Unit 4

Question 1

Responding cell

Answer 1

Has receptor proteins that bind to signaling molecules

Question 2

Signaling molecules

Answer 2

Some are able to cross the plasma membrane and bind to intracellular receptors while others bind to surface receptors

Question 3

Endocrine signaling

Answer 3

Molecule travels through blood stream to reach target cell

Question 4

Paracrine signaling

Answer 4

Acts on neighboring cells (short distance)

Question 5

Juxtracrine signaling

Answer 5

Cell right next to it (have to be touching)

Question 6

Autocrine signaling

Answer 6

Acts on the same cell Ex: Cancer cells, T-cells

Question 7

Signal transduction

Answer 7

Transmission of molecular signals from a cells exterior to interior

Question 8

Cell surface receptors

Answer 8

Integral membrane proteins which communicate signals between the cell and the outside world

Question 9

Negative feedback

Answer 9

Decrease in function.

Question 10

Positive feedback

Answer 10

Enhancement or amplification of an effect

Question 11

Peptide hormones

Answer 11

Affect the endocrine system, polar

Question 12

Synapse

Answer 12

Structure that permits a neuron to pass a signal to another neuron

Question 13

Myelin sheath

Answer 13

Mixture of proteins and phospholipids forming a whitish insulating sheath around nerve fibers, which increases the speed at which impulses are conducted

Question 14

Sympathetic nervous system

Answer 14

Fight or flight

Question 15

Parasympathetic nervous system

Answer 15

Relaxation and decrease of functions

Question 16

GnRH (gonadotropin releasing hormone)

Answer 16

Secretes from hypothalamus and acts on anterior pituitary gland. This then secrets LH and FSH which stimulates testosterone in males and estrogen and progesterone in females

Question 17

B lymphocytes (B-cells)

Answer 17

White blood cells that can either secrete antibodies or create memory responses. Made and mature in the bone marrow.

Question 18

T lymphocytes (T-cells)

Answer 18

Made in bone marrow but mature in thymus(sac above your heart) because they have to learn self vs. non-self. Kill infected cells and pathogens or turn into helper T-cells.

Question 19

Macrophages

Answer 19

2nd cell to arrive. Can phagocytose both pathogens and dead neutrophils. “Hall monitor”

Question 20

Neutrophil

Answer 20

1st cell to arrive to wound or infection. Kill/digest pathogens. Ex: Think of a paper-cut.

Question 21

Herd immunity

Answer 21

If majority is vaccinated, odds of susceptible people decreases

Question 22

Gene rearrangement

Answer 22

Happens in B and T cells. Segments can be mixed and matched. Extra nucleotides can be added. The disadvantage is that you can generate receptors that recognize your own cells as pathogens.

Question 23

Innate immune response

Answer 23

Begins within minutes or hours. No memory response.

Question 24

Adaptive immune response

Answer 24

Takes about 7-10 days. Memory response. Almost limitless, can combat more and very diverse.

Question 25

Pattern recognition receptors (innate)

Answer 25

Deter molecule patterns in pathogens that are different to our host cells.

Question 26

Clonal expansion

Answer 26

Generating clones of cells specific for that pathogen. When the receptor binds to an antigen, the lymphocyte begins dividing.

Question 27

Antigen

Answer 27

Substance that causes the immune system to build antibodies against it. Binds to receptors of immune cells.

Question 28

Primary lymphoid organs

Answer 28

Bone marrow (B cells) and the thymus gland (T-cells)

Question 29

Secondary lymphoid organs

Answer 29

Lymph nodes, tonsils, spleen. Where filtration occurs and lymphocytes are activated. Lymph nodes filter lymph and spleen filters blood.

Question 30

Singaling cell

Answer 30

Secretes signaling molecules

Question 31

Complement

Answer 31

Proteins that coat a pathogen to enhance phagocytosis. “Yummy”.

Question 32

Mast cells

Answer 32

Release histamine at a wound site to induce inflammation by dilating the blood vessels

Question 33

Helper T-cell

Answer 33

Ensures appropriate immune response occurs for the specific type of pathogen. Ex: Don’t want a bacteria response for Influenza A.

Question 34

Hematopisis

Answer 34

Development of all cells in the bone marrow

Question 35

Negative selection

Answer 35

T-cells learn self vs. non-self

Question 36

B-cell receptor

Answer 36

Y-shape. Heavy and light chains held together with disulfide bonds (S-S). Bind to antigens.

Question 37

T-cell receptor

Answer 37

Ladder shape. Can’t bind directly, something (MHC) has to present the antigen.

Question 38

Axon Hillok

Answer 38

If enough signals are received from dendrites, signals an action potential

Question 39

Depolarization

Answer 39

Inside of a nerve cell becomes more positive than the outside

Question 40

Refractory period

Answer 40

No movement of Na+ or K+

Question 41

Calcium pump (action potentials)

Answer 41

Are released due to the movement of Na+ and allows hormones (such as adrenaline) to be released through exocytosis.

Question 42

Repolarization

Answer 42

pushing the K+ back out

Question 43

ACTH

Answer 43

released from anterior pituitary gland acts on adrenal cortex to stimulate secretion of cortisol

Question 44

Ras protein/G-protein signaling

Answer 44

G-protein receptor that is inactive with GDP and active with GTP via a Ras-activated protein that is activated after the tyrosine kinase receptors are dimerized due to a ligand binding. Then goes to MKK cascade to the nucleus for gene rearrangement.

Question 45

Steroid hormones

Answer 45

non-polar (4 rings)