Week 2 - Cells and Tissues Flashcards
Cell
A cell is the smallest living unit in the human body.
Similar cells combine to create tissues
Somatic Cell
Contains the Nucleus Plasma Membrane and Cytoplasm
Intracellular
INTRACELLULAR refers to the inside of the cell
EXTRACELLULAR refers to the outside of the cell
Plasma Membrane
The physical barrier between INTRACELLULAR and EXTRACELLULAR regulates the exchange of substances between them.
Made of a PHOSPHOLIPID bilayer which consists of two HYDROPHOBIC chains linked to HYDROPHILIC phosphate heads.
Plasma Membrane Proteins
INTEGRAL PROTEINS, are large proteins that span the entire thickness of the membrane
PERIPHERAL PROTEINS are small and found on the membrane’s inner or outer surface.
Cytoplasm
Contains cytosol, the liquid that fills the cell, and organelles
Mitochondria
The MITOCHONDRIA is the powerhouse of the cell. It produces ATP, the energy for the cell. Scattered in cytoplasm
Smooth Endoplasmic Reticulum
The SMOOTH ENDOPLASMIC RETICULUM (SER) produces fats and steroid hormones
Ribosomes
RIBOSOMES make protein for the cell’s use. Attached to the RER or floating freely
Rough Endoplasmic Reticulum
The ROUGH ENDOPLASMIC RETICULUM (RER) is involved in protein production for export from the cell
Golgi Apparatus
The GOLGI APPARATUS modifies sorts and packages proteins for secretion
Peroxisomes
PEROXISOMES break down fatty acids
Secretory Vesicle
The SECRETORY VESICLE stores molecules and proteins from the ENDOPLASMIC RETICULUM and GOLGI APPARATUS until they are ready to be released
Lysosome
LYSOSOMES are involved in digestion and waste removal
Centriole
The CENTRIOLES help with cell division
Microtubile
The MICROTUBULE is part of the CYTOSKELETON. They play a structural role in maintaining shape and act as a belt transporting organelles, chromosomes etc. throughout the cell
Nucleus
The NUCLEUS is the control centre containing DNA or genetic material that codes every protein the cell produces
MICROVILLI
The MICROVILLI increases membrane surface area
Nucleic Acids
Two types of NUCLEIC ACIDS; deoxyribonucleic acid, or DNA, and ribonucleic acid, or RNA
DNA
DNA is made up of two strands of nucleotide molecules arranged in a helix structure. The nucleotides in DNA are adenine, cytosine, guanine, and thymine.
RNA
RNA is the template that is produced by DNA to inform the ribosomes which amino acids to add to the polypeptide chain of the protein. RNA contains only one strand of nucleotides and thymine is replaced with uracil in RNA.
Genes
GENES are sections of DNA strands that specify the amino acids that are required to make a specific protein.
Transcription
TRANSCRIPTION is the conversion of DNA to MESSENGER RNA (mRNA) in the nucleus.
Translation
Ribosomes read instructions in mRNA and make proteins using amino acids.
Proteins are packaged and ready for release
Mitotic Phase
The period when cells actively split the replicated DNA and organelles into two new cells.
G0 Phase
The phase in which cells, such as neurons, skeletal muscle and cardiac muscle, permanently cease dividing.
Interphase
Cellular organelles double in number, the DNA replicates, and protein synthesis occurs.
Prophase
Chromosomes become condensed, the nucleolus disappears, the centrioles move to opposite ends of the nucleus, and a MITOTIC SPINDLE begins to form.
Prometaphase
The NUCLEAR ENVELOPE disappears.
Metaphase
Chromosomes line up along the metaphase plate, or the equator of the spindle.
Anaphase
The chromosomes separate and move towards the poles of the cell.
Telophase
The chromosomes have reached opposite poles of the cell and the nuclear envelope begins to form around them. The nucleoli start to reappear and the spindle breaks down.
Passive transport
PASSIVE TRANSPORT requires no energy as it moves along with the concentration gradient
Active Transport
ACTIVE TRANSPORT requires energy using ATP to transport against the concentration gradient
Diffusion
DIFFUSION is a form of passive transport involving a substance moving down the concentration gradient, from an area of higher concentration to lower concentration.
