Unit 1
Lactation is an example of what type of feedback loop?
Positive
Describe saltatory conduction.
Conduction that occurs when an action potential hops down a myelinated axon from one nodes of Ranvier to another
Which hormone, produced by the Pineal Gland, is a modification of tryptophan?
What is agglutination?
antibody cross-links cells forming a clump
What are the secretory cells that produce a substance which decreases the surface tension of water in the alveoli?
Type II alveolar cells (produce surfactant)
What do we call a molecule that prevents pH changes (like bicarbonate in the blood)?
buffer
Which division contains short postganglionic fibers?
parasympathetic
Where do lipid derivative hormones bind?
Intracellular receptors located on the nucleus and/or mitochondria
What is one reason for resistance to blood flow?
Diameter of vessel: larger diameter flows more slowly and meets less resistance
Viscosity of blood: thicker blood flows slower, thinner blood faster
Length: increase in length of vessel increases friction b/c increased surface area
The large intestine houses very beneficial bacteria. Name the product from the bacteria that is an important cofactor needed for clotting.
Vitamin K
What would be the fate of a cell that has a higher concentration of solute within the interstitial fluid?
water leaves the cell, crenation
What type of receptor cell is responsible for transducing pain stimuli?
nociceptor
What is the functional unit of a muscle?
sarcomere
What are the four functions of the nephron and where do each take place?
Filtration: glomerulus
reabsorption: before loop of Henle
secretion: proximal tubule
excretion: collecting ducts
Describe the functions of each section of the small intestine.
duodenum: mix enzymes, juice
jejunum: digestion
ileum: absorption
What are the main differences between endocrine and exocrine glands? Think about ducts.
endocrine glands lack ducts and have hormonal secretions, exocrine glands have ducts
What are the protective layers of the brain and spinal cord referred to as?
meninges (dura, arachnoid, pia mater)
To mitigate osteoporosis, it is recommended that one should consume a diet rich in calcium and vitamin D. How does a diet high in these nutrients diminish the risk of osteoporosis?
Calcium is necessary for forming hydroxyapatite and building bones; vitamin D helps your intestines absorb calcium from food. If calcium or vitamin D is deficient, bones become weaker and less dense.
Contrast the two types of T cells (helper and cytotoxic).
helper: CD4+, Th cells, coordinators, only bind to MHC II molecules
cytotoxic: CD8+, Tc cells, release chemicals to destroy other cells, bind to MHC I
A person with hypertension might be prescribed an ACE inhibitor. How can this help lower blood pressure?
ACE inhibitors prevent conversion of angiotensin I to angiotensin II. This prevents aldosterone and ADH from being released. Because less sodium and water are resorbed, blood volume will be lowered. A lower blood volume would decrease blood pressure.
Describe jaundice. What color would skin/eyes appear? What physiological event causes this discoloration?
Jaundice is the yellowing of skin and eyes. Occurs when liver is unable to excrete bile/buildup of bilirubin in the blood.
Describe the components and role of the limbic system.
Limbic system includes amygdala, hippocampus, thalamus, hypothalamus, basal ganglia and cingulate gyrus. The amygdala is the emotion center of the brain.
Explain who can donate blood to whom and why.
A+, A-, B+, B-, AB+, AB-, O+, O-
A+: A+, AB+
A-: A-, AB-, AB+
B+: B+, AB+
B-: B-, AB-, AB+
AB+: AB+
AB-: AB+, AB-
O+: O+, AB+, A+, B+
O-: A+, A-, B-, B+, AB+, AB-, O+, O-
What is the difference between active and passive immunity? Give an example of each.
Active: body makes its own antibodies (infection, vaccine)
Passive: antibodies received from outside (breastmilk, infusion)
Name two components of saliva that begin the digestion process and what their functions are.
Amylases: breakdown of carbohydrates
Lipases: breakdown of lipids