Module 4

Renal system

 Kidneys filter metabolic wastes and toxins from blood. 

 Anatomy.

Bean shaped

Hilum is the medial surface that leads into the internal space

Adrenal gland sits on top of kidney

Kidneys are retroperitoneal   - this means they are outside of the peritoneal cavity

Covered with:  fibrous capsule

                         Perirenal fat capsule

                         Renal fascia

Internal anatomy  pg 1000  be able to label a picture with a word bank

Cortex

Medulla

Renal artery

Renal vein

Renal pelvis

Nephron – structural and functional unit of the kidney   

Consist of:

• Glomerulus – capillaries
• Renal tubule –
• Glomerular capsule

Renal corpuscle -  glomerular capsule and glomerulus

Physiology of urine formation:

 1.   Glomerular filtration

• High pressure in afferent (incoming) arterioles forces water and chemicals such as glucose, amino acids, nitrogenous wastes out.
• Bigger stuff, like protein can’t pass out
• Proteins maintain the osmotic pressure in the arteriole

 2. Tubular reabsorption

• Glucose, amino acids, ions are resorbed
• Sodium is actively resorbed
• Water, chloride, bicarb, follow the sodium
• Urea, creatinine, and uric acid are not resorbed

 3.   Tubular secretion

• Stuff that is not needed is actively transported back out
• Hydrogen ions, potassium ions, ammonia, drugs, bicarb
•  

  Osmolality – the number of particles dissolved in 1 kg of water. 

 Antidiuretic hormone (ADH)  - prevents excessive water loss

ADH is inhibited by alcohol consumption

 Diuretic – chemical that increases urinary output

Diabetics urinated excessively because glucose that spills over into the glomerular filtrate osmotically draws water along with it.

 Should be clear to deep yellow

Pigment due to hemoglobin breakdown

pH should be around 6

 Specific gravity 1.001 – 1.035

Specific gravity tells how concentrated it is.  If a person is dehydrated, then their urine should be concentrated or have a high specific gravity.  If they have a low specific gravity in the face of dehydration, then there is a problem.

Ureters -  tubes that carry urine from the kidneys to the bladder

Renal calculi – kidney stones.   May be in kidney, ureter, or urethra  (pg 1024)

Urinary bladder –

Trigone area – area with three openings.  One for each ureter.   One for the urethra

Three layered wall.

• Mucosa – has transitional epithelium
• Muscular layer – detrusor muscle
• Fibrous adventia – outer layer

Urethra -  tube that allows urine to be emptied from bladder.

Internal urethral sphincter – involuntary, holds urine in

External urethral sphincter – voluntary

Micturition – urination

Incontinence – urinating involuntarily

Urinary retention – bladder doesn’t empty completely

Reproduction

What is/are?

• Gonads
• Accessory reproductive organs
• Testes
• Ovary
• Scrotum

Dartos muscle – muscle in skin of scrotum

Cremaster muscle – elevate testes

Seminiferous tubules – produce sperm

Interstitial cells – produce testosterone

Cryptorchidism – retained testicles

Why are male gonads outside the peritoneal cavity?

 Answer: sperm won't develop at the warm temperature in the body. The developing sperm must be around 3 degrees Celsius lower than core body temperature.

What is a major risk for testicular cancer? 

Answer - cryptorchidism

What is circumcision?

Answer - removal of the penile foreskin.

Epididymis – for storage of sperm

Ductus deferens (vas deferens) – for sperm transport

What is a vasectomy –

Male accessory glands –  Seminal vesicles, Prostate, Bulbourethral glands

(These three glands add volume and nutrients to the sperm.)

• Spermatogenesis - formation of sperm

• Gamete - egg or sperm

• Haploid - having only one set of chromosomes such as egg or sperm

• Diploid - having two sets of chromosomes such as normal body cells (somatic cells)

Gametes are formed by meiosis

In meiosis, you start with one diploid cell and get 4 haploid cells.

 Somatic cells are formed by mitosis.

In mitosis, you start with one diploid cell and get 2 diploid cells.

