Anatomy and Physiology Lecture Review

Flashcards covering key vocabulary terms from the lecture notes on the hierarchy of life, anatomy, physiology, homeostasis, chemistry of life, cell structure and function, tissues, the skeletal system, bone anatomy, growth, repair, and diseases.

Hierarchy of life

Chemicals ͢ cells ͢ tissues ͢ organs ͢ organ systems ͢ 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 ranges (anatomical and physiological parameters like body temperature, blood glucose, etc.).

Homeostasis imbalance

Disruption of homeostasis, which 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).

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 a loss of balance in positive and negative charges.

Cations

Positively charged ions (e.g., Na+ - most abundant extracellular cation, K+ - most abundant intracellular cation) formed by losing an electron.

Anions

Negatively charged ions (e.g., Cl- - most abundant extracellular anion, H2PO4- - most abundant intracellular anion) formed by gaining an electron.

Acids

Proton (hydrogen ions (H+)) donors.

Bases

Proton acceptors that take up H+ (usually H+ + OH- = H2O neutralization).

Salts

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

pH scale

Measures how acidic or basic a substance is, ranging from 0 to 14, where 7 is neutral, less than 7 is acidic, and greater than 7 is basic. It is logarithmic.

Blood pH

Normally 7.35-7.45, meaning it is slightly basic.

Cell

The smallest unit of life.

Plasma membrane

A component of human cells, consisting of a phospholipid bilayer and membrane proteins.

Cytoplasm

A component of human cells, including cytosol (water with solutes like protein, salts, sugars) and cytoplasmic organelles.

Mitochondria

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

Nucleus

A component of human cells, containing the cell's genetic material.

Selective Permeability

A characteristic of the plasma membrane that allows only certain substances to pass through.

Na+-K+ ATPases (pumps)

Membrane proteins that actively pump Na+ out of the cell and K+ into the cell, maintaining concentration gradients.

Channel-Mediated Facilitated Diffusion

The passive movement of ions or water across the membrane through protein channels (leak or gated) in response to stimuli, without ATP.

Leak channels

Ion or water channels that are always open.

Gated channels

Ion or water channels controlled by chemical, mechanical, or electrical signals.

Osmosis

The movement of water from a dilute solution to a concentrated solution across a partly permeable membrane.

Ligand-Receptor Signaling

The primary method of cell communication, where ligands (e.g., neurotransmitters, hormones) bind to receptors to regulate cellular processes.

Channel-linked receptors

Plasma membrane receptors that, when bound by a ligand (like a neurotransmitter), allow ions into the cell.

Enzymatic receptors (Cell membrane)

Plasma membrane receptors that, when activated by a ligand, function as protein kinase enzymes to phosphorylate other proteins within the cell.

G Protein-Coupled Receptors

Plasma membrane receptors that indirectly activate protein kinase enzymes through second messengers in a chain reaction, leading to phosphorylation of other proteins.

Intracellular Receptors for Steroid Hormones

Receptors inside the cell that bind to steroid (lipid) hormones, which then enter the nuclei to directly activate genes.

Epithelial Tissue (Epithelium)

A primary tissue type characterized by polarity (apical and basal surfaces), closely packed cells, high regeneration rate, and being avascular but innervated. It includes covering and lining epithelia and glandular epithelia.

Apical surface

The upper, free surface of epithelial cells.

Basal surface

The lower surface of epithelial cells, attached to connective tissue.

Connective Tissue

A primary tissue type that provides supporting fabric for organs, functions in binding, support, storage, and insulation, and is characterized by a rich blood supply (with exceptions) and large amounts of intercellular material.

Vascularity of connective tissue

Connective tissue generally has a rich blood supply, though there are exceptions like cartilage.

Connective Tissue Proper

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

Areolar loose connective tissue

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

Regular dense connective tissue

A type of connective tissue proper that forms structures like ligaments, tendons, and aponeuroses.

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 that connect muscle to bone, similar to tendons.

Cartilage

A specialized connective tissue, including hyaline, elastic, and fibrocartilage, characterized by chondrocytes in lacunae within a matrix.

Hyaline cartilage

The most abundant type of cartilage, found in joints.

