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Homeostasis Flashcards

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1
Q

What organisms have high and low tolerance limits?

A

High - rats, bacteria, and cockroaches

Low - polar bears and elephants

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2
Q

What is the photic zone?

A

Upper 200m of the ocean. It is the only zone that light can pass through in the ocean. Light doesn’t pass this layer, therefore all life and living organisms live in this zone.

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3
Q

What is ADH?

A

ADH - anti diuretic hormone. It is a hydrophilic peptide hormone, thus needs to bind to a receptor protein to move through the membrane.
Helps to increase the reabsorption of water into the bloodstream.

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4
Q

What is urine composed of?

A

Composed of urea, ammonia and water

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5
Q

Why do we need to control the pH levels of the blood?

A

Need to control the pH levels of the blood because if not controlled it will disrupt the secondary interactions and hydrogen bonding within the protein as molecules will exceed past its optimum. Disrupting these interactions will change the unique 3D shape of the protein, and hence substrates will no longer bind as protein has denatured.

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6
Q

What are glands?

A

Glands are effectors. They are a group of signal cells.

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7
Q

Where in the world is the highest and lowest light intensity?

A

Highest - the equator

Lowest - the north and south poles

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8
Q

What are biotic and abiotic factors?

A

Biotic - living

Abiotic - non living

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9
Q

What is polarity?

A

Represents the number of signals

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10
Q

What is the synapse?

A

neurons are not attached to one another. Thus, the synapse is the space between the neurons.

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11
Q

What is glycogenlysis and glycogenesis?

A

glycogenlysis - breakdown of glycogen (glycogen to glucose)

glycogenesis - formation of glycogen (glucose to glycogen)

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12
Q

What happens when species falls out of tolerance limit?

A

The species will either adapt to changing environmental conditions, or the species will die.

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13
Q

What is the advantage of plants having bigger leaves?

A

Bigger leaves, increase the surface area, increasing the sunlight, and hence increase photosynthesis.

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14
Q

What are capillaries? What are their characteristics?

A

Capillaries are the site of material exchange. They are the thinest part of the circulatory system.
Characteristics:
High surface area, high pressure, endless supply of blood.

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15
Q

Process when too much glucose.

A

Pancreas detects low glucose levels, and beta cells release the insulin hormone into the blood stream, which travels to insulin receptors on liver cells, bind because they are complementary. Once it binds, sends signal to the cell to activate the glute protein. These proteins transport glucose into the liver cell and it is catalysed into glycogen. Glucose levels decrease.

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16
Q

Polarity of neurones

A

Interneuron and motorneuron - multi polar as they receive many signals
Sensory neuron - unipolar as it has only one neuron goin in

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17
Q

What are nerve cells? What do they do?

A

Nerve cells are differentiated cells. They send electrochemical signals/messages. They are shaped specifically so that electrical pulses can travel down the nerve.

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18
Q

What is presynaptic and postsynaptic cell?

A

Pre - axon terminal

post - dent-rite

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19
Q

Characteristics of glomerulus

A 
High surface area - villi increase SA
High pressure 
High supply of blood 
Moist 
Once cell thick
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20
Q

Cells involved in the endocrine system?

A

Signal cell - make hormones, release the hormones into the blood stream,
Target - Secrete hormones. Hormones act on the target cells. They have membrane receptors that are complementary to hormone, thus only act on certain cells.

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21
Q

What is the endocrine system?

A

Involves the collection of glands that secrete hormones into the circulatory system. Secrete special chemicals that form hormones.

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22
Q

Types of hormones

A

Peptide - they are not lipid soluble. They need to bind to receptor proteins along the cell membrane in order for the signal to be sent into the nucleus and then for the response to be carried out.
Steroid - they are lipid soluble. They pass through the membrane, and bind to receptor proteins in the cytoplasm.

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23
Q

Blood components

A 
Plasma - 55%
45% 
Red blood cells 
White blood cells (fight diseases)  
Platelets (clotting factor)
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24
Q

Water availability

A

Limiting Factor
Bacteria could form spores in response to lack of water and may survive like this until water becomes available.
Low levels cause tadpoles to begin to metamorphose

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25
Q

Ectotherm and Endotherm - ways to regulate temperature

A

Ectotherm - do not regulate body temperature, rely on external heat sources (may need to change location)m to maintain body temperature.
Body temp changes with environment temp.
Endotherm - Maintain body temp by controlling rate of respiration in cells. Energy is released as heat during respiration. Increase resp = more heat, decrease resp = less heat

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26
Q

Liebigs law of minimum

A

Limiting factor present in the smallest amount will function to limit population growth. If the most limiting factor is removed, population will grow until limited by next limited resource.
In aquatic systems, nutrients are the most limiting. If extra nutrients are added, algae populations bloom until light becomes limiting.

