virtual science university · reproductive & endocrine systems texas tek b.10(a) the student...

Reproductive & Endocrine Systems

Virtual Science University

1


Texas TEK B.10(A) The student will interpret the function of systems in organisms (humans) including the reproductive and endocrine systems.

Texas TEK B.10(B) The student will compare the interrelationships of reproductive and endocrine systems to each other and to the body as a whole.

2

Reproductive SystemSexual Reproduction

• The ability to reproduce is one of the unique characteristics of all living things.

• Sexual Reproduction produces offspring that are genetically different from their parents.

• In sexual reproduction new individuals are produced by the fusion of haploid sex cells to form a diploid zygote.

3


• Sperm are male gametes

• Ova or egg cells (ovum singular) are female gametes.

4


• Meiosis produces cells that are genetically distinct from each other

• Fertilization is the fusion of two such distinctive cells that produces a unique new combination of alleles.

5


• Sexual reproduction offers the benefit of generating genetic variation among offspring, which enhances the chances of the population's survival.

• Costs of this process include the need for two individuals to mate and court.

6

Human Development & Reproduction

• Human reproduction employs internal fertilization, and depends on the integrated action of the nervous system, hormones, and the reproductive system.

7

Human Development & Reproduction

• Sex organs produce gametes.

• The male sex organs are the testis, which produce sperm and male sex hormones.

• Female sex organs are the ovaries, which produce eggs (ova) and female sex hormones.

8

Male Reproductive System• Testes are suspended

outside the abdominal cavity by the scrotal sac– A pouch of skin that

keeps the testes close or far from the body at an optimal temperature for sperm development.

• Seminiferous tubules are inside each testis – Where sperm are

produced by meiosis.

9

Male Reproductive System

• About 250 meters (850 feet) of tubules

are packed into each testis.

• Spermatocytes inside the tubules divide by meiosis to produce spermatids that in turn develop into mature sperm.

10

Female Reproductive System• The female sex organs,

ovaries, are located within the lower abdominal cavity.

• The ovary contains many follicles composed of a developing egg surrounded by an outer layer of follicle cells.

11

Female Reproductive System• Each egg begins

oogenesis as a primary oocyte or egg cell.

• At birth each female carries a lifetime supply of developing oocytes, each of which is in Prophase I.

• A developing egg (secondary oocyte) is released each month from puberty until menopause, a total of 400-500 eggs.

12

Endocrine System• The endocrine system is an

integrated system of small organs that involve the release of extracellular signaling molecules known as hormones.

• The endocrine system is instrumental in regulating metabolism, growth development and puberty, and tissue function and also plays a part in determining mood.

13

Endocrine System

• The field of medicine that deals with disorders of endocrine glands is endocrinology, a branch of the wider field of internal medicine.

14

Function of the Endocrine System

• The endocrine system is an information signal system much like the nervous system.

• However, the nervous system uses nerves to conduct information, whereas the endocrine system mainly uses blood vessels as information channels.

15

Function of the Endocrine System

• Glands located in many regions of the body release into the bloodstream specific chemical messengers called hormones.

• Hormones regulate the many and varied functions of an organism, e.g., mood, growth and development, tissue function, and metabolism, as well as sending messages and acting on them.

16

Endocrine Signaling• A number of glands that

signal each other in sequence is usually referred to as an axis, for example, the hypothalamic-pituitary-adrenal axis.

• Typical endocrine glands are:

• Pituitary• Thyroid• Adrenal glands

17

Endocrine Signaling• Features of endocrine glands

are:– their ductless nature – their vascularity, – usually the presence of

intracellular vacuoles or granules storing their hormones

• In contrast, exocrine glands, tend to be much less vascular and have ducts or a hollow lumen such as the: – salivary glands– sweat glands – glands within the gastrointestinal

tract

18

Endocrine Diseases• Diseases of the

endocrine system are common, including –Diabetes mellitus–Thyroid disease–Obesity

19

Endocrine Diseases• Endocrine disease is characterized

by a disregulated hormone release – A productive pituitary adenoma

• Inappropriate response to signaling – Hypothyroidism

• Lack or destruction of a gland – Diabetes mellitus type 1

• Diminished erythropoiesis – In chronic renal failure

• structural enlargement in a critical site such as the neck – Toxic multinodular goiter

20

Endocrine Diseases• Hypofunction of endocrine

glands can occur as a result of – Loss of reserve– Hyposecretion– Agenesis– Atrophy– Active destruction.

