chat 43/46 electrical/ chemical signals

simple nervous system

a nervous system with no centralized management of information; used by jellyfish, anemones, starfish etc..

central nervous system

the brain and spinal cord process information from many sensory neurons

peripheral nervous system

spreads across the body to gather information and transmit signals; feeds into central nervous system

afferent transmission

information gathered from the peripheral nervous system

interneurons

make connections between sensory neurons and motor neurons; turns afferent transmission into efferent

efferent transmission

action required by the peripheral nervous system; from spinal cord to muscle

dendrite

branches of a neuron that collect chemical signals

cell body

part of a neuron that integrates incoming signals and generates the outgoing electrical signal to the axon

axon

part of the neuron that passes chemical signals to the dendrites of another neuron

slightly negative -65-70

what is the charge inside of a neuron at resting potential

Na enters, the cell gets slightly more positive; Na gates open at -55

at what charge does the Na+ gate open

+40

at what charge do the Na+ gates close

+40; K+ rushes out

at what charge does the K+ gate open

-80

at what charge does the K+ gate close

enters, positive

sodium enters/ exits the cell to make it more positive/negative

exits, negative

potassium enters/exits the cell to make it more positive/ negative

it makes sure the impulse always travels forwards, not backwards

why does hyper polarization happen?

Glia

a layer of fatty acids found on long neurons for insulation

Schwann cells

type of glia found in the PNS

oligodendrocytes

type of glia found in CNS

myelin sheet

the layers of the glia cells are called___

nodes of ranvier

openings between the sections of myelin sheet; these openings have gates that restart the signal, giving it strength to go all the way through

autocrine, paracrine, and endocrine signal

testosterone is an example of a chemical signal that affects the very cells that synthesize it, the neighboring cells in the testis, along with distant cells outside the gonads. Testosterone is an example of_____

a structure within the nervous system produces and releases a hormone that regulate the activity of an endocrine gland

which of the following best describes the neuroendocrine-to-endocrine pathway of hormone action?

erythropoietin and kidney

the hormone that stimulates the production of red blood cells and the organ where this hormone is synthesized are____

a cAMP signal cascade, increased blood glucose

epinephrin actives _____ leading to _____

interneuron

what type of neuron exists entirely within the central nervous system?

increasing its membrane’s permeability to K+

hyper polarization of a membrane can be induced by ____

myosin cross-bridges binding to actin and undergoing a power stroke

the contraction of skeletal muscles is based on____

muscle contractions would be prevented, causing paralysis

what would happen to people exposed to a chemical warfare agent that blocked acetylcholine from binding to muscle receptors?

voltage-gated calcium channels in the membrane open

which of the following is a direct result of depolarizing the presynaptic membrane of an axon terminal?

increase K+ permeability

how could you increase the magnitude of inhibitory postsynaptic potentials generated at a synapse?

multiple sclerosis

a diseases caused by an incomplete myelin sheath; causes miscommunication among neurons; the signal gets lost and goes to the wrong place

calcium

the action potential arriving to the end of the axon triggers _______ to rush in, allowing vesicles to form and release neurotransmitters into the synapse

excitatory postsynaptic potentials

action potential that makes a neuron more likely to fire by depolarizing the membrane

inhibitory postsynaptic potentials

action potential that makes a neuron less likely to fire by hyperpolarizing the membrane

sarcomeres

myofibrils are made up of light and dark areas called

actin

thin filaments are made of two coiled chains of protein called ___

myosin

thick filament

z disk

attaches think filaments on one side, other side is free allowing it to move

m line

holds thick filament in place

troponin/ tropomyosin complex

block the myosin binding sites on actin

slow, fast, inhibitory

what are the three functions of the three innervations of invertebrates’ muscles

acetylcholine, t tubule, calcium

when an action potential arrives to the sarcoplasmic reticulum it triggers the release of the neurotransmitter ______. The action potential travels through the _____, and triggers the release of ______

it unbinds from myosin and the myosin binding sites are exposed, allowing actin to bind

what happens when calcium binds to the troponin-tropomyosin complex

parasympathetic nervous system

used for relaxation/ digestion, conserves and restores energy

sympathetic nervous system

consumes energy, stress “fight or flight”

cerebrum

part of the brain that is responsible for complex movements and smell, most prominent in endotherms (forebrain)

diencephalon

part of the brain that is responsible for homeostasis (forebrain)

hypothalamus

part of the brain that is important for auditory and visual information; most prominent in ectotherms (midbrain)

cerebellum/ medulla

part of the brain that is responsible for coordination and balance; most prominent in simple organisms (hindbrain)

autocrine signals

a signal that is sent to its same cell

paracrine signal

signal that is sent to neighboring cells

endocrine signal

signal that can travel long distances, is carried by blood or body fluids

neural signals

a signal that travels a short distance between neurons (neurotransmitters)

neuroendocrine signals

signals that are released from neurons into the blood and act on distant cells

pheromones

signals that are released into the environment and act on a different individual

endocrine pathway

sends hormones directly from endocrine cells to effector cells

neuroendocrine pathway

releases neuroendocrine signals that act directly on effector cells

neuroendocrine-to-endocrine pathway

neuroendocrine signals stimulate cells in the endocrine system, which respond by producing an endocrine signal that acts on effector cells

hypothalamus

part of the brain that is connected to the pituitary gland, decided when to release hormones

pituitary gland

produces hormones that regulate other endocrine glands; controls what hormones will be released

thyroid gland

produces hormones that regulate metabolism and growth

parathyroid glands

regulate calcium levels, embedded in the thyroid gland

adrenal glands

glands on top of the kidneys; release aldosterone and adrenaline

pancreas

produces secretin and cholecystokinin

reproductive organs

produce estrogen and progesterone

epinephrine

hormone for short term stress, “fight or flight”

ecdysone

hormone that induces growth/ metamorphosis in insects; antagonistic with JH

thyroid hormones (T3/T4) and cortisol

when these two hormones show up metamorphosis in amphibians starts

prolactin

when amphibians are babies this hormone is high and causes rapid growth

GH

controls growth, fat, metabolism, blood sugar in higher vertebrates; produced by pituitary gland

secretin

controls the entrance of HCO3- in the intestine; regulates the duodenum; helps digestion

ADH

increases the amount of water collected by the kidneys, so water is reabsorbed from the urine and saved

aldosterone

increases reabsorption of sodium ions in the kidney

insulin/ glucagon

control sugar in the body