Introduction To Nervous And Endocrine Systems Flashcards
1
Q
What does the nervous system consist of?
A
Central nervous system and peripheral nervous system.
2
Q
What does the central nervous system consist of?
A
Brain and spinal cord.
3
Q
The central nervous system controls voluntary AND involuntary action. True or false.
A
True.
4
Q
What is the central nervous system responsible for?
A
Responsible for processing information and coordinating behaviour.
5
Q
What does the peripheral nervous system consist of?
A
Nerves that connect the CNS to limbs, organs and tissues.
6
Q
What is the PNS divided into?
A
Autonomic and somatic nervous systems.
7
Q
What does the autonomic nervous system control?
A
Involuntary functions like heartbeat, digestion and breathing.
8
Q
What does the somatic nervous system control?
A
Voluntary motor actions like moving muscles.
9
Q
What is the ANS divided into?
A
Parasympathetic and sympathetic nervous systems.
10
Q
Name some parasympathetic nervous system functions.
A
- Constricting pupils.
- Stimulating saliva production.
- Slowing heart rate.
- Constricting airways.
- Stimulating stomach and intestinal activity.
- Contracting the bladder.
- Promoting sexual arousal (erection of genitals).
11
Q
Name some sympathetic nervous system functions.
A
- Dilating pupils.
- Inhibiting saliva production.
- Increasing heart rate.
- Relaxing airways.
- Inhibiting digestion.
- Stimulating glucose release from the liver for energy.
- Relaxing the bladder.
- Promoting ejaculation and vaginal contractions.
12
Q
Neurones adapt over time. True or false?
A
True.
13
Q
What does the term plasticity mean?
A
Refers to the brain’s ability to adapt and change in response to new information, experiences or damage. It allows for learning, memory formation and recovering from injury.
14
Q
What are the six areas of the brain?
A
- Frontal lobe.
- Parietal lobe.
- Temporal lobe.
- Occipital lobe.
- Cerebellum.
- Brain stem.
15
Q
What does the frontal lobe regulate?
A
- Planning, problem-solving and decision-making.
- Emotional regulation.
- Voluntary motor activity (movement).
- Speaking and reasoning.
16
Q
What does the parietal lobe regulate?
A
- Sensory processing eg, touch, temperature and pain.
- Body awareness and spatial awareness.
- Interpreting visual information from the environment.
17
Q
What does the temporal lobe regulate?
A
- Understanding language and speech.
- Memory formation.
- Emotional responses.
- Hearing and processing auditory information.
18
Q
What does the occipital lobe regulate?
A
- Vision and interpreting visual stimuli.
- Colour perception.
19
Q
What does the cerebellum regulate?
A
- Balance and coordination of voluntary movements.
- Fine motor control eg, precise hand movements.
20
Q
What does the brain-stem regulate?
A
Basic survival functions such as:
- Breathing.
- Heart rate.
- Sleep-wake cycle.
- Body temperature.
21
Q
How does pain occur?
A
When nerve fibres send signals from an injury site eg, stubbing a toe, to the spinal cord and brain.
22
Q
What are some OTC medicines that can be used to treat pain?
A
NSAIDS:
- Ibuprofen and aspirin.
- Reduce inflammation and block pain by inhibiting enzymes like COX-1 and COX -2.
Local anaesthetics:
- Lidocaine.
- Block nerve signal transmission by inhibiting sodium channels.
Opioids:
- Codeine.
- Bind to opioid receptors in the brain and spinal cord, reducing pain perception.
Complementary therapies:
- Acupuncture and physical therapy.
23
Q
What is the function of the blood-brain barrier?
A
A highly selective barrier that protects the brain by preventing harmful substances from entering.
24
Q
What can pass through the blood-brain barrier?
A
Small, lipid-soluble molecules (less than 400 Da).
25
What does Da stand for?
Daltons.
26
What is the structure of the blood-brain barrier?
Consists of tightly packed endothelial cells in brain capillaries, surrounded by astrocytes and pericytes, which regulate permeability.
27
Why is developing treatments for brain conditions challenging?
Because 98% of drugs can’t cross the blood brain barrier.
28
What are the names of the three hormones in the endocrine system?
- Peptide hormones.
- Steroid hormones.
- Amine hormones.
29
What are peptide hormones made up of?
Amino acids (proteins).
30
Are peptide hormones water-soluble or lipid-soluble?
Water-soluble as they can travel freely in the blood but can’t pass through cell membranes.
31
How do peptide hormones activate intracellular signalling?
By binding to receptors on the surface of target cells.
