The Nervous System

Thicker myelination

Thicker myelination

________ speeds up the transmission of impulses from stimulus to response.

Cerebrospinal fluid

________ is located in the space between the arachnoid mater and pia mater.

THC

________ acts as the body's own anandamide, which ‘ squirts dopamine.

Myelanation

________ → Speeds up the rate of transmission by insulating the axon.

electrical charge

When a neurone is not conducting an impulse there is a difference in the ________ across the plasma membrane.

Synapse→ A synapse

________ is the junction between 2 nerve cells.

Receptors

________ receive external stimuli and transfer information to effector organs via the nervous system or hormones (via blood)/

Synaptic transmission

________ slows down reactions.

Voltage

________- gated sodium channels are closed but some potassium channels allow K+ to leak out of the axon.

Dendrite → Thin

________ fibre carrying impulses towards the cell.

higher concentration

There is a(n) ________ of positively charged ions outside the cell than inside.

Membranes

________ are hyperpolarised when more K+ ions move out than Na+ diffuse in.

Animals

________ in cold habitats have big axons to compensate for the temperature.

Sensory receptors

________ also act as transducers.

synaptic cleft

There is a gap (________) of around 20nm between cells, and chemicals called neurotransmitters diffuse across it.

dendrites

Connectors are called ________.

Nerves

________ are bundles of neurons (which contain axons) enclosed in a sheath of connective tissue.

Warm

________- blooded animals transmit impulses more quickly and have faster responses.

LSD

Sometimes ________ can excite receptors and sometimes it can inhibit the receptors.

Impulses

________ are generated when Na+ and K+ change the balance of ions.

Neurons

________- ELongated cells consisting of cell body and long, thin axons.

locomotion

They can contract, perform ________, hunt and feed without a brain.

Dopamine

________ floods the brain and gives a euphoric sensation.

Nerve nets

________ are the simplest type of nervous system.

Synapses

________ are in the grey matter.

Polysynaptic Reflex

________- These involve more than one synapse and connecting relay interneurons between sensory and motor neurons e.g hand- withdrawal reflex.

Nissl Granules → Cytoplasmic granules

________ comprising ribosomes grouped on the Rough Endoplasmic Reticulum.

motor neurons

Some nerves contain both sensory and ________.

White matter →

________ has a myelin sheath around the neurons.

simple reflex involves

A(n) ________ neurons in the PNS and the spinal cord and often occurs before the conscious brain is aware of it.

Peripheral nervous system

________ (PNS)- Nerves that come off the spinal cord.

Nervous system

The ________ enables us to gather, transmit and coordinate information.

Membrane layers

3 ________- The meninges are 3 membranes that envelop the brain and spinal cord.

Rod cells

________ detect dark and light.

Ca2+

________ causes vesicles to move to the synaptic membrane.

cell body

A(n) ________ may have several dendrites.

Acetylcholine + acetylcholinesterase →

________ ethanoic acid + choline.

Meningitis

________ affect the meningies.

Sodium Potassium pips

________ actively transport sodium ions out of the neurone and potassium ions into the neurone.

Ganglion cells

________ are sensory cells that can detect stimuli e.g light, sound and touch.

Cell bodies of somatic motor neurons

________ are found within the brain or spinal cord and connected to voluntary muscles.

reflex action

A(n) ________ is a rapid, automatic response to a stimulus.

sensory neurons

All ________ have their cell bodies sitting outside the spinal cord dorsal root ganglions,

Cerebrospinal fluid

________ acts as a cushion.

LSD

________ resembles serotonin and elicits its effects by binding to serotonin receptors.

Skin

Pain, Pressure, Temperature

CNS

Brain and spinal cord

Peripheral nervous system (PNS)

Nerves that come off the spinal cord

Monosynaptic reflex

only one synapse between a sensory neuron and motor neurone e.g knee jerk reflex

Polysynaptic Reflex

These involve more than one synapse and connecting relay interneurons between sensory and motor neurons e.g hand-withdrawal reflex

3 Membrane layers

The meninges are 3 membranes that envelop the brain and spinal cord

Fast

up to 120ms-1

Neurons

ELongated cells consisting of cell body and long, thin axons