 For meiosis, you start with one diploid cell and get 4 haploid cells.

How many chromosomes do humans have?  (46, 23 pairs)

 Sertoli cells – protect developing sperm from the immune system

Brain/testicular axis

1.  Hypothalamus in brain releases GnRH

2.  This causes the pituitary to release FSH and LH

3.  FSH cause spermatogenesis

4.  LH causes testosterone secretion

5.  When testosterone level is adequate, it inhibits further GnRH release.

What are some of the secondary sexual characteristics of male humans?

                 Heavy bones and muscles, facial hair, deep voice.

Oocyte – immature egg

Ovarian follicle – sac-like structure on outside of ovary that contains oocyte

Corpus luteum – glandular structure that remains after follicle ruptures, produces hormones to maintain pregnancy in early stages

 Fallopian tubes = oviducts = uterine tubes – carry egg from ovary to uterus; fertilization takes place here

 Ectopic pregnancy - pregnancy outside the uterus (such as a tubal pregnancy)

 Pelvic inflammatory disease - disease that causes inflamation of tissue in the pelvis, especially the uterine tubes. Often leads to tubal pregnancies or infertility due to scarring of tubes.

 Uterus - organ in which embryo develops into fetus and throughout the pregnancy

Cervix - opening of uterus into vagina.

What is a major cause of cervical cancer?  (answer -- human papilloma virus)

What is prolapse of the uterus? (the uterus protrudes into and even out of the vagina due to weak muscles and ligaments)

Perimetrium – outer layer of uterus

Myometrium – middle, muscular layer of uterus

Endometrium - inner lining of uterus

Vulva – female external genitalia

• Hymen
• Perineum

Mammary glands

            Present in both sexes (only function in females)

            Part of the integument

            Modified sweat glands

Areola – pigmented area around nipples

Note: humans have nipples, not teats. Cattle have teats which are elongated structures.

 Mammography – x-ray of mammary glands

 Lactation – milk production

Toward the end of pregnancy

• Hypothalamus releases PRH
• Pituitary release prolactin
• Prolactin stimulates milk production
• Oxytocin is released as nerve impulses from nipple stimulate the posterior pituitary
• Oxytocin causes milk let down.

Colostrum – first milk, rich in antibodies and nutrients

Oogenesis – egg production

In spermatogenesis, you get 4 sperm

In oogenesis, you get one egg and 3 polar bodies (duds)

Ovarian Cycle

1. Hypothalmus release GnRH
2. GnRH causes anterior pituitary to release FSH and LH
3. FSH stimulates follicles to develop  (that’s why it’s called follicle stimulating hormone)

(meanwhile, the endometrium is developing to get ready for the pregnancy)

4. LH causes estrogen production
5. High estrogen level causes burst of LH hormone
6. High level of LH causes ovulation
7. LH causes development of corpus luteum (that’s why it’s called luteinizing hormone)
8. If there is no pregnancy, the corpus luteum degenerates, and the endometrial lining is sloughed off.  (Menstrual period)

Amenorrhea – stopping having periods

Libido – sex drive

            In male- caused by testosterone

            In female – caused by androgens from the adrenal glands

N

Sexually Transmitted Disease   (STD's)

Prevention - condoms, abstinance, mutual monogamy with an uninfected person

Gonnorhea - bacteria; responds to antibiotics;  -  - discharge, painful urination, pelvic inflamatory disease, can infect eyes

Syphilis - bacteria; responds to antibiotics; --    local lesion, then rash, then later (maybe years) infects brain, blood vessels, skin, bones

Chlamydia - bacteria -- discharge, pain, sterility, blindness in eyes of newborn

Trichomoniasis - protozoan; responds to antibiotics - the green vaginal discharge with strong odor

Gentital warts - virus (human papilloma virus); does NOT respond to antibiotics- causes warts on genital area or anus, major cause of cervical cancer

Genital Herpes - virus; does NOT respond to antibiotics; cause blisters to form on genitalia

AIDS - virus (HIV virus) ; does NOT respond to antibiotics; destroys immune system