Explanation:
Positive feedback loops induce/amplify change whereas negative feedback loops reduce change
Answer:
The effector organ is affected by the fourth structure of the reflex arc.
Explanation:
When talking about the reflex arc, we refer to the sequence of events that occur for the body to react to an external stimulus.
In general terms, the peripheric nervous system receives information from a stimulus coming from the external environment. This information is sent to the central nervous system, where it is processed. From the CNS, another signal is sent as a response to the stimulus. This mechanism is known as the reflex arc.
Five elements compose the reflex arc, which are receptors, three types of neurons, and effectors.
There are three types of neurons involved in the mechanism:
• Afferent or sensorial neurons
• Interneurons
• Efferent or motor neurons
Action:
The stimulus reaches the body and is received by the specialized sensory <u>receptors</u>. Information is received by these receptors and converted from stimuli energy (temperature, pressure, light, etc.) to action potential energy. <u>Afferent neurons</u>, placed in the dermis and epidermis, receive information from receptors, react and send the information to the central nervous system as nerve impulses.
Once the information reaches the central nervous system, it is processed by the<u> interneurons</u> that analyze it before sending a response. Interneurons manage many sensorial signals, evaluate and compare them, and send a motor response.
<u>Efferent neurons</u> receive information from the interneurons and are stimulated to carry these new signals from the central nervous system to the cells of the <u>effector organs</u>. The effector organ can be a muscle or a gland.
Finally, the target tissue responds to the stimulus as a contraction, if it is a muscle, or as hormones release if it is a gland.
Answer:
Cranial capacity increased the most from 2 million years ago to the present.
Explanation:
The rate of change is greatest between 2 million years ago and the present.
Nicotine on direct application in humans causes irritation and burning sensation in the mouth and throat, increased salivation, nausea, abdominal pain, vomiting and diarrhea. Predominant immediate effects consist of increase in pulse rate and blood pressure. Nicotine also causes an increase in plasma free fatty acids, hyperglycemia, and an increase in the level of catecholamines in the blood. There is reduced coronary blood flow but an increased skeletal muscle blood flow. The increased rate of respiration causes hypothermia, a hypercoagulable state, decreases skin temperature, and increases the blood viscosity.
For amphetamine the immediate effects are quicker reaction times, feelings of energy/wakefulness, excitement, increased attentiveness and concentration, feelings of euphoria. Side effects of amphetamines can include heart palpitations, dry mouth, headache, hostility, nausea, cognitive impairment, severe anxiety, lack of appetite, teeth grinding, dizziness, increased heart rate, heart palpitations, rapid breathing rate, hypertension (high blood pressure), increased body temperature, erectile dysfunction, irregular heartbeat.
Cocaine causes a short-lived, intense high that is immediately followed by the opposite intense depression, edginess and a craving for more of the drug the side effects are Loss of appetite increased heart rate, blood pressure, body temperature, contracted blood vessels increased rate of breathing, dilated pupils, disturbed sleep patterns, nausea, hyperstimulation, bizarre, erratic, sometimes violent behavior hallucinations, hyperexcitability, irritability, tactile hallucination that creates the illusion of bugs burrowing under the skin, intense euphoria, anxiety and paranoia, depression, intense drug craving, panic and psychosis, convulsions, seizures and sudden death from high doses (even one time)
