Lecture 9 Flashcards
Whats makes up the CNS
- Brain
- Spinal cord
Whats part of the PNS
- Somatic nervous system (conscious actions)
- Autonomic nervous system (unconscious actions)
What makes up the CCN
- CNS
- PNS
- Endocrine system
- Local support and defence system
Explain Alzheimers in comparison to the nervous system
- Lots of neurons going to the brain are lost
- Acetylcholine can be reduced by up to 90%
- Changing in signalling molecules have serious impact on health
What is the input and output of the CNS
Sensory input and motar output
Explain sensory input
Response to external stimuli
Explain the 2 types of sensory input
1) Inputs from internal organs (signalling that you’re feeling full)
2) Input from sensory receptors on skin and joints
Explain motor output
Actions signalled by the CNS
What type(s) of motor output does the SNS direct
Directs voluntary movements
What type(s) of motor output does the ANS direct
Regulates bodily activities such as HR and BR
What are the roles of parasynthetic vs synthetic nervous system on motor output
Parasympathetic nervous system: Governs bodily activities during restful states
Sympathetic nervous system: Prepares body for emergencies
What are the 5 major cell types in adult CNS
1) Neurons
2) Oligodendrocytes (CNS) and Schwann cells (PNS)
3) Astrocytes
4) Microglia
5) Ependymal Cells
What is the role of neurons
Transmit electrical signals
Can neurons be be excitatory or inhibitory
Yes
Explain dendrites, cell body, axon, and axon endings of neurons
- Dendrites: receive info from other neuron or environment
- Cell body: controls cells metabolic activity, generates input from other neurons
- Axon: Conducts nerve impulse away from cell body
- Axon ending: release chemicals called neurotransmitters that affect of the nearby neuron and effector
Where is action potential regenerated in neurons
Action potential regenerated in dendrite vessels
Characteristics of unmyelinated neurons
- Unmyelinated neurons do not have myelin sheath
— Neurons travel 0.5 to 2m/sec
— Very few of these
Characteristics of myelinated neurons
- Myelinated have myelin sheath
— Neurons travel 6m to 120m/sec
— Quicker nerves signaling
MS connection to myelin sheeth
In Multiple sclerosis, there is a disturbance of the myelin sheath, due to an autoimmune disease
Do all neurotransmitters share a general site?
No, there’s very specific sites for neurotransmitters in neurons
Neurons release one type of neurotransmitter at given pre-synaptic neuron
What is net response of neurons based on
Net response based on overall (summation) effect on all imputes
What is needed for generation of action potential
1) More excitatory than inhibitory neurons
2) Action potential threshold met
How does the body maintain homeostasis with neurons
Body will release excitatory or inhibitory neurons to maintain homeostasis
Examples of the body maintain homeostasis with neurons
Acetylcholine in excitatory - increase HR
Epinephrine in inhibitory - decrease HR
If HR is too high, epinephrine will be release to lower heart rate
