Animal Biology BIOL152 Flashcards
what are the common characteristics for animals
multicellular, heterotrophs, no cell walls, nervous tissue, movement, sexual reproduction, extracellular matrix, cell junctions, Hox gene clusters, similar RNA.
how many animal phylae are there
36
how much of the 36 animal phylae are vertebrates
99%
how species of vertebrates are there
42,000
what is the size range of vertebrates
microscopic to whales
what are the morphological and developmental features of animals
presence or absence of different tissue types, body symmetry types, embryonic development features, body cavities and segmentation, exoskeleton or notochord.
what are metazoas
multicellular, eukaryotic organisms in the biological kingdom Animalia (all animals)
how are metazoas based
specialized tissues
what are parazoas
a group of invertebrate animals coextensive with Porifera and comprising multicellular forms; SPONGES
what do parazoa not have
specialized tissues and organs
what are eumetazoas
a major division of the animal kingdom comprising all multicellular forms except the sponges; more than 1 types of tissue and organs.
what is the symmetry of eumetazoans
radically or bilaterally
what are bilateria
bilaterally symmetrical animals
what does it mean to be bilateral
have cephalization, ventral and dorsal sides, and 3 germ sides.
What does it mean to be radial
oral and aboral sides, 2 germ sides.
what are radial animals called
radiata
what is the transverse plane
at the half, leaving the top and the bottom halves
what is the midsagittal plane
down the middle, leaving left and right sides
what is the frontal plane
in half through the side, splitting it into posterior and anterior sides
when do cell layers develop
during gastrulation
what is the endoderm
the innermost layer of cells or tissue of an embryo in early development
what is the ectoderm
the outermost layer of cells or tissue of an embryo in early development
what parts are derived from the ectoderm
epidermis and nervous tissue
what parts are derived from the endoderm
gut lining, respiratory tract, thymus
what is the mesoderm
the middle layer of the three germ layers that develops during gastrulation in the very early development of the embryo of most animals.
what is derived from the mesoderm
muscles, limbs, gonads, and kidneys
what happens at the 8 cell stage
animal becomes distinct
what is the morula
a solid ball of cells resulting from division of a fertilized ovum, and from which a blastula is formed.
what is a hollowed out morula called
blastula
what are the cells around the blastula called
trophoblasts
What happens in invagination (Step 1)
the process of a surface folding inward to form the archenteron. Happens at the vegetal pole. Consists of the folding of an area of the exterior sheet of cells towards the inside of the blastula.
What does invagination establish
the body plan
what happens during involution (step 2)
the inturning or inward movement of an expanding outer layer so that it spreads over the internal surface of the remaining external cells.
What happens during ingression (step 3)
what are the characteristics of a protosome
spiral and determinate cleavage; blastopore becomes mouth.
what happens if a cell(s) are lost during protostome development
development will stop
what are examples of bilateral protostomia
lophotrochozoa (worms)
what are the characteristics of a deutrostome
radial cleavage; indeterminate cleavage; pluripotent stem cells; blastopore become anus
what are examples of bilateral deutrostomia
chordata
why is using coelom presence/absence an unreliable way to construct animal phylogeny
coeloms may have been lost over evolutionary time/coelom may have arisen more than once.
what is a pseudocoelomate
organisms that have false body cavities.
has a endodermic cavity surrounded by mesoderm and ectoderm.
The cavity never makes contact with the endoderm.
There might be spaces within the mesoderm.
Cavities protect the inside; normally have fluid inside them.
what is a acoelomate
flatworms, no cavity
what are other methods of classification
possession of exoskeleton, development of notochord, presence or absence of segmentation
what are muscle tissues characteristics
movement by myofilaments within cells; excitability, contractility, extensibility and elasticity.
characteristics of nervous tissues
respond to stimuli (input and output), transmit electrical impulses and integration.
characteristics of epithelial tissue
polarity, specialized contact, supported by connective tissue, avascular but innervated and high regeneration capacity. Has specialized cell junctions and cytoskeleton.
characteristics of connective tissue
common origin, degrees of vascularity, and extracellular matrix.
