What Is The Digestive System Responsible For?
The digestive system is responsible for taking in food, breaking it down physically and chemically, and absorbing the nutrients into the bloodstream. Once this is all done, it then rids the body of indigestible remains.
The Process of Digestion:
  1. Food enters the digestive tract through the mouth and is then mixed with saliva (a mixture of mucus and serous fluids). The mucus softens the food and forms it into a bolus to make chewing and swallowing easier. Salivary amylase begins the process of starch digestion in the mouth.
  2. The teeth are responsible for mastication (chewing) to break the food into smaller particles
  3. The tongue then forces the food into the pharynx and through the esophagus with the help of peristalsis pushing it down.
  4. Food now reaches the stomach when it is mixed with hydrochloric acid and pepsin allowing the walls of the stomach to stretch.
  5. As this is happening, the food is broken apart physically and is being mixed with gastric juice to form chyme.
  6. Peristalsis begins to take place once again in the stomach and the pyloric valve is approached.
  7. Each contraction of the stomach squirts a little bit of chyme into the small intestine. When chyme enters the small intestine it stimulates the production of secretin and CCK's.
  8. As food reaches the small intestine it is only partially digested. Chemical food digestion is accelerated and takes 3-6 hours to go through the small intestine.
  9. Foods are then mixed with pancreatic juice from the pancreas and bile from the liver to complete the digestion of starch and start the digestion of fats.
  10. Food then reaches the large intestine and contains few nutrients, but still spends 12-24 hours residing there.
  11. Absorption of vitamins, ions, and water occurs in the large intestine.
  12. Feces (solid product containing undigested food residues and water) are then forced through the anal canal and digestion ends.

Short Video Explaining Process of Digestion:

Breakdown of Carbohydrates:
  1. Starch digestion begins in the mouth
  2. Once food is placed in the mouth salivary amylase is an active enzyme that helps to break down the starch
  3. Pancreatic amylase in the small intestine continues to break down the starches even further
  4. The starch is now almost fully digested and is later converted into glycogen and fat, or energy.

Breakdown of Proteins:
  1. Protein digestion primarily takes place in the stomach
  2. Pepsin in the presence of hydrochloric acid breaks the proteins down into large polypeptides
  3. Next, pancreatic enzymes(Trypsin) in the small intestine break the proteins down further into small polypeptides and eventually small peptides
  4. Other enzymes in the small intestine finally break down the proteins into amino acids which are transported to the liver through the hepatic portal vein to be absorbed

Breakdown of Fats:
  1. The digestion of fat begins in the small intestine
  2. Bile salts begin to emulsify the fats
  3. Pancreatic lipase continues the digestion process of fats and finally the fats are broken down into monoglycerides and fatty acids or glycerol and fatty acids

2 Kinds of Chemical Reactions:
  1. Synthesis Reactions
    • When 2 or more atoms bond together to form a more complex structure
      • Example: When the atoms of hydrogen and oxygen bond together to form a water molecules
  1. Decomposition Reactions
    • Complex molecules are broken down into their simple counterparts
      • Example: When a water molecule is broken down into hydrogen and oxygen
        • AB = A + B

2 Types of Metabolic Processes:
  1. Anabolic Process: the buildup of smaller molecules to larger molecules
  2. Catabolic Process: the breakdown of large molecules to smaller molecules and releases energy

Substances that ionize in water
  • Acids: electrolytes that release Hydrogen ions in water
    • Example- Acidic Acids
  • Base: electrolytes that release ions that combine with hydrogen ions
    • Example- Potassium
  • Salts: substances formed by the reaction between an acid and a base
    • Example- Sodium

3 Types of Sugars:
  • Simple Sugars (Mono-saccharides)
    • 6 1 Carbon atoms
      • Examples: Glucose and Fructose
  • Double Sugars (Di-saccharides)
    • Molecules that each have 2 building blocks
      • Examples: Sucrose Maltose, and Lactose
  • Polysaccharides
    • Many simple sugar units joined
      • Example: Starches

