Reflexes

thumb|upright=1.4|Real-time magnetic resonance imaging of the human thorax during breathing thumb|upright=1.4|X-ray video of a female American alligator while breathing Breathing (respiration or ventilation) is the rhythmic process of moving air into (inhalation) and out of (exhalation) the lungs to enable gas exchange with the internal environment, primarily to remove carbon dioxide and take in oxygen.

Perspiration, also known as sweat, is the fluid secreted by sweat glands in the skin of mammals.

thumb|A young child crying |alt=a young child in a pink sweater crying and looking sad

Flatulence is the expulsion of gas from the intestines via the anus, commonly referred to as farting. "Flatus" is the medical word for gas generated in the stomach or bowels. A proportion of intestinal gas may be swallowed environmental air; hence, flatus is not entirely generated in the stomach or bowels. The scientific study of this area of medicine is termed flatology.

A hiccup (scientific name singultus, from Latin for "sob, hiccup"; also spelled hiccough) is an involuntary contraction (myoclonic jerk) of the diaphragm that may repeat several times per minute. The hiccup is an involuntary action involving a reflex arc. Once triggered, the reflex causes a contraction of the diaphragm followed by the closure of the glottis, the space between the vocal cords, in about 35 milliseconds, which results in the "hic" sound.

thumb|thumbtime=0:12|360px|Shadowgraph visualization of the airflow during a sneeze, comparing an unmasked sneeze with several different methods of covering one's mouth and nose: sneezing into a fist, a cupped hand, a tissue, a "coughcatcher" device, a [[surgical mask, and an N95 mask]] A sneeze (also known as sternutation) is a semi-autonomous, convulsive expulsion of air from the lungs through the nose and mouth, usually caused by foreign particles irritating the nasal mucosa. A sneeze expels air forcibly from the mouth and nose in an explosive, spasmodic involuntary action. This action allo

A yawn is a reflex in vertebrate animals characterized by a long inspiratory phase with gradual mouth gaping, followed by a brief climax (or acme) with muscle stretching, and a rapid expiratory phase with muscle relaxation, which typically lasts a few seconds. For fish and birds, this is described as gradual mouth gaping, staying open for at least three seconds and subsequently a rapid closure of the mouth. Almost all vertebrate animals, including mammals, birds, reptiles, amphibians, and even fish, experience yawning. The study of yawning is called chasmology.

emotional state experienced as the result of an unexpected event

In biology, a reflex, or reflex action, is an involuntary, unplanned sequence or action and nearly instantaneous response to a stimulus. thumb|429x429px|The simplest reflex is initiated by a stimulus, which activates an afferent nerve. The signal is then passed to a response neuron, which generates a response. Reflexes are found with varying levels of complexity in organisms with a nervous system. A reflex occurs via neural pathways in the nervous system called reflex arcs. A stimulus initiates a neural signal, which is carried to a synapse. The signal is then transferred across the synapse to

Belching (also called burping and eructation) is the audible release of gas from the upper gastrointestinal tract (esophagus and stomach) of humans, and other animals into the pharynx, and usually out through the mouth.

Swallowing, also called deglutition or inglutition in scientific and medical contexts, is a physical process of an animal's digestive tract (e.g. that of a human body) that allows for an ingested substance (typically food) to pass from the mouth to the pharynx and then into the esophagus. In colloquial English, the term "swallowing" is also used to describe the action of gulping, i.e. taking in a large mouthful of food without any biting.

thumb|right|A woman blushing and covering her face Blushing or erubescence is the reddening of a person's face due to psychological reasons. It is normally involuntary and triggered by emotional stress associated with passion, embarrassment, shyness, fear, anger, or romantic stimulation.

body causing its hairs to stand on end

neural pathways which control the reflex

reflex elicited when the sole of the foot is stimulated with a blunt instrument

reflex controlling the diameter of the pupil in response to the intensity of light

action or movement due to the application of a sudden unexpected stimulus

reflex actions exhibited by normal infants, but not neurologically intact adults, in response to particular stimuli

Infantile reflex

reflex at the back of the throat

reflex movement in brain-dead or brainstem failure patients

thumb|A woman shivering from cold Shivering (also called shuddering) is a bodily function in response to cold and extreme fear in warm-blooded animals. When the core body temperature drops, the shivering reflex is triggered to maintain homeostasis. Skeletal muscles begin to shake in small movements, creating warmth by expending energy. Shivering can also be a response to fever, as a person may feel cold. During fever, the hypothalamic set point for temperature is raised. The increased set point causes the body temperature to rise (pyrexia), but also makes a person feel cold until the new set p

increase in heart rate due to an increase in central venous pressure

Hypohidrosis is a medical condition in which a person exhibits diminished sweating in response to appropriate stimuli. In contrast with hyperhidrosis, which is a socially troubling yet often harmless condition, the consequences of untreated hypohidrosis include hyperthermia, heat stroke and death. An extreme case of hypohidrosis in which there is a complete absence of sweating and the skin is dry is termed anhidrosis. The condition is also known as adiaphoresis, ischidrosis, oligidria, oligohidrosis and sweating deficiency.

monosynaptic reflex

The reflex process in which a mechanical stimulus applied to the eye elicits a response of the eyelid closing.

cats' ability to usually land on their feet

physiological response to immersion of air-breathing vertebrates

muscle contraction in response to stretching within the muscle

stretch reflex that occurs when the Achilles tendon is tapped

human reflex affecting the testicles

reflex where rotation of the head causes eye movement to stabilize vision

Pulse rate connected with eye muscles

Latah (from Malay word) is a condition in which abnormal behaviors result from a person experiencing a sudden shock or other external stressor almost exclusively having been observed in persons from Malaysia, Indonesia, and other Southeast Asian countries. When induced, the affected person typically engages in such behaviors as screaming, cursing, dance movements, uncontrollable laughter, mimicry and command obedience. Physical symptoms include an increased heart rate and profuse sweating, but no clear physiological causality beyond the apparent relationship between sudden shock and/or severe

physiological nervous system response to increased intracranial pressure

400px|thumb|Flowchart showing baroreceptor reflex

primitive and involuntary reflex

reflex test

Cycle of uterine contractions

medical condition

Hyperekplexia (; "exaggerated surprise") is a neurological disorder characterized by a pronounced startle response to tactile or acoustic stimuli and an ensuing period of hypertonia. The hypertonia may be predominantly truncal, attenuated during sleep, or less prominent after one year of age.

Clinical sign

Biological reflex to prevent lung over-inflation

medical maneuver to test reflexes

Temporal reflex action in infants usually for a period of about six months

involuntary contraction of the stapedius muscle in response to high-intensity sounds

diagnostic reflex similar to the Babinski reflex

reflex action of the eye, in response to focusing on a near object, then looking at a distant object

Wikimedia template

kidney reflex used to regulate filtration

reflexive contraction of the external anal sphincter

reflex seen in infants

involves a variety of cardiovascular and neurological processes which cause hypopnea and bradycardia (abnormally low resting heart rate)

Newborn reflex

primitive reflex elicited by repetitive tapping of the glabella

spinal reflex

medical condition

unusual reflexive dilation of the human anus in response to stimulation

reflex of the gastrointestinal tract in humans