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93 Cards in this Set

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  • Back
Why is homeostatic regulation important to humans?
Homeostatic prevents changes in the body's internal environment that could prevent physiological systems from working properly.
What happens to the body when homeostasis breaks down?
When homeostasis breaks down, organ systems cannot perform their functions and disease or death may occur.
Why is positive feedback helpful in blood clotting, but unsuitable for the regulation of body temperature?
Positive feedback increases any change from the desired condition, so it is helpful in situations that need to be resolved quickly (such as a bleeding wound) but it would be dangerous for the regulation of body temperature. If a slight fever occured, the body temperature would continue to rise quickly into dangerous levels.
The study of the structure of tissue is called...
The increasingly forceful labor contractions during childbirth are an example of...
positive feedback
Failure of homeostatic regulation in the body results in...
Define anatomy
Anatomy is the study of the internal and external structures and the relationships between body parts.
Define physiology
Physiology is the study of how organisms perform their vital functions.
What distinguishes autoregulation from extrinsic regulation?
Autoregulation is more local. Cells, tissues, organs, or organ systems change automatically in response to environmental change. Extrinsic regulation is controlled by the nervous or endocrine system and results in more extensive responses.
Which is NOT an example of negative feedback?
A rise in estrogen during the menstrual cycle increases the number of progesterone receptors in the uterus.
A hormone is released in response to increased levels of calcium in the blood. This is controlled by negative feedback. What happens to the calcium levels?
They lower.
On a warm day your body temperature is 1.5 degrees below normal. Why?
Hormones may have decreased the metabolic rate, therefore decreasing heat. Or an infection has temporarily changed the setpoint of the body's "thermostat."
Which kind of bond holds atoms in a water molecule together? What attracts water molecules to one another?
1. Polar covalent bonds hold atoms together.
2. Hydrogen bonds attract water molecules to one another.
Why does a solution of table salt conduct electricity, but a sugar solution does not?
Because table salt disassociates into charged ions in water, which carry electrical charges. Sugar does not disassociate in water because it is held together with covalent bonds.
How does an antacid help decrease stomach discomfort?
Antacids are weak bases that help neutralize an overly acidic stomach.
A food contains organic molecules with the elements C, H, and O in a ratio of 1:2:1. What class of compounds do these molecules belong to, and what are their major functions in the body?
They are carbohydrates and they are mainly used as an energy source.
When two monosaccharides undergo a dehydration synthesis reaction, which types of molecules are formed?
Disaccharides are formed.
Which kind of lipid would be found in a sample of fatty tissue taken from beneath the skin?
A triglyceride
Which lipids would you find in a human cell membrane?
Mostly phospholipids, but also glycolipids and cholesterol.
Proteins are chains of which small organic molecules?
Amino acids
Which level of protein structure would be affected by an agent that breaks hydrogen bonds?
The secondary level
Why does boiling a protein affect its structural and functional properties?
The heat breaks the bonds that form the tertiary and/or quaternary structure. This affects the ability of the protein to perform its normal functions. It's called denaturation.
How might a change in an enzyme's active site affect its function?
If the substrate fits better, the enzyme activity would increase. If the substrate can no longer bind or binds poorly, enzyme activity will decrease or be inhibited.
A large organic molecule composed of the sugar ribose, nitrogenous bases, and phosphate groups is which kind of nucleic acid?
It is an RNA molecule. DNA contains deoxyribose instead of ribose.
What molecule is produced by the phosphorylation of ADP?
All organic compounds in the human body contain all of the following elements except...
calcium (they contain hydrogen, carbon, and oxygen)
All the chemical reactions that occur in the human body are collectively referred to as...
A pH of 7.8 in the human body typifies a condition called....
alkalosis (normal human pH range is 7.35-7.45)
A ___ is a solute that dissociates to release hydrogen ions, and a ___ is a solute that removes hydrogen ions from solution.
acid, base
Chemical reactions in the human body are controlled by special catalytic molecules called...
What 4 major classes of organic compounds are found in the body?
Nucleic Acids
What 3 basic components make up DNA?
And RNA?