32
Name some examples of peptide hormones.
- Insulin - regulates blood sugar.
- Growth hormone - stimulates growth.
33
What are steroid hormones made up of?
Cholesterol (lipid-based).
34
Are steroid hormones water-soluble or lipid-soluble?
Lipid-soluble as they can cross cell membranes.
35
How do steroid hormones influence gene expression?
By acting on DNA.
36
Name some examples of steroid hormones.
- Cortisol - stress hormone.
- Testosterone - male characteristics.
- Oestrogen - female characteristics.
37
What are amine hormones made up of?
Single amino acids eg, tyrosine or tryptophan.
38
Are amine hormones water-soluble or lipid-soluble?
Some are water-soluble eg, adrenaline, and some are lipid-soluble eg, thyroid hormones.
39
Name some examples of amine hormones.
- Adrenaline - fight or flight response.
- Thyroxine - metabolism regulation.
40
Which hormone regulates growth?
Growth hormone (GH) - promotes cell division, bone growth and protein synthesis.
41
Which hormones regulate reproduction?
Luteinising hormone (LH) and follicle-stimulating hormone (FSH) - regulate ovulation in females and sperm production in males.
42
Which hormones regulate energy metabolism?
- Insulin and glucagon - control glucose uptake and release.
- Thyroid hormones - regulate overall metabolism including energy production and usage.
43
Which hormones regulate homeostasis?
- ADH - regulate water balance in the body.
- Aldosterone - controls sodium and potassium levels to maintain blood pressure.
44
How does the hypothalamus control hormone release?
The hypothalamus regulates internal conditions and sends releasing or inhibiting hormones to the pituitary gland.
45
What is the function of thyrotropin-releasing hormone (TRH)?
Stimulates the pituitary gland to release thyroid-stimulating (TSH), which then prompts the thyroid gland to produce thyroid hormones.
46
When are hormones released?
In response to specific triggers eg, low glucose triggers insulin release and stress triggers cortisol release.
47
Explain negative feedback - simple terms.
When hormone levels reach the required amount, the system inhibits further hormone release.
48
Give an example of negative feedback.
High levels of thyroid hormone (T3/T4), inhibit the release of TSH hormone from the pituitary gland, stopping thyroid hormone production.
49
Explain positive feedback - simple terms.
The response is amplified until a desired outcome is achieved.
50
Give an example of positive feedback.
Oxytocin release during childbirth increases uterine contractions, which in turn stimulates more oxytocin release.
51
What is homeostasis?
The body’s ability to maintain a stable internal environment despite changes in the external environment.
52
Name examples of processes regulated by homeostasis.
- Body temperature - maintained through mechanisms like sweating or shivering.
- Blood glucose levels - regulated by insulin and glucagon.
53
Does the endocrine system use hormones or electrical signals, and do they have short-term or long-lasting effects?
The endocrine system uses hormones, which act slowly and have long-lasting effects.
54
Does the nervous system use hormones or electrical signals, and do they have short-term or long-lasting effects?
The nervous system uses electrical signals for rapid, short-term responses.
55
Give an example of negative feedback during homeostasis.
Reducing insulin release when blood sugar levels normalise.
56
How does the body regulate temperature?
Through sweating, increasing blood flow to the skin or producing heat by muscle activity.
57
How does the body control blood glucose levels?
Insulin lowers blood glucose when it’s high and glucagon raises it when it’s low, maintaining stable levels.
58
What are some differences between the nervous system and endocrine system (wired/wireless system, neurotransmitters/hormones, communication and response-timing)?
The nervous system:
- Has a specific structural arrangement of neurones.
- Neurotransmitters are released and travel short distances to target cells.
- Communication depends on anatomical proximity of neurones.
- The response is rapid and short-lived.
The endocrine system:
- There’s no physical connection between the secreting and target cells.
- Hormones are released into the bloodstream and travel long distances to target cells.
- Communication depends on the presence of specific receptors on target cells.
- The response is slower but long-lasting.
59
Describe the normal function of the pain pathway.
- Pain signals travel via afferent nerves from the injury site or stimulus to the spinal cord and brain for interpretation.
- The response is sent back via efferent nerves to initiate actions like withdrawing from the source of pain.
60
What causes chronic pain?
The nervous system may malfunction, resulting in persistent pain signals even without an active injury, leading to long-term suffering.
61
What is the normal function of insulin?
Produced in the pancreas, it lowers blood glucose levels by promoting its uptake into cells.
62
What is the normal function of glucagon?
Raises blood glucose levels by stimulating glycogen breakdown in the liver.
