Human Reproduction Review PDF

**HUMAN REPRODUCTION** A single cell is formed by the union of two sex cells called **an egg and a sperm cell**, each of these sex cells contains **23 chromosomes (haploids)** and forms a **zygote that contains 46 chromosomes (diploid)** ***MALE REPRODUCTION SYSTEM*** TESTES -- The main part wher...

**HUMAN REPRODUCTION** A single cell is formed by the union of two sex cells called **an egg and a sperm cell**, each of these sex cells contains **23 chromosomes (haploids)** and forms a **zygote that contains 46 chromosomes (diploid)** ***MALE REPRODUCTION SYSTEM*** TESTES -- The main part where **sperm cell formation** takes place, found inside the scrotum SCROTUM -- **Protective sac** of skin EPIDIDYMIS -- Long coiled tube where **sperm cells mature** VAS DEFERENS -- Where **mature sperm cells transport** URETHRA -- Larger tube **where sperm cells and urine releases** from the body THE PENIS -- **Male sex organ**, acts as a conduit for urine to leave the body SEMINAL VESICLE -- Secretes 60% of the total volume of semen, **energy source** PROSTATE GLANDS -- **Alkaline fluid that neutralizes acids** in the female women reproductive system BULBOURETHRAL GLANDS -- Alkaline fluid that **neutralizes acidic urine in the urethra** MALE HORMONES AND THEIR FUNCTIONS LUTENIZING HORMONE (LH) -- Stimulates the secretion of the sex hormone testosterone FOLLICLE-STIMULATING HORMONES (FSH) -- Together with the testosterone stimulates the sperm production TESTOSTERONE -- Major sex hormones, essential for growth and development of the male sex organs SPERM CELLS TAIL -- Responsible for the sperm's movement THE HEAD -- Made up of nucleus MITOCHONDRIA -- Supplies Energy 1). Sperm cells are reduced in seminiferous tubules 2.) They enter Epididymis where they mature 3.) Mature sperm cells travel to the vas deferens 4.) Lastly exits the body through the urethra during copulation or ejaculation ***FEMALE REPRODUCTIVE SYSTEM***  OVARIES -- Responsible for producing eggs called ova FALLOPIAN TUBES -- Where the egg cell releases to meet the sperm UTERUS -- Small pear-shaped muscular organ wherein the zygote grows CERVIX -- Narrow opening of the uterus; Birth canal, Channels the blood discharge VAGINA -- Where sperm cells are deposited, as passage that the outside of the female's body VULVA -- The outside part - Ovaries produces Estrogen that triggers development in a female - Egg cells are the biggest cell in the women's body (Approximately 2 million with only 300 to 500 maturing) - Every 28 days an ovum is released in a female adult body and without fertilization dies within 24 to 48 hours - Egg cells mature within the follicles in the ovary, a cluster of cells that provides nutrients and protection FEMALE REPRODUCTIVE CYLES Two cycles every month known as the ovarian and menstrual cycles **OVARIAN CYCLE** - Where the ovary prepares the egg for maturization that spans about 28 days - Ovulation is the monthly the release of an ovum from the ovary Two Stages: Follicular Phase - Begins when the anterior pituitary gland releases the hormones Gonadotropins follicle-stimulating hormones (FSH) and luteinizing hormones (LH). - These hormones cause the follicle to produce estrogen that aids the growth of the ovarian follicle. - When the follicle bursts, ovulation occurs LUTEAL PHASE - LH causes ruptured follicle to form a corpus luteum that produces Progesterone - Progesterone signals the body to prepare for fertilization - Without fertilization corpus luteum will atrophy, progesterone production decreases and FSH and LH declines -- period occurs. **MENSTRUAL CYCLE** - Aside from the series of events in the ovary, a different monthly cycle in the uterus occurs called the menstrual cycle; when the uterus prepares for pregnancy Phases of the Menstrual Cycle MENSTRUAL CYCLE (Days 1-5) - First day of the period, when the lining of the vagina shreds - Cramping, bloating, fatigue, breast tenderness, headache Follicular Phase (Days 1-13) - Begins on the day of the period and ends in ovulation - Increased energy and sex drive, better mood Ovulation Phase (Day 14) - LH increase and releases the eggs - Clear Vaginal discharge, increased body temperature, breast Tenderness Luteal Phase (Days 15 -- 28) - The egg leaves the ovary through the fallopian tube to the Uterus. - Mood changes, acne, bloating HORMONAL REGULATION OF THE MENSTRUAL CYCLE Estrogen -- Plays in ovulation and thickens the lining of uterus Progesterone -- Helps prepare the endometrium FSH -- Highest before ovulation, signals the ovary LH -- Triggers the egg release **HUMAN BODY REGULATION** - Positive feedback mechanism amplifies the effect of a stimulus until the process is completed, less common. - Negative feedback mechanism reduces the effect of a stimulus, bringing the body back to the state of balance (homeostasis). HORMONES - Chemical messengers that carry instructions to cell to change their activities. - Transported to bloodstream to a targeted organ - Produced by the glands of Endocrine system - The Endocrine system keeps all parts of the body working Gland - Organ that secretes materials (Hormone) into other parts of the body Two Types: Exocrine Glands -- Releases substances like sweat, tears