A&PI Ch. 13,14,&15 Central and Automatic Nervous Systems Flashcards
What are the Main Functions of the CNS
-receiving and processing EXTERNAL SENSORY information
-integrating information from a wide range of sources: processing it, acting in it, or storing it in memory
-sending signals that control the main functions of body tissues
-consciousness perception of senses, language, reason, memory, emotion, etc.
What are the two main cell types in nervous tissue?
Neurons and Glial Cells
What is a nerve?
-a bundle of axons outside the brain and spinal cord
- two kinds (cranial and spinal nerves)
Cranial Nerves
originate from the brain; 12 pairs
Spinal Nerves
originate from the spinal cord; 31 pairs
Ganglion
collection of neuron cell bodies outside the brain and spinal cord
Plexus
extensive network of axons, and sometimes neuron cell bodies, located outside CNS
Glial Cells
supportive cells with many functions
5 Important Facts about the CNS
1) The CNS consists of the brain and spinal cord
2) Only 10% of CNS cells are neurons; the rest are neuroglia
3) The CNS is supported by the cerebral spinal fluid (CSF)
4) THE CNS is protected by meninges, CSF, and the BBB
5) White matter is inside the brain, outside the spinal cord
What is the brain protected by?
- Bones of the skull
- Meninges
- (CSF) Cerebral Spinal Fluid (liquid cushion)
- Blood-brain Barrier (controls what passes from the blood to the brain)
Meninges Dura Mater
- superior layer of meninges (under bone layer)
- thick, strong connective tissue layer
Meninges Arachnoid Mater
- 2nd layer of meninges
- thin, transparent fibrous membrane
Meninges Pita Mater
- 3rd layer of meninges
- delicate connective tissue layer
Functions of CSF
-homeostatic regulation of ions and nutrients in extra cellular environment
-support and cushioning of the brain and spinal cord with buoyant forces
-chemical and immunological buffering of the fluid surrounding neurons and glia
CSF Moves through the brain through __________.
Ventricles
Ventricles
-store CSF and provide a continuous flow of CSF between brain and spinal cord
CSF is produced by specialized tissue (_______ _______) and _________ ______ within ventricles.
choroid plexus; ependymal cells
Functions of BBB
-regulates which substances enter the brain’s interstitial fluid
-helps prevent neuron exposure to harmful substances via tight junctions of endothelial cells
-some molecules can pass (alcohol, cocaine, and small bacteria)
-The BBB is reduced in certain regions of the CNS for functional regions- areas of high hormones secretion like hypothalamus
Which arteries are in the Circle of Willis?
Internal Carotid Artery and Vertebral Artery
Internal Carotid Artery
- Portion of the Circle of Willis
- Anterior portion of the brain
Vertebral Artery
- Portion of the Circle of Willis
- Posterior portion of the brain
True or False? There is only one pathway of blood flow in the brain.
FALSE There are multiple paths of blood flow (in case one gets blocked)
True or False? The Circle of Willis allows blood supplying anterior and posterior portions of the brain to overlap
True because there are multiple paths of blood flow, the Circle of Willis allows an overlap to pick up the slack of the other side possibly (safeguards the CNS to maintain blood flow)
Anterior Communicating Artery
- connects both anterior cerebral arteries
- safeguard the CNS to maintain blood flow
Function of the Formation of the Basilar Artery from the two vertebral arteries and spinal arteries
safeguard the CNS to maintain blood flow
What is a stroke?
- Interrupted blood flow to the brain has caused neuronal death (Circle of Willis gets interrupted)
- there are two types (Ischemic and Hemorrhagic)
Ischemic Stroke
-reduced blood flow (blood clot or embolism)
Hemorrhagic Stroke
- bleeding (bleeding out, aneurism)