Human Anatomy and Physiology Flashcards

Vocabulary flashcards covering bones, muscles, nervous system, cardiac system, respiratory system, and nutrition.

Bone functions

Support, protection, movement, body shape, blood cell formation, storage area for essential minerals

Bone classification (shape)

Long bones, short bones, flat bones

Types of Bone Tissue

Compact and Spongy

Osteoblast

Cell responsible for mineralization of the bone

Osteoclast

Multinucleated cell that removes calcified bone matrix

Osteogenic cells

Undifferentiated precursor cells that develop into osteoblasts

Osteocytes

Main cell type in mature bone; assists with nutrition

Bone remodeling

Resorption, reversal, bone formation, mineralization

Organic compounds in bone matrix

Mostly collagen (33%)

Inorganic components in bone matrix

Calcium, potassium, sodium, magnesium, carbonate, phosphate (67% total)

Vitamins affecting bone growth

A, B12, C, D, K

Minerals affecting bone growth

Calcium, phosphorus, magnesium, fluoride, manganese

Hormones affecting bone growth

Insulin-Like Growth Factors, Thyroid Hormones, Sex Hormones

Exercise effects on bone health

Increased stress leads to increased deposition of mineral salts and increased activity of osteoclasts and deposition of collagen

Types of muscle

Skeletal, smooth, cardiac

Function of skeletal muscles

Movement, posture/joint stability, storage (water, ions, glycogen), venous return, maintaining body heat

Agonist

Initiates movement

Antagonist

Muscle that produces the opposite action of the agonist

Isometric contraction

Internal force generated is equal to the external force, no change is muscle length. Essential to maintain posture and to stabilize joints

Concentric contraction

Occurs when the internal force generated by the muscle is greater than the external force to be lifted; muscle shortens.

Eccentric contraction

Occurs when the external force is greater than the internal force generated by the muscle; muscle length increases.

Motor Unit

A group of fibers that work together, includes a single nerve which splits at the end to contact all the fibers in the unit.

Fast Twitch Fibers

Anaerobic, pale, low blood supply, fatigue rapidly, low number of capillaries and mitochondria. E.g., sprinter

Slow Twitch Fibers

Aerobic, red, high blood supply, fatigue slowly, high number of capillaries and mitochondria. E.g., marathoner

Nervous System Divisions

Central (brain and spinal cord) and Peripheral (motor neurons, interneurons, and sensory neurons)

Resting Potential

Potential difference across all cell membranes. In neurons, maintained at -70mV by Na+ and K+ pumps.

Action Potential

Reversal of the potential difference, depolarization. Stimulus causes Na+ channels to open, Na+ rapidly diffuses into the axon.

Proprioception

Provided by kinaesthetic receptors in muscles (spindle), tendons, joints, skin, and in vestibular receptors

Hindbrain Functions

Cerebellum (balance and posture, precise voluntary movements), Medulla Oblongata (heart rate, blood pressure, breathing)

Midbrain Function

Controls cranial reflexes concerned with pupil size and lens shape

Forebrain Functions

Hypothalamus (homeostasis), Corpus Callosum (connects hemispheres), Cerebral Hemispheres (sensory info, motor impulses, memory/learning)

Cardiac System Functions

Circulating oxygenated blood, transporting substances, removing metabolic waste, maintaining blood pressure

Artery structure

Small lumen, elastic fibers and smooth muscle, collagen

Capillary structure

Squamous epithelium, thin wall adapted for diffusion

Vein structure

Collagen, smooth muscle and elastic fibers, large lumen with semilunar valves

Blood pressure

Cardiac output x peripheral resistance

Stroke volume

Volume of blood pumped at each heartbeat

Cardiac Output

Stroke volume x heart rate (beats/min)

Respiratory System Functions

Gaseous exchange, regulation of blood pH, producing chemical mediators, sound production, sensing smell, protection

Alveoli

Thin walls made of semi-permeable membranes: Type 1 alveolar cells (squamous epithelial) = thin and main site for gaseous exchange, Type 2 alveolar cells (cuboid epithelial cells) = secrete alveolar fluid called surfactant

Inhalation

Volume of thorax increases, pressure decreases. Rib cage expands, intercostal muscles contract, diaphragm contracts.

Exhalation

Volume of thorax decreases, pressure increases. Rib cage gets smaller, intercostal muscles relax, diaphragm relaxes.

Oxygen Transport

Physical solution dissolved in fluid (1.5%), combination with hemoglobin as oxyhemoglobin (98.5%)

Carbon Dioxide Transport

Combined with protein portion of hemoglobin (23%), as part of the bicarbonate system (70%), dissolved in plasma (7%)

Heterotrophic Nutrition

Breakdown of complex organic molecules into smaller, soluble molecules that can be absorbed.

Carbohydrate Roles

Key energy source, glycogen storage, carbon skeleton, fiber

Fats (Lipids)

Essential and non-essential, unsaturated and saturated fatty acids, triglycerides, phospholipids, lipoproteins

Vitamins - Fat Soluble

Dependent upon fat for absorption, stored in fat cells, excess can be harmful

Movement of Digestive Tract

Peristaltic movement (involuntary), segmentation movement (involuntary)

Gastric Acid Production

Hormonal control via cephalic, gastric, and intestinal phases; involves gastrin, secretin, and cholecystokinin