and saliva. Not part of the Endocrine system Endocrine Glands -- Releases hormones without ducts and directly into the bloodstream **MAJOR ENDOCRINE GLANDS** HYPOTHALAMUS - Located at the base of the brain, link between nervous system and endocrine glands - Produces hormones that help turn other glands on and off - Main function is to keep your body in as stable state called homeostasis THE PITUITARY GLAND - Pea sized found in the center of the skull, below the hypothalamus of the brain Regulates growth and the reproductive development and function THYROID GLAND - Located just under the larynx or voice box - Secretes three hormones: - Triiodothyronine (T3) and Thyroxine (T4) -- Contains iodine which regulates metabolism -- Plays crucial role in development and maturation - Calcitonin -- Influences bone and calcium metabolism; maintains a homeostasis of calcium PARATHROID GLAND - Four tiny glands, releases the parathyroid hormone which along with the calcitonin regulate blood calcium levels in the body THYMUS - An organ located at the chest behind the breastbone - Produces and develop T cells (white blood cells) that protects the body against infectious agents - Speeds up after puberty but by the age of 65, are unable to make new T cells THE ADRENAL - Above each of your kidney Two parts: - INNER ADRENAL MEDULLA Produces: Adrenaline -- Helps the body to cope against short term physical and emotional stress Dopamine -- Used to treat shock Epinephrine -- Often used to counteract an allergic reaction, -- Speeds up the release of glucose from the liver giving as spurt of energy Norepinephrine -- Released when body is under stress, fight or flight response - OUTER ADRENAL CORTEX -- Secretes corticosteroids which regulates body's metabolism -- Aldosterone that regulates electrolyte and water balance -- Androgens: several hormones including testosterone THE PANCREAS - Also, part of the digestive system - Produces two hormones; Insulin and Glucagon Insulin -- Keeps the level of blood sugar (glucose) in the bloodstream under control Glucagon -- It increases the level of sugar in the body, speeding up the conversion of glycogen into sugar THE GONADS (Reproductive Organs) Ovaries -- Produces estrogen and progesterone Testes -- Produces Androgens; testosterone PINEAL GLAND - Located near the thalamus, secretes melatonin (regulates body rhythms and sleep patterns) **BODY CONTROL AND RESPONSE SYSTEM** Maintaining Internal Balance: The body raises breathing and heart rate signaling an impending danger and after the danger is over, the body brings the breathing and heart back to normal How does your body keep you safe and under control? - Alert senses reports information about the event to your brain, the brain interprets the information as a threat and sending signals to your brain to react your body. - The nerve also controls hormones that triggers rush of emotions **DIFFERENCE OF NERVEOUS SYSTEM AND ENDOCRINE SYSTEM** ENDOCRINE SYSTEM - Maybe slow in response but produces longer lasting effect NERVEOUS SYSTEM - Quickly gathers information from outside and inside the body - Sends information to muscles, glands, organs - Transmit information in the brain and spinal cord - Processes the information to determine best response Neurons - Basic functional unit of the nervous system - Nerve cells that send messages all over the body TYPES OF NEURONS SENSORY NEURONS - To receive initial stimuli from receptors INTERNEURONS - They read the impulses sent by sensory neurons and decides the response required MOTOR NEURONS - When they receive a signal from the Interneuron they stimulate as effector to generate the reaction for the stimulus. Nerve Impulse -- A wave of chemical and electrical signals Reflex -- A response to a stimulus without the need for conscious thought **THE DNA STRUCTURE** Heredity -- The passing of characteristics or traits from parents to offspring Gene -- As sequence of DNA that codes for particular protein -- Short sections of DNA that are contained on a chromosome within the nucleus of a cell Chromosomes -- Components of a cell nucleus that are capable of self-reproduction. **THE DNA STUCTURE (DEOXYRIBONUCLEIC ACID)** - Two strand that make up a DNA are wound around each other (Helix) - The backbone of the helix consists of alternating sugars and phosphates, in opposing directions Base Pairing: C -- Cytosine A - Adenine G -- Guanine T -- Thymine - Adenine pairs with thymine using two hydrogen bonds - Guanine pairs with cytosine using three hydrogen bonds - DNA is organized into chromosomes The Nucleic Acid - Organic compound that function as storage of genetic information DNA (DEOXYRIBONUCLEIC ACID) - Double strand form Helix - In the nucleus - Store genetic information - Made up of building blocks called Nucleotides RNA - Single strand - In the nucleus - Transfers genetic information - Protein synthesis Genotype - The genetic material passed between generations Phenotype - The observable characteristics of organism DNA REPLICATION - The DNA makes a copy of itself before cell division TRANSCRIPTION - Making working copies of the Gene TRANSLATION - Creating of amino acids DNA REPLICATION -- TRANSCRIPTION -- mRNA -- Translation tRNA (Anticodons) -- Amino Acids