Cell Biology, Tissues, and the Skeletal System Practice Flashcards

Comprehensive vocabulary flashcards covering cell structure, cell division, tissues, nervous system conduction, and the human skeletal system based on the lecture notes.

Prokaryotes

Organisms including Bacteria and archaea which are unicellular (1 cell).

Eukaryotes

Organisms including Animals, plants, fungi, and protists which contain a nucleus and membrane-bound organelles.

Cell membrane

A structure made of a phospholipid bilayer with embedded proteins that controls what goes in and out and allows cell communication through receptors.

Cytoplasm

A jelly-like substance (cytosol) that contains all organelles, maintains homeostasis, and is the site of many metabolic/chemical reactions.

Nucleus

Organelle that controls the cell's activities, stores DNA in the form of chromosomes or chromatin, and regulates cell growth and division.

Nucleolus

The site within the nucleus that produces RNA and is involved in stress sensing.

Centrosome

Structure containing a pair of centrioles that organizes microtubules and forms the mitotic spindle during mitosis.

Mitochondria

The site of cellular respiration which produces ATP.

Ribosomes

Structures made of rRNA and proteins that perform protein synthesis by translating mRNA into proteins.

Rough ER

A direct continuation of the nucleus covered with ribosomes that provides mechanical support, divides cytoplasm into compartments, and synthesizes secretory proteins.

Smooth ER

A network of membranous tubules that synthesizes phospholipids, sterols, and other lipids, and is involved in detoxification and storing calcium.

Golgi apparatus

Organelle that modifies, sorts, and packages proteins and lipids, and forms secretory vesicles and lysosomes.

Lysosome

A sac containing digestive enzymes that digests damaged organelles, breaks down waste materials, and destroys bacteria.

Vacuole

A storage sac used for storing water and nutrients.

Peroxisome

Organelle that breaks down fatty acids and detoxifies harmful substances, converting hydrogen peroxide into water and oxygen.

Interphase

Phase of the cell cycle comprising G1 (growth), S (DNA replication), and G2 (preparation for mitosis).

Prophase

Initial stage of mitosis where chromatin condenses into chromosomes, the nuclear membrane dissolves, and spindle fibers begin to form.

Metaphase

Stage of mitosis where chromosomes line up at the center (equator) of the cell and spindle fibers attach to centromeres.

Anaphase

Stage of mitosis where sister chromatids separate and are pulled toward opposite poles as the cell elongates.

Telophase

Final stage of mitosis where the nuclear envelope reforms, chromosomes return to chromatin, and the nucleolus reappears.

Cytokinesis

The division of the cytoplasm resulting in two genetically identical daughter cells.

Tissue

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

Simple epithelium

A single layer of closely packed cells (squamous, cuboidal, or columnar) involved in diffusion, filtration, absorption, and secretion.

Transitional Epithelium

Multiple layers of cells that change shape when stretched, located in the urinary bladder and ureters.

Stratified epithelium

Two or more layers of cells, such as in the skin or oral cavity, designed to protect underlying tissues from friction and abrasion.

Connective Proper tissue

Tissue with cells scattered in an extracellular matrix (ECM) including loose and dense connective tissue, found under skin and around organs.

Contractility

The ability of muscle tissue to shorten to produce force and movement.

Neurons

Nerve cells that receive, process, and transmit nerve impulses.

Glial cells (neuroglia)

Cells that do not transmit impulses but support and protect neurons, supply nutrients, and form the myelin sheath.

Myelin sheath

A fatty insulating layer surrounding the axon to protect it and speed up impulse transmission.

Synapse

The tiny gap between two nerve cells where signals cross using neurotransmitters.

Sensory neurons

Neurons that carry messages from the sense organs to the brain and spinal cord (CNS).

Interneurons

Neurons found only in the brain and spinal cord that connect sensory and motor neurons.

Motor neurons

Neurons that carry messages from the CNS to muscles or glands.

Polarization (resting potential)

The state where a neuron is not sending a signal, with an inside charge of approximately $-70\,mV$.

Depolarization

The stage where a stimulus opens sodium channels, Na+ rushes in, and the membrane potential reaches a threshold of approximately $-55\,mV$ to trigger an action potential.

Repolarization

The stage after an action potential where sodium channels close and potassium channels open, making the inside negative again.

Compact bone

The hard, dense outer layer of bone that provides strength and protection.

Spongy bone

The lighter inner layer of bone filled with tiny holes and containing bone marrow.

Osteoblasts

Cells responsible for building and forming new bone.

Osteoclasts

Cells responsible for breaking down and absorbing old bone.

Osteocytes

Mature cells that maintain the bone matrix.

C1 (Atlas)

The first cervical vertebra that supports the skull and allows the "yes" movement.

C2 (Axis)

The second cervical vertebra which has the dens and allows the "no" movement.

True ribs

Rib pairs 1-7 that attach directly to the sternum through their own costal cartilage.

Floating ribs

Rib pairs 11-12 which do not attach to the sternum and only attach to the thoracic vertebrae.

Clavicle

A long, S-shaped bone that holds the arm away from the chest and connects the arm to the trunk.

Scapula

A flat triangular bone on the upper back that articulates with the humerus to form the glenohumeral joint.

Humerus

The bone of the upper arm featuring a head, greater tubercle, deltoid tuberosity, capitulum, and trochlea.

Acetabulum

A cavity in the pelvis that articulates with the head of the femur to form the hip joint.

Femur

The longest and strongest bone in the body, which forms the hip and knee joints.

Patella

The kneecap, which articulates with the patellar surface of the femur.

Tibia

The shin bone that bears upper body weight and features the medial malleolus.

Fibula

The smaller bone of the lower leg featuring a head, neck, and lateral malleolus.

Talus

The tarsal bone that articulates with the tibia and fibula to form the ankle joint.

Calcaneus

The heel bone and largest tarsal.