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27
Q

Why do organisms regulate body temperature?

A

Regulate body temperature to ensure that metabolic reactions occur at the rate that supports maintenance of the processes. Reactions are catalysed by enzymes.

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28
Q

Lymphatic system

A
  1. Removes the interstital fluid that does not make its way to the blood. Redirects it to place in body with lowest blood pressure (vena cava) and puts fluid back in the blood.
  2. Transports the WBC for immune system
  3. Absorbs the extra lipids involved in the digestive system
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29
Q

Types of neurons

A
  1. Sensory neuron - detect stimuli and carry a nerve impulse towards interneuron in CNS
  2. Interneuron - found in the brain and the spinal cord
    - links sensory receptor to motor receptor
    - receive signals from sensory neuron and transmit to motor neuron
    Motor neuron - carry nerve impluses from CNS to effectors (e.g muscles and glands), results in a response
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30
Q

What happens if CO2 not removed?

A

Since CO2 is acidic, it will lower the pH of the blood. This could cause the hydrogen bonds within the protein to break, causing the protein to denature, changing shape of binding site, therefore protein not performing its function properly.

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31
Q

What are beta cells and alpha cells?

A

Beta cells - secrete insulin

Alpha cells - secrete glucagon

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32
Q

Filtration process

A

occurs in the glomerelus and bowmans capsule
blood comes in from afferent vessel and leaves through the efferent vessel.
Urea, water, amino acids, salts and glucose move out of the blood into the glomeruls due to high pressure. Become filtrate in the bowmans capsule.
RBC and large proteins are too large to be filtered out.

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33
Q

Diabetes

A

Diabetes is the inability to maintain normal blood sugar levels.
Type 1 - destroys the insulin producing cells (alpha cells). Cannot control glucose levels, pancreas cannot produce insulin.
Type 2- developed from too high sugar intake for a long period of time. Body becomes resistant to insulin, unable to make enough.
Gestariord diabetes - body cells have reduced response to insulin during pregnancy.

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34
Q

Role of TSH in the production of thyroxine

A

The hypothalamus release thyroid-releasing hormone (TRH) which stimulate the anterior pituitary gland to secrete the thyroid-stimulating hormone (TSH). This triggers the increase in thyroxine production by the thyroid gland.
Increase in thyroxine increases the metabolic rate, increasing the temperature.

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35
Q

What is thermoregulation? What happens when there is an increase or decrease in temperature?

A

Thermoregulation is the maintenance of body temperature.
Increase in temp, break the hydrogen bonds, causing shape of active site to change, denaturation could occurs and metabolic processes rate decreases.
Decrease in temperature, decrease kinetic energy, decrease frequency of successful collision, decrease rate of reaction. Slow metabolism, impacting the brain.

36
Q

Role of the hypothalamus

A

Provides the bridge between the nervous and endocrine system. It is directly above the pituatory gland. Composed of neurosecreting cells that send hormones and nervous signals.
Detect blood pressure and communicate with pineal gland.

37
Q

What is osmolarity?

A

Number of solutes per unit of water

38
Q

What are diuretics? What do they do?

A

They are ADH inhibitors, which inhibit the blood from retaining water.
E.g
alcohol, coffee, watermelon

39
Q

Blood volume and pressure

A

Increase in water content, increase blood volume, increase blood pressure, decrease osmolarity
Decrease in water content, decrease in blood volume, decrease blood pressure, increase in osmolarity

40
Q

What are tolerance influenced by?

A

They are influenced by abiotic factors (physical and chemical processes)

41
Q

What does euphoric mean?

A

Euphoric environment has a sudden increase/injection of nutrients. E.g could cause algea blooms to form.

42
Q

What does light intensity depend on?

A

Light intensity depends on the variable position of the earth, and how close it is from the sun.

43
Q

What is osmoregulation?

A

Maintenance of water and solute balance in the body. Kidney is the main area involved.

44
Q

CO2 from the blood process

A

Charged particles such as hydrogen carbonate cannot pass through the BBB. Thus co2 passes through the BBB into the CSF. Once in the CSF, the co2 reacts with water to form carbonic acid (Co2 + H2o –> H2CO3). Once it forms carbonic acid catalysed by the carbonic anhydrase enzyme and then it dissociates into hydrogen carbonate and H+ ions (H2CO3 –> HCO3- + H+). The chemoreceptors in the medulla oblongata detect the increase in H+ and send a nervous signal to the intercostal muscles and diaphragm to increase the ventilation rate, decreasing the acidity, increasing the pH.

