chap 3 + 4 Flashcards
Transmission of a synapse
- action potential arrives at axon terminal
- voltage gated ca2+ channels open and ca2+ enters the axon terminal
- ca2+ entry causes the neurotransmitters-containing synaptic vesicles to release their contest by exocytosis.
- Neurotransmitters diffuse across the synaptic cleft and binds to receptors on the post synaptic membrane initiating an action potential
resting membrane potential volatge
-70mv
brain cortex functional area
sensory: interpret impulses from receptors
motor: Control muscle movement
Association: concerned with intellectual and emotional responses
meninges
a membrane composed of three layers
Dura mater the outer layer is top and fibres and therefore provide below protection for the brain it’s Steve closely to the bones of the skull
Arachnoid mater is the middle layer and is a loose mesh of fibre
Parra mater is the inner layer and is far more delicate it contains many blood vessels and sticks closely to the surface of the brain and spinal cord
Cerebrospinal fluid
Occupies the space between the middle and inner layer of meninges. It has three functions
Protection act as a shock absorber cushioning any blades or not to the central nervous system
Support: the brain is suspended inside the cranium and floats in fluid surrounds it
Transport: form from the blood and circles around the central nervous system
medulla oblangata
Contains;
The cardiac Centre, which regulates the right and force of heartbeat
The respiratory centres which control the rate and depth of breath
The vet so meter centre which regulates the blood vessels diameter
action potential
The opening and closing of voltage gated channels which causes the rapid depolarisation and repolarisation of the membrane lasting around one milli second.
Grey matter and white matter
Grey matter contains neuron cell bodies and processes information from the sensory organ and areas\
White matter contains mile unaided axons and connects the brain with the body receptors and effectors
Difference between involuntary action and a reflex action
A voluntary action new pathway would include connections to and from the brain by the spinal-cord.
A reflex action goes through the spinal-cord via the internueron runs information about the action will be sent to the brain after the action has happened
Dopamine
Is the neurotransmitter responsible for relaying messages that plan and control body movement for coordination between brain and movements
how a nerve fibre generates and propagates a nerve impulse.
Step 5
Resting membrane potential - Nerve fibre is resting and unstimulated. The electrical charge is at
-70mV (difference between outside and inside the cell). The cell is polarised/ charged.
Step 1
Stimulus applied - When a stimulus of 15mV+ is applied to a nerve fibre, the membrane
becomes permeable to sodium ions (Na+) and they move into the cell through sodium ion
channels. The threshold for an action potential is reached (-55mV).
Step 2
Depolarisation – Sodium ion channels open along the membrane and sodium ions (Na+)
continue to move/ flood into the cell. The cell membrane voltage rises and the inside becomes
positively charged, while the outside becomes negatively charged in comparison.
Step 3
Repolarisation - At approximately 35mV, sodium ion (Na+) channels shut and potassium ion (K+)
channels open. Potassium ions (K+) move out of the cell. Inside the cell returns to being
negatively charged and the outside positively charged.
Step 4
Hyperpolarisation – potassium ions (K+) continue to move out of the cell. Inside of cell becomes
more negative than resting potential. Sodium-potassium pumps restore a resting membrane
potential of -70mV.
Differences between cranial and spinal nerves
Cranial nerves the nerves that emerge directly from the brain. They really miss information between the brain and parts of the body primarily to regions from head a neck
Spinal nerves emerge from the spinal-cord between the vertebrae. They take nerve impulses to and from the central nervous system to the rest of the body
fluid inside cell
Intracellular fluid has a low concentration of sodium irons and a cord irons. Its main positive irons of potassium and negative irons come from a variety of organic substances made by the cell.
Sodium potassium pump
Move to potassium ions into the cell for every three sodium ions that are moved
- Sodium potassium pump and three sodium ions and molecules of ATP
- The splitting of the ATP to provides energy to change the shape of the channel. The sodium ions are driven through the channel
- The sodium irons are released to the outside of the membrane and the new shape of channel allows two potassium irons to bind
- Release of the phosphate allows the channel 2 about its to original form, releasing the potassium irons on the inside of the membrane.
polarised
When the inside of the soul is more negative than the outside it produces a negative resting membrane potential and is polarised
strong stimulus
caused depolarization of more nerve fibres
produces more nerve impulses in a given time
unmyelinated fibres
Depolarisation of one area causes a movement of sodium irons into the adjacent Area.
Stimulates opening of voltage gated sodium channels which initiate action potential in the next membrane
You cannot go backwards due to the refractory period action potential cannot occur
Grey in colour and slow 2 m/s
myelinated fibres
Sheath insulate nerve fibre but does not nodes of ranvier
Therefore irons cannot flow between the inside and outside of membrane
Instead jumps from one node of ranvier to the next
This is called saltatory conduction
myelinated fibres
Sheath insulate nerve fibre but does not nodes of Ranvier
Therefore irons cannot flow between the inside and outside of membrane
Instead jumps from one node of Ranvier to the next
This is called saltatory conduction
insula
The insula controls autonomic functions through the regulation of the sympathetic and parasympathetic systems.
polarised
When the inside of the cell is more negative than the outside it produces a negative resting membrane potential and is polarised
state 4 types of structural neurons
unipolar- are sensory neurons connect
state 4 types of structural neurons
unipolar- one extension an axon. Censoring neurons connecting receptors to the central nervous system
multipolar- one axon, multiple dendrites. Most common includes most of it into neurons in the brain and spinal cord as well as motor neurons that carry to skeletal muscles
bipolar- rare and sensory neurons associated with the eye ear and nose
Pseudounipolar- sensory neurons found in the dorsal route ganglion and majority of those in the cranial nerve sensory ganglia carry information about touch vibration proprioception pain and temperature
dorsal root ganglion
Contain cell bodies for sensory neurons that carry sensory information to the spinal-cord
types of recepters
Thermo receptors; response to heat or cold
Osmo receptors: concentration of substances the dissolved in the water of blood plasma
Chemo receptors: present and nose and mouth are smelling and tastes internal chemo receptors sensitive to the composition of body fluids
Touch receptors: skin hair receptors pain receptors pressure receptors fine touch stretch pressure and vibration
Pain receptors none in the brain stimulated by damaged tissue
Reflexes
4 properties Required to trigger reflex It is involuntary Responses rapid Is stereotyped
basal ganlia
deep inside cerebrum
grpoup of nerve cell bodies associated with control of skeletal muscle. they initiate desired movements
frontal lobe
frontal lobe
thinking, problem solving, emotions, personality, language and controls movement
parietal
Process temp, touch, pain, pain and movement
temporal
processing memories and linking them to senses
also receives auido information
occiptal
vision
insula
5 th lobe
different sense and
