SB7 - Animal Coordination, Control & Homeostasis Flashcards
1
Q
What’s the endocrine system?
A
A network of glands that produce and secrete hormones into the bloodstream
2
Q
What is homeostasis?
A
The regulation of internal conditions inside cells or organisms, to create the optimum conditions for cell function
3
Q
What is an endocrine gland?
A
Glands of the endocrine system that secrete hormones directly into the bloodstream
4
Q
What glands are the endocrine system made up of?
A
- Pituitary gland
- Pancreas
- Thyroid
- Adrenal gland
- Ovary
- Testes
5
Q
What is the Hypothalamus?
A
Part of the brain which controls water balance, temperature and secretion of hormones by the pituitary gland
6
Q
What is the pituitary gland also known as?
A
The master gland
7
Q
What is the purpose of the pituitary gland?
A
- Secretes hormones into the blood to either have an effect on the body
- Acts on other glands to stimulate them to produce different hormones
8
Q
What is the purpose of the pancreas?
A
- Secretes insulin
- Controls blood glucose levels
9
Q
What is the purpose of the Thyroid?
A
- Secretes thyroxine
- Controls metabolic rate, heart rate and temperature
10
Q
What is the purpose of the Adrenal gland?
A
- Secretes adrenaline
- Involved in the ‘fight or flight’ response
—> (Body’s response to stressful situations)
11
Q
What is the purpose of the Ovary?
A
- Secretes oestrogen
- Is involved in the menstrual cycle and the development of female secondary sexual characteristics
12
Q
What is the purpose of the Testes?
A
- Secretes testosterone
- Is involved in the production of sperm and the development of male secondary sexual characteristics
13
Q
What substance in the body transports the hormone?
A
Blood
14
Q
What is the difference between the hormonal system and the nervous system?
A
- Nervous system is much faster
- Hormonal system acts for longer
15
Q
What is adrenaline?
A
A hormone that is produced by the adrenal glands to prepare the body for a flight or flight response
16
Q
What is a flight or flight response?
A
The body’s response to a dangerous situation
17
Q
What are some aspects of the flight or flight response?
A
- Increased heart rate
- Increased blood pressure
- Increased blood flow to muscles
- Increased blood sugar levels
18
Q
How does increased heart rate & blood pressure aid the flight or flight response?
A
Allows oxygen to reach the muscles more quickly, so we can move out of the path of danger
19
Q
How does increased blood flow to muscles aid the flight or flight response?
A
Blood vessels leading to other vessels dilate - allows more blood to reach them
—> Allows them to contract with greater strength, and more quickly
20
Q
How does increased blood sugar levels aid the flight or flight response?
A
Liver is stimulated to break down glycogen into glucose, which muscles can use to contract
21
Q
What is thyroxine?
A
A hormone secreted by the thyroid gland that controls metabolic rate, heart rate and temperature
22
Q
What is TRH?
A
- A hormone secreted by the hypothalamus when blood thyroxine levels are lower than normal
- Stimulates pituitary gland to release TSH
23
Q
What is TSH?
A
A hormone secreted by the pituitary gland that stimulates the thyroid gland to release thyroxine.
24
Q
What is negative feedback?
A
A corrective mechanism that allows only small shifts from a set point, reversing a change in conditions
25
How are the *levels of thyroxine* controlled by **negative feedback**?
* When the levels increase, it is detected by receptors in the brain
* This inhibits the release of TSH
* This inhibits the release of thyroxine, so levels of thyroxine fall
26
How are **low levels of thyroxine** returned to *normal*?
* Low levels of thyroxine stimulate production of TRH in the hypothalamus
* TRH causes the release of TSH from the pituitary gland
* TSH acts on the thyroid to produce thyroxine
* When thyroxine levels returns to normal level, thyroxine inhibits the release of TRH = stops the production of TSH
27
What is the **menstrual cycle**?
The process the body undergoes each month to prepare for a potential pregnancy
28
At what *day* does **ovulation** occur?
14
29
At what *day* does **the cell lining break down** occur?
28
30
What is a **hormone**?
Chemical messenger produced in glands and carried by the blood to specific organs in the body
31
What is **menstruation**?
The loss of blood and tissue from the lining of the uterus through the vagina during the menstrual cycle
32
What does **FSH** stand for?
Follicle stimulating hormone
33
What is the *purpose* of **FSH**?
Causes the maturation of an egg in the ovary
34
Where is **FSH** produced?
Pituitary gland
35
What does **LH** stand for?
Luteinising hormone
36
What is the *purpose* of **LH**?
Stimulates the release of the egg
37
Where is **LH** produced?
Pituitary gland
38
What is the *purpose* of **oestrogen**?
Involved in repairing and thickening the uterus lining
39
Where is **Oestrogen** produced?
Ovaries
40
What is the *purpose* of **progestorone**?
Maintains the uterine lining
41
Where is **Progesterone** produced?
Ovaries
42
Where is **progesterone** secreted from?
Egg follicle
43
What is a **follicle**?
