Functional organization of the human body

Question 1

Total body water % of the total body weight?

Answer 1

60%

Question 2

What portion is the ICF of the TBW?

Answer 2

2/3

Question 3

What portion is the ECF of the TBW?

Answer 3

1/3

Question 4

The driving force for the water movement between the ICF and ECF is

Answer 4

osmotic pressure difference

Question 5

The driving forces for water movement across the capillary wall are

Answer 5

hydrostatic pressure and oncotic pressure
(Starling forces)

Question 6

What is homeostasis?

Answer 6

Maintenance of ECF constituents as relatively constant

Question 7

When input is greater than output, a state of _____________ exists.

Answer 7

positive balance

Question 8

When input is less than output, a state of _____________ exists.

Answer 8

negative balance

Question 9

-Movement of water between ICF and ECF requires__________

Answer 9

aquaporin protein channels

Question 10

-It is possible to say that the homeostatic control system is made up of three components:

Answer 10

1. Sensor: a system that detects specific signals.
2. Integration center: receives information from the sensor and it is usually located in the brain.
3. Set points: information “contained” in the integration center. They are reference points, specific for each substance present in the body, used to measure deviations from normal condition and assure maintenance of homeostasis

Question 11

-In the composition of the ECF, _______ are represented by the nutrients that enter the fluid, while _______ are metabolic end products

Answer 11

inputs, outputs

Question 12

__________ control- The cell releasing the chemical can control the action of other cells that are located around it, as long as they exhibit a receptor

Answer 12

Paracrine

Question 13

__________ control- a cell self-regulates its own activity. Single cell that is releasing the substances and this release is going to change its own activity.

Answer 13

Autocrine

Question 14

___________- two neighboring cells that are physically connected with a bridge. Allows ions to flow from one cell to another. Found in the heart, in the capillary vascular system etc…

Answer 14

gap junction

Question 15

Most control systems use ____________ control. It removes the initiative stimulus by simple or complex method

Answer 15

negative feedback,
Simple method- the target cell removes the stimulus that activated the endocrine cell.

Complex method- hypothalamus pituitary endocrine feedback loops. There are negative feedbacks for each one of the levels because each cell composing the complicated system has a negative feedback of its own, which means that there is a strict communication on each cell composing this type of loop.

Question 16

_______________- increase of the sensitivity of the cell to the stimulus. Occurs in a few instances in the body. At a certain point, another feedback system is required to remove the stimulus

Answer 16

-Positive feedback

Question 17

___________- moderate the activity of a specific cell. Never turning something on or off, we are just changing the tonic activity

Answer 17

-Tonic control
-E.g. smooth muscle of blood vessels is at basal state of contraction. The sympathetic nervous system signals for vasoconstriction. And when it doesn’t, there’s vasodilation. This occurs for a relatively longer period of time.

Question 18

____________- control mechanism is mediated by the CNS, there are essentially two types, the parasympathetic and the sympathetic that work in opposite directions

Answer 18

-Antagonist control