Man Anatomy And Physiology

MAN ANATOMY AND PHYSIOLOGY Ch 10 - Muscles I) Muscle Mechanics A) Lever Systems: Bone-Muscle Relationships 1. bones & muscles operates as levers to create motion 2. depending upon the position of the effort, fulcrum and resistance ... there are 3 types a. first-class levers i. effort and resistance are on opposite sides of the fulcrum ii. an example would be lifting your head off of your chest b. second-class levers i. the resistance is between the effort and the fulcrum ii. an example would be the act of standing on your toes c. third-class levers i. the effort is between the resistance and the fulcrum ii. an example would be the biceps flexing the arm

B) Relationships of Fascicle Arrangement 1. there are several structural arrangements of muscle fascicles a. circular - ie. orbicularis oculi b. convergent - ie. pectoralis major c. parallel - ie. biceps brachii d. unipennate - ie. extensor digitorum longus

e. bipennate - ie. rectus femoris f. multipennate - ie. deltoid C) Muscle Interactions 1. muscles work by contracting (pulling) ... nevery by pushing 2. the insertion is the attachment of a muscle on the movable bone 3. the origin is the attachment of a muscle to its fixed or immovable point of attachment 4. muscles can be classified into four functional groups a. prime mover (agonist) - the muscle that provides the major effort in movement b. antagonist - muscle that opposes the motion of the prime mover c. synergists - muscles that help other muscles d. fixators - muscles that immobilize a bone D) Naming Skeletal Muscles - muscles are named for a variety of reasons 1. location of the muscle - ie. the frontalis is over the frontal bone 2. shape of the muscle - ie. the trapezius is roughly in the shape of a trapezoid 3. relative size of the muscle - ie. the gluteus maximus is the largest of 3 gluteal muscles 4. direction of muscle fibers - ie. the oblique muscles run diagonally 5. number of origins - ie. the triceps have 3 origins 6. location of the muscle's origin and/or insertion - ie. the extensor digitorum inserts into the digits 7. action of the muscle - ie. the adductor magnus acts to adduct the leg

II) Major Muscles of the Body NOTE: Anterior & posterior diagrams with the major muscles are at the bottom of this page.

A) muscles of the scalp 1. epicranius a. frontalis - over the frontal bone; furrows the forehead b. occipitalis - over the occipitalis bone B) muscles of the face 1. corrugator supercilii - over the eyebrows; pulls the eyebrows medially 2. orbicularis oculi - around the eye; for winking 3. zygomaticus - from the zygomatic bone to the corner of the mouth; helps you smile 4. risorius - horizontal muscle from the corner of the mouth extending laterally 5. levator labii superioris - from below the eye to the upper lip; lifts the upper lip 6. depressor labii inferioris - from the lower lip down to the chin; pull the lower lip down 7. depressor anguli oris - from the lower lip /corner to the chin; pulls the lip

down at an angle 8. orbicularis oris - around the mouth; puckers the lips 9. mentalis - at the chin 10. buccinator - cheek muscle 11. platysma - sheet-like muscle from the jaw over the neck C) muscles of mastication (chewing) 1. masseter - over the ramus of the jaw; prime mover for closing the jaw 2. temporalis - at the side of the head; pulls the jaw up and back in chewing 3. medial pterygoid - inside the face; pulls the jaw side-to-side and forward for chewing 4. lateral pterygoid - inside the face; pulls the jaw side-to-side and forward for chewing 5. buccinator - cheek muscle D) muscles promoting tongue movements 1. genioglossus 2. hyglossus 3. styloglossus E) suprahyoid muscles - from the mandible to the hyoid bone 1. digastric - from the tip of the chin back to the hyoid bone 2. stylohyoid 3. mylohyoid 4. geniohyoid F) infrahyoid muscles - from the hyoid bone to the neck 1. sternohyoid 2. sternothyroid 3. omohyoid 4. thyrohyoid G) pharyngeal constrictor muscles H) anterolateral neck muscles 1. sternocleidomastoid - from the sternum/clavicle back to the mastoid process; bend the neck forward 2. scalenes - from the cervical vertebra to the top ribs I) intrinsic muscles of the back 1. splenius - from the occipital bone down to the spine; pulls the head back 2. erector spinae - extend vertically down the back; keeps your back straight and extends it a. iliocostalis b. longissimus c. spinalis

