Answers - Exam A+ Guaranteed
1. What is the basic structural and functional unit of life?
Answer: Cell.* The cell is the smallest independently functioning unit in the body. All living
tissues are made of cells. Each cell has a cell membrane, cytoplasm, nucleus and organelles
like mitochondria which is the powerhouse for ATP production, ribosomes for protein synthesis,
and endoplasmic reticulum. In anatomy, we study cytology as the first level of organization: cell
-> tissue -> organ -> system -> organism.
2. What are the 4 basic tissue types?
Answer: Epithelial, Connective, Muscle, Nervous.* Epithelial covers surfaces and lines cavities,
classified into squamous, cuboidal, columnar, simple or stratified. Connective supports and
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, binds, includes loose, dense, blood, bone, cartilage, adipose. Muscle is for movement - skeletal
voluntary striated, cardiac involuntary striated with intercalated discs, smooth involuntary non-
striated in walls of viscera. Nervous tissue consists of neurons and neuroglia for communication.
3. What is the study of structure of the body called?
Answer: Anatomy is the study of structure, while Physiology is the study of function.* Anatomy is
divided into Gross anatomy studied by dissection, Microscopic anatomy or Histology,
Developmental anatomy or Embryology, and Systemic vs Regional anatomy. It comes from
Greek 'anatome' meaning to cut up.
4. How many bones are in an adult human body?
Answer: 206 bones in adults.* At birth we have about 270-300 bones because many are
cartilage and later fuse. The axial skeleton has 80 bones - skull, vertebral column, ribs, sternum.
The appendix has 126 - limbs and girdles. Bones are classified as long, short, flat, irregular and
sesamoid. They serve support, protection, movement via muscle attachment, mineral storage
for calcium and phosphate, and blood cell formation in marrow.
5. Which is the longest bone in the body?
*Answer: Femur or thigh bone.* It is the longest, heaviest and strongest bone, about 19 inches
in an average adult, making up about 25% of height. It extends from the hip joint at the
acetabulum to the knee joint. It has a head, neck, greater and lesser trochanter, shaft, and
condyles distally. It bears body weight and withstands large compressive forces. Its length is
used to estimate stature in forensic anatomy.
6. Which is the smallest bone in the body?
*Answer: Stapes in middle ear.* It is stirrup-shaped, about 3mm x 2.5mm, weighing 2-4mg. It is
one of three auditory ossicles - malleus, incus, stapes - in the tympanic cavity. Stapes footplate
fits into the oval window of the inner ear and transmits vibrations from incus to cochlear fluid,
essential for hearing. Its small size allows high frequency vibration.
7. What bone forms the forehead?
*Answer: Frontal bone.* It is a single flat bone of the skull forming the forehead, upper part of
orbit, and anterior part of cranial vault. It is formed by intramembranous ossification. It contains
frontal sinuses within it, which are air-filled cavities that lighten the skull and are lined by
mucosa. At birth, frontal bone is two halves separated by metopic suture which fuses around
age 8.
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