Chapters 10 and 11- Removal of wastes and the muscular system Flashcards
why do we have to excrete wastes?
most of these wastes are toxic and would be harmful to one’s health allowed to accumulate
what is excretion?
removal from the body of the wastes produced by metabolism
what organs are involved in excretion?
lungs, liver, sweat glands, alimentary canal, kidneys
what is the liver and its function?
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)
what is deamination?
the removal of the amino group from an amino acid molecule
what is the deamination equation?
amino acid + oxygen——- (enzymes)——carbohydrate + ammonia
what is the excretion of urea equation?
energy + carbon dioxide + ammonia—- urea + water
what is the main function of the skin?
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
what is the kidney’s structure and function?
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
what are the 3 major processes of urine formation?
glomerular filtration, selective reabsorption, tubular secretion
what is glomerular filtration?
the filtration of blood in the kidney
what is selective reabsorption?
in the renal tubules, reabsorption of some substances and not others
what is tubular secretion?
the process whereby ions and drugs are secreted from the blood from the kidney tubule
what is the relationship between the structure and function of the kidney?
- the glomerular capsule surrounds the glomerulus to collect the fluid filtered out of the blood capillaries
- the arteriole leading out of the glomerulus has a smaller diameter than the arteriole leading in
- the tubule has two sets of convolutions and a long loop so that each tubule has a large surface area for reabsorption and secretion
- each kidney has over a million nephrons so the total surface area available for reabsorption and secretion is extremely large
what is urine composition?
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
what is the percentage of urine composition?
water- 96%
urea- 2%
various ions- 1.5%
other- 0.5%
what are kidney stones?
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
what is kidney failure?
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
what is dialysis?
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
because of muscles cells’ form, what does it allow them to do?
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
what are skeletal muscles?
muscle attached to bones; under voluntary control; also called voluntary or strained muscle
what are smooth muscles?
muscle that is not under our conscious control; found in walls of internal organs; also called smooth muscle
what is cardiac muscle?
the muscle that forms the wall of the heart
KNOW THE MICROSCOPIC STRUCTURE
GO LABEL A DIAGRAM
what is the sliding filament model?
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
what are myofilaments?
one of the structures that make up myofibrils of skeletal muscle fibres
what is myosin?
one of the contractile proteins of skeletal muscle
what is actin?
one of the contractile proteins of skeletal muscle
what are sarcomeres?
the contractile unit of skeletal muscle; consists of actin and myosin filaments
what is sarcolemma?
a thin, transparent membrane surrounding a muscle cell
what is sarcoplasm?
the cytoplasm of striated muscle fibres
what is myofibrils?
a thread-like structure found in the cytoplasm of muscle fibres
what are tendons?
fibrous tissue that attaches muscle to bone
what is the agonist?
contracting muscle (bicep)
what are antagonists?
relaxing muscle… (triceps) pairs of muscles working together that have opposite actions
what are synergists?
help of an agonist / stabilisers
what are fixators?
protection of muscles
what is muscle tone?
partial contraction of skeletal muscles
what is posture?
the way a person holds their body when standing or sitting