3. semispinalis - same function as the erector spinae, but closer to the spine 4. quadratus lumborus - lower back muscle attached to the pelvis J) muscles of the thorax: breathing 1. external intercostals - rib muscles 2. internal intercostals - rib muscles 3. diaphragm - a single muscle that pulls down to draw air in and relaxes (and moves up) to push air out K) muscles of the anterior and lateral abdominal wall 1. rectus abdominus - vertical straight muscle in the middle front of the abdomen 2. external oblique - superficial angled muscle at your sides 3. internal oblique - internal (under the external) angled muscle at your sides 4. transversus abdominus - horizontal muscle at your sides that holds things in L) muscles of the pelvic floor and perineum 1. muscles of the pelvic diaphragm a. levator ani b. coccygeus 2. muscles of the urogenital diaphragm a. deep transverse perineus b. sphincter urethrae 3. muscles of the superficial space a. ischiocavernosus b. bulbospongiosus c. superficial transverse perineus M) muscles of the anterior thorax 1. pectoralis minor 2. serratus anterior - muscles that insert into your ribs; boxer's muscle 3. subclavius N) muscles of the posterior thorax 1. trapezius - kite-shaped muscle that goes from the cranium to the shoulders and down to the spine; pulls the head back or shrugs the shoulders 2. levator scapulae - attached to the top of the scapula to lift it up 3. rhomboids - from the spine to the scapula; pulls the scapula medially towards the spine O) muscles crossing the shoulder joint 1. pectoralis major - chest muscle; pulls the arm forward 2. latissimus dorsi - lower back muscle ... along the lower half of the spine and inserting onto the humerus 3. deltoid - shoulder muscle; lifts your arm 4. subscapularis

5. supraspinatus 6. infraspinatus 7. teres minor 8. teres major 9. coracobrachialis P) muscles crossing the elbow joint [cross section through the upper arm] 1. posterior muscles of the elbow joint a. triceps brachii - posterior muscle of the upper arm; extends the arm b. anconeus - posterior muscle at the elbow that helps to pronate the arm 2. anterior muscles of the elbow joint a. biceps brachii - anterior muscle of the upper arm; flexes the arm b. brachialis - underneath the biceps (can be seen poking out on each side at the distal end of the biceps) c. brachioradialis - extends to the radius; at the top of the forearm Q) muscles of the forearm [cross section through the forearm] 1. anterior muscles of the forearm a. superficial muscles of the anterior forearm i. pronator teres ii. flexor carpi radialis - on the palm side of the forearm on the thumb edge; helps make a fist iii. palmaris longus - on the palm side of the forearm in the middle; helps make a fist iv. flexor carpi ulnaris - on the palm side of the forearm on the little finger edge; helps make a fist v. flexor digitorum superficialis - flexes the fingers b. deep muscles of the anterior forearm i. flexor pollicis longus - flexes the thumb ii. flexor digitorum profundus - flexes the fingers iii. pronator quadratus 2. posterior muscles of the forearm a. superficial muscles of the posterior forearm i. extensor carpi radialis longus - on the back of the forearm on the thumb edge; extends the fingers ii. extensor carpi radialis brevis - on the back of the forearm on the thumb edge; extends the fingers iii. extensor digitorum - on the back of the forearm in the middle; extends the fingers iv. extensor carpi ulnaris - on the back of the forearm on the little finger edge; extends the fingers b. deep muscles of the posterior forearm i. supinator - helps to twist the forearm so that it's face-up ii. abductor pollicis - abducts the thumb iii. extensor pollicis brevis - extends the thumb

