms internal organs
animal has ectoderm and endoderm
- animals have an intervening mesoderm layer - these include all bilaterians
gives rise to CT, muscle, BV's, lining of body cavities, lining of joint cavities
Graded Potential
Amount of change in potential is directly related to the intensity of the stimulus 
voltage-gated ion channels
ion channels that open and close in response to change in membrane potential
Chemical Synapse
more common the electrical synapse specialized for the release and reception of neurotransmitters and hormones
Speed of propagation of action potential depends on:
1) myelin 2) axon diameter
excitatory post synaptic potential
local depolarization of PSM that brings the neuron closer to the action potential thresholdd -allows Na+ & K+ to pass simutaniously -(-70mV)
The nervous system: Peripheral nervous system
The sensory and motor neurons that connect the central nervous system to the rest of the body. (brings info into CNS and carry out of the CNS) - sensory receptors, muscles, and glands Lie outside the brain and spinal chord 2 parts somatic - voluntary muscles automatic - involuntary (…
- not about multiple personalitties, it is a psychotic disorder involving exteme delusions both physically and mentally - low (e),(c), and (a) -paranoid (hallucinations) disrogranized (scrambled speech) Catatonic (muscle spasms) -dopamine released rapidly= symptoms -blockage of glutam…
Items showing exteme pessimism & hopelessness. major depressive disorder bipolar disorder- mood swings from high to low 
Drug Addiction 
compulsive consumption of a drug and loss of control in limiting intake. The reward system of the brain provides motivation for activities that enhance survival and reproduction and addictive drugs use reward system= enhance dopamine pathway 
Alzheimers Disease
dementia characterized my confusion or memory loss. Death of neurons in many parts of the brain. (Beta)-amyloid build up in plaques around neurons to cause death of surrounding neurons. 
Parkinson's disease
A progressive neurological disorder that is characterized by tremor and weakness in the muscles and a shuffling gait. Death of neurons midbrain that normally release dopamine.
Gastrovascular cavities
-Are digestive compartments surrounded by cells -Have only a single opening - Cells remain moist on inside and outside of body to gain nutrients. -Cells diffuse nutrients to other close surrounding cells
Open Circulatory system
bathes the organs directly and is not confined to vessels     --- Hemolymph Advantages: chap to build and maintain     - no blood vessels     - no high pressure system           --ex: arthropods and most molluscs
closed circulatory system
blood is kept separate from the interstitial fluid -blood is pumped through the vascular system by one or more hearts
Vessels that carry oxygenated blood away from the heart.
A network of microscopic blood vessels. They're the blood cell that must be squeezed through in single file. Their walls are thin and porous making it possible for gases, nutrients, and waste to transfer across walls rapidly.
Blood vessels that carry blood from the tissues to the heart Have all three tunics Walls are thinner than arteries Lumen larger Media is poorly developed 65% blood flow Pressure is low
single circulation
blood passes through the heart once in a complete circuit
double circulation
oxygen-poor and oxygen-rich blood are pumped separately from the right and left sides of the heart; maintains higher blood pressure
Gas Exchange
uptake of molecular O2 from the environment and the discharge of CO2 to the environment 
Countercurrent Exchange
in which two fluids exchange substances while flowing in opposite directions. ex: fish gills 
tracheal system
An respiratory system consisting of trachea, fine chitinous tubes in the body of an insect, conveying air directly to the tissues.

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