Endocrine system and Reproductive system

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Chapter 39

• Endocrine system and Reproductive system

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39-1 Endocrine System

• Hormones chemicals released in one part of the
  body that travel through the bloodstream and
  affect the activities of cells in other parts of
  the body. Regulated by feedback mechanisms to
  maintain homeostasis.
• Target CellsThe cells that hormones bind to and
  affect.
• Exocrine Glands release secretions directly
  into the organs that use them.
• Ex Sweat, tears, digestive juices.
• Endocrine Glands release secretions directly
  into blood stream.
• Ex Hormones!

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39-2 Human Endocrine Glands

• Pituitary Gland
• Divided into two parts Anterior and Posterior.
• Base of the skull, secretes 9 hormones that
  directly regulate many body functions and
  endocrine glands.
• See pg. 1004 for hormones.
• Hypothalamus
• Attached to the posterior pituitary, controls the
  secretions of the pituitary gland through the
  usage of control hormones.
• Allows the nervous and the endocrine systems to
  work closely together.

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• Thyroid Gland
• Wraps around trachea, major role in regulating
  metabolism by releasing 2 hormones with opposite
  effects.
• Ex if blood calcium levels are high, releases
  calcitonin to reduce calcium absorption if
  levels are low, releases PTH to increase
  absorption of calcium
• Parathyroid Gland
• Attached to thyroid, maintain homeostasis and
  calcium levels in blood
• Adrenal Glands
• Sit at the top of the kidneys, release hormones
  that help the body prepare for stress.
• Cortex produces corticosteroids.
• Cortisol
• Medulla releases epinephrine and norepinephrine
  (adrenaline)
• Fight or Flight response begins here!

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• Pancreas
• Has exocrine and endocrine functions
• Releases digestive enzymes into the small
  intestine (exocrine) and releases hormones
  (insulin and glucagon) into the blood to regulate
  blood sugar levels
• Reproductive Glands
• Serve two functions To produce gametes and also
  to secrete sex hormones.
• Ovaries produce ova (eggs), secrete estrogen
  and progesterone (hormones)
• Testes produce sperm, produce testosterone
  (hormone)

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39-3 The Reproductive System

• Puberty period of rapid growth and sexual
  maturation when the reproductive organs are fully
  developed

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• Male Reproductive System
• Main function is to produce and deliver sperm
• Structures
• scrotum external sac that holds the testes
• seminiferous tubules produces sperm
• epididymis stores mature sperm
• vas deferans some sperm move into this tube
• urethra tube that connects to the vas
  deferens and leads to the outside of the
  body
• penis anatomical structure of a male
• semen combination of sperm and seminal fluid

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• Female Reproductive System
• Main function to produce ova and nourish the
  embryo produce one mature egg each month
• Structures
• Follicles clusters of cells surrounding an egg
• Ovulation mature egg is released
• Fallopian tubes tube that moves the egg to the
  uterus
• Uterus organ where embryo grows
• Vagina canal that leads to the outside of the
  body
• Menstrual cycle (4 phases)
• Follicular phase follicle matures and uterine
  lining thickens
• Ovulation egg released into fallopian tube
• Luteal phase at beginning of luteal phase is
  best chance for pregnancy also when embryo
  implants in uterus
• Menstruation occurs if egg is not fertilized,
  uterine lining and ova exit the body

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39-4 Fertilization and Development

• Fertilization process of an egg being joined by
  a sperm (NN2N)
• Zygote fertilized egg cell
• Implantation blastocyst attaches itself to the
  uterine wall
• Gastrulation formation of three cell layers
• Neurulation development of the nervous system
• Placenta connection between mother and embryo

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• Fetus after eight weeks of development
• Control of development
• Still an unknown process
• End of three months all organs are developed
• Later Development
• 4th 5th and 6th month tissues and organs
  become more highly developed
• Last 3 Months organ systems develop further and
  fetus grows in size

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• Childbirth
• Hormone Oxytocin Causes contractions to start
  cervix expands and baby is pushed out of the
  vagina
• Infancy first 2 years of life
• Childhood from infancy to puberty
• Adolescence from puberty to adulthood
• Adulthood 25 - 35 years of age and beyond