Lecture Review

Flashcards covering key vocabulary terms and definitions from the lecture notes on hierarchical organization of life, homeostasis, fundamental chemistry, cell structure and transport, cell signaling, tissue types (epithelial, connective), bone anatomy, physiology, growth, remodeling, joints, and common skeletal/joint disorders.

Hierarchy of life

Chemicals organize to form Cells, which form Tissues, which form Organs, which form Organ Systems, ultimately forming an Organism.

Anatomy

The study of the structure of a living organism.

Physiology

The study of how living organisms function.

Complementary of structure and function

Structures are designed to carry out a specific function, and vice versa.

Homeostasis

The body’s need and ability to maintain its internal environment within certain anatomical and physiological ranges (e.g., body temperature, blood glucose).

Homeostasis imbalance

A disruption of homeostasis that results in disease.

Negative feedback

A common homeostatic control mechanism where the output of the system shuts off the original stimulus, maintaining a set point (e.g., a thermostat).

Positive feedback

A homeostatic mechanism where the response exaggerates the original stimulation, accelerating the activity (e.g., platelet aggregation, uterine contractions).

Atoms

Electrically neutral particles composed of sub-atomic particles: neutrons, protons, and electrons.

Neutrons

Sub-atomic particles with no charge.

Protons

Sub-atomic particles with a positive charge.

Electrons

Sub-atomic particles with a negative charge.

Ions

Charged particles formed when electrons are transferred between atoms, causing an imbalance of positive and negative charges.

Cations

Positively charged ions (loses an electron), like Na+ (most abundant extracellular) and K+ (most abundant intracellular).

Anions

Negatively charged ions (gains an electron), like Cl- (most abundant extracellular) and H2PO4- (most abundant intracellular).

Acids

Proton (hydrogen ion, H+) donors.

Bases

Proton acceptors that take up H+ (neutralizing with OH- to form H2O).

Salts

Ionic compounds containing cations other than H+ and anions other than the hydroxyl ion (OH-).

pH scale

A logarithmic scale ranging from 0 to 14 that measures how acidic or basic a substance is.

Cell

The smallest unit of life, composed of three main parts: plasma membrane, cytoplasm, and nucleus.

Plasma membrane

A phospholipid bilayer with membrane proteins that surrounds the cell.

Cytoplasm

Consists of cytosol (water with solutes) and cytoplasmic organelles.

Cytosol

The watery component of the cytoplasm, containing solutes like proteins, salts, and sugars.

Mitochondria

Cytoplasmic organelles often referred to as the 'powerhouses' of the cell.

Nucleus

A main part of human cells that contains genetic material.

Selective Permeability

The property of the plasma membrane that allows only certain substances to pass through.

Membrane Transport

The movement of substances across the plasma membrane.

Channel-Mediated Facilitated Diffusion

A passive process where ions or water move across the membrane through protein channels, requiring no ATP.

Leak channels

Ion channels that are always open, allowing continuous passage (resting, no stimuli).

Gated channels

Ion channels controlled by chemical, mechanical, or electrical signals, opening in response to stimuli.

Na+-K+ ATPases (pumps)

Active transport proteins that maintain the concentration gradients of Na+ (higher outside) and K+ (higher inside) across the cell membrane, requiring ATP.

Active processes

Membrane transport mechanisms that require energy (e.g., ATP) to move substances, such as Na+-K+ ATPases.

Passive processes

Membrane transport mechanisms that do not require cellular energy (ATP), such as diffusion and osmosis.

Osmosis

The movement of water from a dilute solution (high water concentration) to a concentrated solution (low water concentration) across a partly permeable membrane.

Ligand-Receptor Signaling

The process by which most cell communication occurs through ligands binding to specific receptors.

Ligands

Signaling molecules (e.g., neurotransmitters, hormones) that bind to cell receptors to regulate cellular processes.

Channel-linked receptors

Plasma membrane receptors that, when bound by a ligand (e.g., neurotransmitter), open an ion channel, allowing ions into the cell.

Enzymatic receptors

Plasma membrane receptors that are intracellular protein kinase enzymes, activated by ligand binding to phosphorylate other proteins within the cell.

G protein-coupled receptors

Plasma membrane receptors that indirectly activate protein kinase enzymes through secondary messengers, initiating a chain reaction within the cell.

Intracellular receptors

Receptors located inside the cell (e.g., in the cytoplasm or nucleus) that bind to lipid-soluble ligands like steroid hormones.

Steroid Hormones

Lipid hormones that can enter cells and bind to intracellular receptors, then activate genes directly within the nucleus.

Epithelial Tissue (Epithelium)

One of the four primary tissue types, characterized by closely packed, polar cells with high regeneration rates, avascularity, and innervation, serving as covering/lining or glandular tissue.

Covering and lining epithelia

Epithelial tissue found on external and internal surfaces of the body.

Glandular epithelia

Epithelial tissue specialized for secretion, forming the secretory tissue in glands.

Apical surface

The upper, free surface of an epithelial cell.

Basal surface

The lower, attached surface of an epithelial cell, bound to connective tissue.

Connective Tissue

One of the four primary tissue types, providing supporting fabric for organs, with functions including binding, support, storage, and insulation, characterized by rich blood supply and widely spaced cells in an intercellular matrix.

CT Proper (true)

Subcategories of connective tissue including loose (reticular, areolar, adipose) and dense (regular, irregular, elastic) types.

