Human Musculoskeletal and Reproductive Systems Vocabulary

A review flashcard set covering key vocabulary terms, cellular components, skeletal structures, joints, gametogenesis, menstrual cycle phases, and contraceptive methods from Unit 5.

Musculoskeletal system

A body structure made up of bones of the skeleton, muscles, cartilage, tendons, ligaments, joints, and connective tissues that provide shape, support stability, allow movement, and protect vital organs.

Tendons

Connective structures that attach muscles to bones.

Ligaments

Fibrous connective tissues that attach bone to bone.

Cardiac muscle

An involuntary, striated muscle tissue forming the myocardium wall of the heart, whose individual cells are joined together by intercalated discs.

Skeletal muscle

Voluntary, striated muscles arranged in opposing systems around joints attached to bones, comprising $30$ to $40$ percent of total body mass.

Smooth muscle

Involuntary, non-striated, unconsciously controlled muscles found in the walls of hollow organs and passageways, such as the digestive tract, blood vessels, and uterus.

Motor unit

A group of skeletal muscle fibers innervated by a single motor axon.

Sarcomeres

Chains of contractile units within myofibrils containing organized thin actin filaments and thick myosin filaments.

Myosin

A molecular motor protein that converts chemical energy released from ATP into mechanical energy to pull actin filaments during muscle contraction.

Troponin

A complex system of three regulatory proteins integral to muscle contraction in skeletal muscles.

Isometric contraction

A type of muscle contraction that generates tension without changing the length of the muscle.

Concentric contraction

A type of muscle contraction that shortens the length of the muscle.

Eccentric contraction

A type of muscle contraction that lengthens the muscle fibers during tension.

Osteoblasts

Bone cells that are involved in new bone formation.

Osteocytes

Mature bone cells that help to maintain mature bone tissue.

Osteoclasts

Bone cells that break down bone tissue and assist in shaping bones correctly.

Osteoprogenitor cells

Bone precursor cells that are important in the repair of bone fractures.

Long bones

Bones that are longer than they are wide, such as the femur and tibia.

Flat bones

Bones characterized by flattened and broad surfaces, such as the cranium, ilium, sternum, and ribs.

Sesamoid bones

Small, flat bones shaped like a sesame seed that are embedded within muscles.

Axial skeleton

The central core division of the human skeleton consisting of $80$ bones, including the skull, auditory ossicles, hyoid, rib cage, sternum, and vertebral column.

Appendicular skeleton

The portion of the skeleton consisting of $126$ bones, comprising the shoulder girdles, pelvic girdle, upper limbs, and lower limbs.

Ball and socket joint

A joint where the rounded head of one bone sits in the cup of another bone to permit movement in all directions.

Hinge joint

A joint that opens and closes in one direction along one plane only, such as the elbow or knee.

Gametogenesis

The process of formation and development of specialized haploid gametes from diploid primordial germ cells through meiosis.

Spermatogenesis

The process by which haploid spermatozoa develop from germ cells within the seminiferous tubules of the testes.

Oogenesis

The process of female egg cell development in the outermost layers of the ovaries, originating from an oogonium.

Sertoli cells

Tall somatic cells located in the seminiferous tubules that nourish developing sperm cells.

Follicular phase

The phase of the menstrual cycle (days $5$ to $13$) where FSH stimulates ovarian follicle growth and estrogen production.

Ovulation phase

The midpoint event of the menstrual cycle (around day $14$) triggered by an LH surge, resulting in the release of a secondary oocyte from the ovary.

Luteal phase

The menstrual cycle phase (days $15$ to $28$) where the ruptured follicle forms the corpus luteum, secreting high levels of progesterone.

Luteinizing Hormone (LH)

A gonadotrophic hormone that triggers ovulation in females and stimulates testosterone production in males.

Follicle Stimulating Hormone (FSH)

A hormone secreted by the anterior pituitary that stimulates the growth of ovarian follicles in females.

Fertilization

The union of a human egg cell and a sperm cell in the ampulla of the fallopian tube to produce a diploid zygote.

Barrier contraceptives

Contraceptive devices that physically block sperm from entering the uterus and reaching the egg, such as condoms and diaphragms.

Intrauterine device (IUD)

A small T-shaped device fitted inside the uterus that thickens cervical mucus and alters the uterine lining to prevent fertilization and implantation.

Vasectomy

A permanent surgical sterilization procedure for males where each vas deferens tube is cut or blocked to prevent sperm from entering semen.

Tubal ligation

A permanent surgical sterilization procedure for females where the fallopian tubes are blocked or cut to prevent sperm from reaching the egg.