Endocrine system

Question 1

What is the other name for sensory neurons?

Answer 1

Afferent neurons

Question 2

What is the other name for motor neurons?

Answer 2

Efferent neurons

Question 3

what is associated with the alarm response?

Answer 3

• contract arrector pili muscles
• increased secretion from sweat glands
• increased heart contraction and rate
• dilation of pupils
• constriction of blood vessels, esp in the skin
• dilation of bronchi
• increased blood pressure+ water retention
• decreased digestion

Question 4

what is associated with the relaxation response?

Answer 4

• decreased heart rate and contraction
• contraction of pupils
• increased salivation
• dilation of peripheral blood vessels
• constriction of bronchi
• increased digestion

Question 5

What are the ti aspects of the autonomic nervous system?

Answer 5

• Parasympathetic division: relaxation, rest, repletion.

- Sympathetic division: exercise, emotion, excitement.

Question 6

What is the difference between the sensory input in the autonomic and somatic nervous systems?

Answer 6

A: mainly interoceptors (internal sensing)
S: Special senses and somatic senses.

Question 7

What is the difference between the control of output in the autonomic and somatic nervous systems?

Answer 7

A: involuntary from the limbic system, hypothalamus, brain stem, and spinal cord.
S: Voluntary from the cerebral cortex

Question 8

What is the motor neuron pathway for autonomic?

Answer 8

two-neuron pathway: pre and post-ganglionic

Question 9

What is the motor neuron pathway for the somatic?

Answer 9

one neuron pathway

Question 10

What are the neurotransmitters for the autonomic system?

Answer 10

Acetylcholine:

• Pre-ganglionic axons
• Post-ganglionic parasymapthetic
• Post-ganglionic sympathetic to sweat glands

Norepinephrine:
-Post-ganglionic sympathetic fibres other than to sweat glands.

Question 11

What are the neurotransmitters for the somatic system?

Answer 11

acetylcholine

Question 12

What are A’s effectors?

Answer 12

Smooth muscle, cardiac muscle, glands.

Question 13

What are S’ effectors?

Answer 13

Skeletal muscle.

Question 14

What is symptomatic of Raynard disease?

Answer 14

• Excessive sympathetic stimulation following emotional stress or exposure to the cold
• Chronic vasoconstriction
• Fingers and toes become ischemic (lack blood) and appear white

Question 15

What is the hypothalamus’ role in the endocrine system?

Answer 15

• Controls internal organs via autonomic nervous system and pituitary gland.
• Regulates behavioural patterns, circadian rhythms, and sleep/wake cycles.
• Controls body temperature
• Regulates eating and drinking behaviour

Question 16

What do circulating hormones target?

Answer 16

Distant target cells

Question 17

What are paracrine cells?

Answer 17

Near-by hormone producing cells

Question 18

What are autocrine cells?

Answer 18

self-hormone regulating cells

Question 19

What is MoA of lipid-soluble hormones? (e.g. steroid hormones and thyroid hormones)

Answer 19

1) Lipid soluble hormones diffuse into the cell
2) Activated receptor-hormone complex alters gene expression
3) Newly formed mRNA DIRECTS SYNTHESIS of specific proteins on ribosomes.

Question 20

What is the MoA of water-soluble hormones? (e.g. peptides, catecholamines, proteins)

Answer 20

1) Binding to receptor activates G-protein which activates Adenyl Cyclase
2) Activated adenyl cyclase converts ATP to cAMP
3) cAMP serves as a 2nd messngers to activate protein kinases
4) Activated protein kinases phosphorylate other enzymes
5) Phosphorylated enzymes catalyse reactions that produce physiological responses

Question 21

How many hormones does the hypothalamus secrete and what do they act on?

Answer 21

• 9 hormones

These are releasing and inhibiting hormones to control the pituitary gland.

Question 22

How hormones does the pituitary gland secrete and what do they act on?

Answer 22

• 7 hormones

These are used to control endocrine groups.

Question 23

What is the adrenal medulla stimulated by?

Answer 23

Acetylcholine form sympathetic pre-ganglionic neurons

Question 24

What hormones does the adrenal medulla secrete?

