Chapters 33+34 quiz Flashcards
What are essential nutrients?
Nutrients required by cells that must be obtained from dietary sources
What does an animal’s diet provide?
- Chemical energy to convert to ATP
- Organic building blocks
- Essential nutrients
What are the 4 classes of essential nutrients?
- Amino Acids
- Essential fatty acids
- Vitamins
- Minerals
What are vitamins and how are they categorized?
Vitamins are organic molecules required in our diet in small amounts. There are fat and water soluble vitamins
What are minerals?
Simple inorganic nutrients usually required in small amounts
What is malnutrition?
The result of long-term absence from the diet of one or more essential nutrients
How are mineral deficiencies prevented?
Animals can consume salt, minerals, shells or stones
What is undernutrition?
The result of a diet that does not prevent enough chemical energy. An undernourished organism will burn it’s fat and eventually the rest of its body
What are the 4 stages of food processing?
ingestion, digestion, absorption and elimination
What is ingestion?
Eating or feeding
What is digestion?
The process of breaking food down into molecules small enough to absorb
What are the two types of digestion?
Chemical: Splits food into small molecules that can pass through membranes
Mechanical: Increases the surface area of food, includes chewing. Typically comes before chemical digestion
What is absorption?
The uptake of nutrients by body cells
What is elimination?
The passage of undigested material out of the digestive system
How do most animal conduct digestion and why?
In compartments to reduce the risk of digesting its own cells and tissues
What are the two types of digestion?
Intracellular: Food particles are engulfed by phagocytosis
Extracellular: Digestion of foods outside the cell
What is a gastrovascular cavity?
A cavity in animals with simple body plans that function in digestion and distribution of nutrients
What is an alimentary canal?
A part of the digestive tract of complex animals with a mouth and an anus with specialized regions that carry out digestion in a stepwise fashion
What is bioenergetics?
The flow and transformation of energy in an animal that determines its nutritional needs
What is metabolic rate?
An animal’s energy use per unit of time
How is metabolic rate determined?
Monitoring animal’s rate of heat loss, amount of O2 consumed or amount of CO2 produced
What is minimum, basal, and standard metabolic rate?
Minimum: The minimum metabolic rate for basic cell functions
Basal: Minimum metabolic rate of a nongrowing endotherm that is at rest, has an empty stomach, and is not experiencing stress
Standard: (BMR) The minimum metabolic rate of a fasting, nonstressed ectotherm at a particular temperature
What is the function of insulin and glucagon? Where are they produced?
To maintain glucose levels, they are produced in the pancreas
What makes insulin levels rise?
A carbohyrate-rich meal
How is glycogen synthesized?
Through glucose entering the liver
What happens with glucose concentrations are low?
Glucagon stimulates the liver to break down glycogen and release glucose into the blood
What is diabetes mellitus?
A diseased caused by deficiency of insulin or a decreased response to insulin in target tissues. Cells are unable to take up glucose to meet their metabolic needs and fat becomes the main substrate for cellular respiration
What are types 1 and 2 diabetes?
1: An autoimmune disorder where the immune system destroys the pancreatic beta cells
2: Diabetes characterized by a failure of target cells to respond normally to insulin
What causes diabetes?
Type 2 is hereditary, excess body weight and lack of exercise increase risk
Which mechanisms regulate appetite?
Ghrelin: Hormone secreted by stomach wall, triggers a feeling of hunger before meals
Insuline/PYY: Hormone secreted by the small intestine after eating, they suppress appetite
Leptin: A hormone produced by fat tissue, suppresses appetite and regulates body fat levels
How do enzymes in chemical digestion break things down?
Enzymatic hydrolysis
Which cells in the body use diffusion?
Small, nonpolar molecules use diffusion. It is only efficient over long distances
What decides diffusion time?
Diffusion time is proportional to the square of the distance traveled
What are gastrovascular cavities?
A cavity that some animals have instead of a circulatory system that functions in digestion and distribution of substances throughout the body
What is true about all circulatory systems?
They have circulatory fluid, a set of interconnecting vessels and a muscular pump(heart). They are all either open or closed
What is an open circulatory system?
Circulatory fluid bathes organs directly, there is no distinction between circulatory and interstitial fluid, making a general body fluid called hemolymph
What is a closed circulatory system?
The circulatory fluid called blood is confined to vessels and is distinct from
interstitial fluid. One or more hearts pumps blood through the vessels, chemical change occurs between blood, interstitial fluid, and body cells.
What circulatory system do human and other vertebrates have? How do they work?
