Nutrition 132 (exam 1)

layers of digestive tract (innermost to outermost)

mucosa, submucosa, muscularis externa, serosa

gastric glands; gastric pits

the stomach contains ____ that empty their secretions into ____.

ileum

the longest part of the small intestine, and its contents empty into the first part of the large intestine

order food passes through the digestive tract

oral cavity, pharynx, esophagus, stomach, small intestine, large intestine

no

is the large intestine responsible for nearly chemical digestion and nutrition absorption

examples of accessory digestive organs

tongue, salivary glands

submucosa

layer of the gastrointestinal tract that is composed of loose connective tissue and interspersed blood vessels, lymphatic, a nerve plexus, glands

three

how many layers of smooth muscle does the muscularis externa contain

two

how many layers of smooth muscle are typically found in most parts the digestive tract

connective tissue

what is the serosa composed of?

inner oblique, middle circular, and the outer longitudinal

what are the three layers of smooth muscle in the muscularis externa? (innermost to outermost)

what is the submucosa?

connective tissue layer that connects muscularis to mucosa. it contains blood vessels, nerve fibers and lymphatics.

what is the mucosa composed of?

simple columnar epithelium, a connective tissue layer known as the lamina propria, and a smooth muscle layer called the muscularis mucosae

mucins (a component of mucus)

what do surface mucous in the epithelium secrete?

protect stomach lining and lubricate food for movement

functions of gastric mucus

regions of the small intestine

duodenum, jejunum, ileum

regions of large intestine

cecum, ascending colon, transverse colon, descending colon, sigmoid colon, rectum, anus

accessory digestive glands

pancreas, liver

what does amylase break down?

starches

if enzyme saturation has been reached in an experiment, adding more substrate will cause__?

no significant changes to the reaction

proteins

trypsin, chymotrypsin, and carboxypeptidase in pancreatic juices assist in the chemical breakdown of__?

how are hormones released

released into the interstitial fluid and passes to the bloodstream

the stomach

where in the digestive tract is salivary amylase inactivated due to pH change?

examples of endocrine glands

pituitary gland, thyroid gland, adrenal glands

what is a target cell

a cell that has a specific receptor for a hormone

hormone

a chemical that enters the blood and travels to eventually affect a target cell is called

produce hormones and are well vascularized

endocrine glands ____?

the presence of a receptor for that particular

what makes a cell a target of a particular hormone?

pH, substrate concentration, temperature

what have significant effects on the reaction rate of enzymes?

chemical classes of hormones

biogenic amine, steroid, peptide

mechanisms that hormones can affect

reproduction, metabolism, growth

parafollicular cells

what cellular component of the thyroid synthesizes and secrets the hormone calcitonin

outside (on the cell membrane)

are hormone receptors outside or inside the cell for proteins

inside

are hormone receptors outside or inside the cell for steroids

calcitonin; decreases

parafollicular cells produce ___, which ____ blood calcium concentration

acini; islets

the pancreas has functionally distinct regions: the ___that are exocrine in nature and the ____ that are endocrine in nature

beta cells

which cell type within the pancreatic islets secretes the hormone insulin

causing skeletal muscle and liver cells to uptake glucose

insulin lowers blood glucose levels by

thyroid hormones (T3 and T4)

what hormones are secreted in response to decrease body temperature

inhibit the enzyme thyroperoxidase and the conversion of T4 in peripheral tissues

how does propylthiouracil (PTU) affects the body?

delta cells

somatostatin

alpha cells

glucagon

ingestion

taking food into the body, involves no chemical change

digestion

breaking food down so it can be absorbed (using mechanical and chemical digestion)

social determinants of health

non-medical factors that influence health outcomes like:

• education access and quality

• health care access and quality

• neighborhood and built environment

• social and community context

• economic stability

Satiety

temporarily stops desire to eat

macronutrients

• provide calories (kcal)

• need in gram (g) quanitities

• examples: carbohydrates, proteins, lipids/fats

micronutrients

• do not provide energy (kcal)

• needing in miligram (mg) or microgram (mcg) quantities

• vitamins

• minerals

examples of carbohydrates

simple sugars (monosaccharides, disaccharides), complex carbohydrates (glycogen, starch, fiber)

carbohydrates (~4 kcal)

what macronutrients provide the most calories in our diet

lipids

• ~9kcal/g

• do not dissolve in water

• Animal fats

  • room temperature: solid

  • saturated fats

• Plant oils

  • Room temperature: liquid

  • heart healthy benefits

  • essential fatty acids

proteins

• ~4kcal/g

• main part of body structures

• part of blood cells, enzymes, and immune factors

• building blocks = amino acids

• Dietary sources

  • animals

  • plants

vitamins

• promote body’s chemical reactions

• organic compounds (carbon atoms)

• Fat-soluble:

  • A, D, E, and K

• Water-soluble

  • B vitamins and C

• cooking destroys water-soluble more readily than fat-soluble

• no useable energy/calories

Minerals

• inorganic substances (no carbon atoms)

• numerous functions in the body

• not destroyed during cooking

• major and trace minerals

• perform electrolyte functions

• no useable energy/calories

Water (H2O)

• solvent and lubricant

• transports nutrients and waste

• temperature regulation

• majority of body weight

• recommended intake is 9 to 14 cups/day

  • biological females: 11.5 cups/d

  • biological males:15.5 cups/d

• main source: fruits, vegetables

• no calories/energy

phytochemcials

“chemical” found in plants (fruits, vegetables) that can provide significant health benefits, and it is better absorbed through food rather than supplements

examples of phytochemicals

• carotenoids

• hesperetin

• anthocyanosides

• resveratrol

• sulforaphane

• lutein

• allyl sulfides

• flavonoids

• lycopene

• ellagic acid

the scientific method

make observations that generate questions → formulate hypotheses to explain events →review current scientific literature that relates to the questions → design, perform test, and collect data → analyze data and draw conclusions based on the results →share results with peers (report findings) → conduct more research to confirm or refute previous findings

cohort studies

• observational

• large groups of people

• prospectively (forward in time)

• retrospectively (backwards in time)

• studying exposure to certain risk factors for disease/cancer

case-control study

subjects with disease/condition compared to those without

cross-sectional study

• observational

• uses data from population group at one specific point in time

• based on particular variable of interest

case reports

• descriptive studies

• based on uncontrolled observations

• 1 patient = case

animal experiments

• animals

• study disease

• understand more about human disease

food security

occurs for a household when “all members, at all times ca access enough food for an active, health life.”

nutritional security

“All Americans have consistent and equitable access to health, safe affordable foods essential to optimal health and well-being

cirrhosis of liver

• occurrence:

  • affects 2 million people

  • 20% of cases of alcohol use disorders

  • 50% chance of death withing 4 years

• advances stages NOT reversible

• destruction of vital tissues regardless of diet

endocrine glands

the glands release their hormones directly in the bloodstream or interstitial fluid, they have no ducts, and the hormones travel distant target cells with the correct receptorse

exocrine glands

these glands release their hormones through ducts into an epithelial surface, either the skin or the lining of a body cavity or organ, these products act locally (near where they are secreted)

exocrine function of pancrease

release of digestive enzymes through pancreatic duct into the small intestine

endocrine function of pancreas

secrete insulin and glucagon into the blood

exocrine function of liver

secrete bile through ducts