45
Q

What does homeostasis mean?

A

The process of maintaining steady internal environment despite changes in the external environment. These changes are self regulating and fluctuate around a pre-set amount. Purpose is to get body back to optimal conditions.

46
Q

What is reabsorption and secretion?

A

Reabsorption - glucose, amino acids, and salts are reabsorbed into the blood via passive transport. Urea remains in the tubule, water moves via osmosis.
Secretion - waste substances that were unable to move into the glomerulus, bowmans capsule and are secreted into tubule. K+, H+, ammonia, drugs and alcohol are secreted through active transport.

47
Q

What are sensory receptors? What do they do?

A

Sensory receptors are located nearest to where they can detect change. This is impacted in order to survive in external environment. - located in PNS
Function:
Detects stimulus - message then gets carried to CNS for it to be processed (sent to effector), (muscles or glands), where a response is then made.

48
Q

What do receptors respond to?

A

Intensity
location
duration

49
Q

Nerve features

A

Cell body - contains nucleus, cytoplasm, mitochondria, ER, etc
Axon - a long fibre that conducts nerve impulses from cell body to denrites
Myelin sheath- an insulating layer that increases the rate of which a nerve impulse is conducted along axon
Axon terminal - small branches of the axon that form the connections with other neurons in CNS
Denrites - extensions of the cell body that release chemical signals from axon terminal and other neurons. Convert these signals into nerve impulses that are transmitted to cell body.

50
Q

Tolerance limit ranges

A

High tolerance limit - widely distributed, may of that species.
Low tolerance limit - not as highly distributed, fewer species

51
Q

What are abiotic factors? What do they do?

A

Abiotic factors influence the distribution of species.

e.g weather, temperature, pH, light intensity, water speed, rainfall, turbidity, nutrient availability.

52
Q

What does the body do when there is an increase in heat, thus need to decrease body temp?

A
  1. Sweating - nerve impulses send to glands that secrete sweat on body surface. the evaporation of sweat on the surface of the skin, will decrease the body temp.
  2. Vasoconstriction - nervous signal sent to the sphincter muscles of the aterioles, causing blood vessels to dilate, increasing blood flow to the surface of the skin, increasing heat lost from the blood.
  3. Decrease thyroxine production, which will decrease the metabolic rate, decrease the head produced, decreasing body temp.
53
Q

What is an ectotherm and endotherm?

A

Eco - do not regulate their own temperature, temperature changes with environment.
Endo - body temperature remain constant, no matter what the temperature is outside.

54
Q

What is BBB and CSF?

A

BBB - blood brain barrier, does not let charged particles through.
CSF - cerebral spinal fluid. It is the fluid that the brain is bathed in and offers protection for the brain. CSF protected by the thin layer of cells BBB.

55
Q

Process to decrease glucose levels in the blood

A

The pancreas detects a decrease in blood glucose levels. Alpha cells secrete the glucagon hormone into the bloodstream. Glucagon bind to receptors on the liver cells due to being complementary. Once binded it is catablysed and sends signals inside the cell, allowing glucose to be released as glycogen is broken down. Response is that the blood glucose levels increase.

56
Q

Pituitary gland roles

A

Anterior Pituitary gland (front)
- linked with the growth/development and production of TSH. TSH acts on thyroid gland, releasing thyroxine, increasing metabolic rate, increasing heat
Posterior Pituitary gland
- ADH signals aquaporins to move into the cell membrane of collecting duct to increase water reabsorption and thus reduce the urine output.

57
Q

What is negative and positive feedback system?

A

Negative - response inhibits the stimulus (occurs in both the nervous and endocrine system)
Positive - response promotes the stimulus (e.g apple ripening, giving birth)

58
Q

What are the pancreas and liver?

A

Pancreas - effector, organ that makes hormones

Liver - stores and releases glucose/glycogen

59
Q

What do the kidneys do?

A

Filter blood to remove wastes
Regulate water levels
Nephron main functional unit of the kidney - found in medulla

60
Q

What is glucose and glycogen?

