Hormones and Behaviour

Question 1

A hormone affects target cells :
A: at a distance from the source
B: close to the source

Answer 1

A

Question 1

What actually is a hormone?

Answer 1

• A chemical messenger that is released into the blood stream
• It affects the function of target cells at a DISTANCE from the source

Question 2

What are the 3 classes of hormones and give me an example of each

Answer 2

**Protein hormones **
e.g insulin, leptin, glucagon or ghrelin
Monamine hormones
e.g. epinephrine (adrenaline), norepinephrine (noradrenaline), melatonin,dopamine, serotonin
Steroid Hormones
e.g. cortisol, testosterone, estradiol

Question 3

What are protein hormones composed of?

Answer 3

**Multiple amino acids **e.g. insulin, leptin, glucagon or ghrelin

Question 4

Where are protein hormones stored ?

Answer 4

In endocrine cells

Question 5

What are monoamine hormones composed of?

Answer 5

Derived form a SINGLE amino acid e.g. melatonin, dopamin or serotonin

Question 6

What can monoamine hormones act as?
A : hormones
B: neurotransmitters
C : Both

Answer 6

BOTH !
The difference is:
Hormones are released into the blood and act on distant target cells.
Neurotransmitters cross the synaptic cleft and act locally.

Question 7

What are steroid hormones composed of ?

Answer 7

3, six - carbon rings and 1, 5- carbon ring

Question 8

Give me the 3 places where steroid hormones are produced?

Answer 8

1. ADRENAL glands
2. GONADS (e..g testes or ovaries)
3. BRAIN

Question 9

**Steroid hormones are : **
A: slow acting
B : fast acting

Answer 9

A - slow acting!
e.g. cortisol, testosterone, estradiol

Question 10

Where do hormones come from ?

Answer 10

Glands !

Question 11

What are glands?

Answer 11

Where hormones come from.
- A gland is a **group of cells **thatis formed by an ingrowth from anepithelial (surface
- NOTE - not ALL glands produce hormones

Question 12

Tell me the two different types of glands

Answer 12

EXOcrine and ENDOcrine

Question 13

Where do ENDOcrine glands secrete hormones?
provide an example

Answer 13

ENDOcrine glands secrete hormones **DIRECTLY **into the bloodstream
e.g. pituitary gland, adrenal gland

Question 14

Where do EXOcrine glands secrete substances?
provide an example

Answer 14

EXOcrine glands secrete substances onto the EPITHELIAL surface via a **DUCT **
e.g. sweat, salivary, mammary

Question 15

Does an endocrine gland secrete hormones ‘within’ the body or ‘outside’ the body?

Answer 15

Within

Question 16

Do exocrine glands secrete the hormone ‘within’ or ‘outside’ the body?

Answer 16

THEY DONT ! EXOcrine glands DO NOT secrete hormones, they secrete products such as sweat and saliva - which are not hormones dumb dumb.

Question 17

Where do Neural messages travel?

Answer 17

Neural messages travel along existing nerve tracks

Question 18

Where do Hormones travel?

Answer 18

Anywhere in the body via the Circulatory system, any cell that receives blood can potentially be affected by hormones!

Question 19

How long do Neural messages take to make an effect?

Answer 19

Immediately, they have rapid onset and offset, this takes place in
milliseconds meaning there is rapid change

Question 20

How long do Hormonal messages take to make an effect?

Answer 20

Minutes to hours, they mediate long-term processes like growth or metabolism.

Question 21

Do we have voluntary control over our hormones?

Answer 21

NO, they are released without us knowing

Question 22

Do we have voluntary control over our Neurons?

Answer 22

**YES **, in this context. For example decision making, movement and learning are all decisions we make.

Question 23

What glands secrete hormones?

Answer 23

ENDOcrine glands.

Question 24

What do **exocrine glands** secrete?

Answer 24

**Sweat, saliva and mucus**... remember - **NOT** hormones

Question 25

What are **Target cells** ?

Answer 25

**"target cells"** refers to cells in the body that have **specific receptors for a particular hormone**

Question 26

Receptors bind to hormones with what **2** things?

Answer 26

**High affinity** = meaning the hormones bonds with 'high affinity' or strongly/tightly to the receptor **High specificty** = meaning the hormones only bond with specific receptors that 'fit' that hormones.

Question 27

Tell me how **steroid** hormones bind to receptors?

Answer 27

1. Steriod hormones are **NOT** water soluble ... 2. So, they require carrier proteins to travel through the bloodstream ... 3. They then bind to receptors **INSIDE** the target cells.

Question 28

Tell me how **protein** hormones bind to receptors?

Answer 28

1. Protein hormones **CANNOT** pass through the plasma membranes of cells 2. Receptors are found on the **SURFACE **of the target cell

Question 29

What are the effects of hormones on a target cell?

Answer 29

1. Hormones interact with receptors that leads to **activation of ENZYMATIC pathways** or changes in gene expression and protein synthesis 2. Hormones may also **change a cell's morphology or size**

Question 30

What does the **responsiveness** of hormones on target cells depend upon? | 3 things

Answer 30

1. Hormone concentration 2. Number of targer receptors 3. Influence of other hormones

Question 31

What is a **positive feedback** loop?

Answer 31

A positive feedback **maintains or accelerates the direction of a stimulus** e.g. childbirth contractions

Question 32

Tell me how contractions during childbirth work? | Positive feeback loop

Answer 32

1. Baby pushed against the cervix (stretching it). 2. This stretching causes nerve impulses to be sent to the brain. 3. The brain stimulated the pituitary glands to release oxytocin. 4. Oxytocin causes the uterus to contract.

