Test 4 (chp 40-43) Flashcards
Homeostasis:
The steady state physiological condition of the body
Internal balance
Maintaining a relatively constant internal environment even when the external environment changes significantly
Positive Homeostasis/Feedback:
Triggers mechanisms that amplifies the stimulus
Enhances changes to enable a system to move away from its equilibrium state and cause it to be more unstable
EX: child birth, clotting, lactation
Longer situation; overtime
Negative Homeostasis/Feedback:
A response that reduces, or “damps,” the stimulus
Buffers change to allow a system to stay at an equilibrium and cause it to be more stable
EX: body temperature, heart rate, breathing rate, blood pressure, etc…
Immediate situations
Epithelial Tissue
Covers the outside of the body for protection,lines organs and cavities within the body, and absorption/secretion
EX: cuboidal epithelium, simple columnar epithelium, pseudostratified ciliated columnar epithelium, stratified squamous epithelium, and simple squamous
Connective Tissue
Binds/supports other tissues in the body; secrete extracellular substance
EX: loose connective tissue, tendons/ligaments, cartilage, adipose tissue, blood, bone, and fibrous connective tissue
Muscle Tissue
Responsible for all types of body movement
EX: skeletal (aka striated)-attached to bones, cardia -heart, and smooth-blood vessels/digestive organs/reproductive organs
Nervous Tissue
Sense stimuli and transmit signals in the form of nerve impulses from one part of the animal to another
EX: Neurons (nerve cells), supporting cells
mouth enzymes
Salivary amylase
An enzyme in saliva, hydrolyzes starch and glycogen into smaller polysaccharides into disaccharide in the oral cavity (if starch-it breaks down into maltose)
esophagus enzymes
none
stomach enzymes
Pepsinogen and HCl
Pepsinogen=a protease, or protein-digesting enzyme in the stomach
Both breaks proteins down to large polypeptides to smaller polypeptides
small intestine enzymes from the small intestine
Occurs in the duodenum
From the sm. intestine: Disaccharidases-Breaks down disaccharides into monosaccharides
Dipeptidase/Carboxypeptidases-Breaks smaller polypeptides into amino acids
Nucleosidare-Breaks down into nitrogen base, sugar, and phosphates
Bicarbonate-Neutralizes the acidity of chyme and acts as a buffer in the small intestine
insulin/glucagon homeostasis
The hormones insulin and glucagon maintain glucose homeostasis by tightly regulating glycogen synthesis and breakdown
function of oral cavity
Mechanical digestion begins as teeth break down the food and increases the foods surface area
Chemical Digestion due to salivary Glands
Secretes saliva into the mouth to being chemical digestion of carbohydrates in the oral cavity
function of pharynx
No digestion
Opens to two passageways: the esophagus and the trachea
The epiglottis prevents food from traveling down the trachea
function of esophagus
Connects the oral cavity to the mouth
Peristalsis occurs to transport the food
function of the stomach
Primarily stores food and continues digestion
Chemical digestion due to the secretions of digestive fluid called gastric juice and then mechanical digestion due to the mixing and muscle contraction that mixes the secretion with the food through a churning action
Breaks down proteins with the help of pepsin
function of the small intestine
Enzymatic hydrolysis of macromolecules
Three Parts:
Duodenum (first 25cm)-Chemical Digestion: Chyme that came from the stomach mixes with digestive juices from the pancreas, liver, and gallbladder, as well as from the gland cells of the intestinal wall itself
Jejunum/Ileum: Absorption of nutrients and water and puts it into the bloodstream
function of large intestine
Absorption of H20
Vitamin production (vitamin K but some E coli)
Includes the colon, cecum, and rectum
Colon: Recover water that has entered the alimentary canal as the solvent of digestive juices
Cecum: Important for fermenting ingested material
Appendix extends from the cecum
Rectum: Where feces are stored before they are eliminated