Protein Synthesis:
  • The process of making new proteins for the cell
  • The most important place for protein synthesis is in the nucleus
  • Codons are chemical code words consisting of three nitrogen-containing bases
    • Each codon is a code word for bringing in a type of amino acid
  • Messenger RNA, made in the nucleus, and moves into cytoplasm to become associated with ribosomes
  • Ribosomes then bind to mRNA and allows a transfer RNA molecule to recognize its correct position
  • Ribosomes contain enzymes needed for synthesis of developing protein

Regulation of Water Intake:
  • Thirst is the primary regulator of water intake
  • The feeling of thirst is usually accompanied with dryness in the mouth

  • Extracellular fluid becomes more concentrated
  • Hypothalamus is stimulated
  • Signals the posterior pituitary gland to release ADH
  • Blood carries ADH to the kidneys
  • This causes water re-absorption
  • Urine output then decreases


Excess Water Intake:
  • Extracellular fluid is less concentrated
  • Pituitary gland decreases the release of ADH
  • Kidneys decrease in water re-absorption
  • Urine output increases and excess water is excreted

Endocrine SystemWhat is the Endocrine System?

The Endocrine System coordinates and directs the activity of the body's cells. This system is much slower than the nervous system and uses chemical messengers known as hormones to be released and transported throughout the body.The major processes that hormones controlled are reproduction, growth and development, mobilizing body defenses against stressors, maintaining balance of the blood, and regulating metabolism.

Chemistry of Hormones:
  • Hormones are the chemical substances that are secreted by cells into the extracellular fluids and regulate the metabolic activity of other cells
  • Hormones can be classified chemically as amino acid-based molecules (proteins, peptides, and amines) or steroids
    • Steroid hormones include the sex hormones and hormones produced by the adrenal cortex
    • All other hormones are non-steroidal amino acid derivatives

Importance on Target Cells:
A given hormone affects only certain tissue cells or organs, these are known as target cells or target organs. For a target cell to respond to a hormone, specific protein receptors have to be present on the plasma membrane so the hormone has the ability to attach. Once the hormone attaches the hormone can now influence the cell and how it works.

