Embryology

1
Embryology

• Chapter 47

2
Sexual Intercourse
3
Stages of ejaculation

• Emission stage
• Nerve impulses from spine trigger epididymis and
  vas deferens to contract.
• Motility causes sperm to enter ejaculatory duct
• Seminal vesicles, prostate gland, and
  bulbourethral glands release their secretions.
• Small amount of secretion from Bulbourethral
  glands may leak from end of penis function to
  clean the urethra of acid and may contain sperm.

4
Stages of ejaculation

• Expulsion stage
• Rhythmical contractions at the base of the penis
  and within urethral wall expel semen in spurts.
• Rhythmical contractions are a release from
  myotonia, or muscle tenseness, a sexual response.
• Retrograde ejaculation

5
After Climax

• Refractory Period
• After ejaculation the penis returns to a flaccid
  state
• Can not achieve erection even with stimulation
• May last minutes to hours

6
Fertilization
7
Fertilization Timeline
8
Pregnancy or Conception

• Embryonic development
• 0-8 weeks
• Fetal development
• 9 weeks-birth
• Gestation
• Generally 266 days
• Parturition
• Birth

9
Fertilization and Cell Division
10
Cleavage and Morula
11
Fertilization and Cell Division
12
Blastocyst and Implantation
13
Blastocyst to Gastrula
14
Extaembryonic Membranes
15
Germ Tissues
16
Embryonic Development
17
Embryonic Development
18
Embryonic Development
19
Fetal Development
20
Summary of Fetal Development
21
Summary of Fetal Development
22
Embryonic and Fetal Development
23
Initiation of Labor
24
Parturition
25
Lactation