Physiology

Structure and function of skeletal muscle. Skeletal muscles have a belly which contains the cells and which attaches by means of tendons or aponeuroses to a bone or other tissue. An aponeurosis is a broad, flat, tendinous attachment, usually along the edge of a muscle. A muscle attaches to an origin and an insertion. The origin is the more fixed attachment, the insertion is the more movable attachment. A muscle acts to shorten, pulling the insertion toward the or…

Sensory: Somatic (skin & muscle) Senses: Postcentral gyrus (parietal lobe). This area senses touch, pressure, pain, hot, cold, & muscle position. The arrangement is upside-down (head below, feet above) and is switched from left to right (sensations from the right side of the body are received on the left side of the cortex). Some areas (face, hands) have many more sensory and motor nerves than others. A drawing of the body parts represented in the p…

Typical Concentration Gradients and Membrane Potentials in Excitable Cells The Na Pump is Particularly Important in the Kidney and Brain All cells have Na pumps in their membranes, but some cells have more than others Over-all Na pump activity may account for a third of your resting energy expenditure! In the kidney the Na pump activity is very high because it is used to regulate body salt and water concentrations Kidneys use enormous amounts of e…

The small intestine Digestion within the small intestine produces a mixture of disaccharides, peptides, fatty acids, and monoglycerides. The final digestion and absorption of these substances occurs in the villi, which line the inner surface of the small intestine. This scanning electron micrograph (courtesy of Keith R. Porter) shows the villi carpeting the inner surface of the small intestine. The crypts at the base of the villi contain stem cells that c…

Lipids: about 40% of the dry mass of a typical cell composed largely of carbon & hydrogen generally insoluble in water involved mainly with long-term energy storage; other functions are as structural components (as in the case of phospholipids that are the major building block in cell membranes) and as "messengers" (hormones) that play roles in communications within and between cells Subclasses include: Triglycerides - consist of on…