exam 3

Question 1

osmoregulation

Answer 1

homeostasis of water levels in body

Question 2

excretory system

Answer 2

deals w/remain of nitrogenous waste products

Question 3

nitrogenous waste

Answer 3

breakdown of proteins + nucleic acids
fishes = ammonia (easy to make but toxic)
mammals = urea (harder to make - less toxic)
birds = uric acid (harder to make - lose less water/less toxic)

Question 4

4 steps of excretory system

Answer 4

1. filtration of blood fluid = plasma
2. reabsorption of nutrients (good) back into bloodstream
3. secrete waste products into filtrate
   4.excrete urine (filtered blood fluid - bad)
   (draw kidney)

Question 5

whats in filtrate?

Answer 5

(draw nephron)
h20?
salts?
hco3- + h+ = stay
urea + go
glucose, amino acids = stay
some drugs - go

Question 6

osmolarity

Answer 6

measured concentration of a solution
solute + solvent = solution
(h20) = aqueous solution
up solute = osmolarity up = low solvent
low solute = osmolarity - high solvent

Question 7

osmolarity (neg feedback loop)

Answer 7

stimulus: up osmolarity
signal cell: hypothalamus in brain - trigger posterior pituitary gland
signal: ADH (aka vasopressin –> antidiuretic hormone)
target cell: collecting duct nephron (keep h20)
response: low osmolarity dur to high solvent

Question 8

blood pressure (neg feedback loop)

Answer 8

stimulus: low BP
signal cell: kidneys
signal: renin
target cell: liver
response: angiotensinogen
then,
signal: angiotensin i
target cell: lungs
response: makes angiotensin converting enzyme
then,
signal: angiotensin ii
–> adrenal gland
—> makes aldosterone
—> tells collecting duct to
keep water
—> higher blood
pressure
target cell: blood vessels
response: constrict blood vessels, higher blood pressure

Question 9

immune system

Answer 9

patrols, searches, and destroys foreign cells.

Question 10

infection != disease unless….

Answer 10

1. infection exposure is high
2. pathogens has strong virulence (ability of pathogen to cause disease)
3. immunity is compromised

Question 11

2 types of immune system

Answer 11

Innate
- born with
- non specific
- fast
- invertebrates/vertebrates
Acquired
- born with + acquire through exposure to pathogens
(ancestral exposure to pathogens) - milk from mammary glands
- specific
- slower to respond
- vertebrates

Question 12

innate immunity (4)

Answer 12

1. first line of defense, prevent pathogens from entering body.
2. cellular defense, leukocytes
3. complement system = 30 circulating in active proteins
4. inflammatory response, nonspecific, local response to an injury/infection to prevent the spread

Question 13

first line of defense

Answer 13

prevent pathogens from entering body.

physical | ex. skin, mucus membranes
interior| saliva /tears - antibacterial enzymes
stomach acids - gastric juices maintain low pH that is inhospitable
“good” bacteria in gut compete w/ pathogens

Question 14

cellular defense, leukocytes

Answer 14

phagocytic leukocytes - destroy pathogens by phagocytosis (cellular eating, lysosome –> eat it –> byebye)
1. neutrophils - most abundant
2. monocytes - travels in blood stream
3. macrophages - travels in tissues
monocytes + macrophages = same

cytotoxic leukocytes - destroy pathogens with toxins.
1. natural killer cells (NK cells) destroy infected (virally tumor) body cells.
2. enzymatic leukocytes
- ex. eosinophils - specific to parasitic worm infections (release enzymes that degrade pathogen)

Question 15

complement system

Answer 15

= 30 circulating in active proteins
activated by exposure to pathogen or by acquired immune system (when activated they accumulate at the pathogen + destroy it by perforations)

Question 16

inflammatory response

Answer 16

non-specific, non response to an injury/infection to prevent the spread

response - redness, heat, edema(swelling), pus

a. injury
b. blood vessel dilation (redness), allow more immune cells into area
c. platelets into area for clotting (edema/swelling) - monocytes escaping blood vessels crawl into tissues –> macrophages
d. phagocytic leukocytes (heat, pus), eat pathogens
* release pyrogens - chemical signals that tell brain to higher body temp (fevers)

recognizing foreign cells - through a “negative test”
identity markers - mark cells as “self”
MHCL - major histocompatibility complex
marker present = self
marker absent = foreign

Question 17

acquired immunity

Answer 17

2 leukocytes = lymphocytes
- B cells = pathogens in body fluids, differentiate/mature in bone marrow
- T cells = infected self cells, differentiate in thymus

antigen - protein on surface of pathogen
antigen receptor - receptor for antigen on B or T cells
(draw b + t cells)

Question 18

B cells (3 steps)

Answer 18

1. recognize pathogens - directly w/variable region an antigen receptor, undergoes clonal selection (mitosis of that specific B cell)
   mitosis - effector cells, shed anti-receptor
   memory cells, keep antigen
   receptor
2. attack w/antibodies aka immunoglobins
   
   • neutralize pathogen
   • agglutinate (clump) pathogen
   • cause macrophages to come to scene
   • activate complement system
   • activate NK cells
3. remember - memory cells

Question 19

T cells (3 cells)

Answer 19

1. recognize pathogen, indirectly via APC’s (antigen presenting cells) ex. macrophages
   (draw apc cell)
2. attack, 3 types
   - helper T-cells, activate other immune cells w/signals
   - cytotoxic T-cells, lyse open pathogens w/ performs (proteins that poke holes)
   - regulating/suppressor T-cells, shut down response.
3. remember - memory cells

Question 20

When immunity goes wrong…

Answer 20

allergies, immune reaction to nonpathogens

autoimmune disorders, immune system attacks own cells
ex. eczema
psoriasis