Fluid filled ball of cells found in the ovary containing an ovum
44
What is the **corpus luteum**?
The remains of the follicle in an ovary after it has released an ovum into the fallopian tube
45
What *hormone* does **FSH** *stimulate* the production of?
Oestrogen
46
What *hormone* does **Oestrogen** *inhibit*?
FSH
47
What happens when *oestrogen* rises to a high level?
Causes a surge in LH - causes ovulation
48
What happens to the **follicle** after the **egg is released**?
Follicle becomes corpus luteum - Produces progesterone and oestrogen (inhibits FSH and LH)
49
What happens to the **lining of the uterus** if the egg has not been **fertilised**?
The corpus luteum dies and progesterone levels drop - uterus lining breaks down & menstruation happens
50
What is **contraception**?
The prevention of fertilisation
51
What are the *types* of **contraceptive pills**?
* Progesterone only
* Progesterone and oestrogen (mixed pill)
52
How does the **mixed pill** work?
* Oestrogen levels are constantly high = inhibits FSH so no
eggs mature
* Lining also stops developing and the mucus in the cervix becomes thick = sperm cannot move through
53
What are some *side-effects* of the **mixed pill**?
* Changes in mood
* Breast pain / tenderness
* Increased blood pressure
54
Name some **non-hormonal** methods of **contraception**
* Physical barrier methods
* Spermicidal agents
* IUD
* Abstaining from intercourse
* Surgical methods
55
How does a **male condom** prevent **fertilisation**?
Placed over erect penis, prevents sperm entering vagina
56
What are the **disadvantages** of **condoms**?
They can tear or rip
57
How does a **diaphragm or cap** prevent **fertilisation**?
Placed over the cervix, prevents sperm from entering the vagina
58
What are the **disadvantages** of **Diaphragms**?
Diaphragms need to be put in just before sex and left in several hours afterwards
59
How does an **IUD** prevent **fertilisation**?
Prevents the implantation of an embryo or release of a hormone
60
What are the **disadvantages** of **IUD**?
Small chance of causing an ectopic pregnancy
61
How does an **spermicidal agents** prevent **fertilisation**?
Kills or disables sperm
62
What are the **disadvantages** of **spermicidal agents**?
Some people may have allergic reactions
63
What are the **disadvantages** of **surgical methods**?
Cannot be reversed - permanent
64
What are **fertility drugs** used for?
To increase the chance of pregnancy
65
What *hormones* are mainly used in **fertility drugs**?
FSH & LH
66
Name a **fertility drug**
Clomiphene
67
When is **Clomiphene** given to a woman?
If the woman doesn't ovulate
68
How does **Clomiphene** work?
Increases the amount of FSH & LH released from the hypothalamus, increasing the chance that a woman will ovulate
69
When are **IVF treatments** used?
If there are issues with the quality of the man's sperm, or if a woman has blocked oviducts
70
How does **IVF treatment** work?
* Mother is given FSH and LH
* Matured eggs are extracted from the mother and fertilised in the lab using sperm
* The fertilised eggs develop into embryos and then one or two are inserted in the uterus
71
Why would a *woman* be given **FSH and LH**?
To encourage the release and maturation of eggs
72
What are the **benefits** of **IVF treatment**?
Provides a way for an infertile couple to have a child
73
What are the **cons** of **IVF treatment**?
* Emotionally stressful
* Physically stressful - Women may have reactions to the hormones
* Can be expensive - if process needs to be repeated
* May lead to multiple births
74
What does **ART** stand for?
Assisted Reproductive Technology
75
What is **ART**?
The use of hormones and procedures, as fertility treatments, to help to achieve pregnancy
76
What are some *examples* of **ART**?
* IVF
* Fertility drugs
77
What does **homeostasis** control?
* Blood glucose concentration
* Body temperature
* Water levels
78
Why is **homeostasis** important?
Maintains enzyme action and all cell functions
79
What is **thermoregulation**?
The act of keeping internal body temperature constant
80
Why is **thermoregulation** important?
If the temperature exceeds 37 degrees the enzymes will become less effective and eventually denature
81
What is **osmoregulation**?
The act of keeping the concentration of the blood at a constant level
82
What will happen if the blood becomes **too dilute**?
| And why is osmoregulation important in this case?
Water will move into cells by osmosis and they will swell, eventually bursting under the pressure
| Osmoregulation keeps the blood at the same concentration
83
What will happen if the blood becomes **too concentrated**?
| And why is osmoregulation important in this case?
Water will move out of cells and they will shrink
| Osmoregulation keeps the blood at the same concentration
84
Where is the **thermoregulatory centre** found in the body?
Hypothalamus
85
What is **vasodilation**?
* Dilation of blood vessels near the surface of the skin
* Allows blood to flow closer to the skin surface, increasing heat loss to the surroundings
86
Describe what happens when the human *body temperature* becomes **too high**?
* Sweat (evaporates from skin surface resulting in increased energy transfer away
from body) is produced from sweat glands
---> The sweat is released onto the surface of the epidermis.
