1/19
Looks like no tags are added yet.
Name | Mastery | Learn | Test | Matching | Spaced |
---|
No study sessions yet.
Which two nervous system divisions control involuntary actions like sneezing and peristalsis?
Both somatic and autonomic nervous systems
In the sodium-potassium pump, which ions move where?
3 Na⁺ out of the cell, 2 K⁺ into the cell
During depolarization of a neuron, which ion moves where?
Na⁺ enters the neuron
During repolarization of a neuron, which ion moves where?
K⁺ exits the neuron
What does Saxitoxin block, and why is it fatal?
Blocks Na⁺ channels, preventing depolarization and nerve impulses
What do mixed nerves contain?
Both sensory and motor fibers
Which hormone type is lipid-soluble and has no second messenger system?
Steroid hormones (e.g., testosterone, estrogen, cortisol, aldosterone, thyroid hormones)
How do peptide hormones exert their effect?
Bind membrane receptors → activate G-protein → adenylate cyclase → ATP to cAMP → protein kinase activation
Which amine hormones act like peptides?
Adrenaline and noradrenaline
Which amine hormones act like steroids?
Thyroid hormones (T3, T4)
Which gland produces ADH and oxytocin?
Posterior pituitary (stores and releases them from hypothalamus)
What happens to TSH levels after thyroidectomy?
They increase due to loss of negative feedback
What type of feedback is oxytocin during childbirth?
Positive feedback
What is the basic functional unit of a myofibril?
Sarcomere (Z-line to Z-line)
Which band shortens during muscle contraction?
I band
Which band stays the same during muscle contraction?
A band
What happens to the H zone during contraction?
It disappears
Where does calcium bind to start muscle contraction?
Troponin on actin filament
What is the role of tropomyosin?
Blocks myosin-binding sites on actin until moved by troponin
What causes myosin to detach from actin?
Binding of a new ATP molecule