Chapter 16 - Digestion Flashcards
digestion
the process of breaking down food by mechanical and enzymatic action in the alimentary canal into substances that can be used by the body
gallbladder
A small, pear-shaped organ on the right side of your abdomen, just beneath your liver. The gallbladder holds a digestive fluid called bile that’s released into your small intestine.
three parts of the small intestine
The small intestine consists of three parts.
The first part, called the duodenum, connects to the stomach.
The middle part is the jejunum.
The third part, called the ileum, attaches to the colon.
small intestine
an organ in the gastrointestinal tract where most of the absorption of nutrients from food takes place.
pancreatic duct
Also called “duct of Wirsung” or major pancreatic duct
It is a duct joining the pancreas to the common bile duct.
common bile duct (CBD)
A tube that carries bile from the liver and the gallbladder through the pancreas and into the duodenum (the upper part of the small intestine). It is formed where the ducts from the liver and gallbladder are joined.
cystic duct
a duct that connects the top of the gallbladder’s neck to the common hepatic duct
motility
(1) the quality or state of being motile (capable of movement)
(2) the ability of the muscles of the digestive tract to undergo contraction
seven mechanisms of the digestive system
ingestion of food
digestion of food
secretion of digestive juices
absorption of nutrients
movement of food through the digestive system (motility)
regulation of digestive processes
excretion of waste products (elimination)
four layers of the gastrointestinal tract
The digestive tract has been described as a tube that extends from the mouth to the anus. The wall of this digestive tube is fashioned of four layers of tissue. Although the same four tissue coats form every organ of the alimentary tract, their structure varies from organ to organ.
The four layers are:
1. Mucosa (innermost)
2. Submucosa
3. Muscularis
4. Serosa (outermost)
[The inside, or hollow space within the tube, is called the lumen.]
peristalsis
the involuntary constriction and relaxation of the muscles of the intestine or another canal, creating wave-like movements that push the contents of the canal forward
bolus
(1) a rounded mass: such as a large pill or a soft mass of chewed food
(2) a dose of a substance (such as a drug) given intravenously
segmentation (digestion)
It is what occurs when digestive reflexes cause a forward-and-backward movement within a single region of the GI tract; segmentation contractions assist in mixing food with digestive juices and helps continue the mechanical breakdown of larger food particles.
mechanics
(1) a branch of physical science that deals with energy and forces and their effect on bodies
(2) the practical application of mechanics to the design, construction, or operation of machines or tools
(3) mechanical or functional details or procedure
mechanical
- of or relating to machinery
- of or relating to artisans or machinists
- done as if by machine: seemingly uninfluenced by the mind or emotions: AUTOMATIC
- relating to, governed by, or in accordance with the principles of mechanics
- caused by, resulting from, or relating to a process that involves a purely physical as opposed to a chemical or biological change or process
- of or relating to technicalities or petty matters
mechanism
(1) a piece of machinery
(2) a process, technique, or system for achieving a result
(3) mechanical operation or action
(4) a doctrine that holds natural processes (as of life) to be mechanically determined and capable of complete explanation by the laws of physics and chemistry
(5) the fundamental processes involved in or responsible for an action, reaction, or other natural phenomenon
artisan
(1) a worker who practices a trade or handicraft: CRAFTSPERSON
(2) a person or company that produces something (such as cheese or wine) in limited quantities often using traditional methods —often used before another noun
technicality
a detail meaningful only to a specialist
handicraft
(1) manual skill
(2) an occupation requiring skill with the hands
(3) the articles fashioned by those engaged in handicraft
philtrum
the depression located between the upper lip and the nose
uvula
a fleshy extension at the back of the soft palate which hangs above the throat
frenulum (plural: frenula, frena)
a small fold of tissue that secures the motion of a mobile organ in the body (e.g. the membrane that attaches the tongue to the floor of the mouth)
diminutive
(1) one that is notably small
(2) a root word that has been modified to convey a slighter degree of its root meaning, to convey the smallness of the object or quality named, or to convey a sense of intimacy or endearment (e.g. Charlie from Charles, duckling from duck, darling from dear)
endearment
a word or an act (such as a caress) expressing affection
crown (teeth)
the portion of the tooth that is exposed and visible in the mouth
three layers of the tooth
The hard outer layer is called enamel. It is the hardest substance in the body.
The middle layer is called dentin. It is harder than bone but softer than enamel.
The center of the tooth is called the pulp. It contains nerves and blood vessels.
cementum
A connective tissue that forms along a tooth’s root and helps solidify it by connecting to fibers that support the tooth’s place in the jawbone. It is like enamel but softer. Cementum also functions to cover the tooth’s dentin.
root (tooth)
The part of the tooth that descends below the gum line, into the upper or lower jawbones, anchoring the tooth in the mouth. Different types of teeth have a different number of roots and root formations. Typically incisors, canines and premolars will have one root whereas molars will have two or three.
neck (tooth)
The part of the tooth between the root and the crown, surrounded by the gums.
three levels of the tooth
Crown on the top, neck in the middle, root on the bottom.
gingiva
another word for the gums
gingivitis
A form of gum disease that happens when plaque builds up on teeth and causes the inflammation of the surrounding gum tissue. If left untreated it will lead to periodontitis.
plaque (teeth)
A sticky film of bacteria that constantly forms on teeth. Bacteria in plaque produce acids after you eat or drink. These acids can destroy tooth enamel and cause cavities and gingivitis (gum disease).
Plaque can also develop under the gums on tooth roots and break down the bones that support teeth.
Untreated plaque can harden into tough-to-remove tartar.
tartar
It is hardened plaque.
It forms at, underneath, and above the gumline and can irritate gum tissues. Because tartar on teeth gives plaque more surface area to grow on and a much stickier surface to adhere to, it can lead to cavities and gum disease.
periodontal ligament (PDL)
Also called the periodontal membrane.
It is the fleshy tissue between the tooth and the tooth socket that holds the tooth in place and enables it to resist the stresses of chewing. It inserts into root cementum on one side and onto alveolar bone on the other.
periodontitis
a severe form of gum disease that causes gum tissue to recede, bone to wear away, teeth to loosen, and teeth to eventually fall out
periodontium
The specialized tissues that both surround and support the teeth, maintaining them in the maxillary and mandibular bones; it consists of four principal components, namely:
- gingiva
- periodontal ligament (PDL)
- cementum
- alveolar bone proper
maxilla vs mandible
The maxilla in vertebrates is the upper fixed bone of the jaw formed from the fusion of two maxillary bones. The mandible (lower jaw or jawbone) is the largest, strongest, and lowest bone in the human face. It forms the lower jaw and holds the lower teeth in place. It is the only movable bone of the skull (discounting the ossicles of the middle ear). It is connected to the temporal bones by the temporomandibular joints.
temporomandibular joints
The two joints that connect your lower jaw to your skull. More specifically, they are the joints that slide and rotate in front of each ear, and consist of the mandible (the lower jaw) and the temporal bone (the side and base of the skull).
temporal bone
Two major bones in the skull. They help form the sides and base of the skull, where they protect the temporal lobe of the brain and surround the ear canal.
dental caries
Also called tooth decay.
It is damage to a tooth that can happen when decay-causing bacteria in your mouth make acids that attack the tooth’s surface, or enamel. This can lead to a small hole in a tooth, called a cavity. If tooth decay is not treated, it can cause pain, infection, and even tooth loss.
baby bottle tooth decay
Also called early childhood caries. It is severe tooth decay in baby teeth.
four types of teeth
- Incisors (central and lateral)
- Canines or cuspids
- Premolars or bicuspids
- Molars or tricuspids