Human Reproduction Flashcards
Ampella
Widened section of the vas defrens
Stages of menstrual cycle
- menstruation occurs
- FSH releasing factor
- FSH is released
- FSH stimulates follicles to grow in ovary
- follicle produces oestrogen
- oestrogen stimulates growth of endometrium
- high oestrogen triggers LH release
- LH causes ovulation
- follicle bursts and ovum is released, forming corpus luteum
- corpus luteum produces progesterone
- no fertilisation- corpus luteum dies
- progesterone levels fall, triggering menstruation
Where is FSH and LH released from
Pituitary gland
Activated by releasing factor- from hypothalamus
What does oestrogen do
Growth of endometrium
High oestrogen triggers LH
How are primary spermatocytes formed
When spermatogonia are pushed away from the centre of the seminiferous tubule and undergo growth
What are the differences between oogenesis and spermatogenesis
Oogenesis occurs in two places not one
Oogenesis - discontinuous, produces 1 large ovum and 1/3 polar bodies
spermatogenesis - continuous, produces 4 equal sperm
What days of the ovarian cycle does follicular phase occur?
1-12
What are the hormones and their roles in the ovarian cycle
- FSH triggers follicle growth
- follicle releases oestrogen & progesterone
- high oestrogen levels trigger LH production
- LH causes ovulation
- corpus luteum produces progesterone
- corpus luteum dies and low progesterone levels trigger endometrial lining shed
What’s the name of the lung bypass in the foetus
Ductus arteriosis
1st stage of ovarian cycle
Follicle grows around developing oocyte
Where is FSH and LH released
Pituitary gland
What does FSH do
Stimulates follicle growth
3rd stage of ovarian cycle
Fluid accumulated in follicle, follicle enlarges and moves to surface of ovary
Epididymus
Stores spermatids while they mature into spermatozoa
What does Leuitenising hormone do?
Causes ovulation
Testes
Produces sperm and hormones (testosterone)
Where does spermatogenesis occur
Seminiferous tubules (testes)
Where is progesterone released from
Corpus luteum
Where is oestrogen released from
Follicles
Some from corpus luteum
Where does Oogenesis occur
Ovaries and Fallopian tubes
Month 5 of foetal development
Fine hair covers body, gripping reflexes developed, increased growth,
What is HCG
Human chorionic gonadotrophin
Produced by developing placenta to maintain corpus luteum
Role of oxytocin in pregnancy
Released from pituitary gland
Stimulates smooth muscle contraction of uterus
Contraction of muscle cells surrounding breast lobules
Mesoderm
Middle layer
Skeleton, muscles, connective tissue, heart, blood
Role of progesterone in pregnancy
From corpus luteum
Development & maintenance of placenta
Development of milk secreting glands in the breasts
Explain what occurs during fertilisation
- where female and male pronuclease form a zygote
- occurs in Fallopian tube
- capacitation ( secretion from the uterus make spermatozoa hyperactive)
- acrosomal reaction (enzymes activated in head of sperm (acrosome) allowing it to break down glycoprotein matrix of zonia pellucid a so sperm can access plasma membrane of oocyte
What occurs during the cleavage stage of the pre embryonic period
The zygote undergoes rapid mitosis in the Fallopian tube. (2,4,6,8,16 - morellula), blastocyst
- enters the uterus day 6 as blastocyst
- nutrients- uterine milk
What happens during implantation
Blastocyst embeds into uterine lining (day 6)
- sinks into endometrium and attaches to uterine wall
- becomes vascularised for nutrients
Whats cell differentiation
When the inner cell mass of the blastocyst (stem cells) become more specific/specialised
What factors affect foetal development
Alcohol, tetrogens, drugs, diet
What days does the literal phase occur of the ovarian cycle
16-28
What are the three primary germ layers
Endoderm
Ectoderm
Mesoderm
What is the endoderm
The innermost germ layer
Forms digestive system, lungs and thyroid
What is the ectoderm
The outermost germ layer
Forms outer layer of the body(skin hair) also forms nervous system
Erectile tissue
Rich blood supply, causes penis enlargement
2nd stage of ovarian cycle
Follicle cells secrete fluid which forces oocyte to edge of follicle (secondary follicle)
Describe foetal alcohol syndrome
Symptoms in mother - nausea, vomiting, headaches, dizziness, constipation, heartburn, fatigue, mood swings.
Symptoms in child- distinctive facial features, learning disabilities, bone and joint deformities, heart defects, hyperactivity.
