chapter 2 all

How do hormones travel through the body to reach their target?

Hormones are chemical messengers that travel through the bloodstream.

According to the transcript, what chemical can act as both a neurotransmitter and a hormone?

Norepinephrine

What is the key difference between neurotransmitters and hormones regarding speed of effect?

Neurotransmitters are released into a synapse making their effects almost instantaneous, while hormones travel through the bloodstream and take minutes or longer to reach their target.

How fast can a neural impulse travel compared to hormones?

A neural impulse can travel over $250\,mph$.

Which part of the brain acts as the control center linking the nervous system with the endocrine system?

The hypothalamus

What types of hormones does the hypothalamus produce to manage the pituitary gland?

Releasing and inhibiting hormones

What are the primary roles of oxytocin when released as a hormone?

It stimulates labor contractions, helps with milk release during breastfeeding, and promotes bonding, trust, and social connection.

Why is the pituitary gland commonly referred to as the "master gland"?

Because it influences all the other endocrine glands, telling them when and how much hormone to release.

Where is the pituitary gland located and what is its approximate size?

It is about the size of a pencil eraser and sits in the center of the brain just under the hypothalamus.

What are the functions of growth hormone (GH)?

GH stimulates the growth of bones and muscles, regulates body composition, and supports metabolism and tissue repair.

Where is the thyroid gland located and what is its primary role?

It is located in the front of the neck and plays a key role in controlling metabolism.

What hormone is released by the thyroid to regulate metabolism?

Thyroxin (or $T4$)

Where are the adrenal glands located?

They sit on top of the kidneys.

What are the two main parts of the adrenal glands?

The adrenal cortex (outer layer) and the adrenal medulla (inner layer).

What is the function of aldosterone produced by the adrenal cortex?

It helps regulate salt balance in the blood and tissues and helps control blood pressure.

What is the role of cortisol in the body?

It manages how the body uses carbohydrates, proteins, and fats and changes metabolism to help handle stress.

Which hormones are produced by the adrenal medulla during the fight or flight response?

Epinephrine and norepinephrine

How do epinephrine and norepinephrine prepare the body for action?

They increase heart rate, blood pressure, and blood sugar.

What is the shape and location of the pineal gland?

It is a small P-shaped gland located deep in the brain.

What hormone does the pineal gland produce to regulate sleep-wake cycles?

Melatonin

Where is the pancreas located and what are its two roles?

It is located behind the stomach and has both endocrine and digestive functions.

What are the two key hormones produced by the pancreas to maintain blood sugar levels?

Insulin and glucagon

How does insulin affect blood sugar?

It helps the body store and use glucose, lowering blood sugar when it is high.

Which hormones are secreted by the ovaries in females?

Estrogen and progesterone

What hormone is produced by the testes in males and what does it control?

Testosterone, which controls sperm production and male secondary sex characteristics like deeper voices and facial hair.

What is the limbic system?

A set of brain structures tucked beneath the cerebral cortex that serves as the brain's emotional and motivational center, controlling emotions, drives, and memory.

Which sensory information does NOT pass through the thalamus?

Smell

What is the primary function of the thalamus?

It acts as the brain's air traffic control tower, directing sensory information to the appropriate part of the cerebral cortex.

What does the word 'hypo' mean in Greek, and how does it relate to the hypothalamus's location?

'Hypo' means under; the hypothalamus literally sits under the thalamus.

What are some of the physiological factors the hypothalamus monitors to keep the body in balance?

Blood pressure, body temperature, and fluid balance.

In addition to metabolic balance, what other cycles and drives does the hypothalamus regulate?

Sleep-wake cycles, sexual arousal, and appetite.

Which brain structure is described as the brain's emotional alert system?

The amygdala

How does the amygdala assist in memory?

It helps us remember events that are emotionally significant.

What is the role of the frontal lobes in relation to the amygdala?

The frontal lobes assess whether a situation is actually dangerous and signal the amygdala to calm down if the threat is gone.

What is the hippocampus shaped like?

A pair of seahorses.

What is the primary role of the hippocampus in human memory?

It is critical for forming new memories from experiences, though it may not store them permanently.

The hippocampus is one of the brain regions affected by which specific disease?

Alzheimer's disease

What unique neural process occurs in the hippocampus?

The generation of new neurons.

What is the name of the field that studies the brain and the rest of the nervous system?

Neuroscience

Which specific subfield of psychology examines how biological systems shape thoughts, emotions, and behaviors?

Biological psychology

The nervous system uses which two types of signals to send messages throughout the body?

Electrical signals and chemical signals

What are the specialized cells designed specifically to send messages within the nervous system?

Neurons

Approximately how many neurons are found in the human brain?

$100$ billion

The neurons in the brain are connected through an estimated number of how many links?

$100$ trillion

Which part of the neuron acts as the headquarters and contains the nucleus?

The cell body

What are the branch-like structures that reach out from the cell body to receive messages from other neurons?

Dendrites

What is the long, thin tube that carries messages away from the cell body?

The axon

What are the branches at the end of an axon called where messages are passed to the next cell?

Axon terminals

What is the name of the fatty coating that insulates axons to help messages travel faster?

Myelin sheath

What are the gaps in the myelin sheath that help the electrical signal jump along the axon?

