Grade 8 Science: How Body Systems Work Together

Comprehensive practice flashcards covering digestive, excretory, cardiothoracic, integumentary, immune, nervous, and endocrine system concepts, structures, functions, and diseases.

What two mechanisms drive the propulsion of food through the digestive tract?

Swallowing in the oropharynx and peristalsis throughout the esophagus, stomach, small intestine, and large intestine.

What types of mechanical digestion occur in the mouth, stomach, and small intestine?

Chewing in the mouth, churning in the stomach, and segmentation in the small intestine.

Based on the human dental anatomy diagram, how are permanent teeth arranged in the upper (maxillary) and lower (mandibular) arches?

Both maxillary and mandibular arches contain central incisors, lateral incisors, canines, first premolars, second premolars, first molars, second molars, and third molars.

What are the three sections of the small intestine, and what is its overall length?

The three sections are the duodenum, jejunum, and ileum, forming a $20\text{-foot-long}$ tube.

What are the three pairs of salivary glands and what digestive enzyme do they produce?

The parotid gland, submandibular gland, and sublingual gland produce salivary amylase to begin starches breakdown.

What are the digestive functions of the liver and gallbladder?

The liver produces bile to emulsify fats (and stores glycogen and nutrients), while the gallbladder temporarily stores and releases bile into the small intestine.

How does protein digestion progress through the stomach and small intestine?

In the stomach, pepsin and stomach acids break proteins into smaller peptides; in the small intestine, pancreatic proteases and intestinal enzymes complete the breakdown into amino acids.

What are the major organs of the excretory system?

The kidneys, ureters, urinary bladder, and urethra.

What structures comprise a nephron in the kidney?

The glomerulus, Bowman's capsule, loop of the nephron, and collecting duct.

What are the causes, symptoms, and treatments for Peptic Ulcers?

Causes: Helicobacter pylori infection and long-term NSAID use; Symptoms: Stomach pain, bloating, indigestion; Treatments: Antibiotics for H. pylori, proton pump inhibitors, and lifestyle changes.

What are the causes, symptoms, and treatments for Chronic Kidney Disease (CKD)?

Causes: Diabetes and hypertension; Symptoms: Fatigue, swollen limbs, and urination changes; Treatments: Controlling underlying conditions, dialysis, and kidney transplant.

Identify the four main internal chambers and two AV valves of the human heart shown in this diagram.

Chambers: Right atrium, Right ventricle, Left atrium, Left ventricle. AV valves: Tricuspid valve (right side) and Mitral valve (left side).

What is the key functional difference between pulmonary and systemic circulation?

Pulmonary circulation moves deoxygenated blood from the heart to the lungs and returns oxygenated blood; systemic circulation delivers oxygenated blood from the heart to the body and returns deoxygenated blood.

According to the blood composition diagram, what three main layers form when blood is centrifuged, and what are their constituent percentages or counts?

Plasma ($92\%$ water, $7\%$ proteins, $1\%$ other solutes), Buffy Coat (Platelets $12\text{--}300\text{ thousand/mm}^3$ and Leukocytes $5\text{--}10\text{ thousand/mm}^3$), and Erythrocytes ($4.2\text{--}6.2\text{ million/mm}^3$).

What are the five main types of leukocytes and their relative percentage abundances in the buffy coat?

Neutrophils ($60\text{--}70\%$), Lymphocytes ($20\text{--}25\%$), Monocytes ($3\text{--}6\%$), Eosinophils ($2\text{--}4\%$), and Basophils ($0.5\text{--}1\%$).

What are the three divisions of the pharynx?

Nasopharynx, oropharynx, and laryngopharynx.

How do the diaphragm and rib muscles function during inhalation and exhalation?

During inhalation, the diaphragm contracts (moves down) and rib muscles contract expanding the rib cage; during exhalation, the diaphragm relaxes (moves up) and rib muscles relax reducing the rib cage size.

What are the causes, symptoms, and treatments for Coronary Artery Disease?

Causes: Plaque buildup in coronary arteries; Symptoms: Chest pain, shortness of breath, heart attacks; Treatments: Medications, lifestyle changes, surgical interventions.

Identify the three primary skin layers and key dermis structures shown in this anatomical diagram.

Skin layers: Epidermis, Dermis, Hypodermis. Dermis structures: Hair follicles, sebaceous glands, arrector pili muscles, and eccrine sweat glands.

What role do melanocytes and keratinocytes play in the epidermis?

Keratinocytes produce the protective protein keratin, while melanocytes in the lower epidermis produce melanin.

What primary function do the spleen, thymus, and Peyer's patches perform in the immune system?

The spleen filters blood and produces antibodies; the thymus produces T-cells; Peyer's patches in the small intestine monitor intestinal bacteria.

What characterizes the three lines of defense in the human body?

First line: non-specific physical/chemical barriers (immediate); Second line: non-specific innate immune responses like phagocytes and inflammation (immediate to rapid); Third line: highly specific adaptive responses involving T cells, B cells, and memory (slower activation, long-lasting).

What are the four sequential stages of wound healing in human skin?

Bleeding, Inflammation, Proliferation, and Remodelling.

What causes Melanoma, and what are its diagnostic visual symptoms?

Cause: DNA damage to skin cells from UV rays. Symptoms: New or changing moles, asymmetrical shapes, irregular borders, multiple colors, and size larger than a pencil eraser.

Identify the primary parts of the brain labelled on this cross-sectional anatomical diagram.

Forebrain (cerebrum), thalamus, hypothalamus, midbrain, pons, medulla oblongata, hindbrain (cerebellum), and spinal cord.

How is the Peripheral Nervous System (PNS) divided functionally?

Into the Somatic Nervous System (voluntary movements) and Autonomic Nervous System (involuntary movements, subdivided into Sympathetic 'Fight or Flight' and Parasympathetic 'Rest or Digest').

Which brain structure links the nervous system to the endocrine system via the pituitary gland?

Hypothalamus.

Explain how insulin and glucagon regulate blood sugar levels according to this endocrine feedback loop diagram.

High blood sugar causes the pancreas to release insulin, promoting glucose uptake in tissues and glycogen formation in the liver to lower blood sugar. Low blood sugar causes the pancreas to release glucagon, stimulating the liver to break down glycogen into glucose to raise blood sugar.

What historical case led scientists to understand that damage to specific brain lobes causes distinct personality and behavioral changes?

Phineas Gage, an 1800s railroad foreman who survived a severe frontal lobe injury after an iron rod pierced his head.

What are the causes, symptoms, and treatments for Parkinson's Disease?

Causes: Loss of dopamine-producing brain cells, genetics, toxins; Symptoms: Tremors, stiffness, slow movements, balance problems; Treatments: Medications to increase dopamine, physical therapy, and sometimes surgery.

How do Addison's Disease and Cushing's Syndrome differ in cause and symptoms?

Addison's Disease is caused by adrenal glands underproducing hormones (symptoms: fatigue, weight loss, low blood pressure, dark skin patches). Cushing's Syndrome is caused by excess cortisol (symptoms: weight gain, fatty deposits, high blood pressure, diabetes).