Chondrocyte

Mature cartilage cells located in lacunae within the cartilage matrix.

Fibro-

A prefix indicating 'fibrous' (e.g., fibroblast).

-blast

A suffix indicating an immature or budding cell (e.g., osteoblast, fibroblast).

-cyte

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

Organ Level

Two or more tissue types working together to perform a particular function.

Organ System Level

Groups of organs working together to carry out a specific function (e.g., integumentary, skeletal, muscular systems).

Organismal Level

All organ systems working together for the entire organism.

Cranial region

The region of the skull.

Cephalic region

The region of the head.

Cervical region

The region of the neck.

Thoracic region

Part of the torso superior to the thoracic diaphragm.

Abdominal region

The region between the thoracic and pelvic regions.

Pelvic region

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

Lumbar region

The inferior part of the back between the ribs and the pelvis.

Skeletal System Functions

Support, protection, movement, storage (phosphate, calcium, fats), and hematopoiesis.

Hematopoiesis

Blood cell formation, occurring only in red bone marrow.

Red Bone Marrow

The specific site for hematopoiesis (blood cell formation).

Inorganic bone composition

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

Organic bone composition

Approximately 35% of total bone mass, providing tensile strength and flexibility, composed of osteoid and cells.

Osteoid

The unmineralized organic matrix of bone, secreted by osteoblasts, composed of ground substance (proteoglycans, glycoproteins, interstitial fluid) and collagen fibers.

Osteoblasts

Bone-forming cells that manufacture and secrete osteoid.

Osteocytes

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

Osteoclasts

Bone-degrading cells responsible for bone resorption.

Osteogenic cells (osteoprogenitor cells)

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

Calcitriol (Vitamin D3)

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., all limbs except patella, wrist, and ankle).

Short Bones

Roughly cube-shaped bones (e.g., wrist, ankle).

Sesamoid Bone

A special type of short bone that forms within tendons (e.g., patella).

Flat bones

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

Irregular Bones

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

Wormian Bones

Tiny 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 between the epiphysis and diaphysis of a long bone.

Diaphysis

The shaft of a long bone, connecting the metaphyses.

Medullary (marrow) Cavity

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

Yellow Bone Marrow

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

Compact bone

Dense bone tissue found all around the periphery of bones, providing strength.

Spongy Bone

Porous bone tissue found inside compact bones, containing trabeculae and forming the foundation for red bone marrow.

Trabeculae

Porous, interconnected plates or bars of bone forming the structure of spongy bone, providing spaces for red bone marrow.

Periosteum

A double-layered membrane surrounding the external surface of a bone, containing an outer fibrous layer and an inner osteogenic layer with osteoblasts and osteoclasts.

Endosteum

A membrane lining the medullary cavity, covering trabeculae of spongy bone, and also containing osteoblasts and osteoclasts.

Osteon (Haversian System)

The structural unit of compact bone, consisting of elongated cylinders parallel to the long axis of the bone.

Lamella (compact bone)

Concentric rings of bone matrix within an osteon, with collagen fibers running in different directions for tensile strength (twister resistors).

Central (Haversian) canal

The canal located in the center of an osteon, containing blood vessels and nerves.

Lacunae

Small cavities or 'caves' within the bone matrix that house osteocytes.

Perforating (Volkmann’s) canals

Canals that run at right angles to the long axis of the bone, connecting the blood and nerve supply of the periosteum to the central canals of each osteon.

Canaliculi

Hairlike canals that connect lacunae to each other and to the central canal, allowing movement of nutrients and wastes between osteocytes.

Osteogenesis (Ossification)

The process of bone tissue and skeleton formation, beginning around 8 weeks gestational age.

Intramembranous Ossification (IO)

The process of bone formation from fibrous membranes, resulting in membrane bones (e.g., cranium bones, clavicle).

Endochondral Ossification (EO)

The process of bone formation where hyaline cartilage is replaced by bone tissue, resulting in cartilage or endochondral bones (e.g., almost all other bones).

Interstitial growth

The process of bone lengthening during infancy and youth, driven by the growth of epiphyseal plates.

Epiphyseal (growth) plates

Plates of hyaline cartilage in long bones where interstitial growth occurs, responsible for increasing bone length.