Deoxyribose, phosphate, nitrogenous bases (ATCG)
Ribose, phosphate, nitrogenous bases (AUCG)
What 3 components are required to create the high-energy compound ATP?
Adenosine, phoshpate groups, and appropriate enzymes
Explain how enzymes function in chemical reactions.
They are specialized protein catalysts that lower the activation energy required for a chemical reaction. They speed up reactions but are not used up or changed in the process.
What is a salt? How does a salt differ from an acid or base?
An ionic compound consisting of any cations other than Hydrogen and any anions other than Hydroxide. Acids release Hydrogen ions and bases remove Hydrogen ions (usually by releasing Hydroxide)
Explain the differences between nonpolar covalent bonds, polar covalent bonds, and ionic bonds.
Nonpolar covalent bonds have an equal sharing of electrons.
Polar covalent bonds have an unequal sharing of electrons.
Ionic bonds lose and/or gain electrons.
The hydrogen bonding that occurs in water is responsible for all of the following except...
the ability of water to dissolve nonpolar substances (it does include the high boiling point and low freezing point of water, the ability to dissolve inorganic salts, and the surface tension of water)
A sample that contains an organic molecule has the following constituents: carbon, hydrogen, oxygen, nitrogen, and phosphorus. Is it more likely to be a carbohydrate, lipid, protein, or nucleic acid?
Nucleic acid. Carbs & lipids don't have nitrogen. Proteins have nitrogen, but only nucleic acids usually have phosphorus.
A buffer system involves carbon dioxide CO2 and bicarbonate ion HCO3- in the reaction CO2+H20>H2CO3>H(+)+HCO3-
If a person becomes excited and exhales large amounts of CO2, how will the pH of the person's body be affected?
The equilibrium will shift to the left, and the level of H(+) will decrease. This will cause the pH to rise.
Which component of the cell membrane is primarily responsible for its ability to form a physical barrier between the cell's internal and external environments?
the phospholipid bilayer
Which type of integral protein allows water and small ions to pass through the cell membrane?
channel proteins
Cells lining the small intestine have numerous finger-like projections on their free surface. What are these structures and what is there function?
They are microvilli and they increase the cell's surface area to improve absorption
Cells in the ovaries and testes contain large amounts of smooth endoplasmic reticulum (SER). Why?
SER synthesizes lipids such as steroids. They produce large amounts of steroid hormones.
What does the presence of many mitochondria imply about a cell's energy requirements?
high demand for energy, mitochondria produce energy in the form of ATP molecules
5 important characteristics of epithelial tissue are...
1. Cellularity
2. Polarity
3. Attachment
4. Avascularity
5. Regeneration
Epithelial surface with a lot of microvilli. What is its probable function?
What is the functional significance of gap junctions?
small molecules and ions can pass from cell to cell. Helps coordinate functions
The secretory cells of sebacous glands fill with secretions and then rupture, releasing their contents. Which mode of secretion is this?
holocrine secretion
A gland has no ducts to carry the glandular secretions, and the gland's secretions are released directly into the extracellular fluid. Which type of gland is this?
endocrine gland
Lack of vitamin C in the diet interferes with the ability of fibroblasts to produce collagen. What effect might this have on connective tissue?
weak and prone to damage, collagen provides strength to connective tissue
Which type of connective tissue contains primarily triglycerides?
adipose (fat) tissue
Cell membranes are said to be...
selectively permeable
The organelle responsible for a variety of functions centering around the synthesis of lipids and carbs is
the smooth endoplasmic reticulum
Our somatic cell nuclei contain ___ pairs of chromosomes
What are 4 general functions of the cell membrane?
1. Physical isolation
2. Regulation of exchange with the env.
3. Sensitivity
4. Structural support
Microvilli are found...
in cells that are actively engaged in absorption
Collections of specialized cells and cell products that perform a relatively limited number of functions are called...
Matrix is a characteristic of which type of tissue?
Functions of connective tissue include
establishing a structural framework for the body & providing protection for delicate organs
Axons, dendrites, and a cell body are characteristic of cells located in...
neural tissue
Differentiate between endocrine and exocrine glands.
Endocrine secrete hormones onto the surface of the gland or directly into the surrounding fluid. Exocrine secrete via ducts.
