Answers, BIO 2310, Introduction to the Human Body

A. INTRODUCTION TO THE HUMAN BODY

1. Anatomy is the study of structure, gross anatomy is big enough to see without a microscope, physiology is the study of function, cytology is the study of cells and histology is the study of tissues.

2. Molecules (glucose), Cells (brain cell), Tissues (epithelial tissue), Organs (stomach), Organ System (digestive system), Organism (you)

3. Standing erect, arms down by your side, palms facing forward

4. Medial/ lateral – Towards/ away from midline, proximal/ distal – towards/away from point of origin, anterior/posterior – front side/back side, superior/ inferior – above/below, external = superficial, deep = internal, ventral/ dorsal – belly side/back side, cranial/ caudal – towards head/towards tail, palmer – palm side, plantar – sole side, ipsilateral – same side of body, bilateral – both sides of body, and contralateral – opposite sides of body.

5. Transverse (cross) cuts the body into superior and inferior portions; sagittal cuts the body into left and right sections, mid-sagittal into equal left and right, frontal (coronal) divides body into anterior/posterior parts.

6. Posterior = Dorsal cavity has the cranial cavity with the brain and the spinal = vertebral cavity has the spinal cord. The anterior = ventral cavity has the thoracic cavity with the heart & lungs and diaphragm as the floor. The abdominal cavity, located inferior to diaphragm houses the liver, stomach, intestines… The pelvic cavity is surrounded by the pelvis and houses reproductive structures, rectum and urinary bladder.

7. Phospholipid bilayer with protein channels scattered throughout it.

8. Some substances can cross the cell membrane and some cannot.

9. Diffusion – movement from high to low concentration, osmosis – water diffusion across cell membrane, solute – dissolves in solution, solvent – substance doing the dissolving, solution – mixture of solvent and solute, osmotic pressure – pressure necessary to oppose osmosis, milliosmole – unit measuring solute concentrations, facilitated diffusion – a.k.a. passive transport – it is diffusion but limited to special sites on the membrane – typically the protein channels, filtration – passive process where a substance passes through the filter based on size; active transport – movement of a substance from low to high concentration requiring ATP; Na+/K+ pump is a classical example of active transport, endocytosis – a cell engulfing a substance, phagocytosis – a type of endocytosis that is cell eating, and exocytosis – discharge of a substance from the cell.

10. Solute difference inside vs. outside of a cell. Not net movement of water for the RBC in an isotonic soln. If the RBC is in a hypertonic solution, its water is drawn out and the cell shrivels up. If the RBC is placed in a hypotonic solution, the water enters the cell and it swells and may burst.

11. Balance, such as responding to a decreased body temperature by shivering to bring your body temperature back to normal.

12. Negative feedback loops have an opposite effect, typically stopping something. If you have too much of hormone A, you will stop the synthesis of hormone A. Positive feedback loops do not lend themselves to homeostasis and would be you have a small blood clot, then a bigger one, bigger….

13. Muscle tissue is capable of contraction; Nervous tissue is the control and communication tissue; connective tissue is the most abundant tissue in the body and many types connect different structures; and Epithelial tissue is a lining and covering tissue.

14. Mucous membrane secretes mucus such as the lining of your mouth; synovial membrane secretes synovial fluid and is found in joints; cutaneous membrane is your skin; serous membrane secretes a watering substance and is found lining your body cavity.