Unit 10—Human Body

Chapter 39

Endocrine & Reproductive Systems

Endocrine System• Ductless glands

– Add secretions that regulate & stimulate activities of other organs into bloodstream

• Non-steroid hormones (proteins)

• Steroid hormones (lipids)• Prostaglandins (non-

hormone fatty acids that affect near-by tissues

Hypothalamus

Anterior Pituitary

Thyroid

TRH

TSH

Thyroxine

Endocrine glands

• Pituitary & hypothalamus– Hanging from a stalk at the

base of the brain– Regulates many other

endocrine glands• Thyroid & parathyroid

– In the neck below the larynx– Regulates the body’s

metabolism• Adrenal glands

– above kidneys– Helps body deal with stress

• Pancreas– maintains blood sugar levels

• Gonads (ovaries & testes)– Produce gametes and secrete

sex hormones

Male Reproductive

Organs

• Testes (male gonads) in outer pouch, scrotum…– regulate temp for

normal sperm development

• Epididymis (cups behind testes)– stores sperm while

they mature• Vas deferens (2 tubes)

carry sperm to urethra• Seminal vesicles(2),

Prostate (1), Cowper’s (2) glands that add fluids to sperm -> semen

• Urethra (within penis) carries semen out

Female Reproductive Organs

• Ovaries (female gonads)

– suspended below oviducts

• Fallopian tubes (oviducts) – carry egg to uterus

& fertilization

• Uterus (womb) , cervix (neck)– where fetus develops

• Vagina (birth canal)

1

2 3

4

5

Menstrual Cycle• Follicle stage (10 days) – development of ovum

within follicle of ovary; uterus lining builds

• Ovulation (1 day) – follicle ruptures, releasing

ovum• Corpus luteum stage (10 days)

– follicle dries up; uterus lining continues to build

• Menstruation (7 days) – new follicle starts; uterus

lining in shed… if egg isn’t fertilized

Development• Fertilization

– The joining of the egg and sperm nuclei

• Zygote formed,– then Cleavage

(division by mitosis)

Development

• Blastula – hollow ball of cells – implants in uterus

lining about 7-10 days after fertilization

• Gastrula – in-folding of “ball” – produces 3 germ

layers & the curved embryo shape

Watch the blue

Development

• Embryo = up to 8 weeks:– Placenta = tissue

attached to uterus & embryo; where exchanges with Mom take place

– Umbilical cord = attaches embryo to placenta

• Fetus = 8 weeks to birth– human characteristics

show

Practice