• Hyperfunction can occur as a result of – Hypersecretion– Loss of suppression– Hyperplastic or neoplastic

change– Hyperstimulation

21

Endocrine Diseases• Endocrine disorders

are classified as • Primary

– Primary endocrine disease inhibits the action of downstream glands.

• Secondary• Tertiary

– Tertiary endocrine disease is associated with dysfunction of the hypothalamus and its releasing hormones.

22

The Pituitary Gland – “The Master Gland”

• Known as the "master gland" • It exerts control over all of

the other glands of the endocrine system

• No larger than a small pea • Pituitary gland is made up of

two separate glands: – Anterior lobe

• An outgrowth of the pharynx, and the

– Posterior lobe• An outgrowth of the brain

composed of neural (nerve) tissue.

23

The Thyroid Gland

• The thyroid is a butterfly shaped gland which is – Located at the

base of the throat • It has two lobes

separated in the middle by a strip of tissue (the isthmus).

24

The Thyroid Gland• The Thyroid itself secretes three

main hormones: • Thyroxine contains iodine which is

essential for the body's normal growth, and metabolism. – Helps control body size,

regulating not only the growth of tissues but also the differentiation or specialization of tissues.

• Triiodothyronine – Similar functions to thyroxine.

• Calcitonin causes a decrease in the concentration of calcium in the blood. – Calcitonin works with secretions

from the parathyroid glands to maintain the balance of calcium necessary for the body to function.

25

The Thyroid Gland

• People who have surgery to remove the thyroid gland (thyroidectomy) for cancer or other thyroid problems usually need to take thyroxine supplements in order to maintain normal weight and body functions.

26

The Parathyroids • There are four

Parathyroid glands – Small and rounded– Arranged in two pairs – Usually located above

and below the thyroid• Each Parathyroid is

– Small– Yellow – Smooth

• Parathyroid sometimes is imbeded in the thyroid

27

The Parathyroids

• Parathyroid hormone increases the blood concentrations of calcium and phosphorous, working to balance the Calcitonin which is secreted by the thyroid to maintain the body's balance of calcium.

28

The Pancreas• The pancreas

– Long– Narrow, – Lobed gland – Located behind the

stomach• The Pancreas has two

types of cells: – Exocrine cells– Endocrine cells

29

The Pancreas• The Exocrine cells

– Secrete Pancreatic juices which are used in the duodenum as an important part in the digestive system.

• The Endocrine cells – Arranged in clusters

throughout the Pancreas, these known as Islets of Langerhans

30

The Pancreas• There are three types of

endocrine cells:– Alpha cells

• Secrete glucagon– Beta cells

• Secrete insulin– Delta cells

• Inhibit the secretion on glucagon and insulin

31

The Pancreas• Glucagon increases the

blood glucose level by stimulating the liver causing convert Glycogen into Glucose (sugar).

• Insulin increases the cells permeability to glucose, which the cells use for energy.

• By promoting the utilization of glucose by the tissue cells, insulin causes a decrease in the concentration of glucose in the blood.

• Insulin also promotes the storage of glycogen in the liver.

32

The Adrenal Glands

• The adrenal glands resemble small caps perched on top of each kidney.

• The adrenal is actually a combination of two glands – Adrenal cortex

• Essential for life– Adrenal medulla

• Important but not indispensable

33

The Adrenal Glands

• The anterior pituitary– Controls the adrenal

cortex by secreting the hormone ACTH.

• All of the secretions of the adrenal cortex are known as steroids, many of which can now be manufactured synthetically.

34

The Adrenal Glands • The adrenal cortex is made up of three

layers associated with three classes of hormones: – Mineralocorticoids

• Produced by the outer layer of the adrenal cortex, the most important of which is aldosterone

– Aldosterone • Promotes the retention of sodium

(Na+) and the excretion of potassium (K+).

• This helps to maintain both the electrolyte and water content of the body.

– Glucocorticoids • Produced by the middle cortex• These affect almost every cell in

the body regulating the metabolism of fats, proteins, and carbohydrates

• Cortisone is one such glucocorticoid

35

The Adrenal Glands • Gonadal hormones

– Produced by the inner cortex

– There are roughly even amounts of two types of hormones secreted: • Androgen (male)• Estrogen (female)

• The adrenal gland is not the only gland to secrete sex hormones.

36

The Adrenal Glands • The Adrenal Medulla is the

inner part of the adrenal gland. • The hormones secreted effect

the structures in the body that are under the control of the sympathetic nervous system, aiding the body to deal with stressful situations such as fright, attack or pursuit.

• They are both associated with an – Increased heart beat– Higher blood pressure– Higher blood glucose levels– Thus preparing the body for

quick action

37

The Adrenal Glands

• Adrenalin (or epinephrine) affects both alpha and beta receptors in the nervous system.