63
What is the cause of type 1 diabetes?
The pancreas fails to produce insulin.
64
What causes type 2 diabetes?
The body’s cells become resistant to insulin, leading to high blood sugar levels and systemic complications.
65
Describe the process of voluntary control eg, picking up a glass of water.
Sensory input:
- Sensory receptors in the body eg, skin and eyes, detect stimuli and send information to the CNS through sensory neurones.
Integration:
- The CNS processes and interprets sensory input to decide on an action eg, picking up the glass.
Motor output:
- The CNS sends motor signals via motor neurones to muscles, causing voluntary movement eg, the arm and hand muscles moving to pick up the glass.
66
Describe the process of involuntary control eg, touching something painful.
- The somatic nervous system also handles reflex actions, which are automatic and don’t require conscious thought.
- Reflex arcs bypass the brain, with the signal travelling directly from sensory neurones to the spinal cord and back to motor neurones, which allows for rapid responses to stimuli.
- Eg, if your hand touches a hot object like a candle, sensory neurones send a signal to the spinal cord.
- The spinal cord immediately sends a signal through motor neurones to move your hand away, even before the brain processes the sensation of pain.
67
What is the function of a neuron’s dendrites?
Receive signals from other neurones.
68
What is the function of a neuron’s cell body (soma)?
Processes incoming signals.
69
What is the function of a neuron’s axon?
Transmits electrical signals (action potentials) away from the cell body to other neurones or muscles.
70
What is the function of a neuron’s myelin sheath?
- Formed by glial cells eg, oligodendrocytes in the CNS and Schwann cells in the PNS.
- Insulate the axon to increase signal transmission speed.
71
What is the function of a neuron’s axon terminals?
Release neurotransmitters to communicate with other cells.
72
What is an action potential?
- The electrical impulse generated in the neurone.
- It propagates along the axon and is facilitated by ion channels that regulate the movement of ions like sodium and potassium.
73
What is a synapse?
The junction between two neurons or between a neurone and a target cell eg, a muscle.
74
How are neurotransmitters released?
When the action potential reaches the axon terminal.
75
What is a synaptic cleft?
A small gap where neurotransmitters cross to the next neurone.
76
What are neurotransmitters?
- Chemicals that transmit signals.
- Some are excitatory (stimulate activity) and others are inhibitory (reduce activity).
77
What is a neuromodulator?
Modify the effects of neurotransmitters.
78
What are the small pores in capillaries called and what is their function?
Fenestrations, which allow substances like nutrients, hormones and waste products to pass between the blood and surrounding tissues.
79
What is the function transport vesicles?
Involved in the transport of larger molecules across the capillary walls.
80
What is the intracellular space?
Spaces between endothelial cells in capillaries which allow small molecules to move freely.
81
What are tight junctions?
A nearly impermeable barrier that prevents most substances from passing between the cells, made by the endothelial cells of brain capillaries.
82
What are endothelial cells?
The single-cell layer that lines the interior of the blood vessel.
83
What is the basal membrane?
Surrounds the endothelial cells and provides structural support.
84
What are astrocytes and what is their function?
- Specialised star-shaped glial cells that enclose the capillaries and play a role in maintaining the integrity of the BBB.
- They help regulate the exchange of substances between the blood and the brain.
85
What are pericytes?
Cells which wrap around the endothelial cells and play a role in maintaining BBB stability and regulating blood flow.
86
What are mitochondria?
Found in endothelial cells, these organelles provide energy required for active transport mechanisms that move essential nutrients into the brain while blocking harmful substances.
87
Why are general capillaries more permeable than brain capillaries?
Due to the presence of fenestrations and large intracellular spaces.
88
How does the BBB act as a selective barrier?
By using tight junctions, astrocytes and pericytes, which only allows specific molecules such as glucose and oxygen to enter the brain.
89
Name the 10 main endocrine glands in the body.
- Pineal gland.
- Hypothalamus.
- Pituitary gland.
- Thyroid gland.
- Parathyroid glands.
- Thymus.
- Adrenal glands.
- Pancreas.
- Ovaries.
- Testes.
90
Where is the pineal gland located and what does it regulate?
Located in the brain, it regulates the sleep-wake cycle through melatonin secretion.
91
Where is the hypothalamus located and what does it regulate?
- Located in the brain, it links the nervous system to the endocrine system via the pituitary gland.
- It controls hormone release.
92
Where is the pituitary gland located and what does it regulate?
Located in the brain, it regulates other endocrine glands and releases growth hormone and oxytocin.
93
Where is the thyroid gland located and what does it regulate?