Question 33

Explain a **positive feedback loop**

Answer 33

1. **Endocrine Gland**: This is where the process begins. An endocrine gland is responsible for producing hormones, which are released into the bloodstream to regulate various activities within the body. 2. **Hormone**: The hormone is the signalling molecule produced by the endocrine gland. It travels through the blood to reach a specific target tissue. 3. **Target Tissue**: This is the tissue or organ that the hormone affects. Once the hormone binds to receptors on the target tissue, it triggers a response appropriate to the function of the hormone. 4. **Product**: The response from the target tissue results in the production of a certain product. This product then has an effect on the activity of the endocrine gland that initially secreted the hormone. **Positive Feedback:** The diagram indicates positive feedback with a plus sign (+). In positive feedback, the product of the target tissue's response increases the activity of the endocrine gland, leading to the production of more hormone. This creates a loop where the initial action (hormone release) is amplified.

Question 34

What is a **negative feedback** loop?

Answer 34

A **negative** feedback loop changes the direction of the stimulus **either increase or decrease**.

Question 35

Tell me how **insulin release** works?

Answer 35

1. High blood glucose level is detcted by cells in pancreas 2. pancrease secretes the hormone insulin causing liver cells to take us glucose and glycogen 3. As body cells take up blood glucose, glucose levels in the blood decline, and insulin release stops (negative feedback) 4. Retrun to homeostatic blood glucose level 5. Stimulus is the blood glucose level rising

Question 36

What is **up-regulation** ?

Answer 36

Up-regulation is where a **cell increases the production of receptors** for a hormone (e.g. when concentrations are low), this **increases how sensitive** cells are in relation to a particular hormone.

Question 37

What is **Down-regulation** ?

Answer 37

Down-regulation is where a cell **decreases the number of receptors** for a particular hormone, this **decreases how sensitive** cells are in relation to a particular hormone.

Question 38

Give me **an example of upregulation** in hormones?

Answer 38

**Pregancy:** Oxytocin ****(hormone) plays a crucial **role in stimulating contractions** in birth **by binding to receptor cells in the uterus**. As the pregnancy nears birth, the uterus changes and becomes **more sensitive to oxyctocin** through the** upregulation of oxytocin receptors** on the muscle walls of the uterus. This means the uterus repsonds better to oxytocin and releases it more effecitvely in birth, encourgaing contractions. **This is a positive feedback loop** because when there is more contractions, there is more oxytocin released therefore resulting in the birth of a baby.

Question 39

Give me an example of **Downregulation** in hormones?

Answer 39

**Chronic Stress** : When we are very stressed our sympathetic nervous system releases **high levels of adrenaline **(epinephrine), these **hormones bind to specific receptors** on target tissue e.g. the heart. Due to **prolonged exposure of hormone** (the high levels of adrenaline), **this causes a down-regulation of the specific receptors**. to reduce stress. This down-regulation occurs as a negative feedback loop to reduce sensitivity of target cells.

Question 40

What is **Hormone** **clearance**?

Answer 40

Process of** lowering hormone** levels in the body

Question 41

Give me **3 ways** Hormones are **broken down?**

Answer 41

1. **Enzyme**s that remove hormones from receptors 2. The** liver** 3. **Disintegrate** in the **bloodstream**

Question 42

Give me the **2 places** where hormones are **excreted** from the body?

Answer 42

1. Bile 2. Urine

Question 43

What do **interactions with a recpetor** lead to?

Answer 43

1. Activation of **enzymatic pathways** 2. effects on **gene expression** and **protein synthesis**

Question 44

What are the **3 interacting components** in an organism that hormones can affect?

Answer 44

1. **Sensory systems** (input e.g. pupil dulation) 2. **Central processing systems** (e..g brain) 3. **Output systems** (effectors e.g. heart)

Question 45

How do Hormones **affect behaviour**?

Answer 45

Hormones **INFLUENCE** behaviour, **not CAUSE** behavioural change. Hormones influence systems in the body so that specific stimuli are more likely to elicit a certain repsonse - changing the **PROBABILITY** of a behaviour

Question 46

Is the **relationship** between **hormones and behaviour**: A - directional B - Bidirectional

Answer 46

**B !** **The relationship is bidrectional.** This means hormones can influence behavior, and at the same time, behavior can also influence hormone levels. e.g. cortisol (stress) makes you behave differently and social situations can release oxytocin (love hormone).

Question 47

Name me a **study**on how **behaviour affects hormones **? | Hint : Rhesus Monkeys

Answer 47

***Rose, Holaday & Bernstein, 1971*** **Male rhesus monkeys** who **lose** a **fight** show **reduced testosterone** for several days after.

Question 48

How do we **determine** if **hormones affect** a certain **behaviour**?

Answer 48

1. If a behaviour is **dependent** on hormones, **when the actions of this hormone are blocked** (or removed) ... 2. In theory the **behaviour should stop**, after it has stopped, **if we reinstate the hormone we've blocked, the behaviour should resume** . 3. **Hormone concentrations and the behaviour should be covariant** - meaning, when hormone levels fluctuate, corresponding changes in behavior are observed, and vice versa. e..g when we are stressed (cortisol) we exhibit quickened pace, same as if we mediate we are more relaxed (less cortisol) and therefore have a slower heartrate.