Download HAP FINAL EXAM REVIEW

HAP SEMESTER 1 FINAL EXAM REVIEW KEY
The following are major topics of study you will see on the final exam. Physiology processes
and major overarching topics that come up regularly over the semester will make up the essay
questions. These are marked with *. Not all the * topics will be used on the essay portion but,
those that are not used from this list will be covered extensively in the objective section:
Unit 1: Intro to the body
1. *Homeostasis: What are the general steps involved in a negative feedback mechanism?
 A control center monitors something (such as the blood) to make sure it is within
range
 It receives a stimulus or signal that it has fallen out of range.
 It releases a message (hormone or nervous signal) to a target organ.
 The target organ undergoes an action to restore the range
 The control center monitors that it has returned back to normal and turns off the
message.
a. How are the nervous and endocrine systems an essential part of the feedback
loop? They are the messages- nervous is electrical; endocrine is chemical
(hormones)
b. Give an example of homeostasis by explain one way the body regulates
something- such as temperature or calcium levels.
Temperature: Hypothalamus monitors the blood temperature within the brain, it
senses it is too hot; sends a nervous message to the skin; skin sweat glands release
sweat that cools the body; the blood temp cools and hypothalamus stops sending
the message so you stop sweating. (you could also use that you are cold the only
change is the target organ is now muscles that make you shiver)
Calcium: Blood calcium is too high; thyroid detects this and sends out calcitonin.
Calcitonin tells osteoblasts to build up bone using ca from the blood. Ca levels
drop in the blood; detected by thyroid. It stops production of calcitonin.
Or
Calcium in blood is too low; parathyroid detects and releases PTH into blood; it
travels to the bone and tells osteoclasts to break down the bone. Ca is added to
the blood, rising its levels; parathyroid detects and stops releasing PTH.
2. *Explain the concept of Complementarity.
a. Give an system example by explaining how systems are always working together
to ensure survival of the body. Focus on the systems we have discussed this
semester:
i. Digestive
ii. Integumentary
iii. Skeletal
iv. Muscle
*You can write other ways they are connected but here is one potential answer:
The sun causes a chemical change to occur to the cholesterol in the skin; making vitamin
D. Vitamin D is absorbed by the blood and travels to the digestive system where it help
absorbs Ca. Ca travels in the blood and is used by the muscles. Muscles use calcium to
bind to actin and create crossbridges which pull myofilaments together and cause muscles
to contract. Any extra calcium in the blood is stored in the bone to make them stronger
and pulled from the bone for the muscles if the levels get too low.
b. Also give an organ example by explaining how the structure of an organ reflects
its function.
The muscle fibers that contract are packaged within a series of connective tissues
that both protect them and allow the myofilaments to pull on them which in turn
causes the bone to move.
3. What are the general structures and functions of each of the systems?
a. Urinary- kidney, ureter, bladder, urethra- filters waste from blood and excretes it
from the body
b. Endocrine- thyroid, pancreas- produces hormones to maintain homeostasis
c. Digestive- mouth, esophagus, stomach, pancreas, liver, gallbladder, small
intestine, large intestine, colon- Digests large food into absorbable portions and
excretes left over solid waste.
d. Respiratory- lungs, diaphragm, trachea- collects oxygen and excretes carbon
dioxide.
e. Nervous- brain, spinal cord, nerves- monitors the environment and sends
messages to move muscles and maintain homeostasis
f. Muscle- skeletal muscles- moves the body
g. Skeletal- bones- used by muscles for movement, provides support and protection
for the body
h. Cardiovascular- heart and vessels- moves the blood throughout the body to
deliver oxygen and nutrients and get rid of waste
i. Reproductive- ovaries and uterus (female); testes and penis (male)- used to make
gametes and produce offspring
j. Integumentary- skin, hair and nails- protects the body; helps maintain temperature
k. Lymphatic- thymus, spleen- immune system; fights infection
Important vocabulary from unit 1:
Cell- smallest living thing within the body
Homeostasis- maintaining a balanced range within the body
Negative feedback- When homeostasis is maintained continually over time by sending
and stopping messages like a thermostat kicks on and off.
Positive feedback- maintain homeostasis in unusual situations where a series of changes
retores order (like blood clotting and pregnancy)
Tissue- a collection of cells
Unit 2: Digestive system and biochemistry
4. *Enzyme Action: Enzymes are globular proteins which are the most advanced level of
protein structure- shaped like a knot of amino acids; held together with hydrogen bonds.
Enzymes are catalysts. They speed up reactions within the body that otherwise take to long
to occur on their own. Enzymes bind to a substrate (the substance they are changing) and
reduce the amount of energy needed to aid in the reaction. The substrate either breaks or
binds to another molecule and then the enzyme releases the substrate and can move on to
another. Vitamins are called co-enzymes which means they help the enzyme work more
efficiently.
5. *Water Molecules: Water is composed of an oxygen, and two hydrogens. They form a
covalent bond, oxygen sharing an electron with each of the hydrogen atoms. Since
oxygen’s nucleus has 8 protons and hydrogen only has one, the shared electrons are more
attracted to oxygen and spend more time in its orbital. This creates an uneven distribution
of the elements and causes oxygen to have a slight negative charge and each hydrogen
will have a slight positive charge (called polarity). This causes the hydrogens to sit in a
V shape since they repel one another. Because of the polarity, water is highly attracted to
charged particles making it a great solvent. Electrolytes and other polar molecules will
attract to the opposite charge which can draw molecules such as salt apart. This is how
water dissolves particles. Water is used in many ways by the body, such as: regulates
temperature (sweating; retaining heat), medium used in reactions (such as dehydration
synthesis), transport (makes up most of the blood and circulates within the brain to carry
nutrients), cushions body parts such as the brain and lubricates organs to reduce friction,
dissolves important minerals within the body.
