nervous system

What are the 2 pats of the nervous system

1. Central nervous system

2. Peripheral nervous system

What is afferent info?

In put

What is efferent info?

Out put

What are the components of a neuron?

• soma

• Dendrite

• Axon

• Axon hillock

• Axon terminal

Where is the nucleus of a neuron held?

Teh soma

What is the role of a dendrite on a neuron?

Recept information

What is the role of An axon on a neuron?

Transmits action potential

What is the role of An axon hillock on a neuron?

Initiates action potential

What is the role of An axon terminal on a neuron?

Releases neurotransmitter

What are the 3 tyoes of neurons?

1. Motor

2. Sensory/ affarent

3. Inter

What is the largest nerve cell?

• motor neuron

What is the role of a motor neuron?

Carry signals form CNS → outer body parts

What is formed when a motor neuron joints another neuron?

Synapse

What is formed when a motor neuron joints a muscle or gland?

Motor end plate

What is teh role of a sensory neuron?

Send signals from outer body→ PNS→ CNS

What is teh role of an inter neuron?

• connect neurons within brain and spinal cord

• Carry info between sensory and motor neurons

Which neuron has a short axon?

Inter

What neuron is only found in Brain, spinal cord and eye?

Inter

What is the role of a neuroglial cell?

• metabolic suppport and immune protection of neurons

What is the ratio of neuroglial: neurons in CNS

10:1

What nervous cell can regerate?

Neuroglial

What is the role of an astriocyte?

• metabolic support pf neuron

• Provides energy

• Gives structural support to nerve tissue

What is the role of microglia cells?

Remove dead cellular waste and bacteria

What is the role of ependyma cells?

• line cerebral spinal fluid cavities of brian

• Some specialed ones produce CSF

What is the charge of a Resting neruon?

Negative

What is the teh resting potential of skeletal muscle cell?

-95mV

What is the teh resting potential of A smooth muscle cell?

-60mV

What is the teh resting potential of Astroglia?

-80 to -90mV

What is the teh resting potential of Neurons?

-60 to -70MV

What is the teh resting potential of Erythrocytes?

-9mV

For every 3 Na+ pumped out of a cell how much k+ is pumped out?

2

Describe an ion channel

• membrane spanning protein that permits ions passing though a membrane

What are the types of ion channels?

1. Passive

2. Leg and-gated

3. Voltage gated

4. Channel pumps

Which ion channel is always open?

Passive channels

Which ion channel opens or closes to ligand binding?

Ligand gated channels

Which ion channel responds to membrane potential changes?

Voltage gated Chanel’s

Factors effecting speed of conduction

Temperature

Diameter of axon

Hope does temperature effect the speed of conductio?

Enzymes work faster at high temps

What are the 3 stucryres of a synapse?

1. Synaptic bouton

2. Synaptic cleft

3. Plasma membrane

How do we have a reflex recation?

• receptors of cells or dendrites respond to a stimuli

• Dendrites stretch caucusing an action potential

• Sensory neurons release Neurotransmitters across synapse

• NT processed by CNS

• Axons of stimulated motor neurons carry action potential

• NT release by motor neuron to give peripheral effector response

What are the 2 parts of the efferent PNS

Somatic nervous system- conscious control

Autonomic nervous system- involuntary

What are the 2 Forbes of the Autonomic nervous system

Parasympathetic

Sympathetic

What is the role of the parasympathetic nerve fibres

• rest and digest

• Regulating involuntary activities that maintain normal body conditions

• Energy conservation

• Refuelling

How does the parasympathetic nerve fibres carry out their role?

• blood pressure lowers

• Heart rate slows

• Digestive system is more active

Where are the parasympathetic nerve fibres found?

• spinal cord

• Midbrain

• Medulla

What are the roles of the sympathetic nervous system?

• regulates involuntary activates in stress response

• Fight or flight

• Energy expenditure and muscle activity

• Stress response to exercise or extreme emotions

How does the sympathetic nervous system carry out its role?

• pupil dilation - more light in

• Slowed digestive system

• Pain perception lowered

Where are sympathetic nerve fibres found?

Lumbar and thoracic spinal cord