Lecture 6: Nervous System Introduction, Brachial Plexus Flashcards
What are the functions of the nervous system?
-sensory -motor -cognitive
What are the divisions and subdivisions of the nervous system?
Central Nervous System (CNS) -brain -spinal cord Peripheral Nervous System (PNS) -cranial nerves -spinal nerves Autonomic Nervous System -sympathetic -parasympathetic
What is the difference between afferent and efferent pathways?
Afferent (sensory): carries information to the CNS Efferent (motor): carries information away from the CNS
How many cranial and spinal nerve pairs are there?
Cranial: 12; I-XII Spinal: 31; C1-8, T1-12, L1-5, S1-5, Co
What is the function of the autonomic nervous system?
Efferent pathways innervating smooth muscles and glands.
What are the subdivisions of the autonomic nervous system? Compare them.
Sympathetic (thoracolumbar): fight or flight Parasympathetic (craniosacral): feed and breed
Describe the development of the neural tube.
Neural plate is formed by thickening of the tissue stimulated by the notochord. The ends of he neural plate pinch together forming neural folds and the neural groove. The neural folds fuse to create the neural tube. This fusion starts from the middle and spreads towards the ends.
What are the divisions of the tripartite brain?
-prosencephalon -mesencephalon -rhombencephalon
What are the divisions of the pentapartite brain?
-telencephalon -diencephalon -mesencephalon -metencephalon -myelencephalon
What do the different parts of the telencephalon develop into?
Lumina: -lateral ventricles Floor: -basal ganglia -olfactory nerves Roof -cerebral hemispheres
What do the different parts of the diencephalon develop into?
Lumen: -third ventricle Roof -epithalmus Walls -thalamus Floor -hypothalamus and infundibulum
What do the different parts of the mesencephalon develop into?
Lumen: -cerebral aqueduct Roof: -tectum Floor: -tegmentum
What do the different parts of the metencephalon develop into?
Lumen: -fourth ventricle Roof: -cerebellum Floor: -pons
What do the different parts of the myencephalon develop into?
Lumen: -forth ventricle Main part: -medulla oblongota Roof: -choroid plexus
What are the parts of a neuron?
Cell body Dendrites Axon
What are the features of the cell body?
-contains the nucleus, Golgi body and endoplasmic reticulum -maintains the rest of the cell
What are the features of the dendrites?
-consists of several to many short branches coming of the cell body -have receptors for neurotransmitters -conduct local potentials
What are the key features of the axon?
-single, relatively long structure -conducts action potential -ends branch into telodendria which end in a terminal bouton -cell membrane is called axolemma; cytoplasm is called axoplasm
Define nucleus
Aggregation of dendrites and cell bodies in the CNS
Define ganglion
Aggregation of dendrites and cell bodies in the PNS
Define nerve
Bundle of axons in the PNS
Define tract
Bundle of axons in the CNS
Define commissary
Tracts in the CNS that cross from one side to the other
Define white matter
Areas of myelinated axons
Define gray matter
Areas of unmyelinated axons, cell bodies, and dendrites
Identify the colored structures
Yellow: dorsal ramus
Orange: ventral ramus
Red: white ramus communicans
Describe the structure of a synapse.
Presynaptic membrane: releases vesicles containing neurotransmitters
Synaptic cleft: gap between pre- and postsynaptic membranes
Postsynaptic membrane: contains neurotransmitter receptors
Distinguish between afferent and efferent pathways.
Afferent: sensory; carries information towards the CNS
Efferent: motor; carries information away from the CNS
Differentiate between a monosynaptic and polysynaptic reflex arc.
Monosynaptic: one synapse consisting of only an afferent pathway and an efferent pathway; no processing, cannot be inhibited
Polysynaptic: more than one synapse; contains interneurons; there can be processing and inhibition
Label the indicated structures