Hormone Release Control:
  • Negative feedback mechanisms are the most important way of regulating blood levels or almost all hormones
    • Hormone secretion is triggered by a stimulus, then rising levels of a certain hormone inhibit further release of hormones
    • The result is that blood levels of many hormones vary within a small range
  • Three stimuli that activate endocrine organs:
    1. Hormonal Stimulus: endocrine organs are put into action by other hormones
      • Example: Hypothalamic hormones stimulate the pituitary gland to secrete its hormones and other organs to release their hormones into the blood
    2. Humoral Stimulus: changing blood levels of certain ions and nutrients to stimulate hormone release
      • Example: The release of PTH by the parathyroid gland is put into action by decreasing blood calcium levels
        • Blood calcium ions then rise and the stimulus for PTH release ends
    3. Neural Stimulus: nerve fibers stimulate hormone release
      • Example: Sympathetic Nervous System stimulates the adrenal medulla to release norepinephrine and epinephrine during times of stress
Organs Involved In Endocrine System:
  1. Pituitary Gland
    • Location: Hangs by stalk from inferior of hypothalamus and is surrounded by the sphenoid bone
    • Hormones of the Anterior Pituitary:
      • Growth Hormone- a general metabolic hormone directed to the growths of skeletal muscles and lone bones of the body
        • Protein sparing hormone and anabolic hormone
        • Causes fats to be broken down and used for energy
          • Hyposecretion: Leads to pituitary dwarfism in which body proportions are normal, but person reaches a maximum of four feet
          • Hypersecretion: Leads to gigantism in which body proportions are normal, but person is extremely tall at 8-9 feet
            • If hyperseretion occurs after long-bone growth has ended, the facial bones enlarge and facial features are malformed
      • Prolactin- protein hormone whose target is the breasts and stimulates milk production
      • Adrenocorticotropic hormone- regulates activity of the cortex of adrenal gland
      • Thyroid-stimulating hormone- influences the growth and activity of the thyroid gland
      • Follicle-stimulating hormone- stimulates follicle development in ovaries and as they mature they produce estrogen and in the testes they stimulate sperm development
      • Lutenizing hormones- triggers ovulation of an egg from the ovary and produces progesterone and some estrogen
    • Hormones of the Posterior Pituitary
      • Oxytocin- releases only during childbirth and in nursing women. It stimulates powerful contractions of uterine muscle during labor, during sexual relations, and when breast-feeding
      • Antidiuretic Hormone- chemical that inhibits or prevents urine production. Causes the kidneys to reabsorb more water from urine causing urine volume to decrease and blood volume to increase
        • Hyposeretion: can cause diabetes insipidus in which people are constantly thirst and drink large amounts of water
  1. Thyroid Gland
    • Location: located at the base of the throat, inferior to Adam's Apple
    • Hormones of the Thyroid Gland:
      • Thyroid Hormone- made up of thryoxine (T4) and triiodothyronine (T3)
        • T4 is secreted by the thyroid follicles and controls the rate of glucose being burned and converted to body heat and chemical energy. It is also very important in tissue growth and development
        • T3 is formed at the target tissues
          • Hyposecretion of T4: if it occurs in early childhood the result is cretinism in which adult body proportions remaining childlike.If this condition remains untreated the result is mental retardation. If discovered early enough hormone replacement will prevent retardation.
          • Hyperthyroidism: results in high basal metabolic rate, intolerance of heat, rapid heartbeat, weigh loss, and agitated behavior
            • Grave's disease is one form of hyperthyroidism and causes the eyes to bulge
        • Calcitonin- decreases blood calcium levels by depositing calcium into the bones and is made of the C cells found in connective tissue between follicles
    • thyroid_parathyroid.jpg
  2. Parathyroid Gland
    • Location: found on the posterior surface of the thyroid gland
    • Hormones of the Parathyroid Gland:
    • Parathyroid Hormone- the most important regulator of calcium homeostasis in the blood
      • When blood calcium levels drop, PTH stimulates bone destruction cells to break down the bone matrix and release calcium
      • PTH is hypercalcemic because it acts to increase blood levels of calcitonin
4. Adrenal Glands
    • Location: Curve over the top of the kidneys
    • Hormones of the Adrenal Cortex:
      • Mineralcorticoids (Aldosterone)- important in regulating the mineral content of blood mainly concerning sodium and potassium ions
        • When blood levels of aldosterone rise, kidney cells increase amounts of soidum ions and secrete more potassium ions into urine
      • Glucocorticoids (Cortisone and Cortisol)- promote normal cell metabolism and help body resist long-term stress
        • When blood levels of these hormones rise, fats are broken down to be converted to glucose to go to the blood
      • Sex hormones (Androgens and Estrogens)- produced in small amounts throughout life
    • Hyposecretion of Adrenal Cortex Hormones- causes Addison's disease in which the skin gets a bronze tone, the body has less ability to deal with stress, and the immune system is suppressed
    • Hypersecretion- can result in Cushing's syndrome in which a buffalo hump forms on the upper back and bones weaken, immune system depressed, and hyperglycemia results
    • Hormones of the Adrenal Medulla:
      • Catecholamines (Adrenaline and Noradrenaline)-when one is threatened physically or emotionally the sympathetic nervous system starts the flight or fight response to help cope with the stress
        • These hormones increase heart rate, blood pressure, and blood glucose levels
5.) Pineal Gland
    • Location: Con-shaped gland in the roof of the third ventricle of the brain
    • Hormones:
      • Melatonin- a sleep trigger that plays an important role in determining the body's day and night cycle
        • Levels of this hormone rise and fall during the day with peak occurring at night to make people drowsy and the lowest levels during the day around noon
        • is also believed to coordinate the hormones of fertility and to inhibit the reproductive system
6.) Thymus Gland
    • Location: in the upper thorax region posterior to the sternum
    • Hormones: Thymosin- during childhood is acts as incubator for the maturation of white blood cells important for immune response
7.) Gonads
  • Hormones of the Ovaries are located in the pelvic cavity
    • Estrogen - stimulate the development of sex characteristics in female (growth and maturation of reproductive organs) and works r to prepare uterus for fertilized egg
      • This causes cyclic changes known as the menstrual cycle
      • This hormone also maintain pregnancy and produce mile
    • Progesterone- quiets the muscles of uterus to embryo will not be aborted and helps prepare breast tissue for lactation
  • Hormones of the Testes are suspended in a sac outside the pelvic cavity
    • Androgens (Testosterone)- causes development of the adult male sex characteristics and promotes the growth and maturation of reproductive organs
      • Testosterone also causes growth of facial hair and lowering of the voice
        • Testosterone is necessary for production of sperm
  • Secretion of Testosterone- causes a man to become sterile and is treated with injections
The Skeletal System

