HOMEOSTASIS Only what teacher said to leanr

What defines positive feedback?

A response that amplifies the original stimulus until an endpoint is reached.

What are the steps of a positive feedback loop?

Stimulus → receptor → control centre → effector → amplified response → endpoint.

What hormone drives childbirth positive feedback?

Oxytocin.

What are the steps of childbirth positive feedback?

Cervical pressure → hypothalamus → oxytocin → stronger contractions → more pressure → more oxytocin → birth.

What hormones regulate lactation positive feedback?

Prolactin and oxytocin.

What are the steps of lactation positive feedback?

Suckling → hypothalamus → prolactin + oxytocin → milk production/ejection → more suckling → more hormone release.

What does the hypothalamus release?

Releasing and inhibiting hormones.

What hormones does the anterior pituitary release?

GH, TSH, ACTH, FSH, LH, prolactin.

What hormones does the posterior pituitary release?

ADH and oxytocin.

What hormones does the thyroid release?

T3, T4, calcitonin.

What hormone does the parathyroid release?

PTH.

What hormones does the adrenal cortex release?

Cortisol and aldosterone.

What hormones does the adrenal medulla release?

Epinephrine and norepinephrine.

What hormones does the pancreas release?

Insulin and glucagon.

What hormone do the testes release?

Testosterone.

What hormones do the ovaries release?

Estrogen and progesterone.

What do the testes produce?

Sperm and testosterone.

What happens in the seminiferous tubules?

Spermatogenesis.

What do Sertoli cells do?

Support developing sperm.

What do Leydig cells produce?

Testosterone.

What are the steps of spermatogenesis?

Spermatogonia → primary spermatocyte → meiosis I → secondary spermatocytes → meiosis II → spermatids → sperm.

What does LH do in males?

Stimulates Leydig cells to produce testosterone.

What does testosterone do?

Stimulates sperm production and male secondary sex characteristics.

What do ovaries produce?

Eggs, estrogen, progesterone.

What do fimbriae do?

Guide the egg into the fallopian tube.

What occurs in the fallopian tube?

Fertilization.

What is the uterus for?

Supports embryo and fetal development.

What is the endometrium?

Inner lining where implantation occurs.

What is the myometrium?

Muscular layer responsible for contractions.

What happens in the follicular phase?

FSH stimulates follicle development; estrogen thickens endometrium.

What triggers ovulation?

LH surge.

What happens in the luteal phase?

Corpus luteum produces progesterone to maintain endometrium.

Why does menstruation occur?

Progesterone drops when the corpus luteum degenerates.

What does FSH do in females?

Stimulates follicle development.

What does estrogen do?

Thickens endometrium and forms female secondary sex characteristics.

What does LH do in females?

Triggers ovulation.

What does progesterone do?

Maintains the endometrium.

What does the frontal lobe control?

Movement, decision-making, planning, Broca’s area.

What does the parietal lobe process?

Touch, pain, temperature, body position.

What does the temporal lobe process?

Hearing, language comprehension, memory.

What does the occipital lobe process?

Vision.

What does the hypothalamus regulate?

Temperature, hunger, thirst, stress, endocrine control.

What does the hippocampus do?

Forms long-term memories.

What do sensory neurons do?

Carry information to the CNS.

What do interneurons do?

Process information within the CNS.

What do motor neurons do?

Carry commands from the CNS to effectors.

What is resting potential?

-70 mV maintained by the sodium-potassium pump.

What causes depolarization?

Na⁺ channels open and Na⁺ enters.

What causes repolarization?

K⁺ channels open and K⁺ leaves.

Why does hyperpolarization occur?

Excess K⁺ leaves the neuron.

What is the all-or-none principle?

If threshold is reached, a full action potential occurs.

What is the refractory period?

Time when the neuron cannot fire again.

Why is saltatory conduction fast?

Action potentials jump between Nodes of Ranvier.

What are the steps of synaptic transmission?

AP arrives → Ca²⁺ enters → neurotransmitter released → binds receptors → postsynaptic response → neurotransmitter removed.