Human Body Organization, Regulatory, Transport, Energy, Excretion, and Support Systems

Vocabulary flashcards generated from the text covering levels of body organization, central and peripheral nervous systems, endocrine glands and hormones, cardiovascular and respiratory circulation, digestive and urinary mechanics, and musculoskeletal divisions.

Macromolecules

Essential complex structures formed by combined molecules in the human body, which include carbohydrates, lipids, proteins, and nucleic acids.

Cellular Level

The organizational level made up of cells, which are the smallest and most abundant structural units of living matter, with the human body containing approximately 100 trillion cells.

Tissue

A collection of numerous cells that share structural characteristics and perform similar functions.

Organ

A structure composed of various types of tissues organized to perform a specific function within the organism.

Anatomy

The branch of medicine derived from Greek words meaning 'to dissect' that focuses on studying body structures and their relationships.

Microscopic Anatomy

Subdivision of anatomy enabled by the microscope that studies structures invisible to the human eye, including cells (cytology) and tissues (histology).

Anatomical Position

Standard body reference position where the body is upright and standing, arms extended at the sides, palms facing forward, and head and feet facing forward.

Sagittal Plane

A longitudinal plane extending from front to back that divides the body or any part into right and left portions, also called the mid-sagittal plane.

Frontal Plane

A longitudinal plane extending from side to side that divides the body into anterior and posterior portions, also called the coronal plane.

Transverse Plane

A horizontal plane that separates the body into upper and lower portions.

Physiology

The scientific discipline studying the functions of living organisms and their components across various levels and systems.

Homeostasis

The relative stability and equilibrium maintained in the body's internal liquid environment, a concept described by Claude Bernard.

Negative Feedback System

An inhibitory control mechanism that opposes change by responding in a direction contrary to the initial alteration to stabilize physiological variables.

Positive Feedback System

A stimulatory control mechanism that tends to amplify or reinforce an ongoing change, such as oxytocin secretion during labor.

Multipolar Neurons

Neurons possessing a single axon and multiple dendrites that integrate information and drive impulses to motor pathways.

Encephalon

Component of the central nervous system protected by the skull that processes information and generates commands; composed of the cerebrum, cerebellum, and brainstem.

Brainstem

Structure connecting the brain with the spinal cord that regulates vital automatic functions and reflexes; composed of the midbrain, medulla oblongata, and protuberance.

Cerebellum

Structure located at the back of the head that maintains balance, motor coordination, movement control, and learned motor tasks.

Hypothalamus

Diencephalon structure responsible for regulating vital functions including temperature, hunger, thirst, sleep, and endocrine system hormones.

Somatic Nervous System

Functional division of the peripheral nervous system that regulates skeletal muscles and voluntary movements using sensory and motor nerves.

Sympathetic Nervous System

Subdivision of the autonomic nervous system that activates the body in stressful situations by accelerating heart rate and respiration.

Parasympathetic Nervous System

Subdivision of the autonomic nervous system that aids body relaxation and energy recovery by lowering heart rate and promoting digestion.

Hormones

Chemical messengers secreted by endocrine glands into the bloodstream that regulate physiological processes at target or white organs.

Insulin

Hormone generated by the pancreas that regulates blood glucose levels.

Major Circulation

Systemic circulation that carries oxygenated blood from the left ventricle through the aortic artery to the body and returns carbon dioxide blood via the vena cava to the right atrium.

Minor Circulation

Pulmonary circulation that carries deoxygenated blood from the right ventricle via the pulmonary artery to the lungs for gas exchange and returns to the left atrium via pulmonary veins.

Alveoli

The smallest structures in the respiratory system where oxygen is transferred into blood and carbon dioxide is removed.

Small Intestine

An abdominal digestive tube measuring up to $6\,m$ long comprising the duodenum ($25\,cm$), jejunum ($2.5\,m$), and ileum ($3.5\,m$), lined with microvilli for nutrient absorption.

Peristalsis

Specialized muscular movement in hollow organs of the digestive system that breaks down, digests, and propels food.

Pancreatic Juice

A mixture of baking soda and enzymes produced by the pancreas to degrade carbohydrates, fats, and proteins in the small intestine.

Kidneys

Urinary system organs that filter blood, produce urine to eliminate wastes, and reabsorb useful substances such as electrolytes.

Hematopoiesis

The production process of blood cells occurring in the bone marrow of long bones like the femur.

Axial Skeleton

Skeleton portion consisting of the cranium, spinal column, and rib cage that protects the brain, lungs, heart, and spinal cord.

Appendicular Skeleton

Skeleton portion consisting of the clavicular waist, pelvic waist, arms, and legs that enables limb movement and stability.