Biology Exam 2 Review Part 2

open circulatory system

the blood exits vessels and enters the open portion of the body; almost entirely independent of gas exchange; arthropods have this

dorsal

arthropods have a ( ) circulatory system because they are protostomes

closed circulatory system

blood is always maintained inside a vessel; main function is to transport O2 to cells and CO2 from cells; vertebrates, annelids (segmented worms), cephalopods all have this

plasma; hemoglobin

blood contains two parts: ( ) (the liquid solution) and blood cells which contain ( ) to carry oxygen

hemoglobin

a pigment (that provides the red color to blood cells) that contains four iron atoms to which O2 can bind in the lungs (oxygenation) and then release to the body cells (deoxygenation)

arteries

move blood from the heart

veins

move blood to the heart

atriums

blood enters the heart into the ( )

ventricles

blood leaves heart from the ( )

cardiac cycle

refers to the rhythmicity of the beating heart in two phases: systole and diastole

systole

when the ventricles contract to push blood out to the lungs and body

diastole

when the ventricles relax to fill with blood from the atriums

gills; body

in fish, deoxygenated blood travels from the heart to the ( ), then oxygenated blood moves directly to the ( ), where it is deoxygenated and moved back to the heart

lungs; heart

in birds and mammals, deoxygenated blood travels from the heart to the ( ), then the oxygenated blood returns to the ( ) to be sent to the rest of the body

valves

veins have to make sure there is constant positive pressure

countercurrent heat exchange

can warm the muscles of marine animals that live in cold waters

loops of Henle

U-shaped structures which retain water and concentrate the urine, limiting the amount of water needed for survival

nerves

bundles of cells called neurons

nervous system

made up of collections of millions to billions of nerves; sends messages between parts of the body

ganglia

arthropods centralize their nervous system into ( )

cephalized

vertebrates have a ( ) nervous system (concentrated in the head), which then communicates with the rest of the body

central nervous system (CNS)

brain and spinal cord

peripheral nervous system (PNS)

everything but the brain and spinal cord

dendrites

look like tree branches; function to receive signals from other neurons

cell body

contains the nucleus and most organelles, functions to integrate the incoming signals into a signal nerve output

axon

long thin part of the cell, functions in long-distance signal conduction

presynaptic axon terminals

where the axon ends with multiple swellings which make synaptic contact with other cells (neurons or muscle cells)

myelin sheath

specialized glial cells that wrap around some axons for insulation

action potential

help nerve impulses travel from one end of a neuron to the other

positive; negative

cell membranes are naturally polarized, more ( ) on the outside, and more ( ) on inside

depolarization

a temporary reversal of action potential polarity that travels down the axon; caused by controlling ion distributions

voltage-gated Na+/K+ channels

to depolarize the resting membrane potential, neurons must actively move ions across the membrane; this is achieved by ( )

graded potentials

membrane potentials do not cross the voltage threshold, they vary in size; can lead to action potentials in some cases

all-or-none action potentials

pass voltage threshold to cause an action potential that moves down the axon with no change in size

larger

action potentials travel faster in ( )-diameter neurons (like those in squid)

myelination

a way that vertebrates increase speed of action potentials

postsynaptic cell

the dendrite of the next neuron

synaptic plasticity

changes in synapse structure/function over time; one hypothesis for the mechanism of learning

mechanoreceptors

respond to stretching/constricting of cells; hearing functions through this as well

frequency

the ( ) of sound waves determines the characteristics of the “sound” (ex. pitch)

chemoreceptors

respond to the presence of chemicals (smell, taste)

photoreceptors

sense the characteristics of light to create visual information to the organism; can be complex, image-forming vision or simple, light-sensing organs

opsins

sensory receptor proteins that all photoreceptors use; contain a protein and a non-protein (derived from Vitamin A) that is photosensitive

photosensitivity

absorbs a photon and changes structure which can then induce action potentials in sensory neurons

rods

specialized photoreceptors responsible for low-light vision

cones

specialized photoreceptors responsible for color vision

autonomic nervous system

controls body functions that don’t require skeletal muscles; both the CNS and PNS participate in this; includes the gut, heart, bladder, reproductive organs, and exocrine glands

exocrine glands

secrete products outside of the blood stream, like tears and sweat

enteric division

division of the autonomic nervous system that controls the gut

sympathetic division

division of the autonomic nervous system that operates under periods of stress (increases heart rate, sweating, adrenaline rushes, etc.); “fight or flight”

parasympathetic division

division of the autonomic nervous system that operates under “normal” conditions; “rest and digest”

skeletal muscle

attaches to bones and tendons for movement of the body; multinucleate; striated, which helps with contraction

smooth muscle

controls contractions in waves for organ functions; no conscious control of these muscles; provides contractile forces for movement in many internal organs, like the digestive tract, bladder, and reproductive organs

