Primary motor cortex

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	[[Category:Brain areas]]		[[Category:Brain areas]]
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	== Background ==		== Background ==
		+	• Primary motor cortex is also called M1
-	â�¢ Primary motor cortex is also called M1	+	• One of the principle areas involved in motor function
-	â�¢ One of the principle areas involved in motor function	+	• Located in the frontal lobe of the brain along the precentral gyrus
-	â�¢ Located in the frontal lobe of the brain along the precentral gyrus	+	• The role is to generate neural impulses that control the execution of movement
-	â�¢ The role is to generate neural impulses that control the execution of movement	+	• Signals from M1 cross the body’s midline to activate skeletal muscles on the opposite side of the body
-	â�¢ Signals from M1 cross the bodyâ��s midline to activate skeletal muscles on the opposite side of the body	+	• The right hemisphere controls the left side of the body
-		+
-	� The right hemisphere controls the left side of the body	+
-		+
-	� The left hemisphere controls the right side of the body	+
		+	• The left hemisphere controls the right side of the body
	== Somatotopic Representation ==		== Somatotopic Representation ==
		+	• Every part of the body is represented in the primary motor cortex
-	â�¢ Every part of the body is represented in the primary motor cortex	+	• Body part representations are arranged somatotopically
-		+
-	� Body part representations are arranged somatotopically	+
-		+
-	� The foot is next to the leg, next to the trunk, next to the arm, which is next to the hand	+
-		+
-	� The amount of brain matter devoted to a particular body part represents the amount of control that the primary motor cortex has over that body part	+
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-	� A lot of cortical space is devoted to complex hand and finger movements; therefore, they have larger representations in M1	+
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-	== Corticospinal Tract ==	+
-		+
-	� Neurons in M1, supplementary motor area, and premotor cortex give rise to fibers of the corticospinal tract	+
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-	� The corticospinal tract is the only direct pathway from the cortex to the spine	+
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-	� This tract is composed of over a million fibers	+
-		+
-	� The fibers descend through the brainstem and cross to the opposite side of the body	+
-		+
-	� The fibers then continue to descend through the spine, terminating at the appropriate spinal levels	+
-		+
-	� This tract is the main pathway for control of voluntary movement in humans	+
-	â�¢ Lesions in the primary motor cortex result in paralysis of the contralateral side of the body	+	• The foot is next to the leg, next to the trunk, next to the arm, which is next to the hand
-	== Works Cited ==	+	• The amount of brain matter devoted to a particular body part represents the amount of control that the primary motor cortex has over that body part
-	� The Anatomy of Movement: http:www.brainconnection.com/topics/?main=anat/motor-anat	+
-	â�¢ Wikkipedia: Primary Motor Cortex: http://en.wikipedia.org/wiki/Primary¬_motor_cortex	+	• A lot of cortical space is devoted to complex hand and finger movements; therefore, they have larger representations in M1

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Revision as of 15:22, 24 April 2008

Background

• Primary motor cortex is also called M1

• One of the principle areas involved in motor function

• Located in the frontal lobe of the brain along the precentral gyrus

• The role is to generate neural impulses that control the execution of movement

• Signals from M1 cross the body’s midline to activate skeletal muscles on the opposite side of the body

• The right hemisphere controls the left side of the body

• The left hemisphere controls the right side of the body

Somatotopic Representation

• Every part of the body is represented in the primary motor cortex

• Body part representations are arranged somatotopically

• The foot is next to the leg, next to the trunk, next to the arm, which is next to the hand

• The amount of brain matter devoted to a particular body part represents the amount of control that the primary motor cortex has over that body part

• A lot of cortical space is devoted to complex hand and finger movements; therefore, they have larger representations in M1