BIOL II Exam2

What is Tetanus

sustained contraction due to multiple twitches that prevent fibers from relaxing

What are oxidative fibers

they rely on aerobic respiration, and are rich in myoglobin (can have slow and fast twitches)

What are glycolytic fibers

They rely on glycolysis, and use less myoglobin in a larger diameter (are only fast twitches)

What are fast-twitch fibers

They develop tension faster, re rapid and powerful, they require more sarcoplasmic reticulum

What re slow-twtich fibers

They develop tension slower, twitch last longer and require less sarcoplasmic reticulum

What is the difference between the endocrine and exocrine glands?

Endocrine glands: secrete hormones in the circulatory system (thyroid, pituitary, etc.)

Exocrine glands: secrete substances through ducts (Sweat glands)

Water vs lipid soluble hormones

Water: secreted by exocytosis and travel freely in the bloodstream to them bind to cell-surface receptors

lipid: diffuse across cell membranes, travel in the bloodstream bound to transport proteins, then diffuse through the membrane of target cells

Positive feedback of oxytocin

suckling stimulates neurons to the hypothalamus, hypothalamus releases oxytocin from pituitary gland, this stimulating more milk release

What is the hormone cascade

Hormones stimulating the release of other hormones(TSH releasing thyroid levels)

How do the hypothalamus and pituitary glands coordinate

Hypothalamus: controls most of the brains control center

Pituitary glands: act as the messenger

What hormones regulate blood glucose levels

Insulin which rises after a carbohydrate-rich meal glucagon which when glucose in concentrated stimulates glycogen breakdown

What is the negative feedback in blood glucose homeostatsis

When sugar rise, insulin is released-when sugar drops the pancreas realses glucagon

What is secretin

targets pancreatic cells and causes them to raise the pH in the duodenum

function of the thyroid gland

hormones control basal metabolic rate & regulate Ca

Function of epinephrine

secrete by adrenal glands that can raise blood glucose, increase air flow, and decrease blood flow in the digestive system

Where are insulin and glucagon produced, and by which specific cell types?

They are produced in the pancreas by Langerhans cells

Type 1 vs type 2 mellitus

type 1: autoimmune disorder that destroys the pancreatic beta cells

type 2: failure to target cells to response normally to insulin

Four essential classes of nutrients

Amino acids

Fatty acids

Vitamins

Minerals

Describe the four stages of food processing in animals.

Ingestion: eating or feeding

Digestion: Breaking down food into smaller molecules

Absorption: uptake of broken-down molecules

Elimination: removal of waste

What is the function of the enzyme amylase, and where is it secreted?

The function is to break down carbs and is found in the salivary glands

What is the role of the stomach in digestion

stores food and secrete gastric juice

How is the small intestine specialized for nutrient absorption

Pancreas secretes bicarbonate and digestive enzymes, the liver makes bile that is stores in the gallbladder

What is the function of bile, and where is it produced and stores

The liver and is stored in the gallbladder; the function is to digests and absorbs fats

Herbivore vs carnivore digestive systems

Carnivores: Have large explandable stomach and short digestive system

Herbivores: Have longe digestive systems

osmoregulators vs osmoconformers

Osmoregulator: Not Isoosmotic with surroundings; spend energy to control water gain/loss

Osmoconformer: Isoosmotic with surroundings; don’t regulate osmolarity

Advantages of secreting Ammonia Urea, and Uric Acid

Ammonia: take zero ATP and is highly soluble and dilutes directly into the surrounding water

Urea: Its less toxic than ammonnia, and land animals can store it in their bodies

Uric acid: least toxic, turns into a solid

disadvantages of secreting Ammonia Urea, and Uric Acid

Ammonia: Highly toxic and requires a lot of water

Urea:Need ATP and requires some water q

Uric Acid:Creating it is very complex and needs a lot of ATP

Filtration

Water & solutes cross membrane due to blood pressure; forms filtrate. Cells & large molecules don’t cross

Reabsorption

Returns substances from filtrate to body

Secretion

Nonessential solutes & waste move into filtrate

Excretion

Processed filtrate released as urine

How does the structure of the Loop of Henle contribute to water and salt conservation

Pumps salt out of the ascending limb into the kidneys and draws water out of the descending limb

What is the role of the antidiuretic hormone (ADH), and what effect does it have on the kidney

Makes the collecting duct more permeable to water and makes the kidneys to reabsorb water back into the bloodstream

How does the RAAS system respond to a drop in blood pressure? What hormones are involved?

Increases water & Na reabsorption and the adrenal gland are involved

How do desert-dwelling animals conserve water in their excretory systems?

They excrete hyperosmotic urin and have long loops of Henle

Describe the role of the collecting duct and how its permeability changes in response to hormonal signals

Reabsorption of water and ions

What is the functional significance of juxtamedullary nephrons compared to cortical nephrons in mammals

specialized for water conservation and urine concentration