Class 1: Basics of Negative Feedback and HPG Axis

Question 1

Gametes

Answer 1

(sperm or egg) are specialized cells, which function are vessels for the DNA destined to participate in sexual reproduction. a mature sexual reproductive cell, as a sperm or egg, that unites with another cell to form a new organism.

Question 2

Germ Cells:

Answer 2

AKA gametes or sex cells. A cell containing half the number of chromosomes of a somatic cell and able to unite with one from the opposite sex to form a new…
An embryonic cell with the potential of developing into a gamete.

Question 3

Gonads:

Answer 3

Specialized organs involved in the production of gametes and steroid hormones.
Products of Gonads:
1. Gametes “sex cells”: Sperm; Eggs
2. Steroid Hormones: Estrogens, Progestins (progesterone), Androgens

Question 4

Hypothalamus:

Answer 4

GnRH=Gonadotropin-releasing hormone- job is to act on Pituitary Gland to enable release gonadotropins

Question 5

Pituitary Gland:

Answer 5

Produces gonadotropins LH and FSH

Question 6

Luteinizing hormone (LH):

Answer 6

Acts on ovary to trigger ovulation
Note: Regulated by Negative Feedback.: Accumulation of hormone turns production OFF. Sensing of low amount of the hormone turns production ON.

Question 7

Combined Oral Contraception:

Answer 7

takes advantage of the feedback loop by providing exogenous steroid to inhibit release of LH & therefore no trigger for ovulation.

Question 8

Steroid Hormones:

Answer 8

Regulate reproductive function. Facilitates processes.
Regulated in Hypothalamus, Anterior pituitary gland (Pituitary).
made of lipids, starting material is cholesterol converting to a hormone via biochemical rxns catalyzed by enzymes.
Acts through receptor proteins that are INSIDE of cells. Effects directly at the genome (DNA) level changing gene expression. (testosterone)

Question 9

Peptide Hormones:

Answer 9

made of protein. Including GnRH & the gonadotropins. Protein made by translation from RNA. Acts through receptor protein located on the plasma membranes of the cells. Effects are in the cytoplasm, initiating a cascade of signals inside of cells (intracellular signal transduction)

Question 10

Ovary:

Answer 10

(A gonad)
· Makes steroid hormones: estrogen & progesterone, androgens (testosterone).
· Makes Eggs.

Question 11

Oviduct:

Answer 11

Where fertilization takes place.

Question 12

Uterus

Answer 12

Embryo implantation occurs here. Travels from Oviduct.

Question 13

Testes

Answer 13

(A gonad)
· Makes Steroid Hormones: Androgens, Estrogen, and progesterone.
· Makes Sperm.

Question 14

Epididymis

Answer 14

Sperm storage and maturation

Question 15

Vas Deferens (Ductus Deferens):

Answer 15

transports sperm from the epididymis in anticipation of ejaculation.

Question 16

Gonadotropin

Answer 16

Hormones LH and FSH

Question 17

Plasma Membrane:

Answer 17

AKA cell membrane, Made of a layer of lipids (lipid bilayer) with embedded proteins surrounding the cell.

Question 18

Cytoplasm

Answer 18

Internal liquid portion of the cell

Question 19

Mitochondria

Answer 19

Membrane bound organelle: Energy producing bodies within the cell, also produce steroids (early steps)

Question 20

Endoplasmic Reticulum (ER):

Answer 20

Membrane bound organelle: Protein synthesis (later steps), calcium storage, steroid synthesis

Question 21

Intracellular:

Answer 21

within the cell

Question 22

Extracellular

Answer 22

outside the cell

Question 23

Types of Macromolecules:

Answer 23

Lipids (steroid hormones), Proteins/peptides (Peptide Hormones like GnRH, FSH, LH), Nucleic Acids (DNA/RNA),

Question 24

Carbohydrates:

Answer 24

(sugars, polysaccharides).

Note: Lipid membranes also surround organelles such as the Nucleus, ER, and Mitochondria