Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology > Homestatis And Excretion > Flashcards

Homestatis And Excretion Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

Suggest how excretion may occur in simple organisms such as amoeba?

A

Diffusion / contractile vacuole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Name two excretory products other than water and give a location in body in which it is produced?

A

Urea - liver

Co2 - cells [respiration]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the effect of an increase in metabolic rate in response to falling external temperatures?

A

Generates heat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What term is used to describe animals that can vary their metabolic rate significantly?

A

Endotherms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Suggest how animals that cannot significantly vary their metabolic rate may respond to falling external temperatures?

A

Hibernate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is piloerection?

A

Erector muscles contract causing hairs to stand up on skin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How is piloerection an important response to falling external temperatures?

A

A layer of warm air is trapped close to the skin and this layer of air acts as an insulator, reducing heat loss in the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Explain how vasoconstriction can be an important response to falling external temperatures

A

Less blood flows close to the surface as blood vessels contract and there is reduced heat loss

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the main source of heat for an endotherm?

A

Metabolism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the relationship between an endotherm’s body temperature and environment temperature

A

Environment temp - affects enzyme activity which is required for metabolism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the main source of an ectotherm’s body heat?

A

Environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Suggest a relationship between an ectotherm’s body temperature and environment temperature?

A

They gain or lose heat from or to environment [temp]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

State how the liver contributes to homeostasis

A

By the absorption of glucose

Release of glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

State how the lungs contribute to homeostasis

A

Excretes water and co2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

State how nephrons of kidneys contribute to homeostasis

A

Excretion of water and salts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Suggest an advantage of being an endotherm

A

Activity independent of env temp

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Adaption of ectotherm

A

Butterflies and moths may orient their wings to maximize exposure to solar radiation in order to build up heat before take-off

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Why is there a drop in body temperature late at night?

A

Human body temp drops when sleep due to inactivity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Why do children typically have higher body temperatures than adults?

A

Growing - more cell division

High metabolism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Mention one method of excretion in flowering plants

A

Through stomata [O2]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Name the blood vessel that supplies blood to the kidney and from which blood vessel does it arise from?

A

Renal artery and from aorta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

In which cavity are the kidneys located?

A

Abdomen / abdominal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Name one substance other than water excreted in the urine

A

Urea

Salts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Give a feature of a kidney that indicates it is an exocrine gland?

A

Does not produce hormones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

A sample of urine was found to contain protein, is this normal and why?

A

No, because protein molecules are too big

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

A sample of urine was found to contain glucose, is this normal?

A

No, reabsorbed in liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

After a long session of heavy exercise, an athletes urine is likely to be concentrated and low in volume, why?

A

Lost water through sweating therefore after level in blood plasma would be low. This produces ADH which causes collecting ducts to become more permeable to water and so extra water is reabsorbed into blood plasma which reduces salt concentration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Name the substance in which urea is derived from

A

Protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Name a substance in which co2 is derived from

A

Carbohydrate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

From which blood vessel is the afferent arteriole derived from?

A

Renal artery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Where in the kidney is the bowmans capsule located?

A

Cortex

[this is where filtration takes place]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Name a group of biomolecules in the blood which are too large to pass through the filtration system of the nephron

A

Proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Suggest situations which may result in a drop in water content of the blood

A

Do not drink enough water, high salt intake, Infection, hot conditions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Give a precise target area for ADH and how does it reach this target area

A

Distal tubule

In the blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Explain golmerular filtrate

A

Plasma that has entered bowmans capsule

36
Q

Explain why red blood cells are normally absent from glomerular filtrate?

A

Too big to pass through

37
Q

The concentration of glucose is the same in plasma as in glomerular filtrate, how?

A

Small, so can pass through

38
Q

Why is glucose normally absent from urine?

A

Reabsorbed

39
Q

Describe the role of ADH [vasopressin] in human excretion

A

Controls the volume of water re-absorbed in the collecting ducts

40
Q

What is meant by the term homeostasis?

A

The maintenance of a constant internal environment of an organism

41
Q

Distinguish between excretion and egestion

A

Excretion - removal of waste products of metabolism from body
Egestion - removal of unabsorbed material from body

42
Q

Graph between body temp and environmental temp on page 86

Which of the plots relates to the dog and why?

A

Temperature is relatively stable - endothermic

43
Q

Describe the role of the skin in controlling body temperature

A

Cold conditions - retains heat
1) piloerection
Erector muscled contract causing hairs to stand up and trap a layer of warm air close to the skin. This layer of air acts as an insulator for reducing heat loss
2) vasoconstriction
Less blood flows close to the surface as blood vessels contract and there is reduced heat loss
Hot conditions - skin reduces heat
1) sweat
produced and when it evaporates it removes heat from body
2) vasodilation
greater blood flow through superficial capillaries - more blood flows close to surface which results in heat loss

44
Q

What is an endotherm?

A

Generate their own heat from metabolic reactions eg, birds and mammals

45
Q

Where in the nephron does filtration take place?

