Anatomy and physiology- Exocrine and Alimentary systems Flashcards
Name the digestive organs in order that food is processed?
The mouth
Pharynx (where have you heard this before?)
Oesophagus
Stomach
Small intestine
Large intestine
Rectum
Anus
What is Peristalsis?
Food is moved through the digestive tract by muscular contractions called peristalsis
what is the function of the flexible temporomandibular joint,
Allows the jaw to move in several directions: from side to side, up and down and backwards and forwards.
what is the The pharynx?
The pharynx (throat) is a channel for both air and food. Its upper parts connect with the nose and mouth: the lower parts connect with the larynx (voice box) and leads into the oesophagus for swallowing
what is the The oesophagus?
The oesophagus is a thick-walled tube consisting of layers of longitudinal and circular muscle fibres, which runs between the pharynx and the stomach
what is the stomach?
The stomach is an elastic sac that forms the widest part of the digestive tract
what is the stomach made up of
Serosa, a membranous coating on the outer surface
Layers of longitudinal, circular and oblique muscles
Submucosa, composed of loose connective tissue
Mucosa, the inner membrane containing cells that produce mucous, acid, digestive enzymes and hormone
What is it called where the oesophagus joins the stomach
Where the oesophagus joins the stomach, a muscular area known as the lower oesophageal sphincter controls the entry of food. At the exit from the stomach, another area of muscle, the pyloric sphincter, opens and closes to allow food to move into the duodenum.
what are gastric folds?
The gastric folds (or gastric rugae) are coiled sections of tissue that exist in the mucosal and submucosal layers of the stomach and allow for expansion of the stomach after the consumption of foods and liquid.
what are gastric pits?
Gastric pits are indentations in the stomach mucosa which indicate the entrances to tubular shaped gastric glands – these glands secrete gastric juice and protective mucus.
what are the different gastric gland cell types?
1.Mucous cells
2.Chief cells
3. Parietal cell
Where are Mucous cells found and what is their function?
Found in the upper section of the gland and secrete mucus to protect the lining of the stomach from the highly acidic environment.
what is the function of Chief cells?
Secrete pepsinogen (when activated breakdown polypeptides from proteins into smaller into smaller peptides) and gastric lipase (helps with the breakdown ingested fats and lipids).
what is the function of Parietal cells?
Parietal cell: secrete hydrochloric acid (aids in digestion of ingested proteins) and intrinsic factor (enquired for the absorption of vitamin B12).
what is the mesentery?
The mesentery is found in your abdomen, where it surrounds your intestines. It comes from the area on the back side of your abdomen where your aorta branches off to another large artery called the superior mesenteric artery. This is sometimes referred to as the root region of the mesentery. The mesentery fans out from this root region to various locations throughout your abdomen.
what are the functions of the mesentery?
- The mesentery attaches your intestines to the wall of your abdomen. This keeps your intestines in place, preventing it from collapsing down into your pelvic area.
- The mesentery also contains lymph nodes that contain several types of immune cells and can trap pathogens, such as viruses and bacteria. Lymph nodes in the mesentery can sample bacteria from your intestines and generate an immune response when necessary.
- The mesentery can also produce a protein called C-reactive protein (CRP), an immune surveillance molecule that can activate the immune system.
What are the three sections of the small intestine
The small intestine has three sections: the duodenum, jejunum and ileum
what is the duodenum?
The duodenum is a short, curved tube attached to the stomach that receives secretions from the liver and pancreas
what is the long coiled section of the small intestine called?
The long-coiled jejunum which is joined to the duodenum
what is the main role of the ileum?
The main role of the ileum, the final and longest section of the small intestine, is to complete the absorption of nutrients from digested food passed along from the other two sections.
what is a lacteal?
Lacteal: is a lymphatic capillary that absorbs dietary fats in the villi of the small intestines. They merge to form larger lymphatic vessels that transport chyle (a milky fluid containing fat droplets) to the thoracic duct where it is emptied into the blood stream.
what are microvilli?
Microvilli: The microscopic microvilli effectively increase the surface area of the cell (and therefore small intestine) allowing more area for nutrients to be absorbed.
Label the large intestine from start to finish.
- Appendix
- Cecum
- Ascending Colon
- Transverse Colon
- Descending Colon
- Sigmoid Colon
- Rectum
- Anus
what are The taenia coli?
The taenia coli are three bands of longitudinal smooth muscle on the colon surface, they function as suspension cables upon which the circular muscle arcs are suspended, facilitating efficient contraction of the circular muscle.
what are the two major organs that are both exocrine and endocrine glands
The liver and pancreas
what are the three exocrine methods of secretion?
Merocrine secretion
Holocrine secretion
Apocrine secretion
what is merocrine secretion?
cells excrete their substances by exocytosis (materials are exported out of the living cell).
what is Holocrine secretion?
The entire cell disintegrates to excrete its substance.
What is Apocrine secretion?
A portion of the cell membrane that contains the excretion buds off.
what are the three pairs of salivary glands?
Parotid
Sublingual
Submandibular
What are parotid glands?
The parotid glands are the largest pair of salivary glands and are located in front of the ear on either side of the face and have a duct that opens inside the cheek.
what are submandibular glands?
The submandibular glands are located deep in the floor of the mouth on each side of the jaw bone. These glands’ ducts open into small swellings on the underside of the tongue, next to the central fold.
what is the sublingual gland?
The sublingual gland is located at the front of the mouth just under the tongue; these are the smallest salivary glands. Their ducts open into the floor of the mouth
what enzyme does saliva contain?
Saliva contains a digestive enzyme called amylase
what are the enzymes made by the pancreas?
Pancreatic proteases
Pancreatic amylase
Pancreatic lipase
what is the function of Pancreatic proteases (such as trypsin and chymotrypsin)?
To help digest proteins
what is the function of Pancreatic amylase?
To help digest sugars (Carbohydrates)
what is the function of Pancreatic lipase?
to help digest fat
What two substances does the pancreas secrete?
digestive juice
sodium bicarbonate to neutralize stomach acid
what is the Major duodenal papilla?
The major duodenal papilla is a rounded projection at the opening of the common bile duct and main pancreatic duct into the duodenum. The major duodenal papilla is the main area for the secretion of bile and pancreatic enzymes that facilitate digestion.
what is the Sphincter of Oddi?
The sphincter of Oddi refers to the smooth muscle that surrounds the end portion of the common bile duct and pancreatic duct. This muscle relaxes during a meal to allow bile and pancreatic juice to flow into the intestine.
what is The minor duodenal papilla?
The opening of the accessory pancreatic duct into the duodenum. The accessory pancreatic duct is an embryological remnant and most people have just one main pancreatic duct, however in a small majority of people the accessory pancreatic duct still drains the pancreas.
what is the function of the gallbladder?
The gall bladder and network of ducts carrying bile form the biliary system. Bile is a greenish-brown fluid that is partly a waste product of the liver’s chemical processes, but it also plays a vital part in the digestion of fats.
How many lobes does the liver have and what ligament divides it?
It is divided by the falciform ligament into two lobes
what are Liver lobule?
Small hexagonal structures of the liver (functional units of the liver – like nephrons of the kidney).
What are the cells of the liver called?
hepatocytes
what produces bile?
Hepatocytes produce bile, which is transported by separate vessels to the bile ducts.
what are the three main types of enzymes involve in digestion?
Amylase – this breaks down carbohydrate into sugars
Protease – this digests protein into amino acids
Lipase – this converts fats (lipids) into fatty acids
Explain Simple diffusion in terms of digestion
Fat is absorbed by a process called simple diffusion and is able freely pass through the plasma membrane. Once fatty acids are absorbed into the cell, they then rebuild into the type of fat needed. They are then further transported via the lymph system as chylomicrons (small fat globules composed of protein and lipid).
Explain osmosis in terms of digestion
Osmosis is the movement of water (through the cell membrane) from a low concentrated solution to a high concentrated solution. Osmosis is passive transport, meaning it does not require energy to be applied.
Explain Facilitated diffusion in terms of digestion
Simple sugars are absorbed in a process called facilitated diffusion. Nutrients are carried across the cell membrane by specific carrier molecules that then free them once inside the cell.
Explain Active transport in terms of digestion
Large molecules like amino acids need energy for their absorption in a process known as active transport. Molecules outside the cell pick up nutrients and work against a concentration to move inside the cell where the nutrient is released. The energy required for active transport of nutrients varies, depending on the type of nutrient and its size.
Name the stages of digestion from start to finish
Ingestion
Propulsion
Mechanical digestion (breakdown)
Chemical digestion (breakdown)
Absorption
Defecation
Name 5 functions of the liver
Filtration.
Digestion.
Metabolism and Detoxification.
Protein synthesis.
Storage of vitamins and minerals.
Briefly describe the blood flow to and from the liver
The liver receives a blood supply from two sources. The first is the hepatic artery which delivers oxygenated blood from the general circulation. The second is the hepatic portal vein delivering deoxygenated blood from the small intestine containing nutrients.
Briefly describe the lining of the small intestine, what makes the lining so well suited to its function of absorption
The lining of the small intestinal mucosa is very highly specialized for maximizing digestion and absorption of nutrients. The lining is highly folded to form microscopic finger-like projections called villi which increase the surface area to help with absorption.
Where in the body would you find ‘Eccrine glands’?
Eccrine sweat glands are simple, coiled, tubular glands present throughout the body, most numerously on the soles of the feet
What is the name of the acid contained within the stomach
Gastric acid which is made of hydrochloric acid.
