Chapter 32/37

Question 1

Homeostasis

Answer 1

Steady state, maintaining the internal environment. Humans maintain around 37 degrees Celsius.

Question 2

Endothermic

Answer 2

Warmed by heat generated by metabolism i.e. mammals and birds.

Question 3

Ectothermic

Answer 3

Gaining heat from external sources. i.e. lizards

Question 4

Structure of a Homeostatic System

Answer 4

1. Animals maintain a set point.
2. Fluctuations above or below the set point actor as the stimulus, detected by a sensor (the receptor)
3. A control center generates output that triggers a response.

Question 5

Endocrine System

Answer 5

Signaling molecules released into the bloodstream by endocrine cells are carried to all locations in the body.

Question 6

Nervous System

Answer 6

Neurons transmit signals along dedicated routes connecting specific locations in the body.
(Can only affect other neurons, muscle cells, endocrine cells, and exocrine cells)

Question 7

Hormones

Answer 7

Signaling molecules broadcast throughout the whole body used by the endocrine system.

Question 8

Pineal

Answer 8

Hormone: melatonin.
Action: circadian rhythm.

Question 9

Anterior Pituitary

Answer 9

Hormone: GH
Action: cell growth.

Question 10

Posterior Pituitary

Answer 10

Hormone: ADH
Action: water balance.

Question 11

Thyroid

Answer 11

Hormone: T3/T4, Calcitonin
Action: metabolism.

Question 12

Parathyroid

Answer 12

Hormone: PTH
Action: Raises blood Ca.

Question 13

Pancreas

Answer 13

Hormone: insulin
Action: Lowers blood sugar.

Question 14

Adrenal Cortex

Answer 14

Hormone: glucocorticoids.
Action: anti-inflammatory.

Question 15

Adrenal Medulla

Answer 15

Hormone: Epinephrine. (Adrenaline)
Action: Fight or flight.

Question 16

Ovary

Answer 16

Hormone: estrogen.
Action: female sex characteristics.

Question 17

Testes

Answer 17

Hormone: testosterone.
Action: male sex characteristics.

Question 18

Local Regulators

Answer 18

messenger molecules that travel short distances, example? – growth factors - compounds that stimulate nearby target cells to grow and divide

Question 19

Neurotransmitters

Answer 19

Any of a group of substances that are released on excitation from the axon terminal of a presynaptic neuron of the central or peripheral nervous system and travel across the synaptic cleft to either excite or inhibit the target cell.

Question 20

Pheromones

Answer 20

d

Question 21

Water-Soluble Hormones

Answer 21

Unable to pass through the plasma membranes of cells, they bind to cell-surface receptors, triggering events at the plasma membrane that result in cellular response. This is SIGNAL TRANSDUCTION.

Question 22

Lipid-soluble Hormones

Answer 22

The receptors for the hormones are in the cytosol rather than on the cell surface. When it binds, a hormone-receptor complex forms, which then moves into the nucleus.

Question 23

Signal Transduction

Answer 23

The cascade of processes by which an extracellular signal (typically a hormone or neurotransmitter) interacts with a receptor at the cell surface, causing a change in the level of a second messenger (for example calcium or cyclic AMP) and ultimately effects a change in the cells functioning

Question 24

Simple Endocrine Pathway

Answer 24

1. A stimulus in an endocrine cell causes the excretion of hormones.
2. This travels to targets via the bloodstream.
3. From here it binds to specific receptors.

Question 25

Glucose Homeostasis:

Answer 25

Insulin is a hormone released by the pancreas to maintain homeostasis.
Insulin facilitates glucose transport into cells from the bloodstream.
Insulin also lowers blood glucose levels.
It also inhibits glucose production from amino acids, fatty acids, and glycogen.
Glucagon is another hormone produced by the pancreas; it raises blood glucose levels by stimulating glycogen breakdown into glucose.

Question 26

Hypothalamus

Answer 26

Integrates the endocrine and nervous systems.
Receives information from nerves throughout the body, including the brain.
Signals from the hypothalamus travel to a gland located at its base, the pituitary gland, which has discrete anterior and posterior parts.

Question 27

Pituitary Gland

Answer 27

Anterior Pituitary: synthesizes and releases hormones that regulate other endocrine glands.
Posterior Pituitary: an extension of the hypothalamus. It stores and releases two hormones, oxytocin and ADH, which are synthesized by the hypothalamus’ neurosecretory cells.

Question 28

Hormone

Answer 28

Signaling molecules broadcast throughout the body via the endocrine system. It gets a response from cells that have a receptor for the signal.

Question 29

Schwann Cells

Answer 29

Myelinating and non-myelinating; Myelinating Schwann Cells wrap around the axons of motor and sensory neurons to form the myelin sheath.