Biology Study Sheet March 26

Biology Study Sheet Endocrine System vs. Nervous System – –

Take the nervous system and consider it like a phone The nervous system relays a quick message to a single destination (useful b/c of speed) Take the endocrine system and compare it to the internet While the relaying of messages through using hormones is a bit slower, mass broadcasts messages

The endocrine system works using positive and negative feedback. Exocrine glands consist of ducts. Endocrine glands are ductless and the hormones are secreted directly into the bloodstream. Hormones are proteins and steroid based lipids. Endocrine Glands Hypothalamus

Pituitary

Para thyroid

Thymus Adrenal

Thyroid

Hormones/Functions – Controls the secretions of the pituitary gland, secretions and amounts are based on information collected by the nervous system – Secretes nine hormones controlling the functions of other body glands/ systems – ADH regulates reabsorption of water in the kidneys – TSH stimulates the secretion of thyroid hormones which speed up metabolism – Parathyroid hormones increase the concentration of calcium ions in the blood – Tymosin which stimulates the formation of other hormones – Aldosterone regulates the reabsorption of sodium ions and the excretion of potassium ions by the kidneys – Cortisol helps regulate the rate of metabolism – Epinephrine and norepinephrine increase heart rate, blood flow, flow to muscles, air passageways to widen, and the release of extra glucose into the blood – TSH increases metabolism

Pancreas

–

Testes and ovary

– –

Secretes insulin and glucagon which regulate blood sugar (insulin removes sugar from the blood and stores it while glucagon uses stored sugar to increase amounts in the blood) Testosterone triggers sperm production Estrogen stimulates the menstrual cycle

The Reproductive Systems MaleFirst the sperm cells are produced in the seminiferous tubules which are tightly coiled and twisted objects within the testes. After creation sperm move to the epididymis which is the structure where sperm fully mature. From here they go through vas deperens which eventually merge to the urethra which is the exit out the body through the penis. Seminal Vesicle- secretes sugars for sperm to get energy Urethral gland- secretes lubrication fluid Vas deperens- a series of glands Prostate gland secretes alkaline fluid to make basic

Female- I think this is easy enough not to include. The Menstrual Cycle – – – –

Egg released once a month If not fertilized, it is expelled from the body along w/ blood, tissue from uterine lining Ovaries (there are two) alternate and release an egg each month If it is fertilized the zygote will implant itself within the uterine lining

Hormones Role

Negative Feedback

Follicle FSH Estrogen FSH helps ovary mature an egg. In response estrogen builds up the uterine lining. Estrogen tells pituitary gland

Ovulation LH

Corpus Luteum Progesterone

Menstruation FSH

Tells follicle to release the maturing egg.

Builds up the uterine lining.

Starts over the cycle

Tells pituitary gland to slow

to slow down release of FSH.

down release of FSH.

In menstruation the egg, blood, and the broken uterine lining are expelled. Follicle is that thing surrounding the egg within the ovary. Cleavage a zygote’s mitotic divisions Ball of cells blastocyst uterus implantation *Hereditary is extremely easy so I will just put in these key terms Gene- code that’s written in DNA to determine traits Trait- physical characteristic Allele- version of gene (blue eyes vs. brown eyes) Genotype- genetic makeup or alleles received from mother + father Phenotype- physical appearance Homozygous- genes are the same Heterozygous- genes are different 1% of sperm released in through vagina reach the fallopian tubes b/c of mutations and stuff. Egg surrounded by thick protective layer covered with binding sites. When a sperm attaches to a binding site a sac in the head of the sperm releases strong enzymes to break down the layers. Once sperm enters the egg the nuclei fuse with the sperm’s becoming one with the egg’s making a zygote. A sperm joining with an egg is called fertilization. Zygote goes through cleavage. Forms a group of cells called a blastocyst which is then implanted in the uterine lining. In gastrulation the cells in the blastocyst forms in ectoderm, mesoderm, and the endoderm. After implantation the blastocyst creates the membranes amnion and the chorion. The chorion becomes the placenta which is the connection between the mother and the developing uterus. This organ is the organ of respiration, nourishment and excretion. The mother and child shares halves of the placenta and when something needs to be exchanged diffusion occurs.