Four classes: bones, blood, connective tissue proper, cartilage.
Mesenchyme tissue.
characteristics of skeletal muscles
voluntary.
Striated due to actin and myosin.
Multinucleated.
Cylindrical in shape.
characteristics of smooth muscle
involuntary.
Not striated.
Not multinucleated.
Spindle shaped; kind of like a net.
Surrounds all hollow cavities, like blood vessels.
characteristics of cardiac muscle
involuntary.
Semi-striated.
Not multinucleated.
Branched shaped, where it connects with other branched cells.
The cell that is contracting the fastest sets the pace.
what is nervous tissue made up of
neurons
where is the input of the neuron placed
dendrite
what is the dendrite
the branches off the soma
what is the axon
where electrical impulses from the neuron travel away to be received by other neurons.
what is the soma
he region of the neuron containing the nucleus is known as the cell body
what does the soma determine
determining whether or not a signal is strong enough to be transmitted; support the chemical processing of the neuron; the most important of which is the production of neurotransmitters.
what are the nodes of ranvier
specialized regions in the axonal membrane that are not insulated by myelin.
what do the nodes of ranvier do?
facilitate the rapid conduction of nerve impulses.
what are myelin sheaths
an insulating layer, or sheath that forms around nerves, including those in the brain and spinal cord.
what do myelin sheaths do
allows electrical impulses to transmit quickly and efficiently along the nerve cells.
what are myelin sheaths mades of
Schwann cells (body) and oligodendrites (brain and spinal chord)
what are microglial cells
parts of the myelin sheath that creates a barrier between the brain and the rest of the body; phagocytic; part of the immune system
what are astrocytes
parts of the myelin sheath that provide nutrients to the neuron.
what are the cell shapes of epithelial cells
squamous, cuboidal, and columnar
what are the arrangements of epithelial cells
layered, simple, pseudostratified, stratified.
what kind of arrangement does exchanges
simple
what are the two types of epithelial cells
epithelia (covering, layering) and glandular (endocrine and exocrine)
what does endocrine systems lead to
tissues and bloodstream
what does the exocrine systems lead to
sebaceous glands and sweat
what are the three elements of connective tissue
ground substance, fibers, cell types; all above are extracellular matrix.
what is ground substance include
nterstitial fluid (washes cells from the water that comes from the blood vessels), adhesion proteins (laminin (gives orientation to cells) and fibronectin), proteoglycans (large structures that are negatively charged, which brings in water to the tissue to maintain volume; made of sugar).
what are fibers made of
collagen (~23 different types in humans; sturdy, long protein that anchors cells), elastin (stretches), and reticular fibers (in between collagen and elastin; not abundant; found in immune parts of the body).
cell types of connective tissue
osteoblasts (bones), chondroblasts (cartilage), fibroblasts (collagen), hematopoietic cells (blood and its components), diplocytes (fats).
what are the two types of connective tissue proper
dense and loose
what is determinate cleavage
cleavage of an egg in which each division irreversibly separates portions of the zygote with specific potencies for further development
what is indeterminate cleavage
cleavage in which all the early divisions produce blastomeres with the potencies of the entire zygote
what are the 5 key innovation of animal evolution
tissues, cavities, symmetry, development, and segmentation
what animal only has one type of tissue
parazoa
Bilaterally symmetrical animals are divided into two lineages, what are they.
protostomes and deuterostomes:
how are protostomes different from deuterostomes
blastopore opening becomes mouth; determinate cleavage; spiral cleavage
how are deuterostomes different from protostomes
radial cleavage; Cleavage is indeterminate – pluripotent stem cells; blastopore becomes anus.
What is segmentation and why is it advantageous?
Segmentation provides the means for an organism to travel and protect its sensitive organs from damage. The ability to divide functions into different portions of the body allows an organism to perform increasingly complex activities and use different segments to perform varying functions.
What phyla belong to the deuterostome lineage?
