Introduction to Anatomy, Physiology, and Homeostasis

Flashcards covering definitions, organ systems, anatomical directions and cavities, and homeostatic mechanisms from the lecture notes.

How does anatomy differ from physiology?

Anatomy describes the physical structures of the body (what they are made of, where they are located, and associated structures), whereas physiology is the study of the functions of anatomical structures.

What is the main distinction between gross anatomy and microscopic anatomy?

Gross (macroscopic) anatomy examines large structures visible with the unaided eye, while microscopic anatomy examines cells and molecules.

What are the two major subdivisions of microscopic anatomy?

Cytology, which is the study of cells, and histology, which is the examination of tissues.

In a clinical evaluation, what is the difference between a sign and a symptom?

A sign is an objective observation (such as a fever), whereas a symptom is a subjective experience reported by the patient (such as tiredness).

What are the six 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 organism level.

How many organ systems are present in the human body?

Humans have 11 organ systems.

What are the major functions of the integumentary system?

It protects against environmental hazards, helps regulate body temperature, and provides sensory information.

What are the primary functions of the skeletal system?

It provides support and protection for other tissues, stores calcium and other minerals, and forms blood cells.

What are the primary functions of the muscular system?

It provides movement, provides protection and support for other tissues, and generates heat that maintains body temperature.

How do the nervous system and endocrine system differ in their regulation of other organ systems?

The nervous system directs immediate responses to stimuli and coordinates rapid, short-term activities, whereas the endocrine system directs long-term changes and adjusts metabolic activity and energy use.

What are the primary functions of the respiratory system?

It delivers air to alveoli (sites in lungs where gas exchange occurs), provides oxygen to the bloodstream, removes carbon dioxide from the bloodstream, and produces sounds for communication.

What is the standard anatomical position?

A stance where the hands are at the sides with the palms facing forward, and the feet are together.

What is the difference between supine and prone positions?

Supine describes a person lying down in the anatomical position face up, whereas prone describes a person lying down face down.

What do the directional terms proximal and distal mean?

Proximal means toward the point of attachment of a limb to the trunk, while distal means away from the point of attachment of a limb to the trunk.

How do frontal, sagittal, and transverse planes divide the body?

A frontal (coronal) plane divides the body into anterior and posterior portions; a sagittal plane divides it into right and left portions; and a transverse plane divides it into superior and inferior portions.

What is the difference between a midsagittal plane and a parasagittal plane?

A midsagittal plane passes through the midline to separate the body into equal right and left sides, whereas a parasagittal plane misses the midline and separates it into unequal right and left sides.

Which structure divides the ventral body cavity into thoracic and abdominopelvic cavities?

The diaphragm.

What are the two layers of a serous membrane and what are their roles?

The parietal layer lines the inner surface of the body cavity wall, and the visceral layer covers the internal organs (viscera).

What anatomical cavities are located within the thoracic cavity?

The right and left pleural cavities (surrounding each lung) and the mediastinum (containing blood vessels, trachea, esophagus, thymus, and the pericardial cavity surrounding the heart).

Which organs are located in the retroperitoneal space?

The pancreas, kidneys, ureters, and parts of the digestive tract.

What is the difference between autoregulation and extrinsic regulation in homeostasis?

Autoregulation (intrinsic) is an automatic local cell, tissue, or organ response to an environmental change, while extrinsic regulation results from activities of the nervous system or endocrine system.

What three components make up a homeostatic regulatory mechanism?

A receptor (receives the stimulus), a control center (processes the signal and sends instructions), and an effector (carries out instructions).

How does a negative feedback mechanism maintain homeostasis?

The response of the effector negates or opposes the original stimulus, bringing the internal condition back within normal range.

How does a positive feedback mechanism function, and what is an example?

An initial stimulus produces a response that amplifies or reinforces the original change, moving the body away from normal range to complete a process quickly; an example is blood clotting.

What temperature threshold values trigger thermoregulatory responses in the human body?

The hypothalamus acts as a thermostat with a set point of $37 modern^\times 10^0 = 37\,^\circ\text{C}$; heat loss responses are triggered if body temperature exceeds $37.2\,^\circ\text{C}$, and heat generation responses occur if it falls below $36.7\,^\circ\text{C}$.