Human Anatomy: Skin & Nerve Cells

• Exam final

Skin as a Protective Barrier

• Defense against microorganisms.
• Protection against UV radiation.
• Prevents injuries.
• Prevents dehydration using the stratum corneum, which is formed by dead keratin cells.

Superficial Layers of the Skin (Epidermis)

• Melanin provides skin color and protects it from the harmful effects of ultraviolet radiation.
• Greater sun exposure leads to more melanin production.

Deep Layer (Dermis)

• Hair follicles produce hair.
• Glands regulate temperature and skin lubrication.
• Receptors perceive stimuli.
• Blood vessels supply nutrients to the skin and help regulate body temperature.

Innermost Layer

• Adipose tissue protects organs by acting as a thermal insulator and shock absorber.

Parts of the Nerve Cell

• Neurons transmit electrical impulses throughout the body.
• Neuroglia protect, nourish, surround, and insulate neurons.
• Dendrites are neuron extensions that receive signals from other nerve cells.
• Axons transmit nerve impulses to other cells.

Accessory Organs of the Digestive System

• Tongue detects flavors and begins mastication.
• Esophagus transports food.
• Pancreas secretes digestive enzymes and hormones to regulate glucose levels.
• Small intestine carries out digestion and nutrient absorption.
• Large intestine (colon) absorbs water and minerals.

Absorption of Carbohydrates, Lipids, and Proteins in the Small Intestine

• Carbohydrates break down into monosaccharides (glucose).
• Lipids break down into fatty acids and glycerol.
• Proteins break down into amino acids.

Definitions

• Villi are small projections on the walls of the small intestine that increase the surface area for absorption.
• Esophagus transports the bolus of food from the mouth to the stomach.
• Large intestine absorbs water and minerals.

Benedict's Test for Simple Sugars

• Blue indicates the absence of sugars.
• Green indicates a small amount of sugars.
• Yellow indicates a moderate amount of sugars.
• Red indicates a large amount of sugars.

Amylase

• Inactivation occurs when heated to 100°C, causing denaturation and loss of shape.
• Activation requires the body's temperature (37°C).

Excretory System

• Kidneys filter blood to remove waste products and excess substances.
• Ureters transport urine from the kidneys to the urinary bladder.
• Urethra transports urine from the urinary bladder to the exterior of the body.

Simulation of the Excretory System Using a Dialysis Membrane

• Helps visualize the renal process of waste elimination, water and electrolyte balance regulation, and the retention of useful substances.
• Urea is eliminated.
• Glucose and proteins are retained.

Concepts of the Male Reproductive System

• Epididymis is the site of maturation and storage of spermatozoa.
• Seminiferous tubules are where spermatogenesis occurs.
• Spermatogonia are stem cells that give rise to spermatozoa.

Concepts of the Female Reproductive System

• Corpus luteum is a structure formed after ovulation from the ruptured follicle.
• Follicle is the structure of the ovary that contains the oocyte.
• Endometrium is the inner layer of the uterus that thickens during the menstrual cycle.

Hormonal Functions

• FSH stimulates follicle maturation in the ovary and spermatogenesis in seminiferous tubules.
• LH causes ovulation in women and stimulates Leydig cells to produce testosterone in men.
• Estrogen promotes the development of female secondary sexual characteristics and endometrial growth.
• Progesterone maintains the endometrium for implantation and pregnancy.

Ecology

• Population: A group of individuals of the same species.
• Community: A group of different species in the same location.
• Ecosystem: A community plus its physical environment.

Trophic Levels

• Producers use solar energy to produce their food through photosynthesis.
• Primary consumers feed on producers (herbivores).
• Secondary consumers feed on primary consumers (carnivores).
• Decomposers break down organic matter.

Biomass in Ecological Pyramids

• Biomass indicates the amount of organic matter present at a specific trophic level in a food chain.
• It is measured in g/m².
• Producers form the broad base.
• Biomass decreases as the pyramid ascends.
• Biomass from highest to lowest: producers, primary consumers, secondary consumers.

Botany

• Diameter at Breast Height (DBH) is measured at 1.30 meters above the ground.
• Size Classes:
  • Regeneration: 0-3 inches (less than 7.9 cm).
  • Young: 4 inches (8-24 cm).
  • Small: 10-14 inches (25-37 cm).
  • Medium: 15-19 inches (38-49 cm).
  • Large: 20-29 inches (50-75 cm).
  • Giant: 30 inches or more (76 cm).

Percentage Calculation Example

• Trees in cm: (8, 12, 15, 22, 9, 28, 31, 18, 11, 35)
• Total: 10 trees -0-10 cm (2 trees): 20%
• 10-20 cm (4 trees): 40%
• 20-30 cm (2 trees): 20%
• 30+ cm (2 trees): 20%

Cardiovascular System

• Atria (auricles) are the superior chambers that receive blood.
• The right atrium receives deoxygenated blood from the body via the vena cava.
• The left atrium receives oxygenated blood from the lungs via the pulmonary veins.

Ventricles

• Inferior chambers that pump blood.
• The right ventricle pumps blood to the lungs for oxygenation via the pulmonary artery.
• The left ventricle pumps oxygen-rich blood to the body.

Blood Pressure

• Systolic pressure of 110 indicates the contraction phase of the heart.
• Diastolic pressure of 70 indicates the relaxation phase of the heart.
• Systolic pressure reflects the force of blood being pumped into the arteries, indicating arterial contraction.

Respiratory System

• Function: the exchange of O2 and CO2. With O2 entering and CO2 exiting
• Sequence:
  • Nose
  • Pharynx
  • Larynx
  • Trachea
  • Bronchi
  • Bronchioles
  • Alveoli

Alveoli

• Sac-like structures surrounded by blood capillaries.
• Thin walls facilitate gas exchange.
• O2 enters the blood.
• CO2 exits the blood.
• Exchange occurs through simple diffusion.

Function of Anatomical Parts in Men

• Testicles produce sperm and testosterone.
• Epididymis stores and matures sperm.
• Vas deferens transports sperm from the epididymis to the urethra.
• Prostate gland secretes a fluid that protects sperm and forms part of semen.
• Urethra carries both semen and urine to the exterior.
• Scrotum protects and regulates the temperature of the testicles.

Function of Anatomical Parts in Women

• Ovaries produce eggs and sex hormones.
• Fallopian tubes transport the egg from the ovary to the uterus, the site of fertilization.
• Uterus nourishes the embryo during pregnancy.
• Endometrium is the inner lining of the uterus that thickens to receive a fertilized egg and is shed during menstruation.
• Cervix connects the uterus to the vagina.
• Vulva is the external genital organs.
• Clitoris is a highly sensitive organ that participates in sexual pleasure.