Echinodermata (e.g., starfish, sea urchins), Chordata (e.g., sea squirts, lancelets, and vertebrates), Chaetognatha (e.g., arrowworms), and Brachiopoda (e.g., lamp shells)
what is the common feature of muscle cells
Muscle tissue is composed of cells that have the special ability to shorten or contract in order to produce movement of the body parts.
what cells make up nervous tissue
neurons
what is the major function of nervous tissues
coordinating and controlling many body activities. It stimulates muscle contraction, creates an awareness of the environment, and plays a major role in emotions, memory, and reasoning.
why is blood a connective tissue
it consists of blood cells surrounded by a nonliving fluid matrix called blood plasma.
what features do all connective tissues have in common
Cells,
Large amounts of amorphous ground substance,
And protein fibers.
what is homeostasis
process of maintaining a relatively stable internal environment despite changes in external environment
what are conformers
These animals are also known as ectotherms as they cannot regulate their own internal temperature. It adapts its behaviour to the surroundings or migrates to environments with optimal temperatures. Conformers are referred to as cold-blooded animals.
what are regulators
The organisms are capable of controlling their internal environment irrespective of their external surroundings to an extent (warm blooded animals).
what is negative feedback regulation
the response will reverse or cause the opposite effect of the original stimulus.
Examples of negative feedback
insulin production and release
what is positive feedback regulation
when a change in a variable triggers a response. which causes more change in the same direction.
Examples of positive feedback
childbirth and when a body part is cut
Can an animal be both a conformer and a regulator?
yes, because some mammals engage in hibernation, a form of dormancy. In doing so, these regulators act as endothermic conformers.
how is homeostasis controlled
Maintenance of homeostasis usually involves negative feedback loops. These loops act to oppose the stimulus, or cue, that triggers them. For example, if your body temperature is too high, a negative feedback loop will act to bring it back down towards the set point
what is action potential
a rapid rise and subsequent fall in voltage or membrane potential across a cellular membrane with a characteristic pattern.
what are graded potentials
are changes in membrane potential that vary in size, as opposed to being all-or-none.
what are glial cells
cell which are non-neuronal and are located within the central nervous system and the peripheral nervous system that provides physical and metabolic support to neurons, including neuronal insulation and communication, and nutrient and waste transport.
examples of glial cells in the CNS
oligodendrocytes, astrocytes, and microglia
what do oligodendrocytes do
specialized glial cells that wrap themselves around neurons present in the CNS. Oligodendrocytes are primarily responsible for maintenance and generation of the myelin sheath that surrounds axons. They also participate in axonal regulation and the sculpting of higher order neuronal circuits
what do microglial cells do
immune cells of the central nervous system and consequently play important roles in brain infections and inflammation; interconnected with bloodstream and filters.
what do astrocytes do
regulate blood flow, but also transfer mitochondria to neurons, and supply the building blocks of neurotransmitters, which fuel neuronal metabolism; interconnected with bloodstream and filters.
which glial cells are only found in the PNS
Schwann cells
what do schwanns cells do
insulating (myelinating) and supplying nutrients to individual nerve fibers (axons) of the PNS neurons.
what is the central nervous system
The central nervous system is made up of the brain and spinal cord: The brain controls how we think, learn, move, and feel. The spinal cord carries messages back and forth between the brain and the nerves that run throughout the body.
what is the peripheral nervous system
part of your nervous system that lies outside your brain and spinal cord. It plays key role in both sending information from different areas of your body back to your brain, as well as carrying out commands from your brain to various parts of your body.
how is resting membrane potential established
determined by concentration gradients of ions across the membrane and by membrane permeability to each type of ion.
What would happen to the resting membrane potential if you increased the extracellular
concentration of K+?
resting potential of the membrane will be less negative, depolarizing.
What are inhibitory and excitatory signals on a neuron?