Nodes of Ranvier

What is the term for the place where communication occurs between neurons?

The synapse

How wide is the synaptic gap according to the transcript?

$$0.000127\,mm$$

How many synaptic gaps would need to be stacked together to equal the thickness of a single sheet of printer paper?

$$800$$

What are the special chemicals used by neurons to communicate with each other?

Neurotransmitters

What is the name of the electrical signal that travels down the axon to the terminals?

Action potential

What are the little sacs that release neurotransmitters into the synaptic gap?

Vesicles

Where do neurotransmitters land on the dendrites of the receiving neuron?

Receptor sites

The process of a neurotransmitter fitting into a receptor site is compared to what?

A key fitting into a lock

What is the process called when neurotransmitters are taken back into the original neuron to be recycled?

Reuptake

What is the process called when neurotransmitters simply drift away from the synapse?

Diffusion

What was the first neurotransmitter discovered by scientists?

Acetylcholine

The primary job of acetylcholine is to send messages to which part of the body to make movement possible? What is it involved with?

Muscles Involved in memory and learning

What happens if there is too much ACH?

Muscle Spasms

What happens when there is too little ACH?

Paralysis

Low levels of acetylcholine in the brain are linked to which disease?

Alzheimer's disease (memory, language, thinking problems)

What type of neurotransmitter is glutamate, which functions to kick neurons into action? (makes them fire)

Excitatory neurotransmitter that plays a key role in cognitive functions such as learning and memory.

Too much glutamate activity is linked to what specific health problem?

Strokes

Too little glutamate activity is linked to what specific health problem?

May contribute to schizophrenia symptom

What type of neurotransmitter is GABA (Gamma-Aminobutyric Acid), which functions to put the brakes on neuron activity?

Inhibitory neurotransmitter

GABA is especially important for controlling sleep and wakefulness and regulating which two emotions?

Fear and anxiety

What are the effects of having problems with GABA activity?

Can lead to increased anxiety, insomnia, seizures, and other mood disorders, due to the loss of inhibitory control over neuron excitability.

Which neurotransmitter prepares the body for stressful situations and helps regulate arousal and attention? What does it help maintain?

Norepinephrine helps maintain attention and alertness

What imbalances/disruptions can high levels of Norepinephrine have?

Overarousal, hypervigilance, difficulty thinking and focusing

What are the naturally produced chemicals that work like opioids and are released in response to pain?

Endorphins

The word "endorphin" is a combination of which two terms?

Endogenous and morphine

Which neurotransmitter helps regulate appetite, mood, aggression, sleep, and breathing?

Serotonin

What does the acronym SSRI stand for in the context of antidepressant medications?

Selective serotonin reuptake inhibitors

How do SSRIs like Prozac and Zoloft increase serotonin's effects?

They block the reuptake process so serotonin stays in the synapse longer

Which neurotransmitter is involved in the brain's pleasure circuit, reward-based learning, and body movements?

Dopamine

In Parkinson's disease, the deterioration of neurons that produce which neurotransmitter leads to movement disruption?

Dopamine

Which chemical is unique because it can act as both a neurotransmitter and a hormone involved in romantic love?

Oxytocin

According to research, when are oxytocin levels usually very high in a relationship?

In the first few months

According to the transcript, why does the euphoria of early love also come with stress?

The stress reflects the risk of losing the relationship

What are the two main parts that the nervous system is divided into?

The central nervous system (CNS) and the peripheral nervous system (PNS).

What elements comprise the central nervous system (CNS)?

The brain and the spinal cord.

What is the primary role of the peripheral nervous system (PNS)?

To connect the central nervous system to the rest of the body, including muscles, glands, and organs.

The peripheral nervous system (PNS) is divided into which two branches?

The somatic nervous system and the autonomic nervous system.

What is the function of the somatic nervous system?

It controls voluntary movements.

What functions does the autonomic nervous system handle?

Things you do not have to think about, such as your heartbeat, digestion, and breathing.

How is the spinal cord described in terms of its function as a pathway?

It is a superhighway of neurons that allows the brain and the peripheral nervous system to communicate.

What are the two main jobs of the spinal cord?

First, it receives information from the body to send to the brain; second, it takes commands from the brain to deliver them throughout the body.

What would be the result if sensory signals could not travel up the spinal cord?

The brain would not know what is happening in the body, such as feeling a hot burner or a massage.

What is the specific role of sensory neurons?

They pick up information from the environment (sights, sounds, touch, and temperature) and send it to the brain for processing.

What is the specific role of motor neurons?

They carry commands from the brain and spinal cord out to the body, telling muscles to contract or glands to release chemicals.

What are the bundled structures in the PNS that act like electrical cables called?

Nerves.

What examples of internal information do PNS nerves send to the central nervous system?

Heart rate, blood pressure, and temperature.

What two types of nerves does the somatic nervous system use to perform its jobs?

Sensory nerves and motor nerves.

In the context of the somatic nervous system, what metaphor is used for sensory nerves?

They are like the reporters of your body.

In the context of the somatic nervous system, what metaphor is used for motor nerves?

They are like messengers.

What three examples of voluntary movements are provided for the somatic nervous system?

Writing with a pencil, opening a door, or climbing into bed.