Unit 2: Respiratory System and Nervous System Flashcards

Question

What is a monosynaptic stretch reflex

Answer 1

Simplest spinal reflex Only relies on the single connection between primary afferent fibres and motor neurons of the same muscle. Extremely quick and automatic

Answer 2

one or more interneurons lie between the primary sensory fibers and the motor neurons.

Answer 3

The knee-jerk is often used to demonstrate this type of reflex. A tap below the kneecap stretches the patellar tendon and acts as a stimulus, initiating a reflex arc that causes the exterior muscle on top of the thigh to contract. As the tendon and muscle fibre are stretched, information is sent to the spinal cord. These nerve signals act directly on motor neurons that then quickly proceed to contract the quadriceps femoris, the extensor muscle that serves to extend the lower leg Sequence of nerve impulses: The receptor muscle senses the action of the hammer against the patella ligament through the muscle spindle’s sensory neuron; The message is transmitted along the afferent (sensory) nerve axon to the spinal cord; The afferent neuron then synapses with the efferent pathway (motor neuron) of the same muscle; An impulse is transmitted along the efferent pathway (motor neuron) to the muscle fibre; and The motor units contract simultaneously, which in turn brings about a knee-jerk action to accommodate the additional stretch.

Answer 4

An example is the withdrawal reflex, which involves the withdrawal of a body part from a painful stimulus (such as a sharp or hot object). the reflex action involves transferring the impulse from a sensory neuron to a motor neuron through a connecting interneuron in the spinal cord. The withdrawal reflex process occurs before the brain itself has time to interpret the information. The sequence of nerve impulses and stages activated in the crossed leg extensor reflex action are as follows: The stimulus is detected by receptors (say, on the skin) The receptors initiate nerve impulses in the sensory neurons leading from the receptors; The impulses travel into the spinal cord where the sensory nerve terminals synapse with interneurons; Some of these interneurons synapse with motor neurons that travel out from the spinal cord to the effector organ; The knee flexors withdraw the foot from the danger zone; and Still other sensory neurons synapse with interneurons that affect motor neurons in the opposing leg and cause these muscles to come into action.

Answer 5

Central nervous system and Peripheral nervous system

Answer 6

Consists of brain and spinal cord Processes information sent by PNS and acts as a command center Can execute motor responses or regulate body mechanisms

Answer 7

Provides sensory information for the CNS Further divided into SNS and ANS

Answer 8

Automatic nervous system and somatic nervous system

Answer 9

deal with the internal environment: Can be divided into Sympathetic and Parasympathetic

Answer 10

Rest and Digest Heart rate will decrease

Answer 11

Part of the quick flight or fight response Increased heart rate Increased breathing rate