Endocrine coordination: blood carries the message
הוצג| English | משמעות |
|---|---|
| target organ/ˈtɑːɡɪt ˈɔːɡən/ | איבר מיועד |
| endocrine gland/ˈendəʊkraɪn ɡlænd/ | בלוטת אנדוקרינה |
What would explain this observation?
- A hormone travels in blood, yet only suitable targets respond. Transport through the circulation is different from an electrical impulse along a neurone.
Build the model
- The endocrine system consists of glands secreting chemical hormones directly into the bloodstream.
- Blood carries a hormone to a target organ 靶器官, where it produces an effect.
- Compared with nervous responses, hormonal effects are generally slower and last longer.
- The pituitary in the brain releases several hormones in response to body conditions; some stimulate other glands to release hormones.
- endocrine gland 内分泌腺: A gland releasing hormones directly into blood.
- target organ: An organ responding to a particular hormone.
Which route describes hormonal coordination?
רמת קושי 1/5 · 100 מטבעות + בונוס קטן בהשלמה הראשונה היום
A hormone is released from a gland into the blood, which carries it to its target organ - gland to blood to target. The blood reaches all cells, but only cells with the matching receptors respond.
Match each technical term to its precise meaning.
רמת קושי 2/5 · 140 מטבעות + בונוס קטן בהשלמה הראשונה היום
Use the definitions to distinguish related quantities and processes.
Choose evidence that can test it
- Locate the pituitary below the brain, thyroid in the neck, adrenal glands above the kidneys and pancreas in the abdomen.
- Ovaries lie in the pelvis and testes in the scrotum.
- These positions help identify glands on a body diagram; a gland’s position is not the location of every target it affects.
- The term master gland describes the pituitary’s coordinating role, not production of every hormone.
In the lab: Label a teacher-provided body outline, then trace gland → blood → target → effect for a supplied hormone. Contrast that route with receptor → nerve pathway → effector. Use model data only; classroom investigations must not involve administering hormones or collecting sensitive personal medical information.
Which two habits make the investigation or model in this case more defensible?
רמת קושי 2/5 · 140 מטבעות + בונוס קטן בהשלמה הראשונה היום
Stating the conditions and assumptions lets others repeat the work exactly, and recording the supporting evidence lets them check the conclusion. Hiding disagreeing results removes the evidence that could challenge a wrong conclusion, and one measurement can never establish a wider claim.
Work from known quantities
- Known: in a fictional transport model, a stated messenger travels a 30 cm route in 6 seconds.
- Model mean transport speed = distance/time = 5 cm per second.
- This arithmetic concerns the supplied model, not a universal hormone response time.
- Transport, target detection and the resulting cellular response are separate stages.
Your turn: A supplied model route is 42 cm and transport takes 7 s. Calculate mean transport speed.
A supplied model route is 42 cm and transport takes 7 s. Calculate mean transport speed.
רמת קושי 2/5 · 140 מטבעות + בונוס קטן בהשלמה הראשונה היום
The result is 6 cm/s. Known: route 42 cm; time 7 s. Use speed = distance / time. Speed = 42/7 = 6 cm per second. This is arithmetic on the supplied model, not a universal hormone response time.
Check the conclusion and its limits
- The pancreas is a gland, while insulin is a hormone it produces.
- Blood distribution does not mean all cells respond identically.
- A hormonal response cannot be assigned a fixed universal speed from one fictional transport calculation.
Not true: The pituitary produces every hormone in the body. The pituitary produces several important hormones, but many glands - thyroid, pancreas, adrenals, ovaries, testes - produce their own. No single gland produces every hormone.
- The endocrine system consists of glands secreting chemical hormones directly into the bloodstream.
- Locate the pituitary below the brain, thyroid in the neck, adrenal glands above the kidneys and pancreas in the abdomen.
- Watch for: the pancreas is a gland, while insulin is a hormone it produces.
The pituitary produces several important hormones, but many glands - thyroid, pancreas, adrenals, ovaries, testes - produce their own.
רמת קושי 1/5 · 100 מטבעות + בונוס קטן בהשלמה הראשונה היום
True. The pituitary produces several important hormones, but many glands - thyroid, pancreas, adrenals, ovaries, testes - produce their own. No single gland produces every hormone.
A gland releasing hormones directly into blood: write the technical term.
רמת קושי 1/5 · 100 מטבעות + בונוס קטן בהשלמה הראשונה היום
endocrine gland means A gland releasing hormones directly into blood.