Human Anatomy & Physiology - Levels of Organization & Body Basics

Comprehensive Question and Answer flashcards covering structural levels of organization, organ systems, homeostasis, directional terms, body planes, cavities, and serous membranes from Dr. Youssef Tohme's lecture.

What is human anatomy?

Human anatomy is the scientific study of the body's structures.

What is human physiology?

Human physiology is the scientific study of the chemistry and physics of the structures of the body and how they work together to maintain life.

What are the six main levels of structural organization in the human body from simplest to most complex?

Chemical level, cellular level, tissue level, organ level, organ system level, and organismal level.

What are the percentages of the major chemical elements that make up the human body?

Oxygen ($65.0\%$), Carbon ($18.5\%$), Hydrogen ($9.5\%$), Nitrogen ($3.2\%$), Calcium ($1.5\%$), and Phosphorus ($1.0\%$).

What is a cell?

A cell is the smallest independently functioning unit of a living organism.

What primary structures comprise a typical human cell as shown in the diagram?

The cell membrane, cytoplasm, nucleus, and organelles such as mitochondria.

What is a tissue?

A tissue is a group of many similar cells that work together to perform a specific function.

What is an organ?

An organ is an anatomically distinct structure of the body composed of two or more tissue types that performs one or more specific physiological functions.

What is an organ system?

An organ system is a group of organs that work together to perform major functions or meet physiological needs of the body.

What are the key functions of the integumentary system?

Encloses internal body structures and serves as the site of many sensory receptors.

What are the key functions of the skeletal system?

Supports the body and enables movement (in coordination with the muscular system).

What are the key functions of the muscular system?

Enables movement (with the skeletal system) and helps maintain body temperature.

What are the key functions of the nervous system?

Detects and processes sensory information and activates bodily responses.

What are the key functions of the endocrine system?

Secretes hormones and regulates bodily processes.

What are the key functions of the cardiovascular system?

Delivers oxygen and nutrients to tissues and equalizes temperature in the body.

What are the key functions of the lymphatic system?

Returns fluid to the blood and defends against pathogens.

What are the key functions of the respiratory system?

Removes carbon dioxide from the body and delivers oxygen to the blood.

What are the key functions of the digestive system?

Processes food for use by the body and removes wastes from undigested food.

What are the key functions of the urinary system?

Controls water balance in the body and removes wastes from blood and excretes them.

What are the key functions of the male reproductive system?

Produces sex hormones and gametes, and delivers gametes to the female.

What are the key functions of the female reproductive system?

Produces sex hormones and gametes, supports the embryo/fetus until birth, and produces milk for the infant.

What are the essential survival time limits for human life regarding oxygen, water, and nutrients?

Humans cannot survive for more than a few minutes without oxygen, a few days without water, and a few weeks without carbohydrates, lipids, proteins, vitamins, and minerals.

Why is inorganic compounds defined differently from organic compounds?

Inorganic compounds (such as water, salts, acids, and bases) do not contain both hydrogen and carbon, whereas organic compounds (such as carbohydrates, lipids, proteins, and nucleotides) contain both carbon and hydrogen.

What components make up the chemical structure of Adenosine Triphosphate (ATP)?

Adenine and ribose (which form adenosine) joined to three phosphate groups by high-energy bonds.

What is homeostasis?

Homeostasis is the activity of cells throughout the body to maintain the internal environment (physiological state) that is compatible with life.

What four basic components form a homeostatic control mechanism?

Stimulus, sensor (receptor), control center, and effector.

How does a negative feedback loop differ from a positive feedback loop?

A negative feedback loop resists a stimulus to return the body to homeostasis, whereas a positive feedback loop intensifies the response until an end point is reached.

What is the standard anatomical position?

Body standing upright, feet shoulder width apart and parallel, toes forward, upper limbs held out to each side, and palms of the hands facing forward.

How are the prone and supine positions defined?

Prone describes lying face down on the stomach, while supine describes lying face up on the back.

What do the directional terms anterior (ventral) and posterior (dorsal) mean?

Anterior (ventral) describes the front or direction toward the front of the body; posterior (dorsal) describes the back or direction toward the back of the body.

What do the directional terms superior (cranial) and inferior (caudal) mean?

Superior (cranial) describes a position above or higher than another part of the body proper; inferior (caudal) describes a position below or lower than another part of the body proper.

What do the directional terms medial and lateral mean?

Medial describes the middle or direction toward the middle of the body; lateral describes the side or direction toward the side of the body.

What do the directional terms proximal and distal mean?

Proximal describes a position in a limb that is nearer to the point of attachment or trunk of the body; distal describes a position in a limb that is farther from the point of attachment or trunk.

What do the directional terms superficial and deep mean?

Superficial describes a position closer to the surface of the body; deep describes a position farther from the surface of the body.

What is the distinction between unilateral and bilateral?

Unilateral involves one side of the body, whereas bilateral involves both sides of the body.

What is the distinction between ipsilateral and contralateral?

Ipsilateral means on the same side of the body, whereas contralateral means on opposite sides of the body.

In a right temporal bone fracture with epidural hematoma, why does pupillary dilation occur ipsilaterally while weakness occurs contralaterally?

Right oculomotor nerve (CN III) compression causes ipsilateral (right-sided) pupillary dilation, whereas corticospinal tract compression causes contralateral (left-sided) limb weakness.

What is the sagittal plane, and how do midsagittal and parasagittal planes differ?

A sagittal plane divides the body or an organ vertically into right and left sides. A midsagittal (median) plane runs directly down the midline, while a parasagittal plane divides into unequal right and left sides.

What is the frontal (coronal) plane?

The frontal (coronal) plane divides the body or an organ vertically into an anterior (front) portion and a posterior (rear) portion.

What is the transverse plane?

The transverse plane divides the body or an organ horizontally into upper and lower portions, producing cross sections.

What major body cavities are found within the dorsal and ventral compartments?

The dorsal cavity contains the cranial and vertebral (spinal) cavities. The ventral cavity contains the thoracic cavity (superior mediastinum, pleural, and pericardial cavities) and abdominopelvic cavity (abdominal and pelvic cavities).

What are the nine abdominopelvic regions and four quadrants?

The 9 regions are Right hypochondriac, Epigastric, Left hypochondriac, Right lumbar, Umbilical, Left lumbar, Right iliac, Hypogastric, and Left iliac. The 4 quadrants are RUQ, LUQ, RLQ, and LLQ.

What is the structural difference between parietal and visceral serous membranes?

The parietal layer lines the walls of the body cavity, while the visceral layer covers the internal organs (viscera).

What are the three specific serous cavities in the body and their corresponding membranes?

Pleura (surrounds lungs in pleural cavity), Pericardium (surrounds heart in pericardial cavity), and Peritoneum (surrounds organs in abdominopelvic cavity).