Musculoskeletal System, the Kidney and Osmoregulation Flashcards

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1
Q

Difference between endo and exoskeleton

A

Exo - hard protective skeleton on the outside of the body
Endo - Skeleton on the inside of the body made of two types of tissue bones and cartilage.

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2
Q

What is a first-class lever

A

Have the fulcrum placed between the resultant and effective force, ex. contractions in the neck

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3
Q

What is a second-class lever

A

the resultant force between the effort force and the fulcrum, ex. calf muscle contracting

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4
Q

What is a third-class lever

A

effort force is between the resultant force and te fulcrum, ex. elbow

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5
Q

How do levers work in the skeleton?

A

Bone is a lever. A joint is a fulcrum. A muscle contraction is the effective force, the body part moved is the resultant force.

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6
Q

What is a flexor muscle?

A

A muscle that decreases the angle between the 2 sides of the joint. Ex, flexing the bicep.

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7
Q

What is an extensor muscle?

A

A muscle that increases the angle between the 2 sides of the joint. Ex, flexing the tricep.

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8
Q

Explain the movement of grasshoppers through levers and muscles.

A

When the tibia moves out it is an extensor muscle, fist class lever. When the tibia moves in the flexor muscle contracts, class three lever.

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9
Q

What is a synovial joint?

A

Most common type of joint. Features a fluid-filled space between smooth cartilage parts at the ends of articulating bones such as those in the spine.

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10
Q

What are the two types of joints?

A

Ball and Socket: Move bones along several axes. Shoulder and hip.
Hinge: Move along one axis. Elbow and knee.

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11
Q

What is smooth muscle fibre?

A

Located in the walls of blood vessels, stomach and intestines. Moves internal organs. Contractile, uninuclear cells.

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12
Q

What is cardiac muscle?

A

Located on the heart. Pumps blood. Cylindrical and striated cells.

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13
Q

What is skeletal muscle?

A

Attached to the bones. Used for locomotion. Long cylindrical, striated, multinuclear cell bundles.

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14
Q

Skeletal muscle structure

A
  • Each bundle runs the length of the muscle and is attached to at least one motor neuron.
  • Each bundle contains multiple myofibrils.
  • Myofibrils are made up of chains of sarcomeres.
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15
Q

Structure of myofibrils

A
  • Actin is at the ends between Z-lines, myosin is in-between actin
  • Light bands are just actin
  • Dark bands are actin and myosin overlap
  • H zone is just myosin
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16
Q

Contraction of muscles in the myofibril

A

Actin slides over myosin causing the sarcomere to shorten. Light bands shorten, dark bands stay the same, H zone disappears.

17
Q

Control of skeletal muscle contraction

A
  1. Action potential arrives
  2. Causes the release of ACh
  3. ACh causes another action potential along the sarcomere and the t-tubules.
  4. Ca channels on the sarcoplasmic reticulum open, Ca moves to myofibrils
  5. Ca creates ‘cross bridges’ b/w actin and myosin, sarcomere contracts.
18
Q

What is the role of ATP in the sliding fillaments

A
  1. Myosin heads are ‘cocked’ by ATP to ADP + P
  2. Myosin attached to expand actin binding sites, form cross bridges, P released
  3. ADP released to bend myosin towards centre of sarcomere, actin pulled inwards
  4. ATP binds to myosin, heads detach from actin sites
19
Q

What is nitrogenous waste?

A

Metabolic waste from the body. AA and nucleic acids are broken to produce nitrogenous waste.
Aquatic - release NH3 directly into the environment to dilute it
Terrestrial - NH3 is converted to less toxic molecules
Mammals - metabolize NH3 into urea
Reptiles and birds - metabole NH3 into uric acid, which is less toxic

20
Q

What is osmolarity

A

the solute concentration of a solution

21
Q

What is an osmoconformer?

A

Maintain constant internal solute concentrations that are the same as in the environment.
- Most are marine invertebrates (starfish)

22
Q

What is osmoregulation?

A

How kidneys regulate the amount water absorbed. It cost ATP. More common (Fish)

23
Q

What is a malphigian tubue system?

A

A form of homeostasis of osmoregulation in which the [] of hemolymph (in insects) or blood is kept in a certain range. Carries out osmoregulation and removes nitrogenous waste. Pseudo kidney for insects.

24
Q

What do the parts of the kidney do?

A

Medulla - reabsorption of water
Cortex - ultrafiltration and selective absorption of blood contents
Ureter - carries urine to bladder
Pelvis - collecting ducts deliver urine to pelvis to be passed to ureter

25
Q

Blood in renal vein and artery

A
  • Vein still has proteins, artery doesn’t
  • Vein has less urea and toxins
  • Vein has less oxygen and more CO2
  • Vein has less salts and ions
  • Vein has less water and glucose
26
Q

What are the three steps of urine formation?

A
  1. Ultrafiltration - blood and fluid pass through a selective membrane
  2. Reabsorption - transfer of water, ions and nutrients back to blood via passive and active transport
  3. Secretion - Removal of waste materials from the blood and intercellular fluid into the urine
27
Q

Ultrafiltration

A
  • separation of small molecules from the blood
  • blood is forced at a high pressure through a ‘filter’ that only allows the small molecules through not larger ones (proteins, blood cells)
  • resultant liquid ‘glomerularfiltrate’
28
Q

Reabsorption

A
  • useful substances in the glomerularfiltrate enter the proximal convoluted tubule, reabsorbed back into blood
  • cells in the PCT have microvilli
  • Transport proteins are embedded in the microvilli (pumps and channels)
29
Q

Loop of Henle

A
  • generates a high [] of solutes in tissue fluid of the medulla compared to filtrate in nephron
  • descending limb is permeable to water, not salt
  • ascending limb is permeable to salt, not water
  • therefore, fluid is saltier and more hypotonic as it descends
  • Blood surrounding LoH runs in a counter-current
  • Salts released are drawn down the medulla establishing a salt gradient.
30
Q

Water reabsorption by the collecting duct

A
  • water is drawn out from the salty medulla into the collecting duct via osmosis and flows to capillary
  • flow in duct and capillary is counter-current [] gradient
  • water collected is controlled by ADH (anti-diuretic hormone)
31
Q

Function of ADH

A

If dehydrated, ADH acts on cell walls creating aquaporins more permeable to water. More water is transferred to blood. Urine output is hypertonic, less urination

32
Q

Length of the LoH

A
  • Longer loop means more water absorption and larger medulla
  • Animals in dry habitats have longer LoH
  • Higher [] in medulla = greater water absorption, high [] of urine, water conserved in dry habitats
33
Q

Consequences of dehydration

A

More water leaving than entering, fluids become hypertonic. Results in thirst, dark urine, low blood pressure, high heart rate and body temp.

34
Q

Consequences of overhydration

A

More water entering than leaving, fluids become hypotonic. Clear urine, swelling of cells, disruption of nerve function, seizures, coma, death.

35
Q

Kidney failure

A
  • Kidneys fail to adequately filter waste products from blood
  • Can be treated through:
    Kidney transplants and hemodialysis
36
Q

Hemodialysis

A
  • Purifies the blood if kidney don’t work
  • Lasts 4 hours, 3x a week
  • You can be treated this way for years
37
Q

Kidney stones

A
  • Salt and minerals from dehydration
  • treated by ultrasonic waves targeted at a stone causing it to fragment
  • leaves via urine
38
Q

Testing kidney function

A

Urinalysis: physical and chemical analysis of urine to look for drugs, diabetes, UTI, tumours, stones
Test Strips: indicates presence of chemicals
Microscopy: using a microscope to look for blood, yeast or bacteria.