A

Glucose - not stored, monosaccaride, found in the blood

Glycogen - stored, polysaccaride, synthesised from glucose, found in liver, fat, muscle cells and is stored

61
Q

Glucose as a tolerance limit

A

Below tolerance limit (Hypoglycaemia)
- Role of respiration, decrease ATP, cannot maintain life processes.
- Difficulty thinking due to brain cells not readily getting enough glucose
- person will enter a coma
Above the tolerance limit
Hyperglycaemia - high concentration of blood glucose, cause coma and death
Glycosuria - glucose enters urine, more water moves out through osmosis, thus increased urination
Polyphagia - person eats excessively if too much glucose is urinated out

62
Q

Controlling blood glucose levels (osmosis )

A

Excess glucose - too high solute concentration, water moves into the RBC via osmosis towards the higher concentration, causing crenation in RBC
Low glucose - move into the liver cell (higher concentration), causing the cell to burst (lysis)

63
Q

Transport by blood (signal and target cells)

A

Signal cells release/synthesise hormones into the blood stream, travelling all around. Target cells act on a certain hormones, as their cell membrane receptors are complementary shape to hormones. When it binds to (hormones) send signals to nucleus to carry out information.

64
Q

The pineal gland

A

Located in the back of the brain
Linked to photoreceptors located in the retina, detect decrease in light at night.
Message is sent to pineal gland to increase melatonin production, ceases when light increases.

65
Q

Transport of blood with veins and arteries

A

Arteriole end
Blood comes in, fluid is rich in nutrients such as glucose, o2 and antibiotics. Blood pressure increase, fluid is pushed out into the cell, leaving the RBC behind, forming osmotic pressure.
Venue end
Osmosis pushes fluid into capillaries due to increase osmotic pressure. Fluid comes back in with wastes allowing it to be decomposed correctly.

66
Q

General statements about what tolerance limits do?

A

Defined by environmental conditions required by the species.
They relate to abiotic factors in the environment of the organisms.
They determine the distribution and abundance of the animal

67
Q

What are the two parts of the nervous signal and their function?

A

CNS - interneurons
- Brain and spinal cord - receive and send signals, in charge of decision making.
Receive input, decrease output (response)

PNS- sensory and motor neurons
Detect stimulus and carry information between peripheral or other organs, or CNS. Made up of voluntary and involuntary systems.

68
Q

The role of ADH

A

Chemoreceptors in the hypothalamus detect the decrease in water levels. These receptors send a message to the posteria pituitary gland to secrete ADH. ADH (hydrophilic peptide hormone) travels in the blood stream and binds to ADH receptors that line the collecting duct, due to being complementary. Once binded it activates vesicles containing aquaporins. Aquaporins fuse with the cell membrane, increase the permeability of the membrane, increase water reabsorption in the blood. urine is more concentrated.

69
Q

Where are blood glucose receptors located?

A

Blood glucose receptor located in the pancreas. Hormones are located in the islets of Lagherhans
islets Lagherhans contain alpha (glucagon) and beta cells (insulin)

70
Q

What does the body do when it needs to increase heat gain?

A 
Shivering - nerve messages to skeletal muscles sent to rapidly relax and contact muscle movement 
Vasodilation - nerve impulses sent to the blood vessels which constrict sphincter muscles near arterioles = decreased blood flow to surface of the skin, decrease heat loss from the blood
Thyroxine production (hormonal response) - increase metabolic rate, increased heat production, increase heat gain.
71
Q

Flight or fight response (role of adrenaline)

A

Physical reaction that occurs in response to harmful event, attack or threat to survival
In response, body’s sympathetic nervous signal (SNS) is activated due to release in hormones. SNS stimulate adrenal glands to release adrenaline and incadrenaline. These hormones work to smooth muscles, cardiac muscles, brain and the pancreas. Whereby the parasympathetic system works to bring the body back to the normal state.

72
Q

Neurotransmitter process

A

Neurotransmitter filled with vesicles in axon terminal. Impulse come down toward axon terminal and stimulate the vesicle to move toward end. Vesicle fuse with the cell membrane, releasing transmitter into synapse. on other side of synapse is the dendrite with membrane receptors that are complementary to neurotransmitter. Once neurotransmitter binds, triggers an electrical pulse to continue next neuron.
Post synaptic cell release vesicle into synapse towards pre synaptic cell.

73
Q

Osmoconformers and osmoregulators

A

Osmoconformers
- same osmolarity as the environment
- this property limits diffusion of water between the organism and the environment as solute concentration gradient is minimised (E.g starfish, jellyfish)
osmoregulators
- Regulate their internal osmolarity despite changes to environment
- Organism can regulate diffusion of solutes and water (plants, bacteria, vertebrates)

74
Q

Sympathetic and parasympathetic system

A 
Sympathetic nervous system
dilate pupil 
inhibits the flow of saliva 
accelerate heart rate 
dilate bronchi 
conversion of glycogen to glucose 
secretion of adrenaline 
inhibits bladder concentration
parasympathetic nervous system 
contracts pupil 
stimulate the flow of saliva 
decrease heart rate 
constricts bronchi 
contracts bladder concentration
75
Q

What is the difference between the stimulus and receptor in the stimulus response model?