6. *Protein Structure: Globular proteins are chains of amino acids that are organized in many
levels and then looped in a knot like fashion due to hydrogen bonds. Because hydrogen
bonds are weak and can be broken easily, when enzymes are placed in a solution outside of
it’s acceptable range the hydrogen bonds can break and unfold the enzyme. The loss of the
protein structure is called denaturing. This can occur when temperatures are too high or pH
is too acidic. In basic solutions or very cold temperatures, enzyme effectiveness slows but
they do not denature.
7. *Explain what chemical digestion has occurred to food as it has moved on through the
duodenum. Include all the steps in the break-down for each of the 3 major
biochemicals. For each step, include
a. the biochemical or nutrient
b. what it is changed into
c. the enzyme that speeds up the reaction (or substance that acts on the biochemical) for
each step, and
d. where the enzyme/substance comes from and where it works if different from its
origin.
In the mouth- the complex carbohydrates are digested by salivary amylase into polysaccharides
or disaccharides. Salivary amylase is made in the salivary glands and is active in the saliva.
The bolus is swallowed and travels down the esophagus into the stomach where it is mixed with
HCl (made by the parietal cells of the stomach lining). The HCl activates the enzyme
pepsinogen, turning it into pepsin. Pepsinogen is created by chief cells within the stomach. The
pepsin breaks down proteins into polypeptides and dipeptides. It also denatures amylase, making
it ineffective.
The chyme is transferred to the duodenum where the remainder is digested using enymzes from:
 Liver/gallbladder- secretes bile into duodenum which acts as an emulsifying agent,
breaking up fats into smaller droplets.
 Pancreas- secretes lipase to break down fats and lipids into fatty acids, trypsin and
protease turn dipeptides into amino acids; pancreatic amylase turns disaccharides into
monosaccharides.
8. *After digestion has completed, how are the nutrients delivered to the cells? Explain the
structures of the lower gastrointestinal tract and how they separate nutrients from the
waste and deliver it to the appropriate cells.
After the digestion is completed the nutrients are absorbed into the blood stream using villi and
microvilli. This occurs in the second and third sections of the small intestine (jejunum and
ileum). Anything that remains moves into the large intestine where water and minerals are
absorbed and the rest is compressed into feces and excreted from the body.
9.
Label the parts of the digestive system and list the function of each:
Mouthchemical and
mechanical
digestion
Salivary glands;
creates salivary
amylase enzyme
Esophagus- moves
food to stomach
using parastalsis.
Stomach mechanically and
chemically digests protein
Liver- creates bile
Gallbladder stores excess bile
Large intestine- absorbs water salts
and forms feces
Pancreas creates many enzymes for
duodenum
Rectum- stores feces until
elimination
Small intestine- finishes digestion and
begins absorption of nutrients.
10.
List the components and functions of saliva.
Saliva has many components but the main one is salivary amylase which is the active enzyme
that digests carbohydrates.
11.
Contrast bolus and chyme.
A wad of food when it’s chewed and mixed with saliva is a bolus; chyme is formed when the
bolus mixes with stomach acid.
12.
Describe the main function of bile.
Bile emulsifies fats which means it breaks large droplets of the fat suspended in the chyme into
smaller parts that are distributed through the duodenum
13. Contrast the duodenum, ileum and jejunum.
Duodenum- 1st section; completes digestion ; jejunum- 2nd section starts nutrient absorption;
ileum- 3rd section- completes nutrient absorption and starts water absorption.
14.
Describe the structure and functions of the microscopic anatomy of the small intestine
(villi and microvilli).
Villi are finger like projections on the lining of the small intestine that help increase
surface area for absorption of nutrients. The cells that line them are made with microvilli
which also increase surface area.
Important vocabulary from unit 2:
mechanical digestion breaking down food into smaller pieces using teeth or rugae of
stomach
chemical digestion –breaking down food by changing its molecular structure using
hydrolysis and an enzyme.
Absorption- moving fully digested food out of the intestines into the blood stream using
villi
Ingestion- to eat
Defecation- elimination of feces
Protein- complex molecule made of many amino acids
Lipid- complex molecule made of fatty acids and a glycerol (fats)
Starch- complex carbohydrate made by plants.
Monosaccharide- simple sugar, such as glucose
Carbohydrate- complex molecule made of many monosaccharides; complex sugars
Globular- protein structure where the protein is folded into “knots”; ex. enzyme
Peptide A bond created between two amino acids
Phospholipid- Fats that contain a glycerol head and two fatty acid tails; make up the cell
membrane.
Enzyme- a biological catalyst; protein that lowers the energy needed for reactions to take
place.
fatty acid- strings of carbon on lipids; determines if a fat is saturated or unsaturated.
Buffer- substance in the body that neutralizes an acid or base.
Electrolyte a salt; ionic substance.
Substrate- the molecule that is acted on by an enzyme.
Solvent- A liquid that dissolves another substance; usually polar
covalent bond- when two molecules share an electron
polar- when a molecule contains a charge
pH – method of measuring the degree of acidity
acid (know ions)- substances containing H+ ions; 0-6.9 on pH scale
base (know ions)- substances containing OH- ions; 7.1-14 on pH scale.