U1T7 - Keywords Flashcards
Alimentary Canal
Part of the digestive system which forms a long hollow tube that runs from mouth to anus. Regionalised with highly adapted organs in specific regions.
Chyme
Mix of food and gastric juice.
Duodenum
First loop of the small intestine
Pyloric Sphincter
Ring of muscle situated immediately between the end of the stomach and the duodenum.
Muscularis Mucosa
Thin layer of muscle between mcosa and submucosa which helps movement of villi in mucosa. Keeps villi in contact with digestion products in gut lumen.
Serosa
Very thin outermost protective + supportive lining of connective tissue in alimentary canal. Supports AC as it’s connected to mesentery which is connected to peritoneum of abdominal cavity.
Mesentery
Fold of the peritoneum which attaches
stomach, small intestine, pancreas, spleen, and other organs to posterior wall of abdomen.
Peritoneum
Serous membrane lining cavity of abdomen + covering abdominal organs.
Serous
Serum-producing.
Goblet Cells
Mucus secreting cells within columnar epithelial cells.
Bile
Mixture of substances which aren’t all involved in digestion. Rich in bicarbonate which neutralises acid from stomach.
Bile Salts
Digestive compounds. Emulsify fats by reducing surface tension of fat, breaking into tiny fat droplets, facilitating lipase.
Crypts of Lieberkuhn
Deep folds in duodenum wall. Embedded in tissue between villi.
Brunner’s Glands
Secrete intestinal juice containing water, mucus + sodium hydrogen carbonate. Doesn’t contain enzymes but protects mucosa of duodenum from stomach acid.
Epidermis
Covers + protects leaf. First defence against physical damage.
Upper Epidermis
Consists of 1+ layer rectangular cells. Terrestrial plants have waxy cuticle for waterproofing to reduce surface water loss by transpiration. Thicker on upper surface (shiny). No chloroplasts, transparent so allows light.
Lower Epidermis
Has pores called stomata which allow CO2 + O2 to enter + H2O + O2 to exit. Stoma surrounded by guard cells to regulate open + close (close at night). GC’s have chloroplasts.
Vascular Tissue
Consists of veins adapted for transport around plant. Made of vascular bundles.
Vascular Bundles
Groups of vessels running from root up stem to leaves. Made up of xylem and phloem vessels.
Xylem
Forms upper part of vascular bundle in leaf. Brings water for photosynthesis and minerals (inorganic ions) to leaf.
Phloem Sleeve/Sieve-Tubes
Form lower part of vascular bundle in leaf. Transports sucrose (sugars) and other photosynthesis products from leaf to other parts of plant (translocation). Sucrose to plant storage regions (bulbs/tubers) + converted to starch or to actively growing regions for respiration.
Palisade Mesophyll
Main photosynthesising region of leaf. Beneath upper epidermis to max light harvesting. Palisade cells are regularly arranged + packed with chloroplasts to max photosynthesis.
Spongy Mesophyll
Beneath palisade mesophyll. Loosely packed, irregularly arranged cells. Air spaces for gaseous exchange. CO2 can diffuse up to palisade cells where photosynthesis occurs. Few chloroplasts. Large gas exchange surface.
Tissues
Groups of similar cells that work together to carry out the same function. e.g. mesophyll tissue, muscle tissue.
Organs
Several different types of tissue grouped together to form a structural unit which carries out one or more functions. e.g. leaf, ileum, stomach.
Organ Systems
A group of organs which work together to perform a function. e.g. digestive system (ileum, mouth, oesophagus, stomach, pancreas, liver _ colon)
Pinocytosis
Absorption of some substances. e.g. In babies, antibodies (proteins) pass from breast milk to blood system without being digested.
Venules
Small Vein
Villi
1mm projections of mucosa wall, each containing thousands of cells.
Microvilli
0.6um projections of cell-surface membrane of epithelial cells lining mucosa.
Specialised Cells
Adapted to carry out a particular function.
Cell
Smallest unit that can carry out all 7 life processes. e.g.muscle cell, goblet cell, guard cell.
Peristalsis
Involuntary contraction and relaxation of muscles of the intestine to push food forward.
Segmentation
Division of a cell, cleavage.
Pendular Movement
Swinging movement of intestine without peristaltic action, mixing food.
Smooth Muscle
Muscle tissue in which contractile fibrils aren’t highly ordered, not under voluntary control.
Arteriole
Small branch of artery leading into capillaries.
Petiole
The stalk that joins a leaf to a stem.
Midrib
Large strengthened vein along midline of leaf.
Waxy cuticle
Protective layer covering leaf, reduces water loss by transpiration/evaporation.
Metaxylem
Part of primary xylem which differentiates after protoxylem + is distinguished by broader tracheids + vessels with pitted/reticulate walls.
Protoxylem
First-formed xylem developing from procambium + consisting of narrow cells with annular, spiral, or scalariform wall thickenings.
Collenchyma
Tissue strengthened by thickening of cell walls, as in young shoots.