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Question 1

Define “cell signalling”

Answer 1

The process in which one cell tells another cell to do something

Question 2

Define “Endocrine Signalling”

Answer 2

Signals that are released by specialized cells and released into the bloodstream and carried to target cells in distant parts of the body

Question 3

Define “Paracrine Signalling”

Answer 3

Cells that are near one another communicate through the release of chemical messengers

Question 4

Define “Neuronal Signalling”

Answer 4

Nerve cells transmit signals between the synapse, between two nerve cells where signal transmission occurs

Question 5

Define “Contact Dependant Signalling”

Answer 5

2 cells bind to one another due to their complementary proteins on their surfaces. When the proteins bind to one another, this causes a conformation change, transmitting a signal

Question 6

Describe the possible outcomes of a signal

Answer 6

Migration
Survival
Division
Differentiation
Apoptosis

Question 7

Describe the role of a morphogen

Answer 7

A molecule that defines two or more cell fates at different concentrations (french flag model)

Question 8

Describe the relay system

Answer 8

A signal is sent, which alters the target cells genes, therefore triggering another signal onto the next cell

Question 9

Name the 5 key developmental signalling pathways

Answer 9

Hedgehog pathway
Notch pathway
Wnt pathway
TGFB pathway
FGF pathway

Question 10

Name the 2 parts of a developing gastrula

Answer 10

Hensen’s node

Primitive streak

Question 11

Describe the sections of a blastocyst

Answer 11

The outer layer of a blastocyst consists of cells collectively called the trophoblast. Which gives rise to the placenta. Within the trophoblast there is an inner cell mass (ICM) which subsequently forms the embryo.

Question 12

Why is gastilation so important

Answer 12

Gastilation forms 3 germ layers, which then forms the tissues required for embryo formation

Question 13

What is a nervous system?

Answer 13

A system that allows us to respond to a stimulus

Order:Assessment of the stimulus, Preparation of the response, Communication to responding structures

Question 14

how does The Hippocampal Trisynaptic Circuit work

Answer 14

A signal travels from the entorhinal cortex in layer 2 to the “dentate gyrus”(granule cells) via the perforant pathway, the signal then travels to “CA3” (pyramidal cells) via the mossy fibres, the signal then travels to “CA1” (pyramidal cells) via the chaffer collaterals, and the signal finally ends up at the entorhinal cortex in layer 5

Question 15

what does the Hippocampal Trisynaptic Circuit do

Answer 15

it changes the signal that is passed through, and is “tasted” by 1000s of neurons. The hippocampus and cortex play a role in learning, forming memories and retrieving them

Question 16

Explain neural plasticity

Answer 16

The ability of the brain or neuron to adjust in response to a new situation or environment

Question 17

Where does the PNS transmit information

Answer 17

The PNS transmits information to and from the CNS and regulates movement and the internal environment

Question 18

What are the PNS two efferent components

Answer 18

the motor system and the autonomic nervous system

Question 19

What does the sympathetic division do

Answer 19

regulates arousal and energy generation (“fight-or-flight” response)

Question 20

What does the parasympathetic division do

Answer 20

has antagonistic effects on target organs and promotes calming and a return to “rest and digest” functions

Question 21

What does the enteric division do

Answer 21

controls activity of the digestive tract, pancreas, and gallbladder

Question 22

What are the 2 types of matter the brain and spinal cord contain and what is the difference between them?

Answer 22

Gray matter:which consists of neuron cell bodies, dendrites, and unmyelinated axons
White matter:which consists of bundles of myelinated axons

Question 23

What does an axon hillock do?

Answer 23

The place in a neuron where the action potential is reached

Question 24

What cells are located in the nervous system?

Answer 24

Nerve cells (neurons)
Glial cells (glia)

Question 25

What are the 4 main regions of a neuron

Answer 25

Cell body
Dendrites
Axons (one or more)
Axon terminals

Question 26

Do all cells create an action potential?

Answer 26

no, some just relay information

Question 27

What are the 3 main neurons and their functions

Answer 27

Afferent : carry sensory information into the NS
Efferent: carry commands to physiological and behaviourial effectors
Interneurons : integrate and store information and communicate between afferent and efferent neurons

Question 28

Explain the 3 processes in which the membrane potential can change

Answer 28

depolarisation(decrease in potential)
repolarisation(return to resting potential after depolarisation)
hyperpolarisation(increase in potential)

Question 29

Explain the process in which a signal crosses a synapse

Answer 29

An action potential causes depolarisation of the membrane potential, this depolarisation then causes Ca2+ channels to open. The Ca2+ then molecularly changes the neurotransmitter vesicles which then bind to the membrane at the synapse and releases the neurotransmitters

Question 30

Which neurotransmitters brings about hyperpolarisation

Answer 30

Inhibitory neurotransmitters (negative) due to cl- entry and k+ exit

Question 31

Which neurotransmitters brings about depolarisation

Answer 31

Stimulatory neurotransmitters (positive)

Question 32

What the the membrane resting potential

Answer 32

-70mv

Question 33

How do sensory cells convert stimuli into APs?

Answer 33

Physical and chemical stimuli are converted to neural signals by sensory receptor cells, these are then transmitted to the CNS for processing and interpretation

Question 34

Explain how the stretching of muscle can create an AP?

Answer 34

The stretching of a muscle causes an ion channel to open. This results in the depolarisation of the membrane creating a receptor potential, this then spreads onto the axon hillock which stimulates an AP

Question 35

How are different sensations perceived?

Answer 35

The APs from different kinds of sensory cells arrive at different places in the CNS.

Question 36

What determines the intensity of the sensation?

Answer 36

The frequency of AP

Question 37

What do mechanoreceptors respond to, and where are they found?

Answer 37

Mechanical forces (skin sensations, sensing BP, hearing and maintenance of balance)
Found in muscles, tendons and ligaments

Question 38

What do compound eyes consist of?

Answer 38

ommatidia (optical unit) - the number of ommatidia varies

An ommatidium consists of a ; corneal lens, crystalline cone, pigment cell, and a photoreceptor