Human Cell Organelles, Digestion, Respiration & Nervous System
Human Cell Organelles
Organelle from a human cell:
Mitochondria: Oval-shaped with a double membrane, providing energy.
Vacuoles: Membranous vesicles containing water, waste, and reserves.
Lysosomes: Transform complex substances into simpler ones.
Cytoskeleton: Filaments forming a network for cell structure and movement.
Centrioles: Hollow cylinders directing cytoskeleton movement.
Endoplasmic Reticulum: Sacs and canals for substance manufacturing.
- Smooth: No ribosomes.
- Rough: Ribosomes attached for protein synthesis.
Ribosomes: Small particles making proteins.
Golgi Apparatus: Flattened sacs for secretion.
Endocytosis: Cell membrane engulfs large particles.
Catabolism: Breaking down molecules for energy.
Anabolism: Building complex molecules.
Digestive Tract
Mouth
Opening with teeth, tongue, and taste receptors.
Pharynx
Cavity for food and air passage.
Esophagus
Tube moving food to the stomach.
Stomach
Widening of the tract with muscles and gastric juices.
Intestine
Long tube connecting stomach to large intestine.
Large Intestine
Includes colon, cecum, appendix, rectum, and anus.
Mechanical Digestion
- Crushing: By teeth.
- Swallowing: Food passage through pharynx and esophagus.
- Movements: Mixing and peristalsis.
Chemical Digestion
Transformation of large molecules into small molecules by enzymes.
- In Mouth: Saliva with amylase.
- In Stomach: Gastric juice with hydrochloric acid and pepsin.
- In Small Intestine: Juices with enzymes like lipase.
Respiratory System
Upper Respiratory
Nose, pharynx, larynx.
Lower Respiratory
Trachea, bronchi, bronchioles, alveoli, lungs.
Nose and Mouth: Air pathways.
Larynx: Contains vocal cords.
Windpipe (Trachea): Flexible tube.
Bronchi/Bronchioles: Branching tubes.
Lungs: Organs in the thoracic cavity.
Alveoli: Small pockets for gas exchange.
Kidneys
Bean-shaped organs forming urine.
- Cortex and Medulla: Kidney parts.
- Blood Vessels: Renal artery and vein.
- Ureters: Tubes collecting urine.
- Bladder: Stores urine.
- Urethra: Carries urine outside.
- Nephron: Functional unit.
Nervous System
Central Nervous System
- Brain: Cerebrum, cerebellum, medulla oblongata.
- Spinal Cord: Poles/back.
Peripheral Nervous System
- Somatic: Cranial and spinal nerves.
- Vegetative: Sympathetic/parasympathetic.
Neurons
Cell body (soma) and extensions (dendrites and axon).
Hormones
Substances manufactured by endocrine glands.
- Endocrine: Hormones into the bloodstream.
- Exocrine: Not part of the hormonal system.
Functions: Specific, effective, and controlled production.