Excitatory currents are those that prompt one neuron to share information with the next through an action potential, while inhibitory currents reduce the probability that such a transfer will take place.
what are the pumps and gates neurons use
leaky Na+/K channels, Na+/K+ and ATPase pump, voltage gated channels, ligand gated ion channel
how do Na/K channels function
llow ions to pass through the channel without any impedance. This means that there is no gating mechanism, and ions are free to flow through the channel along the concentration gradient.
how does the sodium potassium pump work
moves sodium and potassium ions against large concentration gradients. It moves two potassium ions into the cell where potassium levels are high, and pumps three sodium ions out of the cell and into the extracellular fluid.
how do voltage gate ion channels work
sensitive to the outside positive and inside negative; when receiving an electric current (a change in charge inside and outside), the channels open up; specific to Na and K.
It can be an open gate, but be inhibited by the inhibitor attachment on the channels.
Closed fully again when the charge goes back to normal.
how do ligand gate channels work
open and close in response to
ligands or chemical
what is a saltatory signal
Action potentials traveling down the axon “jump” from node to node. This is called saltatory conduction which means “to leap.” Saltatory conduction is a faster way to travel down an axon than traveling in an axon without myelin.
what happens to the RMP when Na increases?
Na+ depolarizes, which makes the stimulus strong; making it more positive.
what is depolarization
In neurons, the rapid rise in potential, depolarization, is an all-or-nothing event that is initiated by the opening of sodium ion channels within the plasma membrane.
what happens when a cell is depolarized
the gated sodium ion channels on the neuron’s membrane suddenly open and allow sodium ions (Na+) present outside the membrane to rush into the cell. As the sodium ions quickly enter the cell, the internal charge of the nerve changes from -70 mV to -55 mV.
what is hyperpolarization
when the membrane potential becomes more negative at a particular spot on the neuron’s membrane
what is equilibrium potential
opposing forces of chemical and electrical gradients can create equilibrium when there is not net movement.
what is the charge of DNA
very negative
what is synaptic integration
integrates multiple input to single neurons.
what is spatial summation
when two or more EPSPs or IPSPs are generated at one time along different regions of the dendrites and cell body, their effects sum together.
what is temporal summation
two or more EPSPs arrive at the same location in quick succession.
what does it mean to inhibit
To inhibit is to make it more negative, like sodium/potassium pump and chloride (Cl-).
what does it mean to excite
to be more positve
what is the presynaptic cell
the cell sending the signal
what is the postsynaptic cell
the cell receiving the cell
what is the synaptic cleft
the gap between two neurons
what is the process of receiving a signal
Neurotransmitters being secreted by the presynaptic cell might bind to proteins on the postsynaptic cell or there might be enzymes that degrade the neurotransmitter. They also might be reabsorbed back into the presynaptic cell. It may also just go away, which might affect other surrounding neurons.
what is the process of calcium voltage gate channels
Calcium voltage gated channels open; calcium rushes into cell; calcium binds to the vesicles (full of neurotransmitters); the binding causes the vesicles to fuse with the plasma membrane, which releases neurotransmitters into the cleft and to the next neuron.
how do neurons get rid of calcium
mitochondria within the axon terminal will reabsorb the calcium.
what are metabotropic receptors
has a G-protein coupled receptor to start the cascade once a ligand binds.
what are the two types of ligand channels called
ionotropic and metabotropic
what is acetylcholine
released at neuromuscular junctions.
Excitatory in brain and skeletal muscles but inhibitory in cardiac muscles.
Very widespread.
what are biogenic amines
widespread physiological effects and psychoactive.
Abnormally high or low levels associated with a variety of mental illnesses.
Catecholamines: Dopamine, epinephrine.
what are amino acids
Glutamate: most widespread excitatory neurotransmitter.
GABA: most common inhibitory neurotransmitter.
what are neuropeptides
Often called neuromodulators; can alter the response of a postsynaptic neuron to other neurotransmitters.
Example: Opiate peptides
what are gaseous neurotransmitters
Nitric oxide.