A closed circulatory system called a cardiovascular system. The 3 main blood vessels are called arteries, veins and capillaries(blood flow is one way in these cells)
What are arteries?
Blood vessels that branch in arterioles once inside organs and carry blood away from the heart to the capillaries
What are capillary beds?
Networks of capillaries that are the site of exchange between blood and interstitial fluid
What are venules?
Venules converge into veins and return blood from the capillaries to the heart
What does blood enter and exit from in a heart?
Blood enters through an atrium and is pumped out by a ventricle
What is single circulation?
Circulation with a two-chambered heart where blood leaving the heart passes through two capillary beds before returning
What is double circulation?
Circulation where oxygen-poor and oxygen-rich blood is pumped separately from the left and right sides of the heart
What is the systemic circuit?
Oxygen-rich blood delivers oxygen through the systemic circuit
How does blood pressure compare in single and double and single circulation?
Double circulation maintains higher blood pressure in organs than single circulation
How does oxygen poor blood pick up oxygen?
Through the lungs(reptiles and mammals) and the lungs+skin(amphibians)
How is the heart of reptiles/amphibians typically structured?
3 Chambered: Ventricle pumps blood into a forked artery
How is the heart of mammals and birds usually structured?
4 chambered heart: 2 ventricles and atria, one side for O2 rich and O2 poor blood
What is the endothelium?
The epithelial layer that lines blood vessels, it’s smooth and minimizes blood flow resistance
Why do capillaries have thin walls?
To facilitate exchange of substances
How are the walls of arteries and veins different?
Arteries have thicker walls than veins to accommodate high pressure of blood pumped from heart
What influences blood flow? Where is the velocity of blood flow slowest?
Blood vessel diameter influences blood flow. Velocity is slowest in capillary beds as a result of high resistance and large cross-sectional area, and for exchange of materials
How does blood pressure influence blood flow?
Blood flows from high pressure to low pressure
What is systole and systolic pressure?
Systole is the contraction phase of the cardiac cycle. Pressure at the time of the ventricle contraction is called systolic pressure
What is diastole?
The relaxation phase of the cardiac cycle, always lowers than systolic pressure
What is vasoconstriction?
The contraction if smooth muscle in arteriole walls to increase blood pressure
What is vasodilation?
The relaxation of smooth muscles in arterioles to decrease blood pressure
What causes fainting?
Inadequate blood flow to the head
How does gravity affect blood pressure?
It causes a need for more systolic pressure to pump against it
What mechanisms alter blood flow in capillary beds?
- Vasoconstriction/vasodilation of the arteriole that supplies that bed
- Precapillary muscles that open and close to regulate blood flow
What is the lymphatic system?
A system that returns fluid called lymph that leaks out of capillary beds, it drains into the veins in the neck. The lymph vessels prevent backflow of fluid
What is partial pressure?
The pressure exerted by a particular gas in a mixture of gases
What causes gas to diffuse?
Gas always diffuses form high to low partial pressure
How does gas cross respiratory surfaces?
Diffusion
How are respiratory surfaces typically structured?
They tend to be large, thin, and always moist
What is ventilation?
The movement of the respiratory medium over the respiratory surface
What is a countercurrent exchange system?
A system used in fish gills where blood flows in the opposite direction to water passing over the gills, making the O2/CO2 exchange efficient
What is the tracheal system?
A system in insects that consists of a network of air tubes that branch throughout the body that can transport O2 or CO2
What is the structure of lungs? Which organisms use lungs?
Lungs are an infolding of the body surface, usually divided into numerous pockets. The circulatory system transport gases between lungs and the body. Vertebrates that lack gills use lungs
Where does air pass when a mammal breathes?
Air passes through the larynx, trachea, bronchi, and bronchioles to the alveoli(air sacs at tip of bronchioles) where gas exchange occurs
How are sounds created in mammals?
Air passes over the vocal chords
What are surfactants?
Secretions that coat the surface of the alveoli to prevent contamination
How does the respiratory system stay clean?
Cilia and mucus line the epithelium of air ducts and move particles up to the pharynx(the mucus escalator) where particles can be swallowed into the esophagus
Why do the lungs have sacs?
To increase surface area
How are hormones spread throughout the body?
The go into the interstitial fluid, then enter he circulatory system
How is hemolymph moved?
Heart contractions put in through he veins into spaces surrounding the organs, and relaxation draws it back in
What controls movement of fluid between capillaries and surrounding tissues?
- Blood pressure tends to drive fluid out of capillaries
2. Presence if blood proteins pulls fluid back
