Cells And Tissues Flashcards
Prokaryotic
Sing cell organisms-lack nucleus, hereditary material in cytoplasm, no organelles, cell wall and capsule
Eukaryotes
Multi cellular organisms-nucleus (karyon) with DNA, extensive organelles
The plasma membrane
Defines boundaries, interactions with other cells, controls the flow of substances; selectively permeable, maintains cellular homeostasis, made up of lipids and proteins, fluid mosaic
Receptors located on the plasma membrane
Determine cell responses, define cell function
The nucleus
Control centre-contains DNA and in the nucleolus-RNA
Endoplasmic reticulum
Component productio/assembly line
Smooth ER
Lipid synthesis
Rough ER
Protein synthesis
Golgi complex
Assembly and packaging-carbohydrate modification packaging-modifying and sorting proteins into vesicles
Mitochondrion
Energy production-site of ATP synthesis
Lysosomes
Recycle centre-contains enzymes, breaks down small foodstuffs destroys unwanted proteins and chemicals
Secretory granules
Container transport-contains a product to be released into the circulation. Granules bind to plasma membrane and their contents are released by exocytosis
Epithelia
Layers of closely bound cells, covering internal and external surfaces-protective/barrier, control absorption and secretion-GI tract
Simple
One layer
Simple squamous epithelial cells are found where?
Blood vessels, alveoli exchange of nutrients and gases-flat surface cells one later thick
Stratified squamous
Flat surface cells, many layers, protection/barrier found in oral cavity, anus, vagina, Oesophagus, skin
Keratinised stratified squamous
Flat surface cells, many layers-protection, barrier (waterproofing) found-skin, hair, footpads of animals
Simple cuboidal epithelium
One layer-secretion and absorption found in glands, kidney tubules
Simple columnar epithelium
Tall cells with nasally located nuclei-one layer-absorption and secretion found in gastrointestinal tract
Modified simple columnar epithelium
Tall cells with basally located nuclei, one layer-surface modifications e.g microvilli function absorption & secretion found in the gastrointestinal tract
Complex columnar epithelium
Appear stratified -all cells touch basement membrane (Cillia & goblet cells) functions micocillary escalator found in trachea and large respiratory airways