Week 2 - Cells and Tissue

A set of vocabulary flashcards covering the cellular level of organisation, transport mechanisms, cell division, cell death, and the four primary tissue types based on human anatomy and physiology lecture notes.

Cell biology

The scientific study of cells.

Plasma membrane

The outer boundary of the cell that regulates the movement of substances in and out.

Cytoplasm

Contains cytosol and organelles that carry out many cellular functions.

Nucleus

Contains the cell's DNA and controls many cellular activities.

Prokaryotic cells

Cells that lack a true nucleus and membrane-bound organelles, typically smaller with circular DNA, such as bacteria.

Eukaryotic cells

Larger, complex cells with a true nucleus, linear chromosomes, and membrane-bound organelles, such as human, animal, and plant cells.

Mitochondria

Organelles that produce ATP and generate cellular energy.

Ribosomes

The site of protein synthesis within the cell.

Golgi apparatus

An organelle that modifies, packages, and transports proteins.

Rough endoplasmic reticulum

A network involved in synthesising and transporting proteins.

Smooth endoplasmic reticulum

A network involved in synthesising lipids and detoxifying chemicals.

Lysosomes

Organelles containing digestive enzymes that break down wastes and damaged cell parts.

Amphipathic

A term describing molecules, like membrane lipids, that contain both hydrophilic and hydrophobic regions.

Cholesterol

A lipid that makes up about $20\%$ of the plasma membrane and helps maintain membrane stability.

Glycocalyx

The carbohydrate chains of glycoproteins and glycolipids that help cells recognise each other and support cell adhesion.

Integral proteins

Membrane proteins embedded within the lipid bilayer that often span the membrane.

Peripheral proteins

Proteins loosely attached to the inner or outer surface of the plasma membrane.

Ligand

A specific molecule that binds to a receptor to alter a cell's function.

Passive transport

Transport across the plasma membrane that does not require cellular energy, moving substances down their concentration gradient.

Simple diffusion

Movement of molecules directly through the lipid bilayer, such as oxygen and carbon dioxide.

Osmosis

The diffusion of water across a selectively permeable membrane.

Primary active transport

The movement of substances across the membrane using energy directly from ATP, such as transporting $Na^+$ or $K^+$ ions.

Tetrodotoxin

A venom found in the blue-ringed octopus that blocks sodium ion channels in nerve cell membranes, leading to paralysis.

Crenation

The shrinkage of cells that occurs when they are placed in a hypertonic solution.

Mitosis

Division of the nucleus in somatic cell division, resulting in two genetically identical daughter cells.

Cytokinesis

The process of cytoplasmic division during cell reproduction.

Meiosis

Reproductive cell division that produces four genetically distinct haploid gametes, each with $23$ chromosomes.

Necrosis

Uncontrolled or traumatic cell death where the cell lyses and releases contents, causing an inflammatory response.

Apoptosis

A highly controlled process of programmed cell death where the cell shrinks and the membrane blebs off.

Free radicals

Unstable molecules with unpaired electrons that can damage lipids, proteins, and nucleic acids.

Antioxidants

Substances like Vitamin E, Vitamin C, and zinc that neutralise free radicals to reduce cellular damage.

Tissue

A collection of similar cells that together carry out a specific function.

Epithelial tissue

Tissue consisting of tightly packed cells in sheets, serving as boundaries; it is avascular but innervated.

Endocrine glands

Ductless glands that secrete hormones directly into the bloodstream to control long-term activity.

Exocrine glands

Glands with ducts that release secretions like sweat, enzymes, or sebum onto internal organs or external surfaces.

Connective tissue

The most abundant tissue type which binds, supports, and strengthens other tissues; it consists of widely spaced cells and an extracellular matrix.

Extracellular matrix (ECM)

The material between cells and protein fibres, such as collagen, that allows connective tissue to bear weight and withstand tension.

Areolar connective tissue

A widely distributed loose connective tissue called the 'packing material' of the body, providing strength and elasticity.

Adipose tissue

Loose connective tissue specialised for the storage of triglycerides (fats) to reduce heat loss and serve as energy reserves.

Hyaline cartilage

The most abundant, bluish-white cartilage in the body that provides smooth surfaces for joint movement.

Skeletal muscle tissue

Voluntary, striated muscle tissue attached to bones by tendons for motion and posture.

Cardiac muscle tissue

Involuntary, branched, striated tissue found in the heart wall, containing intercalated discs for quick signal conduction.

Smooth muscle tissue

Involuntary, nonstriated, spindle-shaped cells found in the walls of hollow internal structures like blood vessels and intestines.

Neurons

The principal cells of nervous tissue responsible for responding to stimuli and transmitting electrical impulses.