Animal Responses & Excretion Flashcards
Which type of muscle is under voluntary control?
skeletal muscle
Which type of muscle has the slowest contraction speed?
smooth muscle
What two types of muscles are striated?
cardiac and skeletal muscle
Which type of muscle is branched?
cardiac muscle
Which type of muscle is multinucleated?
skeletal muscle
Which type of muscle is capable of remaining contracted for relatively long periods of time?
smooth muscle
What is actin?
a molecule that forms the thin protein filaments in myofibrils in muscle fibre.
What is myosin?
a molecule that forms the thick protein filaments in myofibrils in muscle fibre.
What is sarcomere?
the distance between adjacent Z-lines on a myofibril.
What is the name of the band on a sarcomere where actin and myosin do not overlap?
the I-band.
What is the name of the band on a sarcomere where actin and myosin do overlap?
the dark-band (A-band).
Which protein filament is present in the H zone of a sarcomere?
myosin (filament).
What is a neuromuscular junction?
where a motor neurone meets a skeletal muscle fibre.
Which ions are released when an action potential reaches a neuromuscular junction?
Calcium ions (Ca2+).
What is the neurotransmitter found in the neuromuscular junction?
acetylcholine (ACh).
Which enzyme breaks down the neurotransmitter found in the neuromuscular junction?
acetylcholinase (AChase).
What change occurs when an ATP molecule binds to the myosin head during muscle contraction?
the myosin head detaches from the actin filament.
What change in the myosin head takes place when energy is released by the hydrolysis of ATP?
The myosin head changes its shape causing it to return to its original position.
Energy from the hydrolysis of ATP is needed for what two processes during muscle contraction?
Movement of myosin heads and active transport of calcium ions back into the sarcoplasmic reticulum.
What is the role of creatine phosphate in muscle contraction?
to act as a reserve supply of phosphate ions to reform ATP quickly during short bursts of high activity.
Which part of the brain controls learning, memory and conscious thoughts?
cerebrum
Which part of the brain controls unconscious actions including posture and balance?
cerebellum
Which part of the brain controls breathing rate and heart rate?
medulla oblongata
Which part of the brain is the regulatory centre for temperature and water balance?
hypothalamus
What is the pituitary gland?
the part of the brain that stores and secretes hormones.
Define the term excretion.
The removal of waste products of cell metabolism from the body.
What are the three main waste products which need to be excreted in mammals?
- CO2
- bile pigments
- urea
How do hepatocytes respond to insulin?
They take up glucose and convert it into glycogen for storage.
What is deamination?
a process where the liver removes the amine group from amino acids when breaking down excess proteins.
What does the ornithine cycle do?
combines ammonia with carbon dioxide to produce urea (in the liver).
What is detoxification?
The breakdown of alcohol and drug molecules.
Name the three main areas which can be seen when a whole kidney is cut open.
- cortex
- medulla
- pelvis
What is a nephron?
the microscopic functional units of the kidney responsible for producing urine.
What are the four main mechanisms that must occur in the nephron to convert filtrate into urine?
- ultrafiltration
- selective reabsorption
- secretion
- excretion
What are the five main structures found in a nephron?
- Bowman’scapsule,
- proximal convoluted tubule,
- loop of Henle
- distal convoluted tubul
- collecting duct
What is the name of the knot of capillaries found within the Bowman’s capsule?
glomerulus.
In relation to kidney function, what is meant by the term “diuresis”?
an increase in the production of urine by the kidney resulting in a large volume of dilute urine.
Where is ADH made in the body?
the hypothalamus.
Where is ADH stored in the body?
In the posterior pituitary gland.
What is the role of the hypothalamus in osmoregulation?
- osmoreceptors in the hypothalamus are sensitive to changes in the water potential of the blood.
- nerves from the hypothalamus control the release of ADH by the posterior pituitary gland.
ADH exerts its effect by binding to receptors on the surface of which cells?
Cells in the walls of the collecting duct.
What is the name given to the outer region of the adrenal glands?
adrenal cortex.
What is the name given to the inner region of the adrenal glands?
adrenal medulla.
What are the two main hormones produced by the adrenal cortex?
- aldosterone
- cortisol
What does aldosterone do?
helps control the balance of water and salts in the kidney by keeping sodium in and releasing potassium from the body.
What are the two main hormones secreted by the adrenal medulla?
- adrenaline
- noradrenaline
Which adrenal hormone is released in response to stress and helps regulate metabolism?
cortisol.
Which two adrenal hormones increase heart rate, increase blood pressure and widen pupils?
- adrenaline
- noradrenaline
Within muscle, thin and thick filaments can be found in…
myofibrils.
Thin and thick filaments are examples of…
protein filaments.
Thin filaments are made up of a protein called…
actin.
How many actin filaments are wrapped around each other in a thin filament?
2.
Within a thin filament, wrapped around the actin filaments is another protein chain called…
tropomyosin.
Thick filaments are made up of a protein called…
myosin.
Myofibrils are made up of what?
many repeating sarcomeres.
Sarcomeres are…
- vertical sections inside a myofibril.
- made up of thin and thick filaments.
What is the minimum number of thin filaments inside a sarcomere?
4.
What is the minimum number of thick filaments inside a sarcomere?
1.
What is the area in the middle of a sarcomere called?
the m-line.
The area between two M-lines is called a…
Z-line.
Where is the Z-line positioned?
actin filaments/thin filaments
How many M-lines make up a sarcomere?
1.
How many Z-lines make up a sarcomere?
2.
What are the parts of a sarcomere that are located in an area made up of thin filaments?
- I-band
- Z-line
- A-band
What are the parts of a sarcomere that are located in an area made up of thick filaments?
- M-line
- A-band
- H-zone
What is the part of a sarcomere that is located in an area made up of both actin and myosin filaments?
A-band.
What are the parts of a sarcomere that are located in an area made up of only actin filaments?
- I-band
- Z-line
What is the part of a sarcomere that is located in an area made up of only myosin filaments?
H-zone.
