Monday, 28 May 2012

Reproductive system

1.a)Testes-located in the scrotrum , site of sperm reproduction and has seminiferous tubules where sperm are produced from.
b)Seminiferous tubules & intestitial cell- produces sprems in the testes and the cells produce testosterone are produced.
c)epididymis -it stores sperms, in the testes.
d)Vas deferens- from the epididymis to the urethrea helps the sperm travles and stores.
e)prostate gland-it secretes basic fluid and enhances sprem mobility.
f)\cowpers gland-helps in lubricatiuon by producing mucus.
g)seminal vesicles-provides energy for sperm by prducing fructose.
h) penis-it cindcuts the semesn to the vgina durind sexual intercourse.
i)urethra-joins the vas deferens with the penis, to help transport the semen.


2.The semen travels from the seminiferous tubules in the testes to the epididymis and then enters the vas deferens , the sperm then enters the urethra which connecs to the penis. during this process the sperms develops and is ready to be fretilized.

3)Seminal fliuds contains the seminle vesicle that sectres fructose that supplies energy for the sperm, the prostate gland that excretes base and enhances sperm mobility and the cowpers gland that produces mucus for lubrication.

4)The  tailr helps the sperm move and is a flagella , the midpiece has mitochindria that provides energy for the sperm, the head protects the DNA (haploid) within it and the acrosome covers the head that has digestive enzymes which penetrates the egggs shell.

5)The testosterone is the male sex hormone that is necessary for sperm production , and secondary sex characteristice(voice deeper, pubic hair, muscular development)>

6)The endocrine system triggers the GnHR(gonadotropin releasing hormone) whick targets the anterior pituitory secreting LH(leutron hormone ) and FHS(follicle stimulating hormone, which are responsible to produce testosterone.

7) a)ovaries- are the organs that develop the follicle, produce egg and hormone production.
b)follicles and corpus luteum-follicle produce estrogen and rebuild and thickens endometritium, corpus luteum thickens the endometrium and releases mucus as progeterone releases.
c)oviducts(fallopiab tube)- propels the egg towqrads the uterus where it gets fertilized.
d)uterus-where the egg is fertilized and the embyo is developed if fertilized or gets shed every month as mensruation.
e)cervix-entrance to the uterus and hold the baby.
f)vagina-its the exit for menstruation, receptable for penis and the canal where the baby comes out of while giving birth.
g)clitoris-erectile tissue , similar to penis and has many nerve endings.

8)Estrogen is the female sex hormone produced by the follicle that atrgets the uterus and thickens the endometrium , also responsible for sencondary sex characteristics ( puberty hair, breast development, body fat deposition).

9)In the ovarian cycle, the follicle develops and the egg is released with hormone production inside the ovary. In the uterine cycle. there are three phages. Menstrual phase, the endometrium is broken down and discharged,The proliferation phase where the endometrium is rebuilt and thickened . And the secretory phase where the endo metrium doubles in thickness and mucus is secreted.

10)In the ovarian cycle,the FHS( follicle stimulating hormome) triggers the ovary to develop the development of the follicle. In the uterine cycle, the LH (luteal hormone) releases progesterone and estrogen hormone. In the menstrual phase, the hormone decreases and the endometrium breaks down.In the proliferation phase, estrogne hormone increases and the endometrium rebuilds and thickens. In the secretory phase, prgesterone is produced and the endometrium doubles in thickness and mucus is secreted,

11)Oxytocin is the hormone that targets the uterus and mammary galnds. It helps the uterus contract during childbirth , so more oxytoxin equals more contraction.And also triggers release of milk , so more suckling equals more milk.

