Lecture 1 Flashcards
What does Sexually dimorphic mean?
Males and females are physically different
3 elements that male and female reproductive systems have in common?
- General process 2. production of hormones. 3. maturation of reproductive capabilities
What are the male gonads?
Testes
What are the female gonads?
ovaries
What are the sex cells produced by the testes and ovaries
Spermatozoa for males and oocytes for females (stem cells)
What is sexual reproduction?
a process where a genetically novel individual is formed as a result of mixing genes from two individuals
What is a hormone?
internal molecular messenger
What is the importance of hormones in reproductive physiology
They regulated all aspects of reproduction.
What are the roles that hormones play in both males and females?
FSH and LH
what are the structures/ organs that have endocrine function
the hypothalamus, anterior pituitary gland, gonads, pineal gland and placenta.
what is a paracrine?
A hormone that acts on a neighboring cell.
How are hormones structurally classified?
Water soluble ( protein/peptide hormones) and lipophilic ( steroid hormones and fatty acid hormones)
All steroids are derived from?
Cholesterol
what are the 3 classes of sex steroid hormones ?
Androgens, estrogens, and progesterone.
What is a ligand
a molecule that binds to a receptor. Hormones are ligands.
list the male and female hormones that belong to the class of peptide/protein hormones?
How does the location of a receptor for a protein hormone vs a steroid hormone
protein receptors are on the cell membrane and steroid hormones are inside the cell
Describe the mechanism of action of a peptide-protein hormone
use a second messenger to carry out its function.
how is upregulation different from downregulation
too much chemical => down regulated, and too little => up regulation.
What is the mechanism of a steroid hormone
Diffuse through the phospholipid membrane.
what does affinity mean?
strength of receptor and ligand binding.
how can a receptor have different affinities?
external factors.
what is the role of sex steroid binding globulin ?
It transports lipophilic hormones through the blood.
what are the factors that determine the responsiveness of a target cell to a hormone ?
Blood concentration, receptor density, receptor sensitivity ( affinity) , and hormone interactions.
what are the 3 modes of hormone secretion?
Pulsatile, circadian , episodic
describe the analogs of FSH/LH levels and fertility
GnRH is an analog as both agonist and antagonist. GnRH continuously decreases LH and FSH and GnrH pulsatile release stimulates LH and FSH.
what 3 sets of structures make up the sex organs of both males and females?
Gonads, internal genitalia
, external genitalia
What is an exocrine gland?
Glands that secrete hormones or chemicals into ducts. Example sweat glands.
an example of a paracrine
Prostaglandins
describe the mechanism of action of a peptide-protein hormone
Us a secondary messenger to enter the cell or signal to the cell.
What are the 3 modes of hormone secretion?
Hormonal , humoral , neural
