cellular

Question 1

why do humans have a curve in their nervous system and what is it called?

Answer 1

because we are standing up so the axis has changed
it is called cephalic felxure

Question 2

how can the brain be cut and what are the sections called?

Answer 2

cut down midline forms sagittal sections
brain cut horizontally from left to right forms coronal sections
brain cut through the middle leaving top and bottom sections called horizontal sections

Question 3

how can the spinal cord be cut?

Answer 3

cut length-ways and downwards is longitudinal
cut width-ways horizontally it is transverse

Question 4

what are the 3 areas of the brain and what are they made up of?

Answer 4

forebrain: cerebral hemispheres, thalamus and hypothalamus
midbrain
hindbrain: pons, cerebellum and medulla

Question 5

what are the 2 areas of the cerebral hemispheres?

Answer 5

ridges called gyri and grooves called sulci

Question 6

what is the main function of the cerebellum in the hindbrain?

Answer 6

motor functions such as balance and coordination

Question 7

what is the brainstem?

Answer 7

the pons, cerebellum and medulla that work together to perform neural functions

Question 8

what is the ventricular system?

Answer 8

a system made up of cavities that run throughout the nervous system and is filled with cerebrospinal fluid

Question 9

what is the role of cerebrospinal fluid?

Answer 9

it surrounds the brain and protects it, maintains the correct levels of ions and removes waste products

Question 10

what are the 4 ventricles in the ventricular system

Answer 10

the first two lateral ventricles sit under the cerebral hemispheres and come together to form the third ventricle that sits above the hypothalamus
the fourth ventricle is close to the pons and medulla

Question 11

what is the cerebral aqueduct?

Answer 11

a small tube that connects the third and fourth ventricles

Question 12

what is the central canal?

Answer 12

a tube that runs through the spinal cord from the fourth ventricle and is also filled with cerebrospinal fluid

Question 13

what are the 4 divisions of the spinal cord?

Answer 13

cervical, thoracic, lumbar and sacral
they all have the same structure but have specialised functional groups

Question 14

where does each spinal cord division innervate?

Answer 14

cervical division innervates the arms
lumbar division innervates the legs
thoracic division innervates the heart
sacral division innervates the organs of the autonomic nervous system (e.g. bladder)

Question 15

why do the cervical and lumbar divisions have enlargements and which is bigger?

Answer 15

they contains lots of motor neurones
the lumbar enlargement is bigger

Question 16

what are the functional 2 divisions of the spinal cord and what do they contain?

Answer 16

the dorsal division which is where sensory information comes in so it has lots of afferent fibres
the ventral division which is where motor neurones sit so it has lots of efferent fibres

Question 17

what are the 2 types of nervous tissue?

Answer 17

grey and white matter

Question 18

what is grey matter?

Answer 18

where neuronal cell bodies sit and contains axons that go from cell bodies
it also contains glia that surrounds neurones

Question 19

what is white matter

Answer 19

where myelinated axons are located
the myelin is what creates the white colour

Question 20

what are the 2 main groups of neural cells?

Answer 20

neurones and glia

Question 21

what are neurones?

Answer 21

excitable cells that conduct impulses and integrate and relay information within a neural circuit

Question 22

what are glia?

Answer 22

supporting cells that protect neurones, connect them so there are no gaps and integrate signals

Question 23

what is white matter?

Answer 23

white matter is where myelinated axons are located
the myelin is what creates the white colour

Question 24

what stain is used to distinguish between neurones and glia and what area does it stain?

Answer 24

Nissl stain
binds to negatively charged RNA in the nucleolus in neurons

Question 25

what does Nissl staining allow us to see?

Answer 25

variation in size, density and distribution of neurones

Question 26

what is the soma and what is it made up of?

Answer 26

the cell body within neurones made up of a nucleus and organelles for protein synthesis (ribosomes, golgi, rough endoplasmic reticulum)

Question 27

how is the soma adapted?

Answer 27

high density of mitochondria to produce ATP for active transport of ions

Question 28

what stain is used to show processes within a neuron and what is it made of?