What is the Skeletal System?
The skeletal system is made up of a variety of bones that are strong, yet light and is perfectly adapted for body protection and motion.

Functions of the Bones:
1. Support-bones form the internal framework that supports the soft organs in the body. The bones in the legs support the body trunk and the rib cage supports the thoracic wall

2.)Protection-Bones protect soft body organs. For example the vertebrae surround the spinal cord and the rib cage protects organs of thorax.

3.) Movement- The skeletal muscles are attached to bones by tendons and use the bonds as levers to move the body. This allows humans to walk, run, swim, and breathe.

4.) Storage-Bone serves as a storehouse for minerals, most importantly calcium and phosphorus.

5.) Blood Cell Formation: Hematopoiesis occurs within the marrow cavities of certain bones.

Classification of Bones:
  • Compact Bone- dense and looks smooth and homogenous
  • Spongy Bone- composed of small needle-like pieces of bone and lots of open spaces
  • Long Bones-longer than they are wide and are mostly compact bone
    • Example: Bones of the limbs
  • Short Bone- cube-shaped and contain mostly spongy bone
    • Example: Bones of the wrist
  • Flat Bones- thin, flattened, and usually curved with two thin layers of compact bone around a layer of spongy bone
    • Example: Bones of the skull, ribs, and sternum
  • Irregular Bones- bones that are irregular in shape and do not fit any of the previously mentioned bones
    • Example:Hip Bones

Bone Formation:
  • Bones develop using hyaline cartilage and the process of bone formation is known as ossification. The first step to ossification is the hyaline cartilage model is covered with bone matrix by bone forming cells known as osteoblasts. Next, the enclosed hyaline cartilage is digested away, which opens the medullary cavity in newly formed bone.
  • After bone growth has ended, bones are remodeled continually in response to changes in calcium levels of the blood and the pull of gravity and muscles on the skeleton.
    • Example: When calcium levels in the blood are low, PTH is secreted and activates osteoclasts to break down bone matrix and release calcium ions into the blood
  • A fracture is a break that results from exceptional trauma that twists or smashes the bones
  • There are six major fracture types
    • Comminuted: bone breaks into many fragments and is particularly common in the aged because bones are more brittle
    • Compression: bone is crushed and is common in porous bones
    • Depressed: the broken bone portion is pressed inward and is typical of skull fractures
    • Impacted: Broken bone ends are forced into each other and occurs when one falls with outstretched arms
    • Spiral: ragged break when excessive twisting forces are applied to a bone (Commonly occurs in sports)
    • Greenstick: bone breaks incompletely like the was a green twig breaks and is common in children because bones are more flexible than adults
  • Repairing Bone Fractures:
    • A hematoma is formed (blood-filled swelling) and bone cells deprived of nutrition die
    • The break is splinted by a fibrocartilage callus, which has some cartilage matrix, some bony matrix, and collage fibers to close the gap
    • The bony callus is formed
    • Bone remodeling occurs and over next few months the callus is removed so a permanent patch is at the fracture site

