Week 3 Digestive System Flashcards
GASTROINTESTINAL TRACT ORGANS
Mouth Throat Oesophagus Stomach Large Intestine Small Intestine Rectum Anus
ACCESSORY ORGANS
ACCESSORY ORGANS are the SALIVARY GLANDS, the PANCREAS, the LIVER, and the GALLBLADDER
MOUTH
The GASTROINTESTINAL TRACT starts at the MOUTH with mastication (chewing) breaking food into smaller pieces. It also releases some enzymes to start carbohydrate digestion
secretes mucus
PHARYNX/THROAT and OESOPHAGUS
The PHARYNX/THROAT and OESOPHAGUS swallow and transport food from the mouth to the stomach
secretes mucus
STOMACH
The STOMACH begins digestion by releasing acid and mixing food
secretes gastric juice containing HCl pepsin and mucus
SMALL INTESTINE
The SMALL INTESTINE is made of the duodenum, jejunum and ileum, the majority of digestion and absorption occurs
secretes mucus salt enzymes
bile duct
The bile duct is a tube that carries bile from the liver and gallbladder, through the pancreas, and into the small intestine.
LARGE INTESTINE
The LARGE INTESTINE, or colon, absorbs the last of the water and salt and converts the luminal contents into faeces which end up in the rectum and anus
secretes mucus
MOTILITY
MOTILITY refers to muscular contractions that mix and move food along the digestive tract. Movements can be propulsive, such as peristalsis, or mixing, such as segmentation
SECRETION
EXOCRINE & ENDOCRINE GLANDS
SECRETION includes both exocrine and endocrine functions in both the gastrointestinal tract and accessory organs.
EXOCRINE glands secrete their substances through ducts into the body’s surfaces. ENDOCRINE glands secrete their substances directly into the bloodstream
DIGESTION
DIGESTION breaks down the three macromolecules; protein, carbohydrate and fat. Occurs via hydrolysis
hydrolysis
where a molecule is split into two by adding molecules of water via the catalytic actions of enzymes
ABSORPTION
ABSORPTION absorbs digestion end products with water and electrolytes to transfer to blood and lymph. Primarily occurs in the small intestine
BASIC STRUCTURE OF THE WALL OF THE GASTROINTESTINAL TRACT
Mucosa: MUCOUS MEMBRANE
LAMINA PROPRIA: LYMPHOID TISSUE
MUSCULARIS MUCOSA
THE SUBMUCOSA
MUSCULARIS EXTERNA:
INNER CIRCULAR LAYER
LONGITUDINAL LAYER SEROSA
MUCOSA
THE MUCOSA consists of the MUCOUS MEMBRANE, a protective barrier of epithelial tissue containing specialised cells for absorption or secretion.
LAMINA PROPRIA
LAMINA PROPRIA is a thin middle layer of connective tissue containing tiny blood vessels and LYMPHOID TISSUE
MUSCULARIS MUCOSA
MUSCULARIS MUCOSA is a very thin layer of smooth muscle that upon contraction can expose different areas of surface folding
THE SUBMUCOSA
THE SUBMUCOSA is a thick layer of connective tissue which gives elasticity and contains larger blood and lymph vessels and a nerve network