HPNU 3060 - Human Physiology Test Review With
Complete Solutions
Local communication types - ANSWER gap junction - connection between adjacent cells
which allows for chemical and electrical communication
contact dependent - cells have to touch for a ligand to go to a receptor on the second
cell
autocrine - signal is released from a cell and acts on its own receptor
paracrine - signal is released from a cell and acts on the adjacent cell and binds to a
receptor
Long distance communications types - ANSWER Endocrine system - slower than nervous,
longer period of time; endocrine cell secretes hormone that is released into the blood
stream; hormone binds with a target cell that has a receptor and initiates response;
sensor and integrating center are the same cell
Nervous system - faster than endocrine, shorter time period; electrical signal goes from
neuron straight to target cell and initiates a respone
Neurohormones - mix of both; electrical signal is fast going through axon and releases
chemicals into the blood stream that move slowly to target cell with receptor
, Basic signal transduction - ANSWER 1. signal molecule (ligand) is produced
2. ligand is released into body (1st messenger)
3. combine w/ receptor, activation of target cell
4. intracellular signal occurs (secondary messenger)
5. target proteins
6. response
Lipophilic vs. lipophobic - ANSWER lipophilic - ligand diffuses through cell membrane
and attaches to receptor in cytoplasm or nucleus; slower response related to gene
activity
lipophobic - ligand binds to receptor on cell membrane wall; rapid response
signal amplification - ANSWER signals are "expensive" and are hard for the body to make
so the body amplifies the signal until it reaches its destination
simple pathway vs. complex pathway - ANSWER simple = faster
complex = slower
up regulation - ANSWER is example of exocytosis; cell creates more receptors to be
more responsive
Complete Solutions
Local communication types - ANSWER gap junction - connection between adjacent cells
which allows for chemical and electrical communication
contact dependent - cells have to touch for a ligand to go to a receptor on the second
cell
autocrine - signal is released from a cell and acts on its own receptor
paracrine - signal is released from a cell and acts on the adjacent cell and binds to a
receptor
Long distance communications types - ANSWER Endocrine system - slower than nervous,
longer period of time; endocrine cell secretes hormone that is released into the blood
stream; hormone binds with a target cell that has a receptor and initiates response;
sensor and integrating center are the same cell
Nervous system - faster than endocrine, shorter time period; electrical signal goes from
neuron straight to target cell and initiates a respone
Neurohormones - mix of both; electrical signal is fast going through axon and releases
chemicals into the blood stream that move slowly to target cell with receptor
, Basic signal transduction - ANSWER 1. signal molecule (ligand) is produced
2. ligand is released into body (1st messenger)
3. combine w/ receptor, activation of target cell
4. intracellular signal occurs (secondary messenger)
5. target proteins
6. response
Lipophilic vs. lipophobic - ANSWER lipophilic - ligand diffuses through cell membrane
and attaches to receptor in cytoplasm or nucleus; slower response related to gene
activity
lipophobic - ligand binds to receptor on cell membrane wall; rapid response
signal amplification - ANSWER signals are "expensive" and are hard for the body to make
so the body amplifies the signal until it reaches its destination
simple pathway vs. complex pathway - ANSWER simple = faster
complex = slower
up regulation - ANSWER is example of exocytosis; cell creates more receptors to be
more responsive
