Exam 4 - Pregnancy And Parturition Flashcards
Steps of pregnancy
- Fertilization
- Implementation
- Placentation
- Fetal Growth
Pregnancy
Condition while female animal develops young in the uterus
Gestation
From fertilization to parturition; occurs in four main phases
Oviduct
Primary site of fertilization
After ejaculation the __________ become mobile
Spermatozoa
The first arriving spermatozoa typically do not accomplish _____________
Fertilization
Oxytocin is released as a result of a _______ _______ promotes contraction of the _______ _______ in the female tubular genitalia to assist with ___________ transport
Neural reflex; smooth muscle; spermatozoa
Oxytocin release from the ___________ _________ _______ can be triggered with nontactile stimuli
Posterior pituitary gland
Oxytocin release and effects can be dampened by ________ that _______ sympathetic tone
Stressors; increase
Capacitation
Physiologic process that conveys the capacity to fertilize the ovum
Insemination most often occurs _________ ___ ________ so that viable spermatozoa are present when ova arrive for fertilization
Prior to fertilization
Viability and survival times of spermatozoa is
Matter of hours
Presence of semen in the female reproductive tract results in an _________ __________ and _________
Immunologic reaction; inflammation
As the spermatozoa become nonviable, the female’s ______ _______ will clear the remaining debris from the reproductive tract
Immune response
Cumulus Oophorous
Variable number of granulosa cells surround the zona
Female develops only a _____ mature gamete (also called the ovum, egg, or oocyte) the genetic material that is discarded is referred to as a ______ ______
Single; polar body
Zona Pellucida
Semipermeable membrane made of glycoproteins
Contains receptor sites for attachment of sperm (Z3)
After penetration of the zona, the cell membrane of the single spermatozoon that will accomplish fertilization attaches to and fuses with the _______ ________ of the ovum
This initiates the second meiotic division by the ovum, which results in ________ ___ ____ _______ ______ ______
Vitelline membrane; formation of the second polar body
Polyspermy
Entry of more than one spermatozoon into the ovum
Gamete fusion ALSO stimulates release of cytoplasmic granules by the ovum and depolarization
of the plasma membrane of the egg
Fast = Depolarization of vitelline membrane prevents further attachment
Slow = Depolarization ALSO stimulates increase in intracellular Calcium, release of cytoplasmic granules, and ZP3
become inactiv
What happens to the embryo if polyspemic fertilization occurs?
Embryonic death
What layer of the uterus provides site of attachment for placental membranes
Endometrium
Implantation
Attachment of a blastula to the uterine epithelium and penetration of the epithelium by embryonic tissue
Need _______ within the lumen before implantation
Migration
In litter‐bearing animals, _______ permits the spacing of embryos so that each has adequate room for development and ensures that each ________ ______ contains some embryos
Migration; uterine horn
Placentation
Development of the extraembryonic membranes, or placenta
Layers of placenta:
_______ – Amniotic sac surrounding fetus
________ – allantoic sac
________ – outer layer that attaches to the lining of the uterus
Amnion
Allantois
Chorion
Amnion
Amniotic sac surrounding fetus
Allantois
Allantoic sac
Chorion
Outer layer that attaches to the lining of the uterus
