A5 Revision

A5 Revision

Mammals

Lesson Objectives

• RAG rate A5 topics

• Recap A5 content

• Identify areas for self-directed revision

Poll

How confident do you feel about A5?

1 - not confident at all

3 - I know some, but there are areas that are difficult

5 - very confident!

• 1

• 2

• 3

• 4

• 5

A5 content (Mammals)

• Structure and function of male and female reproductive system

• Role and effects of changing levels of hormones on gametogenesis, oestrous cycle, parturition, lactation

• Fertilisation

• Gestation length

• Applies to cats, cows, dogs, rabbits and pigs

Male Reproductive System

• Produce and store sperm

• Discharge sperm into the female

• Fertilise the egg

Open Ended

What is the function of the epididymis?

Structural Differences

• Tom (cat) - penile spines directed backwards

• Boar (pig) - anti-clockwise spiral

• Bulbus glandis - enables the male to lock into the female

Multiple Choice

Which structure is responsible for carrying sperm, semen and urine?

• Ureter

• Urethra

• Epididymis

Open Ended

Explain how the structure of a toms penis is linked to its function (2 marks)

Multiple Choice

Which tube carries sperm away from the testes?

• Vas deferens

• Urethra

Multiple Choice

What is label A?

• Epididymis

• Urethra

• Vas deferens

Female Reproductive System

• Produce eggs

• Provide perfect environment for fertilsation

• Protects and nourishes foetus until birth

Multiple Choice

Where does a fertilised egg implant?

• Oviduct

• Uterus

• Cervix

Placenta

• Provides a connection between the foetus and maternal tissue to provide nutrition, respiration, digestion, protection and excretion.

• Temporary organ

Multiple Choice

What type of uterus does a rabbit have?

• Duplex

• Bicornuate

Fertilisation & Implantation

• Fertilisation = when the DNA of two gametes combines

• Implantation = when a fertilisation egg attaches itself to the lining of the uterus

Gestation

• The length of time is take from conception to birth

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Multiple Choice

What is the average gestation of cattle?

• 114-155 days

• 279-287 days

• 300-310 days

Gonadotopin releasing hormone (GnRH)

• Secreted by hypothalamus to control other reproductive hormones

• Secretion of GnRH stimulates production of LH and FSH

Testosterone

• Produced by testes

• Enables development of sex organs and secondary sexual characteristics

• Matures sperm

Oestrogen

• Rebuilds uterine lining after menstruation

• Stimulates the release of LH

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Progesterone

• Maintains lining of uterus ready for fertilised egg

• Inhibits production of FSH

• Mostly produced by corpus luteum

• Corpus luteum = sac of cells remaining after ova has been released

Different oestrous cycles

• Polyoestrous - animals become fertile more than once per year

• Seasonally Polyoestrous - animals have more than one oestrous cycle but only during certain periods of the year

• Monooestrous - animals have one oestrous cycle every year

The role of hormones in parturition

The role of hormones in lactation

Multiple Choice

Which hormone triggers the production of LH and FSH?

• Oestrogen

• Testosterone

• GnRH

Multiple Choice

Which hormone triggers uterine contractions?

• Cortisol

• Oxytocin

• Prolactin