Simple Diffusion
Non-polar, lipid soluble and plasma membrane compatible substances diffuse directly across the plasma membrane down a concentration gradient.
Carrier mediated facilitated diffusion
Diffusion in which specific ions or molecules are carried across the plasma membrane by integral proteins, called CARRIERS, in the plasma membrane.
This can be active (if against the concentration gradient) or passive (if with the concentration gradient).
Osmosis
OSMOSIS is the diffusion of a solvent, such as water, through a SELECTIVELY PERMEABLE MEMBRANE. The solvent moves from areas of high amounts of solvent to low amounts of solvent to balance it out.
Endocytosis
ENDOCYTOSIS is the process of transporting substances from the extracellular fluid to inside the cell, with vesicles forming at the plasma membrane.
Channels
CHANNELS are transmembrane proteins able to transport substances across the membrane that can otherwise not cross the lipid layers.
LIGAND-GATED channels (requiring a specific chemical to bind to its receptor)
MECHANICALLY GATED channels (requiring pressure or other mechanical force)
VOLTAGE-GATED channels (requiring a change in membrane potential to open).
Exocytosis
EXOCYTOSIS is the process of transporting substances from inside the cell to the extracellular fluid.
Epithelial Tissue
EPITHELIAL TISSUE consists of epithelial cells covering exposed surfaces of the body. They are AVASCULAR, containing no blood cells and therefore receive nutrients through diffusion or absorption
Squamos Cells
SQUAMOUS CELLS are thin and flat.
SIMPLE SQUAMOUS EPITHELIUM has a thin structure and smooth surface allowing for easy passage for diffusion or exchange. found in blood vessels and cavities.
STRATIFIED SQUAMOUS EPITHELIUM protects from abrasion, which allows the top layer of cells to be damaged without damaging underlying tissue. Found on the skin and in the mouth.
Cuboid Cells
CUBOID CELLS are short and square.
SIMPLE CUBOIDAL secretes substances. Lined along ducts and glands.
STRATIFIED CUBOIDAL is rare, found along ducts of sweat and mammary glands
Columnar Cells
COLUMNAR CELLS are tall and thin.
SIMPLE COLUMNAR EPITHELIUM is involved in secretion and absorption with enough space to store substances waiting for secretion or absorption.
STRATIFIED COLUMNAR EPITHELIUM is rare
Found lining large ducts of the pancreas or salivary glands.
PSEUDOSTRATIFIED COLUMNAR EPITHELIUM lines the respiratory tract.
It appears stratified but all cells connect to the basement membrane
Transitional Epithelium
TRANSITIONAL EPITHELIUM can stretch and recoil. Found lining the bladder, as the bladder fills, the epithelial cells flatten, and then recoil when empty
Cilia
Found on the respiratory epithelium. Contain filaments to help them move.
Connective Tissue
Fills internal spaces and provides structural support.
Stores energy and transports materials within the body.
Consists of specialised cells, ground substance and extracellular protein fibres such as reticular, elastic, and collagen fibres.
Connective Tissue Proper
Includes connective tissue with many types of cells and extracellular fibres in a ground substance.
LOOSE CONNECTIVE TISSUE PROPER has an open mesh type structure and includes adipose tissue, which stores fat.
DENSE CONNECTIVE TISSUE PROPER has a more condensed structure where the fibres are densely packed, and includes the ligaments.
Fluid Connective Tissue
FLUID CONNECTIVE TISSUE consists of blood (cardiovascular system) and lymph (lymphatic system).
Supporting Connective Tissue
SUPPORTING CONNECTIVE TISSUE includes bone and cartilage. It has a less diverse cell population and a matrix containing densely packed fibres. Protects soft tissues and supports the weight of the body.
Muscle Tissue
MUSCLE TISSUE is specialised in contraction
SKELETAL MUSCLE is involved in voluntary movement
CARDIAC MUSCLE is in the heart and gives contractility to its walls
SMOOTH MUSCLE is incorporated into the walls of organs, regulating the organ and function
