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Overview of Anatomy and Physiology01:24

Overview of Anatomy and Physiology

Human anatomy is the scientific study of the body's structures. Some of these structures are very small and can only be observed and analyzed with the assistance of a microscope. Other larger structures can readily be seen, manipulated, measured, and weighed. The word "anatomy" comes from a Greek root that means "to cut apart." Human anatomy was first studied by observing the body's exterior and the wounds of soldiers and other injuries. Later, physicians were allowed to dissect the bodies of...
The Pineal Gland01:02

The Pineal Gland

The pineal gland, a diminutive endocrine structure named for its pinecone-shaped appearance, is situated atop the third ventricle within the diencephalon region of the forebrain. This gland, composed of secretory cells known as pinealocytes arranged in compact cords and clusters around dense particles of calcium salts, plays a pivotal role in hormonal regulation.
The primary secretion of the pineal gland is the hormone melatonin, derived from serotonin. The concentration of melatonin in the...
Structural Organization of the Human Body: An Overview01:18

Structural Organization of the Human Body: An Overview

It is convenient to consider the body's structures in terms of fundamental levels of organization that increase in complexity: subatomic particles, atoms, molecules, organelles, cells, tissues, organs, organ systems, and organisms.
To study the chemical level of organization, scientists consider the simplest building blocks of matter: subatomic particles, atoms, and molecules. All matter in the universe is composed of one or more unique pure substances called elements, familiar examples of...
Characteristics and Functions of Blood01:26

Characteristics and Functions of Blood

Blood is specialized connective tissue comprising about 8% of the body mass. It has a thick, liquid extracellular matrix that contains cells, dissolved proteins, and electrolytes, making it five times more viscous than water. Blood is warm, around 38°C, and has an alkaline pH ranging from 7.35 to 7.45.
The primary function of blood is to transport oxygen and carbon dioxide between tissues and the lungs. Oxygenated blood is bright red, while oxygen-depleted blood is darker. It also carries...
Five-Factor Theory of Personality01:29

Five-Factor Theory of Personality

The five-factor model, often called the Big Five personality traits, is widely accepted in psychology as a comprehensive framework for understanding personality. These five traits — Openness, Conscientiousness, Extraversion, Agreeableness, and Neuroticism — are often remembered using the acronym OCEAN.
Openness reflects creativity, curiosity, and openness to new experiences. Individuals scoring high in openness are imaginative, have a wide range of interests, and are independent thinkers. Low...
Anatomy of the Circulatory System02:03

Anatomy of the Circulatory System

The human circulatory system consists of blood, blood vessels that carry blood away from the heart, around the body, and back to the heart, and the heart itself, which acts as a central pump. The systemic circuit supplies blood to the whole body, the coronary circuit supplies blood to the heart, and the pulmonary circuit supplies blood flow between the heart and lungs.