Cartilage

A specialized connective tissue type, including hyaline, elastic, and fibro- varieties, providing support and cushioning.

Bone

A specialized connective tissue type that forms the skeletal framework, providing support, protection, and storage.

Adipose tissue

A type of loose connective tissue proper specialized for fat storage.

Areolar loose connective tissue

A common type of loose connective tissue proper found as part of the skin and forming membranes that cover organs.

Regular dense connective tissue

A type of dense connective tissue proper that forms structures like ligaments, tendons, and aponeuroses, with collagen fibers arranged in parallel.

Irregular dense connective tissue

A type of dense connective tissue proper with collagen fibers arranged in an irregular pattern, providing strength in multiple directions.

Ligaments

Fibrous connective tissue that connects bone to bone.

Tendons

Fibrous connective tissue that connects muscle to bone.

Aponeuroses

Wide sheets of fibrous connective tissue, similar to tendons, that connect muscle to bone or muscle to muscle.

Hyaline cartilage

The most abundant type of cartilage, found in joints, characterized by chondrocytes in lacunae within a clear matrix.

Elastic cartilage

A type of cartilage containing elastic fibers in its matrix, providing flexibility (e.g., ear, epiglottis).

Fibrocartilage

A type of cartilage containing collagen fibers in its matrix, providing high tensile strength and compression resistance, found in joints and intervertebral discs.

Chondrocyte

Mature cartilage cells located within lacunae.

Matrix (cartilage)

The extracellular material of cartilage that surrounds chondrocytes, providing its physical properties.

Lacuna

A small space or cavity within the cartilage matrix or bone, where chondrocytes or osteocytes are housed.

Organ Level

A level of organization where two or more tissue types work together to perform a particular function.

Organ System Level

A level of organization where groups of organs work together to carry out a major function for the body.

Organismal Level

The highest level of organization, where all organ systems work together to ensure the survival and function of the entire organism.

-blast

A suffix indicating budding, immature, or formative cells (e.g., osteoblast, chondroblast).

-cyte

A suffix indicating a mature cell (e.g., osteocyte, chondrocyte).

Cranial

Pertaining to the skull region of the body.

Cephalic

Pertaining to the head region of the body.

Cervical

Pertaining to the neck region of the body.

Thoracic

Pertaining to the part of the torso superior to the thoracic diaphragm.

Abdominal

Pertaining to the region between the thoracic and pelvic regions of the torso.

Pelvic

Pertaining to the region inferior to the pelvic brim of the hip bones.

Lumbar

Pertaining to the inferior part of the back, between the ribs and the pelvis.

Skeletal System

The organ system composed of bones, cartilages, and ligaments, providing support, protection, movement, storage, and hematopoiesis.

Hematopoiesis

The process of blood cell formation, which occurs in red bone marrow.

Red Bone Marrow

Tissue responsible for hematopoiesis (blood cell formation), found within spongy bone.

Inorganic components of bones

Approximately 65% of total bone mass, primarily mineral salts like calcium phosphate, responsible for hardness and resistance to compression.

Organic components of bones

Approximately 35% of total bone mass, including osteoid (ground substance and collagen fibers) and bone cells, providing tensile strength and flexibility.

Osteoid

The unmineralized organic matrix of bone, made and secreted by osteoblasts, composed of ground substance and collagen fibers.

Osteoblasts

Bone-forming cells that manufacture and secrete bone tissue (osteoid).

Osteocytes

Mature bone cells that maintain the bone matrix and act as stress or strain sensors.

Osteoclasts

Large, multinucleated cells that resorb or degrade bone tissue.

Osteogenic cells (osteoprogenitor cells)

Actively mitotic stem cells found in the periosteum and endosteum that can differentiate into osteoblasts.

Vitamin D3 (calcitriol)

The active form of vitamin D, which stimulates the absorption of calcium ions from the small intestine into the blood.

Long Bones

Bones that are longer than they are wide, with two enlarged ends (e.g., limb bones, except patella, wrist, and ankle).

Short Bones

Bones that are roughly cube-shaped (e.g., wrist, ankle bones), including sesamoid bones.

Sesamoid Bone

A special type of short bone found embedded within tendons (e.g., patella/kneecap).

Flat Bones

Thin, flat, and usually curved bones (e.g., sternum, scapula, ribs, skull bones).

Irregular Bones

Bones with complex, irregular shapes that do not fit into other classification categories (e.g., vertebrae, hip bones, some skull bones).

Wormian Bones

Tiny, irregular bone pebbles found at the junction between cranial bones, within suture joints.

Epiphysis

The expanded ends of long bones, covered with articular cartilage at the joint surface.

Metaphysis

The region of a long bone located between the epiphysis and the diaphysis.

Diaphysis

The shaft or main body of a long bone, connecting the metaphyses.

Medullary (marrow) Cavity

The space inside the diaphysis of a long bone, filled with yellow bone marrow.

Yellow Bone Marrow

Bone marrow primarily composed of fat, found in the medullary cavity of long bones.

Compact bone

Dense, outer layer of bone found around the periphery of the bone, composed of structural units called osteons.

Spongy Bone

Porous bone tissue found inside compact bones, containing trabeculae and red bone marrow for hematopoiesis.

Trabeculae

Needle-like or flat pieces of bone that form a porous network within spongy bone.