- Located in the neck, it regulates metabolism through hormones like thyroxine (T4) and triiodothyronine (T3).
94
Where are parathyroid glands located and what does they regulate?
Located in the neck, they’re small glands on the thyroid’s surface which regulate calcium levels in the blood.
95
Where is the thymus located and what does it regulate?
Located in the chest, it plays a role in immune function, particularly during childhood, by producing thymosins.
96
Where are adrenal glands located and what do they regulate?
Locate above the kidneys, they produce stress hormones eg, cortisol and adrenaline, and aldosterone for fluid balance.
97
What does the pancreas regulate?
Produces insulin and glucagon to regulate blood sugar levels.
98
What do ovaries regulate?
Produce oestrogen and progesterone, which regulate the menstrual cycle and reproduction.
99
What do testes regulate?
Produce testosterone, which is essential for sperm production and male secondary characteristics.
100
What’s the relationship between the hypothalamus and pituitary gland?
- The hypothalamus releases regulatory hormones which act on the pituitary gland.
- The pituitary gland releases hormones to control various target glands.
101
What does anti-diuretic hormone (ADH) do?
Affects kidney water retention.
102
What does thyroid-stimulating hormone (TSH) do?
Stimulates the thyroid gland to release thyroid hormones.
103
What does adrenocorticotropic hormone (ACTH) do?
Stimulates cortisol release from adrenal glands.
104
What do luteinising hormone (LH) and follicle-stimulating hormone (FSH) do?
Control reproductive hormones in ovaries and testes.
105
What does prolactin do?
Stimulates milk production in the breasts.
106
What does growth hormone (GH) do?
Influences growth and metabolism.
107
What is the mechanism of action of water-soluble hormones?
- Hormones bind to signal receptors on the surface of the target cell membrane as they can’t pass through the lipid bilayer.
- This activates intracellular signalling pathways eg, second messengers like cAMP, which lead to a response.
108
What is the mechanism of action of lipid-soluble hormones?
- Lipid-soluble hormones diffuse through the cell membrane.
- They bind to intracellular receptors, forming a hormone-receptor complex, which then enters the nucleus to induce a response.
109
Name some examples of water-soluble hormones.
- Insulin.
- Glucagon.
110
Name some examples of lipid-soluble hormones.
- Cortisol.
- Oestrogen.
- Testosterone.
111
What is the body’s response to cold?
- Vasoconstriction - reduces blood flow to the skin, minimising heat loss.
- Shivering - muscles contract to generate heat.
- Behavioural adjustments - body prompts actions like putting on warm clothing.
112
What is the body’s response to heat?
- Vasodilation - increases blood flow to the skin, prompting heat loss.
- Sweating - sweat glands produce sweat, which evaporates, cooling the body.
- Behavioural adjustments - actions like drinking water or seeking shade.
113
Describe the process which occurs after eating, when blood glucose levels rise.
- Rising blood glucose levels are detected.
- The pancreas secretes insulin which stimulates glucose uptake by cells for energy or storage.
- Insulin promotes glycogen formation in the liver.
- Excess glucose is stored as glycogen.
- This decrease blood glucose levels back to normal.
114
Describe the process which occurs between meals, when blood glucose levels fall.
- Declining blood glucose levels are detected.
- The pancreas secretes glucagon which stimulates the liver to break down glycogen to glucose (glycogenolysis).
- This releases glucose into the bloodstream.
- This increased blood glucose levels to normal.
115
How does the body react to low calcium levels?
The parathyroid glands release parathyroid hormone (PTH).
116
What does parathyroid hormone do?
- Stimulates the release of calcium from bones into the bloodstream.
- Increase calcium absorption from food in the intestines.
- Releases calcium excretion in urine, conserving calcium in the blood.
117
How does the body react to high calcium levels?
Calcitonin, produced by the thyroid, lowers calcium levels by promoting its storage in bones, reducing absorption in intestines and increasing excretion in urine.
118
Where is the thermoregulation centre located and what does it do?
Located in the hypothalamus, it detects changes in blood pressure (via internal thermoreceptors) and external temperature (via thermoreceptors in the skin).
119
What happens during the anterior pituitary (adenohypophysis) pathway?
The hypothalamus secretes releasing or inhibiting proteins that act on the anterior pituitary, which then produces hormones like ACTH (affecting adrenal glands) and TSH (affecting thyroid).
120
What happens during the posterior pituitary (neurohypophysis) pathway?
The hypothalamus produces hormones like ADH and oxytocin, which are stored and released by the posterior pituitary.