12)After implantation occurs, the hormone HCG(human chronic gonadtruim is released.This maintains the level of progesteron and estrogen which tells the interior pitutary not to produce FHS( no follicle development) , also released in the urine and also maintains the endometruim lining,

Wednesday, 23 May 2012

Study Notes; Digestive system :)unit3

1
.a)Mouth- start of digestion where the food enters from.
b)tongue-helps to move food and in breaking it down.
c)teeth- helps to tear food apart and chew it .
d)pharynx-is the opeing to the esophagus , at the back of the neck.
e)salivary glands-they help to digest starch into maltose.
f)epiglottis- its the flap that opens and closes while eating food.
g)esophagus- the long pipe that connects from the mouth to the stomach to swallow food.
h)cardiac sphincter- the opening between the esophagus and stomach which prevents heatrburn .
i)stomach- helps to digest food and turn in into chyme ( kill bacteria).
j)pyloric sphincter-oening between deodenum and stoamch helps to move chyme to the small intestine.
k)duodenum- food particles are broken down into monomers to be absorbed.
l)liver- produces bile juice that emulisifies fat.
m)gall bladder- where bile juice is stored after liver secrets it.
n)pancreas-produces pancreatic juices that break down food into fatty acides, peptide bond and neutalizes cgyme.
o)small intestine-absorbs nutrients through villi and transports in to the bosy to carry out vital functions.
p)apppendix-no specific functions, but may cause problems if the large intestines fails to function peroperly.
q)large intestine-absorbs water and contains bacteria wuili , and stores indestable material to be thrown out later.
r)rectum-stores undested food until it is released.
s)anus-openng from where undigested food is released from.

2. Swallowing and peristalsis - The food that we eat when moves towrads the stomach throught he esophagus from the mouth is called swallowing. And the rhythmic contraction and expansion of involuntary muslces in the esophagus, that help this process is called peristalsis.The whole process is the start of digestion.

3. Functions of liver- The main functions of liver are to process protien, carbohydrates and fats so that the body can use it,helps to deoxify and purify blood,bile production( emulsify fats) ,enzyme acivation, stores glycogen , vitamons , minerals and excretion of bilirubin, choleTsterol, hormones, and drugs.

4.Bile is produced from liver that helps to emulsifies fat which makes the fat droplets disperse in water and thus, can be broken down( digested).

5.The wall of the small intestine is made up of villi , and has an outer layer made up of columnar epithelial cells  where nutrients are absorbed . Enzymes, sugars , amino acid  are also absorbed which through the villus and glycerol and fatty acid enter through the epithelial cellls whose SA is increaed by the microvilli.

6.The villus is located in the small intestine which creates a soft velevety layer wihting it. There are small finger like prjections called microvilli that increase the SA to increase absorbtion.The capilllaries inside the villus is where the nutrients enter from and also to the lacteals(vessels that carry fluid to the cardiovascular veins) . From here sugar, glycerol, fatty acid and amoni acid enter from where it is distributed tot he body.

7.a)Salivary amylase-secreted from the salivary glands in the mouthb( three pairs) that help digest starch into maltose and breakdown food .
b)pancreatic amylase- secreted in the pancreas amd helps to digest starch into maltose.
c)proteases (pepsinogen,pepsin, trypsin)-produced in the stomach and the pancreas, pepsinigen turns into pepsin that makes protein into peptide, and trrypsin that catalyzes protein to peptide reactions.
d)lipase- produced in the pancreas that breakdown glycerol to fatty acid.
e)peptidase- produced in the small intestine that breaks peptide to amino acid.
f)maltase -produced in the small intestine that breaksdown maltose into glucose.
g)nuclease-produced in the pancreas and breaks down nucleic acid into nucleotides(sugar, bases and phosphate).

8.Water helps in transportation and breakdowna and then eventually help the body absorb the digested nutrients( sugarm, glycogen , fatty acid, nucleotides).And it also help the body be in homeostat so that all the reactions can be performed normally.

9.sodiun bicarbonate in the pancreatic helps to neutralize chyme and thus priects small intestine from being exposed to acidic food.

10.Hydrochloric acid in the gastirc juice help kill the bacteria and activates pepsinogen by creating a PH level of 2 in the stomach.

11.Mucus in the gastric juices help protect the stomach from HCL( heartburn) and also prevent ulcer by protecting the inner lining.

12.The mouth has a PH level of 7(neutral) becasue of the food that ts exposed too but this increase in the stomach , PH level 2( acidic) becasue of the presence of HCL that helps kill the bacteria,And then in small intestine it becomes more basic, PH level 8, becasue of Sodiun bicarnoate so that the intestine to not malfunction.All this helps keep a balance in the body and the change helps prevent the broken down molecules from being damaged so that the body can use it. Thus, PH level is important it provides a safe and