Bone Markings:
Sites of muscle and ligament attachment
  • Tuberosity: Large, rounded projection; may be roughened
  • Crest: Narrow ridge of bone; usually prominent
  • Trochanter: Very large, blunt, irregularly shaped process (The only examples are on the femur)
  • Line: Narrow ridge of bone; less prominent than a crest
  • Tubercle: Small, rounded projection or process
  • Epicondyle: Raised area on or above a condyle
  • Spine: Sharp, slender, often pointed projection
  • Process: Any bony process

Projections that help to form joints
  • Head: Bony expansion carried on a narrow neck
  • Facet: Smooth, nearly flat articular surface
  • Condyle: Rounded articular projection
  • Ramus: Armlike bar of bone

Depressions and openings allowing blood vessels and nerves to pass
  • Meatus: Canal-like passageway
  • Sinus: Cavity within a bone, filled with air and lined with mucous membrane
  • Fossa: Shallow, basinlike depression in a bone often serving as an articular surface
  • Groove: Furrow
  • Fissure: Narrow, slitlike opening
  • Foramen: Round or oval opening through as bone
The skull has two sets of bones known as the cranium and the facial bones. All but one of the skull bones are joined together by interlocking, immovable joints known as sutures.

  • Frontal Bone: forms the forehead, projections under eyebrow, and eye orbit
  • Parietal Bone: form most of the superior and lateral walls of cranium and meet at sagittal suture and form coronal suture
  • Temporal: inferior to parietal bones and join them at squamous suture
    • External acoustic meatus: canal leading to middle ear
    • Styloid process: sharp, needle-like projection where many neck muscles attach
    • Zygomatic Process: thin bone that joins with cheek bone
    • Mastoid Process: rough projection full of air cavities and provides attachment site for muscles on neck
    • Jugular foramen: allow passage of jugular vein and drains the brain
  • Occipital Bone: joins the parietal bones at lambdoid suture
  • Sphenoid Bone: butterfly shaped and forms part of the floor of cranial cavity
  • Ethmoid Bone: very irregularly shaped and forms the roof of the nasal cavity and medial walls of the orbits
Facial Bones:
  • Maxillae: fuse to form the upper jaw and all facials bones except mandible join to it. Palatine processes form anterior part of hard palate of mouth.
  • Palatine Bones: form posterior part of the hard palate and failure to fuse results in cleft palate
  • Zygomatic Bones: referred to as cheekbones
  • Lacrimal Bones: fingernail size bones and has grooves to serve as passageways for tears
  • Nasal Bones: small rectangular bones forming bridge of nose
  • Vomer: forms most of the nasal septum
  • Inferior Nasal Conchae: thin, curved bones
  • Mandible: largest and strongest bone of the face and forms the only freely moveable joints in the skull

Vertebral Column:
Extends from the skull to the pelvis and can transmit the weight of the body to lower limbs. The spine is actually formed from 26 irregular bones that are connected and reinforced by ligaments. Before birth the spine has 33 vertebrae, but 9 are then fused to form the sacrum and coccyx. This leaves 24 singles bones, 7 of which are in the cervical vertebrae, 12 in thoracic vertebrae, and 5 in lumbar vertebrae.

Bones that Help Move Muscles:
Humerus:a long bone located in the arm that runs from the shoulder to the elbow. This bone helps with mobility.
Tibia: a large and strong bone located below the knee and connects to the ankle bone
Fibula:located on the lateral side of the leg just below the knee
Ulna: extends arm and allows for flexion back and forth
Radius:helps with motion and connects with many joints

The Muscular System:

The function of muscles is contraction, or shortening. Due to this muscles are necessary for all body movement and are considered one of the main machines of the human body.

