18) Consists of an ipsilateral withdrawal reflex and a contralateral extensor reflex; important in maintaining balance.…
The sensory receptor detects a stimulus. The interneurons receive inputs from sensory receptors and synapse on motor neurons. The effects on motor neurons can be excitatory or inhibitory. Lastly, motor neurons produce muscle contraction, and motor response. Reflexes often have effects in groups of motor neurons to different muscles; sometimes at different joints in the same limb or in a different limb. Reflexes are valuable tools for clinical evaluation of how our nervous system is functioning. For reflex to occur, all elements must be functional and our pathways must be intact. If reflexes are absent, the physician can diagnose where the pathway has been interrupted and can diagnose where function is compromised.…
B. The functions of components of a reflex arc are the receptor, sensory neuron, center, motor neuron and the effector. The receptor is responsible for activating a nerve impulse in a sensory neuron that responds to a change in the body’s internal and external environment. The sensory neuron conducts the impulse needed from the receptor to travel to its axonal end in the CNS.…
A muscle twitch is the fasciculation , or "muscle twitch", is a small, local, involuntary muscle contraction and relaxation visible under the skin.…
Define the terms reflex and spinal reflex and identify the components of a reflex arc.…
A good example of a reflex is the “knee-jerk” response the doctor tests during a physical examination. In a healthy person, this stretch reflex maintains posture and allows our muscles to hold up our body. Doctors can check this reflex by tapping on the tendon just below the kneecap. This tap causes contraction of the quadriceps muscle and extension of the leg. Stretching of the muscle activates nerve impulses which travel to the spinal cord. Here the incoming impulses activate motor neurons, which travel back to the muscle and result in muscle contraction.…
Spinal reflexes don’t require input from brain – may be modulated by higher input from brain but integrated in spinal cord…
Babies at birth – most are born at 40 week and premature babies more often need a little more time to reach the same level of development as babies born in and after the 40th week. Most are born with just reflexes for survival at first. These would be swallowing, sucking reflexes to help feed. Rooting reflex baby will move its head if the cheek is touched to find a nipple or teat. Grasp reflex babies will grip objects touching their palm. Startle reflex they will often move arms outwards and clench fists is a sound movement or light suddenly startles them. Walking reflex when babies are held upright with their feet on a firm surface they usually mimic walking.…
10/23/12: CHAPTER 9: MUSCLES AND MUSCLE TISSUE 10. 10/30/12: CHAPTER 10: THE MUSCULAR SYSTEM EXAM REVIEW: CHAPTERS 6-10 11. 11/6/12: EXAM II: CHAPTERS 6-10 12. 11/13/12: CHAPTER 11: FUNDAMENTALS OF NERVOUS SYSTEM AND NERVOUS TISSUE CHAPTER 12: THE CENTRAL NERVOUS SYSTEM 13. 11/20/12: CHAPTER 13: THE PERIPHERAL NERVOUS SYSTEM AND REFLEX ACTIVITY 14.…
3. Reflex actions arern’t voluntary. They’re automatic and defensive, usually without thought though you may be in a conscious state.…
The reflex arc is the nerve pathway involved in a reflex action including at its simplest a sensory nerve and a motor nerve with a synapse between. The components are receptor, sensory neurons, motor neurons, relay neurons, and effector.…
|Startle reflex; when hearing a sudden sound or bright light will react by moving their arms outwards and clenching their fists. |…
C. The component of the reflex arc that is most likely to be damaged in Nick’s situation is the integrating center because one or more regions within the CNS relay impulses from sensory to motor neurons, so the impulses are never reaching the motor neurons and effectors.…
Child laying on their front lies in a fetal position with knees tucked up. Child is unable to raise head or stretch limbs.…
The purpose of this lab is focus towards testing our reflexes and sensory physiology. We use these every day but we rarely do understand how much they contribute to our ability to function normally. A reflex is a rapid, involuntary motor response to stimuli. We will be conducting several experiments to test our reflexes throughout this lab.…