cardiac muscle

muscles of the heart; no conscious control of these muscles; only one nucleus per cell

neuromuscular system

the nervous system and skeletal muscles work together; responsible for reflexes

muscle contraction

refers to the development of a force, not always the shortening of muscles

multinucleate

many nuclei per cell, which helps control them because they’re so large

antagonistically

to bend a limb at a joint, two or more muscles work ( ) (one contracts, one relaxes)

immediate system

muscle cells can store some ATP temporarily, or in chemically-altered forms that can be turned into ATP as needed

glycolytic system

anaerobic process (no O2 required); synthesizes ATP from carbohydrates, which produces lactate as a waste product (often referred to as lactic acid); fast glycolytic cells (“fast twitch”)

oxidative system

typical cellular respiration with the Krebs cycle and electron transport chain; aerobic process (requires O2 to function); produces H2O and CO2 as waste products; slow oxidative cells (“slow twitch”)

intercalated discs

unique to the cardiac muscles where cells meet, which provides continuity of the cytoplasm; makes excitation spread between cells quickly

pacemaker cells

generate the heartbeat partially without nervous stimulation from the brain (“endogenous” - doesn’t need external input)

peristalsis

waves of contractions of smooth muscle

hydrostatic skeletons

use internal fluid pressure to make the body more rigid in soft-bodied animals

exoskeleton

a tough exterior that protects the body of an animal

exoskeletons

muscles in arthropods connect to the inside of their ( ) and pull so appendages swivel on joints

asynchronous flight muscles

one excitation can result in multiple contractions; used in flight; have evolved many times because they are more efficient

catch muscles

contract and maintain that state for extended periods of time with very little ATP consumption (ex. adductor muscle in bivalve mollusks)

sodium-potassium pump

one of the channels that maintains the resting potential; moves Na+ outside and K+ inside

nervous system

rapid communication between nerves and muscles; directed at specific, neighboring target cells; happens in milliseconds; drives the fine-scale control of skeletal muscle

endocrine system

slow and broadcasted; hormones are released into the blood stream and carried throughout the body, eventually arriving at target cells; can take several seconds or minutes to have an effect; mostly affects slower processes like growth, development, reproduction, and metabolism

target cells

will have binding proteins specific to that hormone; no other cells will be affected

neurosecretory

endocrine cells that are excitable and can generate action potentials; located in the CNS; instead of releasing neurotransmitters, they release hormones into the blood stream

non-neural

endocrine cells that are not excitable, stimulated by other hormones; located in glands throughout the body

hormone cascade

hormones stimulating the secretion of another hormone (ex. hypothalamus —> pituitary gland —> adrenal gland —> cortisol)

cell surface receptors

receptor proteins on the cell membrane of a target cell

intracellular receptors

receptor proteins inside a target cell

vesicles

synthesize and store some hormones

urinalysis

can be used to test for physiological status (ex. pregnancy)

the time required for half of a group of simultaneously secreted hormone to be removed

adrenal medulla

produces epinephrine and norepinephrine

adrenal cortex

produces steroid hormones: glucocorticoids, mineralocorticoids, and sex steroids

tropic hormones

hormones whose target cells are other endocrine glands

pituitary gland

in mammals, secretes many hormones which control the activity of other glands

non-tropic hormones

hormones that are released and act directly on target cells (like growth hormone influencing tissue growth)

releasing hormones

stimulate activity in the pituitary; produced by neurosecretory cells in the hypothalamus

inhibiting hormones

stop the release of hormones in the pituitary; produced by neurosecretory cells in the hypothalamus

HPA axis

refers to the hypothalamus-pituitary-adrenal axis responsible for stress hormone secretions

cortisol

a “stress hormone;” almost every receptor contains receptors for this hormone; can stimulate many process: influencing the autonomic nervous system, controlling blood sugar levels, reducing inflammation, influencing memory formation, controlling salt and water balance, influencing blood pressure, initiating labor during pregnancy, and helping fetal development

ecdysone

hormone that stimulates the activity of molting in arthropods

juvenile hormone

controls what the insect molts into; circulating this means the larva molts into another larva, but molting in the absence of this makes the insect develop into a pupa

pathogens

microorganisms that cause disease

parasites

infect hosts for resources

immunity

refers to a multitude of mechanisms that result in an organism successfully defending against a pathogen

innate defenses

non-specific, always present or activated rapidly; all animals have this type of immunity

adaptive defenses

aimed at defending against a specific pathogen; not active until the organism has interacted with that pathogen

behavior

first line of defense against disease

mechanical

second line of defense against disease; skin, cuticle, exoskeleton, etc.; mucus inside the nose can capture invading particles (bacteria, viruses, allergens, etc.) before they enter the body

toll-like receptors

membrane proteins that recognize pathogenic bacteria, viruses, etc