• Noradrenalin (Norepinephrine) affects only the alpha receptors of the nervous system.

38

The Gonads• The gonads consist of

– ovaries in the female – testes in the male

• These glands produce hormones important in the development and functioning of the reproductive organs.

• They are under the control of the pituitary gland, and produce the secondary sexual traits.

39

The Gonads• Male testes

– Egg shaped glands – Located in the sac like

scrotum– Serve two main functions:

• The production of sperm cells

• The secretion of testosterone

• Testosterone is the masculizing hormone inducing male secondary sexual characteristics after puberty.

40

The Gonads• Female ovaries

– Two almond shaped glands

– Located on each side of the uterus

• They have three main functions: – Containing immature

ova (eggs)– The secretion of

oestrogen– The secretion of

progesterone.

41

The Gonads• Estrogen is secreted by the adrenal

cortex as well as the ovaries, and is present in the blood of all females from puberty through to the menopause.

• Estrogen acts on the structure of the reproductive organs, especially during the menstrual cycle.

• This induces and maintains female secondary sexual characteristics.

• Progesterone works on the uterus to prepare it for the implantation of a fertilized ovum (egg).

• It causes the development of the breasts, and is essential for the complete development of the maternal proportion of the placenta.

42

Hormones

• Giantism- too much HGH is secreted before puberty.

• Dwarfism is caused by a lack of HGH before puberty.

43

Hormones• Diabetes Mellitus is a

condition with under-secretion of insulin, causing the cells to lose their permeability to glucose preventing them from getting sugar needed for energy.

• Sugar remains in the blood and often the body will try and remove this leading to a high sugar content in the urine– Causing polyuria

• Passing of large volumes of urine

– Causing Polydipsia• Excessive thirst

44


Texas TEK B.10(A) The student will interpret the function of systems in organisms (humans) including the reproductive and endocrine systems.

Texas TEK B.10(B) The student will compare the interrelationships of reproductive and endocrine systems to each other and to the body as a whole.

45

They Swim, And They Roll• Gametes in the male, that swim, that swim, that

swim when they squirm• They swim they swim, they swim --------when

they squirm!• Gametes in the female, that roll, that roll, that

roll when they flow• They roll, they roll, they roll, they roll, -----when

they flow!

46

• This is a song about the Birds and the Bees• So sing with me, sing with me, sing with me

Please!

• One in your Mom and one in your Dad• Ovaries and testes are called a gonad• Each produce hormones and a gamete• During fertilization they finally meet.

47

• It’s all about hormones, reproduce, reproduce• It’s all about hormones, so don’t let them

loose.• Meiosis occurs in the girl and the Male• Genetic duplication, cell division won’t fail.

• From Diploid to Haploid, the chromosomes divide.

• Keeping the alleles on an even stride.• In testes of the male, and in the ovary named

Gayle• We will begin the reproductive tale.

48

• Gametes in the male, that swim, that swim, that swim when they squirm

• They swim they swim, they swim --------when they squirm!

• Gametes in the female, that roll, that roll, that roll when they flow

• They roll, they roll, they roll, they roll, -----when they flow!

49

• Gonads are testes in the mature male, that produce a hormone

• The hormone is called the testosterone• Spermatocytes to spermatid, creating a

sperm• These are the male gametes, that swim, that

swim, that swim when they squirm• They swim, they swim, they swim --------

when they squirm!

50

• While Ovaries in mature females, produce eggs and a hormone

• The two hormones are called, estrogen and progesterone

• Primary, secondary oocyte, and finally, one egg and not two

• The female gametes, that roll, that roll, that roll when they flow

• They roll, they roll, they roll, they roll, -----when they flow!

51

• One in your Mom and one in your Dad• Ovaries and testes are called a gonad• Each produce hormones and a gamete• During fertilization they finally meet.

52

• Endocrine hormones down the blood you do flow

• Regulating cell function and helping us grow

• Endocrine, exocrine glands are two• Let’s outline the difference for you• Endocrine glands are vascular, store in a

granule and are lacking a duct• Exocrine are less vascular, and release

hormones into the duct.

53

• It’s all about Hormones, Reproduce, Reproduce

• It’s all about Hormones, So don’t let them loose.

• This has been a story about the Birds and

the Bees• Keep on singing it, and you will learn it

with ease!

54

Contact Information

www.VirtualScienceUniversity.com1-877-920-5550

55

virtual science university · reproductive & endocrine systems texas tek b.10(a) the student...

Documents