Carbon monoxide
Not sequestered into vesicles
Produced locally as required
what are the functions of the skeleton
support, protection, source of stem cells, storage for triglycerides, stores different ions (calcium and phosphate), hormone production (osteocalcin), and locomotion.
what are the three types of skeletons
hydrostatic, exoskeleton, endoskeleton
describe hydrostatic skeleton
combination of muscle and water; examples include worms; when muscles relax, they extend, when contracted water is pushed, which pushes forward.
describe exoskeleton
uses chitin; examples include insects, spinder, fungi, crustaceans (arthropods); crustaceans go through molting for growth and the shell is segmented.
describe endoskeleton
internally based; examples include sponges, echinoderms (calcium carbonate), and vertebrates (calcium phosphate); attached to muscle.
what are the 2 parts of the skeleton
axial and appendicular
what is the axial skeleton
main longitudinal axis (skull, vertebral column, ribs); 80 bones.
what is the appendicular skeleton
limb bones and girdles; 126 bones.
how many bones are the human body approx
206
what is the function of bones
stem cells to red and white blood cells, storage of minerals, fat storage in the form of triglycerides.
what is a joint
where two or more bones come together
what are the 3 types of bones
Immovable
Slightly moveable
Freely moveable
what are the three types of cartilage
hyaline, elastic, and fibrocartilage
describe hyaline cartilage
Glass-like; most abundant; provides support through flexibility.
Examples: trachea, larynx, ends of bones.
describe elastic cartilage
Contains many elastic fibers; able to tolerate repeated bending; not much in the body.
Examples: epiglottis.
describe fibrocartilage
resists strong compression between hyaline and elastic cartilage.
Examples: in between vertebrae; meniscus.
examples of immovable joints
sutures/ gophers
examples of freely movable joints
synovial joints and fluid
examples of slightly movable joints
cartilaginous joints; between vertebrae.
what are the types of movable joints
pivot, hinge, ball-and-socket
what is the organic composition of bones
collagen and bone cells
what is the inorganic composition of bones
Calcium, phosphate, hydroxides.
describe long bones
characterized by being long.
Examples: humerus.
describe short bones
short.
Examples: wrist and ankle bones.
describe flat bones
sternum and skull sometimes.
describe irregular bones
vertebrae
what is the shaft of the bone called
diaphysis
what are the ends of the bone called
proximal and distal
what is the spongy bone
honeycomb-shaped; inside the bone at the ends; holes arranged specifically for structural support due to pressures the body is put under.
what is the outside of the bone called
compact
what is the trabeculae
the small ‘beams’ the spongy bone.
what is the osteoblast
makes the collagen/matrix, which makes the bone.
what are gap junctions
aggregates of intercellular channels that permit direct cell–cell transfer of ions and small molecules.
describe the process that osteoblasts go through
Osteoblasts stay linked when they divide through gap junctions. The cells will link together to form concentric rings. If one cell dies in the link, they all die because they are connected.
what are osteocytes
cells surrounded by bone matrix
what are osteoclasts
breaks down the bone in order to absorb bone to remodel it.
what happens when there is not enough calcium
osteoclasts will break down bone in order to supply the entire body with calcium. Osteoclasts will slow or shut down when calcium is taken in.
what is the reasoning behind osteoporosis
osteoclasts working too much or osteoblasts working too little.
what is the lacunae
small, spindle-shaped spaces, each containing an osteocyte that is left behind by osteoblasts during the process of remodeling.
what do lacunae do
provide housing to the cells it contains and keeps the enclosed cells alive and functional.
what are canaliculi
small canals running through the bone solid matrix, hosting osteocyte’s dendrites, and saturated by an interstitial fluid rich in ions.
what is the function of canaliculi
supply nutrients via blood vessels, remove cellular wastes, and provide a means of communication between osteocytes.