No cure
Describe gestational diabetes
- diabetes that occurs during diabetes
- sugar in urine
- insulin resistance
- testing- between weeks 23-27
- effect on baby- risk of respiratory distress syndrome, hypoglycaemia afterbirth, preterm birth
What does the prostate gland do?
Where the two vas defrentia join, forming urethra
Secretes a thin milky fluid that becomes part of the semen
Seminal vesicle
Pouch like, connects to vas deferens and secrets fluid rich in sugars. Makes up 60% of semen
Bulbo urethral gland
Secretes fluid that becomes part of semen, alkaline
Urethra in male
Transports urine and sperm out of the body
Scrotum
Holds testes, maintain temp
Ureter
Transports urine from kidneys to bladder
Month 9 of foetal development
Eyes open, nose well formed, sucking and grasping reflexes apparent, fine body hair is shed
Uterus female
Contains embryo/foetus during pregnancy
What does progesterone do?
Develops endometrium lining for if implantation occurs
4th stage of ovarian cycle
Mature follicle - looks like bulge on ovary surface
Fallopian tube
Carries eggs to the uterus, where fertilisation occurs
Fimbriae
Directs eggs from the ovaries into Fallopian tubes
What is gastrulation
The formation of primary germ layers.
Outer layer of blastocyst forms placenta
Inner layers become the foetus
Ovaries
Produces eggs and hormones
Vagina
Received penis during intercourse, forms birth canal
Month 6 of foetal development
Respiratory movements, digestive glands begin to function, tooth buds evident, eyebrows and eyelashes
Month 3 of foetal development
Forelimbs well developed, eyelids closed, outer ear completed, bone marrow formed, sex distinguishable,
Month 4 of foetal development
Arms and hands fully shaped, skeleton completed, exercising of muscles evident, ears stand out from head
What are the three stages of labour
Dilation, expulsion, placental
What occurs during dilation (labour)
The time from onset of labour to complete dials toon of the cervix.
- waves of muscle contraction occur from the upper uterus to the cervix
- cervix is opened - complete dilation(10cm)
What occurs during expulsion (labour)
- membrane surrounding foetus bursts and fluid exits (waters break)
- birth (20mins - 2hrs)
- foetus moves through cervix and it’s head stretches vagina, stimulating contraction of mothers abdominal muscles and uterus
- baby’s head turned towards uterus
- mother pushes
- once head is out, turns sideways
What occurs during the placental stage of labour
- babies respiration occurs
- umbilical chord is cut
- uterus continues contraction & umbilical chord, placenta and other membranes are expelled
- uterine contractions squeeze shut uterine vessels that supply blood to placenta
What’s the liver bypass in the foetus called
Ductus venosus
Why is the ductus arteriosis a thing?
The lung is collapsed (offers resistance to blood flow) all blood is oxygenated from the placenta and deoxygenated blood exits through placenta. Only needs oxygen to keep alive.
What’s the foramen ovale
The opening between the right and left atria to allow more rapid delivery of oxygenated blood
Month 8 of foetal development
Accumulation of fat beneath skin, growth slowed
What’s the function of the vas deferens
Carries sperm (semen) away from the testes (epididymus - urethra)
Clitoris
Contains erectile tissue
Month 7 of foetal development
Period of greatest growth, all systems functional except respiratory
Stages of Ovarian cycle
- 1) primordial follicle
1) follicle grows around developing oocyte
2) follicle cells secrete fluid which forces oocyte to the edge of follicle
3) fluid accumulates within follicle, it enlarges and moves to the edge of ovary
4) mature follicle - bulge on ovary
5) ovulation
6) corpus luteum
Where does spermatogenesis occur
Seminiferous tubules & mature in epididymus
Where does Oogenesis occur?
Ovaries and Fallopian tube
What are the differences between Oogenesis and spermatogenesis
Product (ovum/sperm), number of locations, location, discontinuous/continuous, amount able to be produced, equal/unequal cytokines
What’s the process of sperm movement
Ejaculation - cervix - uterus - uterine tubes - fertilisation ( with help from muscular contractions of uterus and uterine tubes
What’s gastrulation
Formation of the 3 primary germ layers (endoderm, mesoderm, ectoderm). Also the outer layer of the blastocyst forming the placenta
During gastrulation, what changes occur?
Outer blastocyst layer becomes placenta
Inner layer becomes primary germ layers.
What does the endoderm become
Innermost germ layer - becomes the digestive system, lungs and thyroid
What does the ectoderm become
Outermost germ layer. Forms outer layers of the body (skin, hair) and nervous system
What does the mesoderm become
Middle layer. Becomes the skeleton, muscles, connective tissue, heart, blood)
