EXERCISE NO. 6 Flashcards
Title
Reflex Physiology
is a rapid, predictable motor response to a stimulus.
reflex
is an involuntary and automatic response that occurs in response to a specific stimulus. These responses are typically rapid and are mediated by the nervous system. It serves to protect the body as they enable quick reactions to potentially harmful situations without the need for conscious thought and decision making. Thus, leading and maintaining to homeostasis.
reflexes
Reflexes may be __________ or _________ and involve only __________ and ________ but may involve higher brain centers as well.
inborn (intrinsic) and learned (acquired);
peripheral nerves and spinal cord
are motor responses that involve the striated muscles of the skeletal system
somatic reflexes
are a type of reflex that involves the contraction of skeletal muscle. These reflexes are responsible for controlling voluntary movements and maintaining posture. They are typically mediated by the SNS (_____), which includes motor neurons that control skeletal muscles. They help protect the body from injury by allowing rapid, automatic responses to external stimuli and play a crucial role in body’s balance, coordination, and overall control over voluntary movements.
Somatic Reflexes
Somatic Nervous System
are motor responses that involve the smooth muscle of organs, glands, and the vascular system
autonomic reflexes
are a type of reflex that involve the ANS (_____) and control involuntary physiological processes in the body. It regulates the activities of smooth muscles, cardiac muscles and glands. These play crucial role in maintaining the body’s internal environment such as blood pressure, digestion, and temperature regulation, and they occur without conscious control.
Autonomic Reflexes
Autonomic Nervous System
system that is commonly attributed with managing voluntary, directed motor responses
somatic system
system that is commonly attributed with managing involuntary, non-directed motor responses
autonomic system
system that also manages number of involuntary, non-directed reflexes involving the muscular skeletal system such as salivation
somatic system
- governs the operation of reflexes
- is a neural pathway that controls a reflex action. It consists of a series of organized neural elements that work together to enable a rapid and involuntary response to a specific stimulus
reflex arc
The __________, as defined by Sir ______________ in the early 1900s, provides the simplest physiological explanation of how reflexive activity in the body works.
reflex arc;
Charles Sherrington
Five reflex arc components
- receptor
- sensory neuron
- integration center
- motor neuron
- effector
reacts to a stimulus
receptor
conducts the afferent impulses to the CNS
sensory neuron
consisting of one or more synapses in the CNS
integration center
conducts the efferent impulses from the integration center to an effector organ
motor neuron
__________, ___________ or ____________ that then respond to the efferent impulses by contracting or secreting a product, respectively
effector, muscle fiber or glands
Reflexes can be classified as (4)
- development: innate or acquired reflexes
- response: somatic or autonomic (visceral)
- complexity of circuit: monosynaptic or polysynaptic
- processing site: spinal or cranial reflexes
classification of reflex (based on experiment)
- development: innate
- response: somatic
- complexity of circuit: polysynaptic
- processing site: spinal cord reflexes
chemical used to test the reflex
10% HCl
What part is removed during decerebration of the frog? which organ is out of action? and which organ is still alive?
cranium;
brain;
spinal cord
what organ is removed to block the sensory part?
skin
nerve between the frog’s thigh muscles that block the motor component
sciatic nerve
evolutionary significance of importance of somatic reflexes
Somatic reflexes, such as the withdrawal reflex, are evolutionarily significant as they provide rapid, automatic responses to potential threats, helping organisms avoid harm or injury. These reflexes have been shaped by natural selection to enhance survival by enabling quick and protective reactions to external stimuli, contributing to an organism’s fitness and safety.
give example of events where autonomic reflexes are important
Autonomic reflexes are crucial for regulating involuntary bodily functions. One important example is the pupillary light reflex, where the autonomic nervous system controls the size of the pupils in response to changes in light intensity, protecting the eyes from excessive light and ensuring optimal vision. These reflexes help maintain homeostasis and adapt the body to varying environmental conditions, contributing to overall physiological balance and well-being.
What is a synapse
A synapse is a specialized junction between two nerve cells or a nerve cell and an effector cell (e.g., muscle or gland cell) where information is transmitted. Neurotransmitters released from one cell’s axon terminal travel across the synapse to influence the electrical activity in the target cell, enabling communication in the nervous system.
