Ch 56: Nervous System Flashcards
Autonomic Nervous System (ANS)
Divided into sympathetic and parasympathetic
Governs involuntary cardiac muscle, smooth muscle, and gland functions
Blood-brain barrier
A physiologic barrier between blood capillaries and brain tissue
protects the brain from harmful agents
Allows gases and nutrients to enter brain
Central Nervous System (CNS)
Consists of the brain, spinal cord, and cranial nerves I and II
Cerebrospinal Fluid (CSF)
Fluid that provides cushion for the brain and spinal cord, circulates within the subarachnoid space that surrounds the brain, brainstem, and spinal cord
Cranial Nerve (CNs)
the 12 paired nurse composed of cell bodies with fibers that exit from the cranial cavity,
have both afferent sensory and efferent motor fibers
some only sensory, some only motor, some both
Dermatome
area of skin innervated by the sensory fiber of a single dorsal root of a spinal nerve
Glial cells (glia or neuroglia)
provide support, nourishment, and protection to neurons
Lower Motor Neurons (LMNs)
The final common pathway through which descending motor tracts influence skeletal muscle
Meninges
Three protective membranes that surround the brain and spinal cord
- Dura mater
- Arachnoid
- Pia Mater
Neurons
3 characterists
1: excitability
2: conductivity
3: influence
Neurotransmitters
Chemicals that affect the transmission of impulses across the synaptic cleft
Peripheral Nervous System (PNS)
Consists of nerves III to XII, spinal nerves, and peripheral components of the ANS
Reflex
An involuntary response to stimuli
Synapse
Structural and functional junction between two neurons
Upper Motor Neruons (UMNs)
Originate in the cerebral cortex and project downward
