Tetrapoda

Hypertension
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Synonyms	N/A
Pronounce	N/A
Specialty	N/A
Symptoms	Headache, dizziness, shortness of breath
Complications	Heart disease, stroke, kidney failure
Onset	Gradual
Duration	Long term
Types	N/A
Causes	Genetics, diet, lifestyle
Risks	Obesity, smoking, alcohol consumption
Diagnosis	Blood pressure measurement
Differential diagnosis	N/A
Prevention	N/A
Treatment	Lifestyle changes, medication
Medication	N/A
Prognosis	N/A
Frequency	Common
Deaths	N/A

Hypertension, also known as high blood pressure, is a chronic medical condition in which the blood pressure in the arteries is persistently elevated. It is a major risk factor for cardiovascular disease, including heart attack and stroke.

Signs and Symptoms

Hypertension is often called the "silent killer" because it typically has no symptoms until it has caused significant damage to the heart and arteries. Some people with high blood pressure may experience headaches, dizziness, or shortness of breath.

Causes

The exact cause of hypertension is often unknown, but several factors can contribute to its development, including:

• Genetics
• Unhealthy diet, particularly high salt intake
• Lack of physical activity
• Obesity
• Excessive alcohol consumption
• Smoking

Diagnosis

Hypertension is diagnosed by measuring blood pressure using a sphygmomanometer. A reading of 140/90 mmHg or higher is generally considered high.

Treatment

Treatment for hypertension typically involves lifestyle changes and medication. Lifestyle changes may include:

• Eating a healthy diet
• Reducing salt intake
• Engaging in regular physical activity
• Maintaining a healthy weight
• Limiting alcohol consumption
• Quitting smoking

Medications used to treat hypertension include diuretics, beta-blockers, ACE inhibitors, and calcium channel blockers.

Complications

If left untreated, hypertension can lead to serious health problems, including:

• Heart disease
• Stroke
• Kidney failure
• Vision loss

Prevention

Preventing hypertension involves adopting a healthy lifestyle, such as eating a balanced diet, exercising regularly, and avoiding tobacco and excessive alcohol use.

See Also

• Cardiovascular disease
• Blood pressure
• Heart attack

External Links

• World Health Organization: Hypertension
• CDC: High Blood Pressure

Tetrapoda (Greek: τετραπόδης "four-footed") is a superclass of amphibians, reptiles, birds, and mammals that have four limbs or, as in the case of some snakes and whales, evolved from ancestors with four limbs. The first tetrapods emerged approximately 395 million years ago in the late Devonian period as descendants from certain fish, specifically the group known as lobe-finned fish. This evolutionary transition from a water-based to a land-based life is one of the most significant events in the history of life on Earth.

Evolution

The transition from water to land life entails numerous significant adaptations that facilitated the survival of these organisms in a terrestrial environment. These adaptations include the development of lungs, a stronger and more flexible spine, limbs with digits, and changes in sensory systems. The earliest known tetrapods, such as Acanthostega and Ichthyostega, still possessed many aquatic features, indicating a gradual transition from water to land.

Classification

Tetrapoda is divided into four major groups: Amphibia (amphibians), Reptilia (reptiles), Aves (birds), and Mammalia (mammals). Each group has adapted to life on land in its unique way, with varying degrees of dependency on aquatic environments.

Amphibia

Amphibians, such as frogs, salamanders, and caecilians, are characterized by a life cycle that typically includes both aquatic larval and terrestrial adult stages. They have moist skin that assists in respiration, a feature that ties them closely to water.

Reptilia

Reptiles, including turtles, snakes, lizards, and crocodilians, have developed scaly skin that prevents water loss, enabling them to thrive in a wide range of terrestrial environments. Many reptiles lay hard-shelled eggs, which is a significant adaptation to life on land.

Aves

Birds, descendants of theropod dinosaurs, have evolved feathers, wings, and lightweight skeletons, adaptations that have enabled the capability of flight. This group exhibits a wide variety of lifestyles, from fully terrestrial to aquatic.

Mammalia

Mammals are characterized by the presence of mammary glands, which produce milk for feeding their young, and fur or hair, which helps in thermal insulation. Mammals have adapted to a wide range of environments, from terrestrial to marine.

Significance

The emergence of tetrapods was a pivotal event in evolutionary history, opening up new ecological niches and leading to a dramatic increase in biodiversity. The adaptations that allowed these organisms to colonize terrestrial environments have been key to their success and diversification.

Challenges

Despite their success, tetrapods face numerous challenges, including habitat destruction, climate change, and pollution, which threaten their survival. Conservation efforts are crucial to protect these diverse groups of organisms and the ecosystems they inhabit.