Muscle Types:
The three types of muscles are skeletal, cardiac, and smooth and they differ in their cell structure, body location, and how contraction occurs. Both skeletal and smooth muscles are elongated and are called muscle fibers.

  • Skeletal muscle fibers- packaged into organs to attach to the body's skeleton
    • Fibers are cigar-shaped, multinucleated cells, and the largest of the muscle fiber types
    • Skeletal muscles are striated and voluntary due to conscious control
    • These can contract rapidly and with great force, but they tire easily
  • Smooth muscle- have no striations and are involuntary
    • They are found mainly in the walls of hollow visceral organs
    • Spindle-shaped and have a single nucleus
    • Arranged in sheets or layers
  • Cardiac Muscle- found only in the heart
    • It is striated and is involuntary because it cannot be consciously controlled

Muscle Functions:
  1. Produce Movement: almost all movements in the human body are due to the work of muscles
    1. Muscles allow us to respond quickly to change like running out of the way of a moving car
  2. Maintain Posture: muscles function all the time by making tiny adjustments so humans can remain in an erect or seated position
  3. Stabilize Joints: muscles pull on bones to cause movements, which in turn stabilizes the joints of the skeleton
  4. Generate Heat: generating heat is a by-product of muscle activity
    1. ATP is used to cause contraction causing three quarters of energy to escape as heat

Important Terms for Muscles:
  • Sarcolemma: where many oval nuclei can be seen beneath the plasma membrane
  • Myofibrils: contractile organelles found in the cytoplasm of muscle cells
  • Light and Dark Bands: alternate along the length of myofibrils that give the muscle its striped appearance
  • Sarcomeres: the smallest contractile unit of muscle
  • Myofilaments: filaments composed of the myofibrils (actin or myosin)
  • Thick Filaments: made mostly of bundled molecules of the protein myosin
  • Myosin: one of the principal contractile proteins found in muscle
  • Cross Bridges: projections that link the thick and thin filaments together during contraction
  • Thin Filaments: composed of the contractile protein actin
  • Actin: a contractile protein of muscle
  • Sarcomplasmic Reticulum: specialized smooth endoplasmic reticulum

Sliding Filament:
  1. A motor neuron sends signal to muscle fiber and involves the release of calcium
  2. Calcium binds to troponin on actin
  3. Troponin moves and this exposes actin to the head of myosin
  4. Myosin head binds to actin
  5. ATP attaches to 2nd binding site
  6. ATP breaks down into ADP and phosphate
  7. Phosphate is released and angle changes
  8. Actin pulls closer to the M-line
  9. ADP is released
  10. Myosin head moves back to original position and detaches from actin
  11. Cycle continues as myosin binds to another area on actin

Types of Body Movements:
  • Flexion: movement usually in the sagittal plane that decreased the angle of the joint and brings two bones closer together
  • Extension: a movement that increases the angle between two bones
  • Rotation: movement of a bone around its longitudinal axis
  • Abduction: moving a limb away from the midline of the body
  • Adduction: moving a limb toward the midline of the body
  • Circumduction: combination of flexion, extension, abduction, and adduction
  • Dorsiflexion and plantar flexion: up and down movements of the foot at the ankle
    • Dorsiflexion- lifting the foot so that the superior surface approaches the shin
    • Plantar Flexion- depressing the foot
  • Inversion and eversion: special movements of the foot
    • Inversion- turning the sole medially
    • Eversion- turn the sole laterally
  • Supination and pronation: refer to movements of the radius around the ulna
    • Supination- forearm rotates laterally so that the palm faces anteriorly and radius and ulna are parallel
    • Pronation- forearm rotates medially so the palm faces posteriorly and brings the radius across the ulna so two bones form an X
  • Opposition: action by which one can move their thumb to touch the tips of other fingers on the same hand