* Vasodilation
87
In which part of the skin is **sweat glands** located?
Dermis
88
What is **vasoconstriction**?
* Constriction of blood vessels near the surface of the skin
* Less blood flows close to the skin surface, decreasing heat loss to the surroundings
89
Describe what happens when the human *body temperature* becomes **too low**?
* Skeletal muscles contract rapidly ( shivering ) to generate heat from respiration
* Hairs stand on end to create an insulating layer, trapping warm air
* Vasoconstriction
90
What is the human **body temperature**?
37.5 degrees Celsius
91
What does the **thermoregulatory centre** contain?
Receptors sensitive to the temperature of the blood
92
How does the *hypothalamus* respond to **information related with the thermoregulatory centre**?
By sending nerve impulses to effectors in the skin to maintain body temperature
93
What are the *layers* of **skin**?
* Dermis
* Epidermis
* Fatty tissue
94
What are the *parts* of the **body control systems**?
* Receptors
* Effectors
* Coordination centres
95
What is a **Receptor**?
Organ, tissue or cell that detects a stimulus
96
Give an *example* of what a **effector** will *respond to*
Temperature change
97
What is a **Effector**?
The organ, tissue or cell that produces a response
98
Give an *example* of what a **effector** will *respond to*
Temperature change
99
How is **water** lost through the **body**?
* Sweat from the skin
* Water vapour, from the lungs when we exhale
* Urine from the kidneys
100
What happens if the **glucose levels** in the blood are too **high**?
The pancreas produces insulin
101
What is **glycogen**?
A store of glucose in the liver and muscle tissues
102
What is **glucagon**?
A hormone secreted by the pancreas when blood glucose concentration is too low
---> Causes the breakdown of glycogen to glucose in the liver
103
What is **insulin**?
A hormone that regulates the level of sugar in the blood and can be produced by genetically modified bacteria
104
How does **insulin** control **high blood glucose concentrations**?
* Glucose to move from the blood into muscle cells for respiration
* Excess glucose to be converted into glycogen which is stored in the liver
105
How does **glucagon** control **low blood glucose concentrations**?
* Pancreas produces the hormone glucagon
* Glucagon binds to to the liver cells causing glycogen to be broken down into glucose
* Glucose is released into the blood, increasing the blood glucose concentration
106
What *hormones* keep **blood glucose concentrations** constant?
* Insulin
* Glucagon
107
Why can the **actions of insulin & glucagon** not occur continually?
Because when the blood arrives at a certain glucose concentration the other hormone is produced, resulting in the opposite effect.
108
What relationship does **insulin & glucagon** work in?
Negative feedback loop
109
What is **diabetes**?
Where the body cannot control blood sugar levels properly
110
What is **type 1 diabetes**?
Where the pancreas cannot produce enough insulin
--->This is congenital
111
What are the *symptoms* of **type 1 diabetes**?
* Lots of urine
* Individual may be thirsty
112
How can **type 1 diabetes** be *controlled*?
* Insulin injections at meal times, which results in glucose being taken up from the bloodstream
* Advised to limit the intake of simple carbohydrates
113
What is **type 2 diabetes**?
The body cells no longer respond to insulin
---> This is acquired
114
What are the *symptoms* of **type 2 diabetes**?
* Obesity
* Lots of urine
115
How can **type 2 diabetes** be *controlled*?
* Reducing the number of simple carbohydrates in diet
* Losing weight
* Increasing exercise
* Drugs are available to make insulin more effective on body cells
116
What is **obesity**?
A Body Mass Index over 30
117
How do you calculate **BMI**?
118
What are some *ways* to **evaluate body mass**?
* BMI
* Waist : hip ratio
119
If you have a **high body mass** are you more **likely** to have **type 2 diabetes**?
Yes
120
What is the **urinary system**?
The bodily system that removes impurities and waste products from
our blood
121
Describe the **route** for **blood purification**
1. Blood containing impurities travels in the renal artery to the kidneys
2. The kidneys regulate the levels of salt, ions and urea in the blood. ----> Any excess is sent to the ureter for excretion, and eventually the bladder
3. The purified blood returns to the circulation by way of the renal vein.
122
Where are the **kidneys** located?
Both sides of the lower lumbar reigon
123
Label the *structure* of the **kidney**
124
Label the *structure* of the **nephron**
125
What is the *functions* of the **kidney**?
* They regulate the water content of the blood (vital for maintaining blood pressure)
* They excrete the toxic waste products of metabolism
126
Name the *parts* of the **nephron**?
* Bowman's capsule
* Proximal convoluted tubule
* Loop of Henlé
* Distal convoluted tubule
* Collecting duct
127
What is the **medulla**?
Inner part of the kidney
128
What is the **cortex**?
Outer part of the kidney
129
What *structure* supplies the **kidney blood**?
Renal artery
130
What *structure* **takes away** the **blood** from the **kidney**?
Renal vein
131
Where does **ultrafiltration** occur?
The glomerulus
132
What is the **glomerulus**?
A collection of capillaries at the start of the nephron
133