What 3 methods do the glands use to secrete their products?
merocrine, apocrine, and holocrine
Why are the tight junctions near the exposed surfaces of cells lining the digestive tract important?
they block the passage of water and solutes between the cells, they keep enzymes, acids, and waste products from damaging delicate underlying tissues
Describe the fluid connective tissues in the body. Compare them with supporting connective tissues. What are the main differences?
They have a liquid, watery matrix. They have many soluble proteins and do not have insoluble fibers.
How could you tell the difference between an apocrine and a merocrine secretion?
Apocrine would have cell membrane components, merocrine wouldn't
How does the nucleus control the activities of the cell?
Nucleus contains DNA, which codes for polypeptide and protein production. Some proteins are structural, some are enzymes, which control all the cell's activities
What process would be affected by the lack of the enzyme RNA polymerase?
The cell would not be able to transcribe RNA from DNA
Which nucleotide sequence would the complementary mRNA strand have from this DNA strand:
CTC-ATA-CGA-TTC-AAG-TTA. How many amino acids are coded?
6 amino acids
Shedding of cells from the oter layer of skin on the scalp come from which epidermal layer?
the stratum corneum
A splinter in the 3rd layer of the epidermis is in which layer?
the stratum granulosum
Why does swimming in fresh water for an extended period cause epidermal swelling?
fresh water is hypotonic, so it moves into the cells by osmosis
Does sanding the figertips permanently remove fingerprints? Why or why not?
the ridges are formed in layers that are constantly regenerated, so they will reappear eventually, the patterns come from the dermis
Why does exposure to sunlight or sunlamps darken skin?
UV radiation causes melanocytes to produce melanin, darkening the skin
Why does the skin of a fair-skinned person appear red during exercise in hot weather?
blood is delivered to the superficial dermis to eliminate heat
Why do people who don't get any sunlight have problems with their bones?
the hormone cholecalciferol (vitamin D3) is needed to form healthy bones and teeth, UV light begins the synthesis of it
Where are the capillaries and sensory neurons that supply the epidermis located?
in the papillary layer of the dermis
What accounts for the ability of the dermis to undergo repeated stretching?
elastic fibers and the resilience of skin turgor allow the dermis to stretch and recoil
The 2 major components of the integumentary system are...
the cutaneous membrane and the accessory structures
Begin at the basal lamina and toward the surface... the layers are
germinativum, spinosum, granulosum, lucidum, corneum
Which is not a function of the integumentary system
synthesis of vitamin C
Exposure of the skin to UV light...
can result in damage to the DNA of cells in the stratum germinativum
The 2 major components of the dermis are the...
papillary layer and reticular layer
The cutaneous plexus and papillary plexus consist of...
a network of arteries providing the dermal blood supply
The stratum corneum of the nail root, which extends over the exposed nail, is called the...
Muscle weakness and a reduction in bone strength in the elderly result from decreased...
vitamin D3 production
In which layer(s) of the epidermis does cell division occur?
stratum germinativum
What 2 major layers constitute the dermis and what components are in each layer?
papillary layer- loose connective tissue, capillaries, sensory neurons
reticular layer- dense irregular connective tissue & bundles of collagen fibers
Both contain blood vessels, lymphatic vessels, & nerve fibers
In clinical practice, drugs can be delivered by diffusion across the skin (transdermal administration). Why are fat-soluble drugs more suitable for this than water soluble?
they pass through the permeability membrane better, water-soluble drugs are hydrophobic and don't penetrate the barrier easily
What are the benefits of a tan?
melanin helps prevent skin damage by absorbing UV radiation before it reaches deep layers or damages nuclear DNA
The darker an individual's skin color...
the more melanin their melanocytes produce
In order for bacteria to cause an infection in the skin, what don't they have to accomplish?
penetration to the level of the capillaries
What does sunlight do to promote bone maintenance and growth?
UV radiation converts a cholesterol related steroid into vitamin D3 (cholecalciferol), this is then converted into calcitrol, which is needed for calcium and phosphorus absorption
What can be done if a child can't get enough sunlight to minimize impaired maintenance and growth of bone?
they can drink milk, which is fortified with cholecalciferol