Behavioral Psychology and Physiology

Reflex actions are rapid, involuntary, automatic responses to stimuli that are mediated by the spinal cord. Because they are hardwired into the nervous system from birth, they do not need to be learned through experience or training, which provides a crucial survival advantage by ensuring fast reactions.

• Involuntary actions in response to external or internal stimuli are termed as reflex actions. Peripheral nervous system and the spinal cord are involved in controlling the reflex actions. Here, the brain is not involved.
• The reflex action was discovered by Marshall. He proposed the theory explaining the body's reflex, or involuntary, actions.
  
• So, the correct answer is 'Marshall'.

• A stimulus is anything that can be perceived by a given organism including sight, sound, touch, smell, taste, etc.
•  A response is generally characterized as the behaviour proximal to the stimulus. So if a bell rings and a person jumps the stimulus is the bell and the response is the jump. 
• The ability of an organism or organ to respond to external stimuli is called sensitivity. When a stimulus is applied to a sensory receptor, it normally influences by a simple reflex. Hence, Simple reflex is best to characterize the simple response to simple stimuli. 

The reflex action is defined as the sudden and involuntary movements that are controlled directly by the spinal cord. These actions do not require memory generation most of the time, like blinking of the eyes when something comes close to them. These are called the unconditional reflexes. Some reflex actions may involve learning and these are call the conditional reflexes. For example release of saliva at the sight of the food. Obeying the orders is the voluntary set of actions performed under the command of the somatic nervous system. It involves memory generation so as to remember the tasks and voices.

Closing eyes in response to bright light is a classic example of a simple, involuntary reflex action designed to protect the eyes.

A reflex action is defined as a spontaneous, involuntary, automated, nerve-mediated activity produced at the unconscious level  by stimulating specific receptors. In other words, a reflex action is a sensory impulse, automatically converted into a motor effect with the involvement of the central nervous system. These actions are sudden and automatic and take place even before one can feel the stimulus through the brain. The quick pulling of the hand on touching a hot object is an automated response to stimuli and is controlled and regulated by the spinal cord along with the sensory and motor neurons which connect the receptor and effector organs. Thus, the correct answer is option C.

There are 4 types of spinal reflex action, namely the stretch reflex, the Golgi tendon reflex, the crossed extensor reflex and the withdrawal reflex. The direction of response is opposite in withdrawal reflex action. The withdrawal reflex is also called as flexor withdrawal reflex. It protects the body from damaging stimuli. It is polysynaptic. Hence, it causes the stimulation of sensory, association and motor neurons.  For example, when a person touches a hot iron, he withdraws his hand from it within fraction of seconds. In this, the heat stimulates temperature and danger receptors in the skin, triggering a sensory impulse that travels to the central nervous system. The sensory neuron synapses with interneurons and connects to motor neurons. These motor neurons send motor impulses to the flexors and allows withdrawal.

The voluntary nervous system helps us take voluntary actions which are under the conscious control of the brain. Chewing is an action performed by us knowingly and is, therefore, a voluntary action.

Peristalsis is an involuntary, rhythmic contraction of smooth muscles in the digestive tract, which is regulated by the autonomic nervous system. Swallowing involves both voluntary and involuntary phases, while pupillary reflex and knee jerk are somatic or autonomic reflexes, but peristalsis is the classic example of autonomic control of visceral organs.

•  Locomotion is when the movement of a part of the body leads to change in the position and location of the organism. 
•  In multicellular animals, these movements include walking, running, jumping, crawling, climbing, swimming, flying, galloping, slithering, and so on. Hence, The ability to move from one place to another is called Locomotion.

• Locomotion in biology pertains to the various movements of organisms (single-celled or multicellular organisms) to propel themselves from one place to another.
  
  
• In multicellular animals, these movements include walking, running, jumping, crawling, climbing, swimming, flying, galloping, slithering, and so on. Voluntary muscles are the ones that you can control. 
  
  
• Most of them move your bones around. If you want to run, walk, ride a bike, wave your arms around, or eat your favorite sandwich, it is your voluntary muscles by which u move your arms, legs, and body around. Hence, Locomotion is Voluntary movement.
   

• Your brain sends messages through your spinal cord and the peripheral nervous system to: control the movement of your arms and legs. control the automatic functions of your body, such as the operations of your heart, your organs and your glands. Hence, All movement of the human body is coordinated and controlled by the Nervous system.

Body coordination in complex organisms is managed by the nervous system (fast, electrical signals) and the endocrine system (slower, chemical signals via hormones). Both systems work together to maintain homeostasis.