216-262

Question 1

Sacromere

Answer 1

Located between two z lines in the myofibril

Question 2

Sacroplasm

Answer 2

The cytoplasm of the muscle fiber.

Question 3

Sacroplasmic reticulum

Answer 3

Similar to the smooth endoplasmic reticulum. It functions as a large internal store of Ca^++ ions in the muscle fibers.

Question 4

Saturation

Answer 4

The characteristic feature of protein mediated transport processes. By increasing the concentration of molecules to be transported, the transport speed increases less and less as most of the transporter molecules get occupied after a certain concentration.

Question 5

Scalar electrocardiogram

Answer 5

A signal measured in any of the Einthoven leads, corresponding to the projection of the electrical vector of the heart onto a line connecting two electrodes. It therefor transforms the vector into a scalar variable.

Question 6

Schwann cell

Answer 6

A glial cell forming myelin sheet around axons at the periphery.

Question 7

Second messenger

Answer 7

A small molecule who’s concentration changes after the first messenger (signal) attaches to the membrane receptor.

Question 8

Secondary structure of proteins

Answer 8

The formation of regular structures (alpha-helix, beta-sheet,) in the peptide chain, stabilized by hydrogen bonds.

Question 9

Semilunar valves

Answer 9

Valves at the orifice at the aorta and pulmonary artery

Question 10

Semipermeable membrane

Answer 10

A membrane that separates two solutions and limits the penetration of some solvents from one side to another.

Question 11

Septum

Answer 11

The muscular tissue separating the left atria and ventricle.

Question 12

Side chain

Answer 12

A group bond to the carbon atom of amino acids. Amino acids are distinguished by the chemical composition of this group.

Question 13

Sinoatrial node

Answer 13

A specialized cardiac tissue in the right atrium. It functions as the pacemaker of the heart.

Question 14

Sliding filament hypothesis

Answer 14

A generally accepted theory which explains muscle contraction as the sliding of actin and myosin filaments on each other.

Question 15

Space constant

Answer 15

After traveling a distance equal to the space constant, externally induced and electronically conducted potential changes in the membrane decrease to 37%.

Question 16

Specificity

Answer 16

A receptor, enzyme or transporter molecule can only bind to a limited number of substrate molecules, due to its spatial structure.

Question 17

Spirometer

Answer 17

A devise used to measure lung volumes and aspects of breathing.

Question 18

Starling´s hypothesis

Answer 18

A theory that explains the production and absorption of intestinal fluids.

Question 19

Strength (energy) of a bond

Answer 19

The energy released during the formation of a given bond between atoms. The same energy is needed to break the atoms apart.

Question 20

Sucrose

Answer 20

A disaccharide built up by glucose and fructose.

Question 21

Summation

Answer 21

Summation in time and in space: To add up the effects of two synaptic potentials that occurs at the same synapse with a short delay or in neighboring synapses at the same time.

Question 22

Surface active agent

Answer 22

An amphipathic molecule with both hydrophobic and hydrophilic groups.

Question 23

Surface active substance

Answer 23

Their molecules possess both hydrophobic and hydrophilic parts, and tend to line up at the border separating the two different phases with the hydrophobic and hydrophilic parts located in the appropriate phases.

Question 24

Surfactant

Answer 24

A surface active agent lining the inner surface of the alveoli and which decreases surface tension.

Question 25

Systole

Answer 25

The portion of the heart beat earn the heart muscle is contracting.

Question 26

Tercier structure of proteins

Answer 26

The three-dimensional, spatial form of the protein chain that is stabilized by weak interactions.

Question 27

Tetanic contraction

Answer 27

An uninterrupted muscular contraction caused by high frequency motor impulses.

Question 28

Thrombosis

Answer 28

The blockade of a vessel due to a blood cloth formes in the vessel.

Question 29

Tidal volume

Answer 29

The volume of air moved during a relaxed inspiration or expiration

Question 30

Tight junction

Answer 30

The area of membrane fusion between adjoining cells that prevent the passage of extracellular material between the cells.

Question 31

Time constant

Answer 31

The time required for an externally induced potential change in the membrane to decrease to 37% of the original potential.

Question 32

Trace elements

Answer 32

The elements an organism needs in very low concentration for normal functioning. About 0.01% in total.

Question 33

Trachea

Answer 33

A large respiratory pathway that connect the pharynx with the bronchi of the vertebrate lung.

Question 34

Tricuspid Valve

Answer 34

A valve between the right atrium and ventricle.

Question 35

Triglycerides

Answer 35

Lipid molecules composed of three fatty acid residues esterified to glycerol.

Question 36

T-tubules

Answer 36

Invagination of the sarcolemma, carrying excitation to the sarcoplasmic reticulum.

Question 37

Turbulent flow

Answer 37

A flow pattern in which particles of the fluid move irregularly in all directions of the space.

Question 38

Unipolar neuron

Answer 38

Nerve cells with only one process.

Question 39

Unsaturated fatty acid

Answer 39

A fatty acid containing one or more double bonds

Question 40

Valsalva´s maneuver

Answer 40

A sustained expiration effort against a close glottis.

Question 41

Van der Waal´s forces

Answer 41

Relatively weak attraction between atoms and molecules with hydrophobic properties because of the random fluctuation of the electron clouds.

Question 42

Vena cava

Answer 42

A large, empty vein that returns to the right atrium.

Question 43

Ventilation

Answer 43

The air exchange between the ambient air and the lungs.

Question 44

Venule

Answer 44

A small vessel connecting capillaries to the veins.

Question 45

Vesicle

Answer 45

A small, spherical compartment in the cell surrounded by a membrane.

Question 46

Viscosity

Answer 46

The physical property of fluids which determines the ease with which the layers of a fluid move past each other.

Question 47

Vital capacity

Answer 47

The maximum volume of air that can be inhaled to or exhaled from the lungs.