iv. extensor pollicis longus - extends the thumb v. extensor indicis - extends the index finger R) thigh muscles 1. muscles with the origin at the pelvis a. iliopsoas - from the iliac crest downward i. iliacus ii. psoas major b. sartorius - from the iliac crest, diagonally across the thigh to the medial side of the knee; helps cross the legs 2. medial muscles of the thigh a. adductors - pulls the legs together; medial to the pectineus; laterial to the gracilis i. adductor magnus ii. adductor longus iii. adductor brevis b. pectineus - pulls the legs together; lateral to the adductors c. gracilis - pulls the legs together; medial to the adductors 3. anterior muscles of the thigh a. quadriceps femoris - four muscles in the front of the thigh i. rectus femoris - straight, vertical muscle in the front of the thigh ii. vastus lateralis - to the lateral side of the rectus femoris iii. vastus medialis - to the medial side of the rectus femoris iv. vastus intermedius - underneath the rectus femoris b. tensor fasciae latae - at the lateral sides of the thigh 4. posterior muscles of the thigh a. gluteal muscles i. gluteus maximus - the large muscle that you sit on ii. gluteus medius - located at the hip; used as an injection site iii. gluteus minimus b. lateral rotators i. piriformis ii. obturator externus iii. obturator internus iv. gemellus v. quadratus femoris c. hamstrings - three muscles at the back of the thigh i. biceps femoris - most medial and largest of the three muscles in the back of the thigh ii. semitendinosus - lateral to the biceps femoris iii. semimembranosus - underneath the semitendinosus S) lower leg muscles 1. anterior musces of the lower leg a. tibialis anterior - along the front of the shin bone b. extensor digitorum longus

c. peroneus tertius d. extensor hallucis 2. lateral muscles of the lower leg a. peroneus longus - at the lateral side of the lower leg b. peroneus brevis 3. posterior muscles of the lower leg [cross section through the lower leg] a. superficial muscles i. triceps surae 1. gastrocnemius - the large calf muscle 2. soleus - underneath the gastrocnemius (can be seen poking out on each side at the distal end of the gastrocnemius) ii. plantaris b. deep muscles i. popliteus ii. flexor digitorum longus iii. flexor hallucis longus iv. tibialis posterior

The Skeletal System The skeletal system is made up of your bones, ligaments, and tendons. Humans have an endoskeleton (inside the body) of about 200 bones. The number of bones varies because some bones fuse at different times. Most bones are hollow with marrow cells inside. Ligaments connect bones to bones, and tendons connect bones to muscles. There are 4 types of joints: 1.) Ball and socket allows freedom of movement in several directions. (shoulder, hip) 2.) Hinge joint allows movements in a single plane. (knee) 3.) Pivot joint allows freedom of movement between ball and socket and hinge joining. (wrists, ankles) 4.) Joints of the skull are very strong and immovable. All bones are made of compact and spongy bone tissue. The compact tissue makes the outer part of the bone. The spongy tissue makes up the inner part. Bones come in all shapes and sizes. Smooth and slippery cartilage covers the ends of the bones to reduce friction during movement. There are 5 functions of bones: 1.) to protect internal organs 2.) to support the body 3.) to make red blood cells (in the marrow tissue)

4.) to store minerals 5.) to provide for muscle attachment

Interesting web sites: Powerful Bones/Powerful Girls Inside a bone The Human Body Your Gross and Cool Body Bones: An Exhibit Inside You

1 2 3 4 5 6 7 8

Genital Anatomy Women and men have both external and internal genital organs. The diagrams and information in this module will list the external and internal genital organs, with a focus on their sexual function.

External female genitals The external female genitals are the mons pubis, the clitoris, the labia majora, and the labia minora. Together, along with the opening of the

vagina, they are known as the vulva. The mons pubis is a pad of fatty tissue over the pubic bone. This structure, which becomes covered with hair during puberty, protects the internal sexual and reproductive organs. The clitoris is an erectile, hooded organ at the upper joining of the labia that contains a high concentration of nerve endings and is very sensitive to stimulation. The clitoris is the only anatomical organ whose sole function is providing sexual pleasure. The labia majora are two spongy folds of skin—one on either side of the vaginal opening—that cover and protect the genital structures. The labia minora are the two erectile folds of skin between the labia majora that extend from the clitoris on both sides of the urethral and vaginal openings. (The area covered by the labia minora that includes the vaginal, urethral, Bartholin’s, and Skene’s gland openings is called the vestibule.) The perineum is a network of muscles located between and surrounding the vagina and the anus that support the pelvic cavity and help keep pelvic organs in place.

