14

Question 1

Neurotransmitters?

Answer 1

diffuses across synapses

Question 2

Hormones and neurohormones?

Answer 2

Travels through long distances by the blood stream.

Neurohormones: produced by tissues
Hormones: produced by endocrine glands

Question 3

Distances of continuum of cellular communication systems? 5*

Answer 3

Cytoplasmic contact -> recognition molecules on adjacent cells -> local diffusion -> transport in blood -> outside environment

Question 4

Neurotransmitter?

Answer 4

when a signal travels through a synapse via paracrine communication.

Question 5

Paracrine communication?

Answer 5

when one cell releases a signaling molecule and another cell’s receptor obtain that signal through diffusion.

Question 6

Endocrine system?

Answer 6

cells within specialized endocrine glands that release chemicals called hormones through the blood. It binds to a receptor on the target cells and causes various effects.

When the signal gets in contact with a receptor, it changes the conformation of the receptor.

Question 7

Nervous system?

Answer 7

long distance transport (by the cell being long) of electrical signals within cells and short distance (paracrine) signaling between cells at the synapse through diffusion.

Question 8

How signals travel through the entire nervous system?

Answer 8

*Sensory receptors: mechanoreceptors, photoreceptors

Then through afferent neuron

*integrating center: brain, ganglia

Then through efferent neuron

*effector organs (output pathways): muscles, glands

Question 9

Three main types of neurons and similarities 4*?

Answer 9

*Sensory neuron
*Interneuron
*Motor neuron

•They all have a cell body, processes (some of them called dendrites), and axon.

Question 10

!!!Differences between the structures of the neurons?

Question 11

How does the structure of the neuron work in coordination?

Answer 11

Dendrites receive incoming information, and axons generally communicate electrical signals out from the cell, often across long distances.

Question 12

Parts of the neuron? 4*

Answer 12

Dendrites -> cell body > axon -> axon terminal and synapse

Question 13

Glial cells?

Answer 13

specialized cells that support and maintain neurons.

Question 14

Graded potential?

Answer 14

*Occur in dendrites and cell body
*Only travel short distances
*Vary in magnitude

Question 15

Action potentials?

Answer 15

*Occur in axons
*All or on
*Can be “regenerated” so can be conducted across long distances

Question 16

Synaptic potential?

Answer 16

it cause neurotransmitter release.

Question 17

!!!Neurons work together

Answer 17

sensory receptors get that signal, and then pass it to afferent neurons that conduct the signal towards the integrating centor. The interneuron

Question 18

!!!What is an electrical signal in a neuron?

Answer 18

a change in the electrical gradient across the cell membrane, called the membrane potential. A typical neuron maintains a membrane potential of -70, thus slightly more negative in the inside. An increase in membrane potential is called depolarization, while a decrease is called hyperpolarization.

Answer 19

*Granded potential: occur in dendrites in cell body and travel short distances and vary in magnitude.
*action potentials: occur in axons that when an action potential is triggered, its always the same magnitude and duration within the cell.
*Synaptic potential that cause neurotransmitter release.

Question 20

Sensory receptors?

Answer 20

all types of sensory receptors transducer incoming signals that changes the membrane potential (electrical gradient across the cell membrane).

Question 21

Three types of sensory receptors?

Answer 21

•Chemoreceptor: Receptor protein gets a chemical stimulus, which signal a transduction pathway. It activates an ion channel, and change in membrane potential, which then signal to integrating center.
•Mechanoreceptor: Receptor protein gets a pressure stimulus due to a change in pressure, which activates an ion channel, and change in e membrane potential, which then signal to integrating center.
•Photoreceptor: receptor protein gets a light stimulus, which signal a transduction pathway. It activates an ion channel, and change in membrane potential, which then signal it integrating center.

Question 22

Signaling in a neural circuit?

Answer 22

*sensory neuron detects a signal and generates a type of graded potential called a receptor potential.
*graded potential triggers action potentials that are conducted towards the central nervous system.
*Action potentials trigger the release of neurotransmitter onto the interneuron.
*Binding of that interneuron into the receptor generates a graded potential in the cell body of the interneuron.
*That graded potential in the interneuron e trigger action potentials in the axon of the interneuron.
*action potentials trigger release of neurotransmitter onto the efferent neuron.
*Efferent neurons generate a graded potential which triggers action potentials, which ultimately Results in release of neurotransmitter onto the effector, causing a response.

Question 23

How do receptors determine intensity of signals?

Answer 23

Gentle pressure: modest change of receptor protein, which causes a modest change in opening and closing in ion channel, which cause a small rate of potential, and lower frequency of action potential.

Higher pressure: large rate of potential, and higher frequency of action potential

Question 24

Acute stress?

Answer 24

Sudden fight or flight stress.

Question 25

Stress response is coordinated how?

Answer 25

Coordinated by both the nervous system and the endocrine system working together

Question 26

Steps to processing the signal? 4*

Answer 26

Sensory receptors in which receptor cells detect signal -> send signal to central nervous system -> brain processes the signals -> activates sympathetic nervous system and/or the HPA axis.

Question 27

Where in the brain does the decision process of the signal occur?

Answer 27

in the hypothalamus.

Question 28

the two related pathways between sympathetic or parasympathetic nervous systems? 2*

Answer 28

1. Two neuron chain that directly releases neurotransmitter onto target organ as norepinephrine.
2. One neuron chain in which neurotransmitter stimulate pathway via adrenal medulla (sympathetic) which releases epinephrine and norepinephrine into the blood by the endocrine system to the target organ.

Question 29

Why does the effect of the adrenal medulla take a long time?

Answer 29

Because epinephrine travels through the blood stream.

Question 30

Endocrine system from signals from hypothalamus as hypothalamic-pituitary axis?

Answer 30

Signals from hypothalamus in the form of CRF goes through the blood to the anterior pituitary. Then, ACTH in the blood travels to the adrenal cortex. Cortisol in blood goes to target organs.

Question 31

Cortisol action?

Answer 31

Cortisol signal (being a steroid that is lipid composed and soluble) binds to an intracellular receptor which is translocated to the nucleus. It then binds to DNA and acts as a transcription factor, which changes the synthesis of mRNA.

Question 32

Why is hypothalamic-pituitary axis slower than the sympathetic nervous system?

Answer 32

Because more steps have to go through the blood stream.

Question 33

Why is Hypothalamic-pituitary axis important?

Answer 33

cortisol is helpful for recovery because it takes a long time for an action to occur after a response.

Question 34

Acute stress?

Answer 34

response (fight or flight), short-term stressors

Question 35

Chronic stress?

Answer 35

Long term that cause some negative effects:

*memory loss, lack of concentration
*Immune suppression
*Weight gain/weight loss
*Osteoporosis, irritable bowel syndrome, etc

Question 36

How does chronic stress really works?

Answer 36

neurons in the cortex and hippocampus get smaller (for thinking), while neurons in the amygdala get larger (responsible for fear)

Question 37

Autocrine?

Answer 37

When a cell releases a signaling molecule which gets detected by a receptor of the same cell.

Question 38

Juxtacrine?

Answer 38

Communications in which the cells are touching.