Levels of organisation in the body and homeostasis

Question 1

Define anatomy

Answer 1

The branch of science that deals with the bodily structure of living organisms

Question 2

Define physiology

Answer 2

The branch of science that deals with the normal functioning of living organisms and their systems and organs Basically how the body works, and how it responds to internal and external challenges

Question 3

Levels of organisation in the body (smallest to biggest)

Answer 3

Molecules Cells Tissues Organs Systems Organism

Question 4

Molecules

Answer 4

The chemical level of organisation

Question 5

Functions cells can perform

Answer 5

Protection Secretion Exchange Absorption Communication Movement

Question 6

Can a single cell perform every task cells are required to do?

Answer 6

No They are specialised to their own task

Question 7

Functions of the plasma membrane

Answer 7

Physical barrier Compartmentalises the cell Regulates exchange with the environment Gives structural support Attachment site of proteins Transmits electrical and chemical signals Secretes and takes up substances

Question 8

Ways that substances can cross the plasma membrane

Answer 8

Simple/passive diffusion Facilitated diffusion Exocytosis Endocytosis

Question 9

Tissues

Answer 9

Groups of cells with similar structure and function

Question 10

The four types of tissue

Answer 10

Epithelial Connective Nervous Muscular

Question 11

Types of epithelial tissue

Answer 11

Can be either simple or stratified: Squamous Cuboidal Columnar Pseudostratified

Question 12

What makes simple epithelial tissues simple?

Answer 12

One cell thick

Question 13

What do the epithelial cells sit on?

Answer 13

Basement membrane

Question 14

Epithelial tissue that is more than one cell thick

Answer 14

Stratified

Question 15

Types of connective tissue

Answer 15

Connective tissue proper Fluid connective tissue Supporting connective tissue

Question 16

Types of connective tissue proper

Answer 16

Loose Dense

Question 17

Types of fluid connective tissue

Answer 17

Blood Lympth

Question 18

Types of supportive connective tissue

Answer 18

Bone Cartilage Adipose tissue

Question 19

Types of nervous tissue

Answer 19

Neurones Glial cells

Question 20

What makes up a huge proportion of the brain? What is the percentage?

Answer 20

Glial cells 90%

Question 21

Types of glial cells

Answer 21

Schwann cells Oligodendrocytes Astrocytes Microglial cells

Question 22

Types of muscular tissue

Answer 22

Skeletal muscle Cardiac muscle Smooth muscle

Question 23

Which type of muscle do we have control of?

Answer 23

Skeletal muscle

Question 24

What type of muscle makes up the heart?

Answer 24

Cardiac muscle

Question 25

What type of muscle makes up blood vessels?

Answer 25

Smooth muscle

Question 26

Organ definition

Answer 26

Collection of tissue types with specific structure and function

Question 27

Examples of organs

Answer 27

Heart Lungs Kidneys Stomach Thyroid gland

Question 28

Systems definitions

Answer 28

Organs with complementary functions

Question 29

11 systems

Answer 29

Integumentary Cardiovascular Respiratory Digestive Skeletal Muscular Nervous Endocrine Lymphatic Urinary Reproductive

Question 30

Define organism

Answer 30

The functional entity that is able to breathe, move, feed, reproduce..... idependantly

Question 31

What does the internal environment refer to?

Answer 31

The fluid surrounding cells

Question 32

What are cells surrounded by in the body?

Answer 32

Extracellular fluid

Question 33

What is extracellular fluid?

Answer 33

Interstitial fluid Plasma Surrounds cells

Question 34

Homeostasis

Answer 34

Biological self-regulation The ability of the body to maintain a condition of dynamic equilibrium within the the internal environment when dealing with external changes

Question 35

Examples of things controlled by homeostasis

Answer 35

Concentration of ions (Na+...) Concentration of nutrients Concentration of blood gases Physical characteristics of blood (pressure, volume...)

Question 36

Normal range of blood glucose

Answer 36

3.5 - 6.0 nM

Question 37

Normal range of blood osmolarity

Answer 37

280 - 295 mOsM

Question 38

Normal range of body temperature

Answer 38

36.5 - 37.5 ^oC

Question 39

Normal range of atrial blood pressure

Answer 39

120/80 mmHg

Question 40

Normal range of atrial pO²

Answer 40

80-100 mmHg

Question 41

Normal range of atrial pH

Answer 41

7.35 - 7.45

Question 42

What does p stand for in pO²

Answer 42

Partial pressure The amount of pressure that a gas exerts

Question 43

Steps in homeostatic mechanism

Answer 43

Change in controlled variable This is registered by sensors Sensors send messages via the afferent pathway to the CNS This sends a message via efferent pathways to the effectors Effectors cause a response to return the variable to equilibrium

Question 44

Negative feedback

Answer 44

Homeostasis Reacts to a change in a controlled variable to re-establish equilibrium

Question 45

Example of negative feedback (increase in blood pressure)

Answer 45

Increase in blood pressure detected by receptors in blood vessels CNS responds and lowers heart rate This causes decrease in blood pressure Equilibrium restored

Question 46

How would you describe the equilibrium in homeostasis

Answer 46

Dynamic It fluctuates small amounts around a set value/s

Question 47

Feed-forward regulation

Answer 47

Homeostasis Predictive mechanism Can use behavioural cues to predict how it should respond to the expected change

Question 48

Example of feed-forward regulation

Answer 48

Eat food Signal sent predicting rise in glucose levels Insulin released slightly early to break down glucose straight away

Question 49

Positive feedback

Answer 49

Homeostasis Escalates a change in variable to make it greater Aims to reach an end point When the end point is reached the stimulus disappears and feedback stops

Question 50

Most common form of feedback in homeostasis

Answer 50

Negative

Question 51

Examples of physiological changes of homeostatic control

Answer 51

Cardiovascular variables during exercise (heart rate to supply more oxygen) May be changes throughout the day to give circadian changes

Question 52

What if there are changes that cause conflicting responses?

Answer 52

The body prioritises other variables above others

Question 53

Example of prioritising is homeostasis

Answer 53

Salty diet causes the body to hold onto more water Causes an increase of blood pressure as osmosis causes water to remain in the blood, increasing it's volume and pressure

Question 54

Pathological changes in homeostasis

Answer 54

Pathogens can delude the body's control centre to believe variables should be different Causes response that isn't need and could be dangerous Or can just lose control/be unable to affect changes

Question 55

Examples of pathological changes in homeostasis

Answer 55

Fever - make the body believe body temperature should be higher Cancer - loss of control of cell division Circulatory shock - hypotension following haemorrhage as body tries increase blood pressure by raising heart rate, but failing

Question 56

How cells communicate with each other

Answer 56

Direct (cell-to-cell): mechanical, chemical, electrical Paracrine/autocrine Endocrine Neural Neuroendocrine

Question 57

Pseudostratified epithelial tissue

Answer 57

Gives appearence that it is stratified because how crowded the cells are

Question 58

Image of simple epithelial tissues: Squamous Cuboidale Columnar

Answer 58

Question 59

Image of pseudostratified epithelial tissue

Answer 59

Question 60

Image of stratified epithelial tissue

Answer 60