A

Stimulus is the change in the environment, and the receptor are the specialised cells and tissues that detect the change.

76
Q

What are glial cells?

A

Theglial cellssurround neurons and provide support for and insulation between them.Glial cellsare the most abundantcelltypes in the central nervous. Types ofglial cellsinclude oligodendrocytes, astrocytes, ependymalcells, Schwanncells, microglia, and satellitecells.

77
Q

What are reflex actions?

A

Reflex actions do not involve the brain in the decision making process - instead sensory information is relayed directly to motor pathways within the spine. Immediate response.

78
Q

Examples of different neurotransmitters and what they do

A

Acetylcholineis the chief neurotransmitter of the parasympathetic nervous system, the part of the autonomic nervous system (a branch of the peripheral nervous system) that contracts smooth muscles, dilates blood vessels, increases bodily secretions, and slows heart rate.
Dopamineis an important chemical messenger in the brain that has many functions. It’s involved in reward, motivation, memory, attention and even regulating body movements
Serotoninin the brain is thought to regulate anxiety, happiness, and mood
Noradrenaline(norepinephrine), often referred to as one of the ‘stress hormones’ that normally causes an increased heart rate, increased blood pressure, dilation of pupils, dilation of air passages in the lungs, vasoconstriction…
Adrenaline a hormone secreted by the adrenal glands that increases rates of blood circulation, breathing, and prepares muscles for exertion.
Gamma-aminobutyric acid (GABA) is a neurotransmitter that stops nerve impulses in the brain and spinal cord.

79
Q

What are Excitatory neurotransmitters and inhibitory neurotransmitters? Examples?

A

Excitatory neurotransmitters stimulate the next neuron in the nerve pathway (e.g acetylcholine, dopamin, serotonin, noradrenaline and adrenaline)

inhibitory neurotransmitters block the next neuron in the pathway. E.g GABA, glycine.

80
Q

What are neuromuscular junctions?

A

Neuromuscular junctions is the place where motor neurons reach muscle cells.
This is where neurotransmitters like acetylcholine are involved.
Following their secretion, if neurotransmitters remain in the synaptic cleft they would cause continual stimulation of the next neuron in the pathway or effector. Thus following secretion they are either:
Destroyed by an enzyme (Acetylcholinerase breaks down acetylcholine remaining in the synaptic cleft), Diffuse away or Absorb into cell

81
Q

What are reflex arcs? Examples?

A

Reflexes, or reflex actions, are involuntary, almost instantaneous movements in response to a specific stimulus.
Examples:
Hand on a hot object: a simple reflex arc happens if we accidentally touch something hot. Receptor in the skin detects a stimulus (the change in temperature). Sensory neuron sends electrical impulses to a relay neuron, which is located in the spinal cord of the CNS, whereby the motor neuron will then send message to effector to carry out action)

82
Q

Pathway of reflex responses?

A

Sensory neuron sends electrical impulses to a relay neuron, which is located in the spinal cord of the CNS. Relay neurons connect sensory neurons to motor neurons. Motor neuron sends electrical impulses to an effector. Effector produces a response (muscle contracts to move hand away).

83
Q

What are neurotransmitters?

A

a chemical substance which is released at the end of a nerve fibre by the arrival of a nerve impulse and, by diffusing across the synapse or junction, effects the transfer of the impulse to another nerve fibre, a muscle fibre, or some other structure.

84
Q

What is different about reflux responses?

A

Does not involve the brain

85
Q

examples of reflex responses

A

A few examples of reflex action are: When light acts as a stimulus, the pupil of the eye changes in size. Sudden jerky withdrawal of hand or leg when pricked by a pin. Coughing or sneezing, because of irritants in the nasal passages

86
Q

What is intertestial fluid?

A

It is the fluid that is found all around the body and around the cells. It helps bring oxygen and nutrients to the cells, and helps remove wastes from them.

87
Q

Why are sensory receptors important?

A

major role of sensory receptors is to help us learn about the environment around us, or about the state of our internal environment. Different types of stimuli from varying sources are received and changed into the electrochemical signals of the nervous system. sensory receptors account for our ability to see, hear, taste, and smell, and to sense touch, pain, temperature, and body position. They also provide the unconscious ability of the body to detect changes in blood volume, blood pressure, and the levels of salts, gases, and nutrients in the blood. Therefore they are important as they enable the body to detect the changes in order to maintain the optimal conditions.

Biology Q Cards (4 decks)

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