Topic 1 - Homeostasis & Cell structure/function

Question 1

What is Homeostasis?

Answer 1

-Homeostasis is the ability of the body to maintain its internal environment even when the exterior/external environment changes.
- It helps the body be at optimum
- e.g temperature regulation, pH regulations and so one

Question 2

How is the core temperature managed?

Answer 2

• heat gain from heat inputs (external environment/internal heat production like metabolism)
• heat loss to external environment (cannot lose heat internally)

Question 3

How can the balance be disturbed?

Answer 3

• internal heat production
• external environmental changes (cold/hot weather)

Question 4

What are the 4 mechanisms of heat transfer?

Answer 4

• Radiation (warm->cold transfer e.g hot object transfer heat to colder human)
• Conduction (direct contact - warm -> cool)
• Convection (transfer through air/water currents - warm->cool)
• Evaporation (warm->cold, ONLY COOLING MECHANISM FOR HUMANS - sweat MUST be evaporated for heat loss to occur)

Question 5

What are the ways to minimise heat loss?

Answer 5

• vasoconstriction
• warm clothing
• Piloerection (hairs standing on end + goosebumps - traps air & heat by conduction
• Voluntary movement
• Shivering

Question 6

What are the ways to maximise heat loss?

Answer 6

• Vasodilation
• cool clothing
• Sweating
• Voluntary movement

Question 7

What is the order from cells to systems?

Answer 7

Cells < Tissues < Organs < Organ systems

Question 8

What is the cell made up of?

Answer 8

• Nucleus
• Cell cytoplasm (has all the organelles)
• Cell cytoskeleton (shape, structure & support)
• Cell membrane

Question 9

What are the 4 categories of tissues?

Answer 9

• Epithelial
• Connective
• Muscle
• Nerves

Question 10

How to classify an epithelial tissue?

Answer 10

1. No. cell layers: Single (1 layer), Stratified (>1 layer) & Pseudostratified (1 layer with different size cells)
2. Shape of Cells: Squamous (thin & flat), Cuboidal (cube-like shapes) & Columnar (looks like columns)
3. Presence of cilia or keratin

Question 11

What are the 3 types of connective tissue?

Answer 11

• Connective tissue proper; inc. fibroblasts, macrophages, adipocytes, mast cells &lymphocytes
• Supporting connective tissue; bones & cartilage (cells= Osteocytes & Chondroblasts)
• Fluid connective tissue; Blood & lymph

Question 12

What are the 3 types of muscle?

Answer 12

• Skeletal (Voluntary control & skeleton movement)
• Smooth (Involuntary control & movement of hollow organs - e.g bladder)
• Cardiac (Heart beating responsibility)

Question 13

What cells does the nervous tissue contain?

Answer 13

• Neurons
• Glial cells

Question 14

What is an organ?

Answer 14

Is composed of two or more tissues which perform one or more common functions e.g skin or liver

Question 15

What is an organ system?

Answer 15

Group of organ classified as a system b/c common function/group of functions

Question 16

What are the purposes of epithelial tissue?

Answer 16

• Protection
• Absorption
• Secretion