A

Bowmans capsule or glomerulus

46
Q

Give the part of the nephron where the reabsorption of amino acids occurs

A

Proximal tubule

47
Q

Give two features of the nephron that aid filtration

A

Large surface area

Efferent arteries narrowed than afferent

48
Q

Note one reason why homeostasis is important in the human body

A

Allows organisms to survive efficiently in an environment that is constantly changing

49
Q

Draw a diagram of a section through human skin to show two structures involved in temperature regulation
What are the structures

A

Erector muscle - contracts [piloerection]

Sweat glands - produce sweat [evaporates]

50
Q

What is meant by an ectotherm?

A

Gain or lose heat from/to their environment eg, fish, snakes, lizards

51
Q

How is co2 and urea removed from the body

A

Co2 - lungs

Urea - removed by kidneys and transferred to bladder

52
Q

What internal conditions need to be controlled and how

A

Temperature [piloerection,vasoconstriction,vasodilation, sweat]
Water content
Inc by drinking, lost by sweating and urea
Blood glucose
Inc and dec by hormones

53
Q

What is adipose formed from?

A

Excess fat

54
Q

Why does temperature need to be regulated?

A

Temperature regulates the rate of chemical reactions in the body (esp. enzyme controlled reactions)
•High temps ►can damage enzymes
•Low temps ►slow down reactions

55
Q

What are the three layers of the epidermis of the skin

A

Cornified layer - contains dead cells full of keratin which are continuously being worn away
Granular layer - keratin is formed here
Malphigian layer - contains cells that are constantly dividing by mitosis to replace cellslost from the cornified layer. It also produces melanin(brown or black pigment in skin) which protects skin against harmful effects of UV radiation.

56
Q

What are the three parts of the skin?

A

Epidermis
Dermal
Adipose

57
Q

What does the dermis contain in the skin?

A

Sweat glands
Sebaceous glands
Blood vessels

58
Q

What tissue does the dermal part of the skin consist of

A

Connective tissue which contains collagen for strength

59
Q

What are the functions of the skin?

A

-Protection
[protects body from damage, protects body from the entry of pathogens]
-Release of sebum oil
[keeps skin soft and supple and prevents it from drying out, keeps hair moist and flexible]
-Vitamin production [skins exposure to u.v light causes production of vitamin D]
-Sense organ [contains receptors which allows to act as an organ of touch]
-Excretion [sweat glands - sweat is excreted]

60
Q

Where are sebaceous glands more commonly found?

A

Face and scalp

61
Q

The excessive production of sebum oil may lead to what?

A

Acne

62
Q

What receptors does skin have

A

Temperature, pain and pressure receptors

63
Q

What is sweat made up of?

A

Salts, water and tiny amounts of urea

64
Q

Role of excretory system in relation to homeostasis

A

Regulating body temperature
Removing waste products of metabolism from the body
Regulating water and salt levels in body

65
Q

What are the organs of excretion?

A

Lungs
Kidneys
Skin

66
Q

What is the function of renal arteries in relation to the urinary system

A

carry blood rich in waste and O2 into the kidneys

67
Q

What is the function of renal veins in relation to the urinary system

A

carry clean, deoxygenated blood away from the kidneys

68
Q

What is the function of the kidney?

A
  • Filter waste products from the blood e.g. urea, salts and water [ this happens in the cortex]
  • They reabsorb useful materials the filtrate [ this happens in the cortex and the medulla]
  • osmoregulation
  • maintain blood at PH 7.4
69
Q

What is the function of the ureter

A

Transports urine from the kidneys to bladder

70
Q

What is the function of the bladder?

A

Stores urine

71
Q

What is the function of the urethra?

A

Carries urine out of the body

72
Q

Why must deammination occur?

A

Excess Amino Acids may become poisonous in body

73
Q

What is deamination?

A

is the breakdown of excess Amino Acids to urea in the liver

74
Q

How is urea carried out of the liver?

A

By the blood stream

75
Q

What are nephrons?

A

Structures found in the kidney that make urine

76
Q

Where are nephrons found?

A

In the cortex of the kidney

77
Q

What are the two processes for the formation of urine

A

Filtration

Selective re-absorption

78
Q

Describe filtration of blood in nephron

A

Blood that is high in waste and oxygen enters glomerulus under high pressure.
Part of the blood is forced into the lumen of bowman’s capsule forming the glomerular filtrate which consists of H20, glucose, amino acids, salts, urea, uric acid [theres no blood cells or large proteins present]

79
Q

The blood pressure in the glomerulus is much higher than normal, why?

A
  • Blood in the arteriole is under high pressure
  • Incoming afferent arteriole is wide
  • Outgoing efferent arteriole is narrower (the difference in size increases the already high pressure
80
Q

Describe re-absorption in nephron

A

Substances taken from the filtrate back into the blood
Proximal convoluted tubule - all glucose and amino acids and a lot of NaCl by active transport and a large percentage of water by osmosis
Loop of henle - h20 by osmosis
Distal tubule - H20 by osmosis controlled by ADH
Collecting duct - H2O by osmosis controlled by ADH

81
Q

Where does reabsorption and filtration take place in kidney?

A

Cortex

82
Q

What term is used to denote the functional unit of kidney?

A

Nephron

83
Q

What term is used to denote the dilute solution produced by nephron in early stages of process of urine formation

A

Glomerular filtrate

84
Q

Where is ADH produced?

A

Pituitary gland

85
Q

Which precise area of the functional unit of the kidney does ADH target?

A

Collecting duct

Biology (36 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions