Chapters 10 and 11- Removal of wastes and the muscular system

Question 1

why do we have to excrete wastes?

Answer 1

most of these wastes are toxic and would be harmful to one’s health allowed to accumulate

Question 2

what is excretion?

Answer 2

removal from the body of the wastes produced by metabolism

Question 3

what organs are involved in excretion?

Answer 3

lungs, liver, sweat glands, alimentary canal, kidneys

Question 4

what is the liver and its function?

Answer 4

located in the upper abdominal cavity- very large organ with a host of different functions, one of which is the preparation of materials for excretion (typically proteins)

Question 5

what is deamination?

Answer 5

the removal of the amino group from an amino acid molecule

Question 6

what is the deamination equation?

Answer 6

amino acid + oxygen——- (enzymes)——carbohydrate + ammonia

Question 7

what is the excretion of urea equation?

Answer 7

energy + carbon dioxide + ammonia—- urea + water

Question 8

what is the main function of the skin?

Answer 8

to provide a protective covering over the surface of the body, regulate body temperature and secrete sweat via sweat glands (500 ml of water per day)- dissolved in the water are sodium chloride, lactic acid and urea- sometimes even drugs

Question 9

what is the kidney’s structure and function?

Answer 9

reddish-brown organs located in the abdomen- each is approx 11 cm long KNOW HOW TO LABEL ONE- they maintain overall fluid balance, regulate and filter minerals from blood and filter waste materials from food, medications and toxic substances

Question 10

what are the 3 major processes of urine formation?

Answer 10

glomerular filtration, selective reabsorption, tubular secretion

Question 11

what is glomerular filtration?

Answer 11

the filtration of blood in the kidney

Question 12

what is selective reabsorption?

Answer 12

in the renal tubules, reabsorption of some substances and not others

Question 13

what is tubular secretion?

Answer 13

the process whereby ions and drugs are secreted from the blood from the kidney tubule

Question 14

what is the relationship between the structure and function of the kidney?

Answer 14

1. the glomerular capsule surrounds the glomerulus to collect the fluid filtered out of the blood capillaries
2. the arteriole leading out of the glomerulus has a smaller diameter than the arteriole leading in
3. the tubule has two sets of convolutions and a long loop so that each tubule has a large surface area for reabsorption and secretion
4. each kidney has over a million nephrons so the total surface area available for reabsorption and secretion is extremely large

Question 15

what is urine composition?

Answer 15

the body must excrete its waste products (urea, sulfates and phosphates) on a regular basis- so the elimination of these wastes requires a certain amount of water loss. About half of litre of water must be lost every day. When the water content of the body fluids is low, the urine that is excreted is very concentrated

Question 16

what is the percentage of urine composition?

Answer 16

water- 96%
urea- 2%
various ions- 1.5%
other- 0.5%

Question 17

what are kidney stones?

Answer 17

formed from solid crystals that build up inside the kidneys- usually form when urine becomes too concentrated (insufficient fluids in the diet) these crystals can combine to form stones- which can get stuck in the ureter, bladder or urethra causing intense pain

Question 18

what is kidney failure?

Answer 18

a person can lose up to 90% of kidney function- they affect the glomeruli, reducing the ability to filter blood. Excessive proteins can be lost through the urine, causing blood protein levels to fall and therefore accumulating the tissues

Question 19

what is dialysis?

Answer 19

a method of removing wastes from the blood when kidney failure occurs- 2 types: peritoneal and haemodialysis REFER TO NOTES WITH DETAIL ABOUT THESE 2 TYPES

Question 20

because of muscles cells’ form, what does it allow them to do?

Answer 20

ability to contract or shorten (characteristic distinguishes muscle from any other tissue)- when muscles contract, they reduce the distance between the parts they are connected to or decrease the space they surround

Question 21

what are skeletal muscles?

Answer 21

muscle attached to bones; under voluntary control; also called voluntary or strained muscle

Question 22

what are smooth muscles?

Answer 22

muscle that is not under our conscious control; found in walls of internal organs; also called smooth muscle

Question 23

what is cardiac muscle?

Answer 23

the muscle that forms the wall of the heart

Question 24

KNOW THE MICROSCOPIC STRUCTURE

Answer 24

GO LABEL A DIAGRAM

Question 25

what is the sliding filament model?

Answer 25

a scientific model which has simplified the process of muscle contraction- sarcomeres shorten - suggests that this happens because the action and myosin filaments slide over one another - Z lines are drawn closer together and the sarcomere is shortened - shortening of the muscle fibres and therefore the whole muscle

Question 26

what are myofilaments?

Answer 26

one of the structures that make up myofibrils of skeletal muscle fibres

Question 27

what is myosin?

Answer 27

one of the contractile proteins of skeletal muscle

Question 28

what is actin?

Answer 28

one of the contractile proteins of skeletal muscle

Question 29

what are sarcomeres?

Answer 29

the contractile unit of skeletal muscle; consists of actin and myosin filaments

Question 30

what is sarcolemma?

Answer 30

a thin, transparent membrane surrounding a muscle cell

Question 31

what is sarcoplasm?

Answer 31

the cytoplasm of striated muscle fibres

Question 32

what is myofibrils?

Answer 32

a thread-like structure found in the cytoplasm of muscle fibres

Question 33

what are tendons?

Answer 33

fibrous tissue that attaches muscle to bone

Question 34

what is the agonist?

Answer 34

contracting muscle (bicep)

Question 35

what are antagonists?

Answer 35

relaxing muscle… (triceps) pairs of muscles working together that have opposite actions

Question 36

what are synergists?

Answer 36

help of an agonist / stabilisers

Question 37

what are fixators?

Answer 37

protection of muscles

Question 38

what is muscle tone?

Answer 38

partial contraction of skeletal muscles

Question 39

what is posture?

Answer 39

the way a person holds their body when standing or sitting