Answer 24

Epinephrine and norepinephrine

Question 25

What are the principle actions of epinephrine and norepinephrine?

Answer 25

To enhance sympathetic autonomic alarm response

Question 26

What is the adrenal cortex stimulated by?

Answer 26

- Increased K+ and angiotensin II in the blood | - ACTH from the pituitary which is stimulated by CRH from the hypothalamus

Question 27

What hormones does the adrenal cortex secrete?

Answer 27

- Mineralocorticoids (e.g. aldosterone) | - Glucocorticoids (e.g. cortisol)

Question 28

what are the principle actions mineralocorticoids?

Answer 28

Increases blood Na+ and water and decreases blood K+ leading to increased blood volume and pressure

Question 29

What are the principle actions of glucocorticoids?

Answer 29

Resistance reaction to stress dampens inflammation and depresses immune responses

Question 30

Outline the negative feedback of the effects of the pituitary gland

Answer 30

1) The hypothalamus secretes CRH. 2) This stimulates the anterior pituitary to secrete ACTH 3) This stiumlates the adrenal cortex to secrete cortisol. 4) Once the cortisol exceeds a certain level, elevated cortisol inhibits release of ATCH by the anterior pituitary corticotrophs. 5) Elevated cortisol inhibits release of CRH by the hypothalamus neurosecretory cells.

Question 31

What are the 6 resistance reactions of glucocorticoids?

Answer 31

1) protein breakdown: this occurs in muscle fibres. amino acids released into the bloodstream may be used for synthesis of new proteins and ATP production. 2) Gluconeogenesis 3) Lipolysis 4) Resistance to stress - increased glucose and ATP combat stresses e.g. exercise, fasting, fright, temperature extremes, high altitude, bleeding, infection, surgery, trauma, and disease. 5) Vasconstriction - blood vessels become more sensitive to hormones >> higher bp 6) Anti-inflammatory - inhibits WBCs that participate in inflammatory responses (but this retards tissue repair) 7) Immune depression - high glucorticoid conc. depresses immune responses (used therapeutically for organ transplants i.e. slows graft rejection)

Question 32

What is the difference between eustress and distress?

Answer 32

Eustress is acute and is regarded as being helpful and beneficial. Distress is seen as being associated with undesirable events and is potentially harmful i.e. habitually hostile people will have long term sympathetic activation >> constricted caps>>> greater risk of cardiac infarction.

Question 33

What are the links between the neuroendocrine and immune systems?

Answer 33

neuroendocrine >> immune: autonomic nerves, hormones. neuroendocrine

Question 34

List the types of lipid soluble hormones

Answer 34

1) Steroid hormones 2) ThyroiD HOrmones (T3 & T4) 3) Nitric oxide (synthesised by NO synthase)

Question 35

Where are transport proteins synthesised?

Answer 35

The liver

Question 36

What are the functions of transport proteins?

Answer 36

1) They make lipid-soluble hormones temporarily water-soluble 2) They retard passage of small hormone molecules through the filtering mechanism in the kidneys, slowing down the rate of hormone loss in urine 3) They provide a steady reserve of hormone, already present in the bloodstream.

Question 37

Where are the receptors for lipid soluble hormones located?

Answer 37

Inside target cells.

Question 38

Where are the receptor for water soluble hormones located?

Answer 38

Inside the plasma membrane of the target cells.

Question 39

What kind of receptors do water soluble hormones bind to?

Answer 39

Integral transmembrane proteins.

Question 40

What does the responsiveness of a target cell depend on?

Answer 40

1) the hormone's concentration in the blood 2) the abundance of the target cell's receptors 3) influences exerted by other hormones

Question 41

What are the effects of permissive hormones?

Answer 41

Sometimes increases the number of receptors for the other hormone Sometimes promotes synthesis of an enzyme required for the expression of a hormone's effects

Question 42

How is hormone regulation secreted?

Answer 42

1) Signals from the nervous system 2) Chemical changes in the blood 3) Other hormones

Question 43

How is the pituitary gland attached to the hypothalamus?

Answer 43

By the infundibulum