Muscles of the Body:
Name: Origin/Insertion/Primary Action
  • Trapezius: Occipital bone/Scapular spine and clavicle/Extends neck and adducts scapula
  • Latissimus dorsi: Lower spine and iliac crest/ Proximal humerus/ Extends and adducts humerus
  • Erector Spinae: Iliac crests, ribs 3-12, and vertebrae/Ribs and vertebrae/Extends back
  • Delotid: Scapular spine and clavicle/ Humerus/ Adducts humerus
  • Triceps Brachii: Shoulder girdle and proximal humerus/ Olecranon process of ulna/ Extends elbow
  • Flexor carpi radialis: Distal humerus/ Second and third metacarpals/ Flexes wrists and abduct hand
  • Flexor carpi ulnaris: Distal humerus and posterior ulna/ Carpals of wrist/ Flexes wrist and adducts hand
  • Flexor digitorum: Distal humerus, ulna, and radius/ Middle phalanges/Flexes wrist and fingers
  • Extensor carpi radialis: Humerus/ Base of second and third metacarpals/ Extends wrist and abducts hand
  • Extensor digitorium: Distal humerus/ Distal phalanges of 2nd to 5th fingers/ Extends fingers and wrist
  • Gluteus maximus: Sacrum and ilium/ Proximal femur/ Extends hip
  • Gluteus medius: Ilium/ Proximal femur/ Abducts thigh and steadies pelvis during walking
  • Hamstring Muscles: Ischial tuberosity/ Proximal tibia/ Flex knee and extend hip
  • Gastrocnemius: Distal femur/ Calcaneus/ Plantar flexes foot and flexes knee
  • Soleus: Proximal tibia and fibula/ Calcaneus/Plantar flexes foot

3 Skeletal Muscle Fiber Types:
  1. HOST:
    • Red and aerobic
    • Twitch slowly for slow endurance exercises
    • Resistant to fatigue
    • Good for long distance
  2. HOFT:
    • Red and aerobic
    • Good for endurance exercises
    • Fast twitch
    • Combination is good for long distance
  3. LOFT:
    • White and anaerobic
    • Fast twitch
    • Good for sprinting
  • 1st Class Lever: Example is a head nod
    • Fulcrum is in the center
  • 2nd Class Lever: Example is a toe raise
    • Fulcrum is at end and load is in the middle
  • 3rd Class Lever: Example is a bicep curl
    • Effort is in the middle and fulcrum is at the end

The Reproductive System
Male Reproductive System:
  1. Penis- reproductive sex organ
  2. Testes-produce sperm
  3. Epididymis-stores sperm
  4. Vas deferens- highway for sperm
  5. Seminal vesicle- release fructose
  6. Prostate gland- secretes thin, milky fluid
  7. Cowper's gland- pre-seminal fluid
  8. Urethra- urination and semen
Female Reproductive System:
  1. Ovaries- where eggs are stored
  2. Fallopian Tubes- fertilization of the egg
  3. Uterus-where the home of the baby is
  4. Cervix- opening of the uterus
  5. Vagina- reproductive sex organ
  6. Mons pubis- padding
  7. Labia Majora- outer part
  8. Labia Minora- inner part
  9. Hymen-protective sheath

  • Usually begins at 13 years of age
  • The anterior pituitary gland secretes FSH
    • Follicular cells produce and secrete
  • Anterior pituitary gland increase LH and FSH which stimulate ovulation
  • Estrogen and progesterone inhibit FSH and LH
  • Uterine lining disintegrates and levels of estrogen and progesterone decline
    • This ultimately produces menstrual flow
  • Once anterior pituitary gland is no longer inhibited, FSH is secreted

  • One sperm will penetrate the egg and fertilize it, for pregnancy to occur
  • Pregnancy usually lasts for 9 months
  • First 6 weeks the embryo grows in length and weight
  • At the start of the 3rd week, the embryo is one half to one inch long, or 10,000 times the size of the original cell
  • Embryo becomes a fetus at the end of the 8th week
  • Miscarriage is a spontaneous abortion in which the embryo or fetus is expelled
  • Stillborn is the birth of a dead fetus