Answer 28

golgi (camillo) stain made of silver chromate

Question 29

what is the structure of the neuron cytoskeleton?

Answer 29

made up of microtubules, microfilaments and neurofilaments

Question 30

what is the axon hillock?

Answer 30

connects the axon to the soma

Question 31

what is the axon initial segment?

Answer 31

where action potentials are generated has a high density of specific ion channels

Question 32

what is the axon terminal?

Answer 32

where the axon ends

Question 33

what is the structure of axons?

Answer 33

contains some free ribosomes but no rough endoplasmic reticulum can be myelinated have different membrane compositions, lengths and diameters

Question 34

what was used to identify the initial axon segment?

Answer 34

immunohistochemistry using primary and secondary antibodies with a fluorescent tag

Question 35

what are unipolar neurons and where are they found?

Answer 35

neurons with one neurite (axon or dendrite) projecting from the soma found in the dorsal root ganglion

Question 36

what are pseudounipolar neurons and where are they found?

Answer 36

have on neurite that splits into two one is an axon and the other ends as a dendrite found in the dorsal root ganglion

Question 37

why do pseudopolar neurons not modify or integrate signals?

Answer 37

it only has one axon so transmits signals straight to the brain

Question 38

what are bipolar neurons and where are they found?

Answer 38

have two neurites projecting from different ends of the soma one is an axon and one is a dendrite they are found in the retina

Question 39

why do bipolar neurons not integrate signals?

Answer 39

it doesn't have a large dendritic tree receives a signal from one area and reliably relays it on

Question 40

what are multipolar neurons?

Answer 40

they have a single axon and multiple dendrites projecting from the soma

Question 41

why do multipolar neurons have lots of convergence?

Answer 41

they have a large area for receiving synaptic neurons

Question 42

where are the locations and input of sensory neurones?

Answer 42

dendrites project into the periphery the soma sits in the dorsal root ganglion they input into the spinal cord (or the brain)

Question 43

where are the locations and inputs of motor neurons?

Answer 43

their axon terminals sit in the periphery their cell bodies sit in the CNS

Question 44

what are interneurons?

Answer 44

the largest class of neurons in the brain they can be relay or projection neurons they connect brain regions to form small circuits

Question 45

what is the role of presynaptic terminals?

Answer 45

they allow synapses to fasten together and join neurons

Question 46

how are presynaptic terminals adapted?

Answer 46

they have a high density of mitochondria for transport vesicles they have lots of synaptic vesicles to store neurotransmitters they have specialised proteins on the membrane that binds to vesicles for them to fuse

Question 47

what are boutons en passant in presynaptic terminals?

Answer 47

bulges along the axon where synapses are formed with other neurons

Question 48

what is the process of axoplasmic transport?

Answer 48

amino acids move down microtubules using a kinesin protein and ATP (anterograde transport) another protein dynein uses retrograde transport to move things back up to the soma

Question 49

what is anterograde (or retrograde) labelling?

Answer 49

a chemical is injected into a muscle and is taken up by the presynaptic terminal it is carried back up to the cell bodies in the spinal cord using dynein it is used to find the location of cell bodies

Question 50

what is a dendritic tree?

Answer 50

branches coming off from dendrites that come together and allow inputs from different places (convergence)

Question 51

what are dendritic spines?

Answer 51

where synapses form onto dendrites they are very flexible and dynamic so can develop in different places they are though to isolate chemical reactions

Question 52

how can neurons be classified by structure?

Answer 52

number of neurites dendritic trees where they project to axon length

Question 53

how can neurons be classified by gene expression?

Answer 53

certain genes are expressed which affects the structure of the neuron and what type of neurotransmitter (excitatory or inhibitory) it releases

Question 54

what are astrocytes and satellite cells?

Answer 54

astrocytes: glia found in the CNS satellite cells: glia found in the PNS

Question 55

what are oligodendrocytes and schwann cells?

Answer 55

oligodendrocytes: myelinating cells found in the CNS schwann cells: myelinating cells found in the PNS