Structure Of The nervous System Flashcards
What does the blood brain barrier do?
Creates extracellular environment that is different than the rest of the body, it’s tight junctions produce a sort of immpermeability
Parts of the Cns
Brain, brainstorm and spinal cord
Parts of the brain (three main components)
Forebrain, brainstem and cerebellum
Forebrain parts (and functions)
Cerebrum - main portion of the brain
Dienecephalon- thalamus and hypothalamus… Important for autonomic regulation
Brainstem parts and function
Midbrain, pons, and medulla oblongata Rudimentary functions (respiratory and cardiovascular)
Cerebellum function
Motor functioning..
Thalamus function
Relay center regulates input into the cerebral cortex
For arousal and focused attention
Hypothalamus function
Command center for the autonomic nervous and endocrine system Does Hormone secretion Autonomic effects Thermo regulation Food and water intake Sleep and cicadian rythmns Memory And emotional behavior
Spinal cord function
To transfer messages to and from your peripheral nervous system
Name the two different roots of the spinal cord and there direction
Dorsal root - to the brain
Ventral root - to the body
Why is grey matter grey?
Because there are more neurons that are not myelinated than are myelinated
White matter function
Brings information in and out of the spinal cord.. It includes the meninges has the myelinated axons..
How many pairs of spinal nerves are there!
31
What are ganglions?
Locations where you have lots of synapses
4 regions if nerves in the spinal cord.
Cervical, thoracic, lumbar, sacral
What is the subachnoid space?
The space between the skull and brain tissue
What are the meninges?
Line the subachnoid space with cerebral spinal fluid
What does csf do?
Circulates, cushions and protects the fragile tissue of the brain and spinal cord
What are the three layers of the meninges?
Pia matter (closest to the brain) Archnoid mater (middle layer) Duramater (outer layer and toughest)
What is the function of the Blood supply to the brain? How much blood goes to the brain? Will it ever reduce?
Decreased flow will lead to cell death.. Although it is a small organ it needs a certain amount of blood.. It is never reduced
What are paracrine agents and autocrine agents?
Paracrines- act locally
Autocrines- act on the cell
Define lipophilic
Substances pass through endothelial cell membranes ensures that brain ecf is very distinct from blood
Name the components of the peripheral nervous system
Two main sections afferent and efferent (efferent is separated into somatic and autonomic)
What are the two subsections of the efferent pns
Somatic and autonomic
What is the function of the afferent portion of the pns?
Send information from periphery to the central nervous system
Name 2 examples of reception fields for the afferent pns
Light touch, pain and deep pressure
Where does autonomic information come out of (ventral or dorsal)
Ventral horn
What is the neuromuscular junction
The junction between the neuron and muscle
Which neurotransmitter is used most in the presynaptic synapse/ ganglion?
Acetylcholine (with Nicotinic receptors)
What does the diencephalon do?
Linked to many physiological processes
What’s a major difference between the autonomic and somatic ns
Two neurons vs just one and somatic is voluntary autonomic is involuntary… Somatic has just one target organ (skeletal muscle) while autonomic has many target organs (smooth muscle, cardiac muscle, endocrine glands)
What is similar between autonomic ns and somatic ns
They both come out of the central horn, they both have the neurotransmitter ach in their system.
What kind of receptors are Nicotinic receptors
Epsps
What is a motor unit?
Motor neuron and all muscle fibers it innervates
True or false
The autonomic nervous system leads to only epsps
False, autonomic ns can be either excitatory or inhibitory
In the autonomic ns which neuron (post or pre) is myelinated?
Preganglionic
Parasympathetic information comes from where on the spinal column?
Brain stem and sacral region..
Sympathetic ns information comes from the sacral and brain stem region true or false?
False it comes from the thoracic lumbar region
Which autonomic ns has a shorter preganglionic neuron?
Sympathetic
Why would the sympathetic ns use the alternate pathway of the adrenal medulla?
The effects last longer and they are more wide spread through out the body..
Which neurotransmitter does alpha 1&2 receptors have a greater affinity for?
Norepinephrine
What’s so special about the vagus nerve?
Part of the psns system, involved in cardio respiratory regulation an liver and lung function if blood pressure gets to high you get vagal outflow
Describe autonomic tone
It is the balance during rest between sympathetic innervation and parasympathetic inervation that keeps us alive and moving
What is the purpose of dual innervation?
For the most part it is so a system or organ can be stimulated by the psns and the sns
For example heart rate, and eye dilation
Can dual innervation have cooperative functions
Yes for example during an erection psns is working and during ejactulation sns is working.. Therefore they are working towards a common goal..