what are the three types of muscle
cardiac, smooth, skeletal
how many muscles are in a human body
600
what do tendons do
link muscle to the bone
what is a fascicle
bundle of muscle fibers
why are fascicles built in bundles
for motor recruitment
what is the order of muscle organization big to small
muscle, fascicle, muscle fibers
what are myofibrils
long contractile fibers, groups of which run parallel to each other on the long axis of the myocytes
how much volume do myofibrils take up in a muscle cells
80%
what is found in higher concentrations in muscles
glycogen
what are myofibrils considered
organelles made of myofilaments
what is the sarcoplasm
cytoplasm of muscle cells
what is the sarcolemma
plasma membrane of muscle cell
what is the sarcoplasmic reticulum
the ER of the muscle cell
what are muscle cells surrounded by
endomysium
what is the fascicle surrounded by
perimysium
what is the entire muscle surrounded by
epimysium
what is myosin
a fibrous protein that forms the contractile filaments of muscle cells; 2 heavy chains, 4 light chains; THICK LINES; in the middle
what is actin
a protein that forms the contractile filaments of muscle cells; THIN LINES; composed of long chains of globular heads (G-actin proteins), troponin, and tropomyosin
what is tropomyosin
laced with the G-Actin proteins of the actin filaments.
Blocks actin and myosin binding.
what is troponin
composed of 3 different things and link myosin, actin, and troponin.
When bound by calcium, it changes shape and moves tropomyosin out of the way.
what is titin
connects the myosin to the Z Line; transverses the myosin.
what is dystrophin
anchors filaments to the plasma membrane
what are prime movers
flexors and extensors
what are antagonists
pull muscles back to original position
what are synergists
other muscles surrounding the prime movers to facilitate and isolate movement.
what is the sarcomere
the contractual subunit of myofilaments.
What is the A Band
the dark area in the center of the sarcomere where thick and thin filaments overlap.
what is the H Line
the center of the A band where there is no overlap between the thick and the thin filaments. Disappears muscle contracts
What is the I region
the region of a striated muscle sarcomere that contains thin filaments.
what is the Z line
a dense fibrous structure made of actin, α-actinin, and other proteins. defines the lateral boundaries of the sarcomere and anchors thin, titin and nebulin filaments.
what is the first step of muscle contraction
Calcium binds to troponin, moving tropomyosin out of the way of the active sites.
what is the 2nd step of muscle contraction
ATP binds to the myosin globular head, which is split into ADP+P.
what is the 3rd step of muscle contraction
The globular head is then put in an up-right position, which binds to the actin.
what is the 4th step of muscle contraction
The head then pushes actin, creating a contraction.
what is the fifth step of muscle contraction
When ADP+P is lost, myosin is released from actin, stopping power strokes/contractions.
first step of EC coupling
Action potential generated and propagated along sarcolemma to T-Tubules
second step of ec coupling
Action potential triggers Ca2+ release.
third step of ec coupling
Ca++ binds to troponin; blocking action of tropomyosin released.
fourth step of ec coupling
Contraction via crossbridge formation; ATP hydrolysis.
fifth step of ec coupling
Removal of Ca2+ by active transport.
sixth step of ec coupling
Tropomyosin blockage restored; contraction ends.
what is action potential described as
depolarization of the axon
what does EC coupling cause for calcium
rise is cytosolic Ca2+ released from sarcoplasmic reticulum.
where is calcium stored in the muscle cell
the SR
what do T-tubules in the muscle do
invaginations of PM that conduct the action potential from outer surface to inside.
what needs to be done for muscle to stop contracting
Ion pumps will return calcium to SPM, troponin, and tropomyosin back in place, and contraction stops.
what is the motor unit described as
1 motor neuron plus all of its muscle fibers
what is acetylcholinesterase
enzyme that breaks down acetylcholine in the presynaptic cell.
what kind of channels do the SR have
voltage gated
what are fast fibers
contain myosin with high ATPase activity.
what are slow fibers
have myosin with a lower ATPase activity.
how is maximal force produced
produced by each is the same, only speed varies.
what are slow oxidative fibers
low rates of myosin ATP hydrolysis but makes large amounts of ATP.
Used for prolonged, regular activity.
High levels of mitochondria.
Examples: standing.
what are fast oxidative fibers
High myosin activity, makes large amounts of ATP.
Suited for rapid actions.
Examples: 400 meter dash.
what are fast glycolytic fibers
high myosin activity but cannot make as much ATP.
Suited for rapid, intense actions but fatigues quickly.
Examples: fast twitch actions.
Creatine can get phosphorylated easily, which will donate it’s phosphorous to ADP to make ATP