Internal female genitals The internal female genitals are the vagina, the cervix, the uterus, the fallopian tubes, and the ovaries. The vagina is a muscular, highly expandable, tubular cavity leading from the vestibule to the uterus. The vagina is the structure penetrated during vaginal intercourse, and it serves as an exit channel for menstrual flow. During vaginal intercourse, contact with this structure provides sexual pleasure in some women. The anterior vaginal wall is more densely innervated and more highly sensitive to stimulation than the posterior vaginal wall. Bartholin’s glands are two small, round structures, one on either side of the vaginal opening. These glands secrete a mucuslike fluid during sexual arousal, providing vaginal lubrication. The Grafenberg spot, or G-spot, is a small area (about 1–2 cm) on the front wall of the vagina (closest to the bladder and urethra), about halfway between the pelvic bone and the cervix, that is especially sensitive to sexual stimulation in some women and may be the source of a small amount of fluid ejaculated at orgasm. If stimulated, this area

becomes engorged. The G-spot has no known function for women except as a source of sexual stimulation. After stimulation of the Gspot, some women report temporary difficulty urinating; this may be due to the swelling, which creates pressure on the urethra. The cervix (the lower part of the uterus that protrudes into the vaginal canal) has an orifice that allows passage of menstrual flow from the uterus and passage of sperm into the uterus. During vaginal intercourse, contact with this structure may provide sexual pleasure in some women. The uterus is a hollow, thick-walled, pear-shaped, muscular organ located between the bladder and rectum. It is the site of implantation of the fertilized ovum (egg), the location where the fetus develops during pregnancy, and the structure that sheds its lining monthly during menstruation. The upper portion of the uterus contracts during orgasm. The fallopian tubes (the oviducts) are a pair of tubes that extend from the upper uterus out toward the ovaries (but not touching them), through which ova (eggs) travel from the ovaries toward the uterus and in which fertilization of the ovum takes place. The fallopian tubes contract during orgasm. The ovaries are two organs, located at the end of each fallopian tube, that produce ova (releasing one per month from puberty to menopause). The ovaries produce estrogen and progesterone, the hormones responsible for development of sex characteristics. These hormones are also responsible for elasticity of the genitalia, integrity of the vaginal lining, and lubrication of the genitalia. Testosterone is also produced in the ovaries—although in smaller amounts than produced in men—and is responsible for sexual desire.

Risk of diseases and infections It is important to recognize that women are more vulnerable to diseases of the genital tract than men. The lining of the vagina is a mucous membrane and more permeable than the outside of the penis, and women have more surface area through which infection can occur. Lack of lubrication during intercourse, changes in the cervix during the menstrual cycle, and asymptomatic infections facilitate more efficient transmission of infection to women. Prepubertal girls and adolescents are particularly vulnerable, because their vaginal and cervical tissues may be less mature and more readily penetrated by organisms (e.g., chlamydia and gonococcus). Postmenopausal women

are more likely than younger women to get small abrasions in the vagina during sexual activity as a result of thinning of the tissue and dryness. Women who already have an infection (particularly one that causes genital lesions) are more likely to get or transmit another STI, including HIV. Other biological risks include the use of vaginal douches, which increase the risk of pelvic inflammatory disease, and the influence of hormonal contraceptives on acquiring or transmitting an STI (e.g., increased risk of chlamydial infection with use of oral contraceptives), though this is not fully understood.

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direct hernia Direct Inguinal Hernia • • • •

occurs in the inguinal area, near the inguinal ring occur less frequently than indirect inguinal hernia are more common in men usually occur after the age of 40

Indirect Inguinal Hernia • • • •

located in the groin, a result of a weakness in the inguinal ring the most common type of hernia can be present at birth may occur later in life

Intestine drops into the internal ring Direct Inguinal Hernia • • • •

occurs in the inguinal area, near the inguinal ring occur less frequently than indirect inguinal hernia are more common in men usually occur after the age of 40

intestine pushes through weak muscle

femoral hernia

normal

epi