Week 7 human body systems - tissues and homeostasis

Question 1

Main types of tissue

Answer 1

-Connective tissue
-Epithelial tissue
-Muscle tissue
-Neural tissue

Question 2

Connective tissue

Answer 2

Binds cell and organs: protects
support and integration

Question 3

Epithelial tissue

Answer 3

Covers exterior, lines internal
cavities & some glands

Question 4

Muscle tissue

Answer 4

Excitable, contracts: skeletal
(voluntary), smooth, cardiac

Question 5

Neural tissue

Answer 5

Excitable: allows propagation of
nerve impulses that communicate between different parts of body

Question 6

Tissue support

Answer 6

-Extracellular Matrix (matrix)
-Cell Junctions: hold cells together

Question 7

Extracellular matrix

Answer 7

-Material synthesized and secreted by the cells of a tissue
-Proteoglycans (glycoproteins) and insoluble protein fibre (collagen, fibronectin, laminin)
-Very abundant in connective tissue

Question 8

Cell Junctions

Answer 8

-Cell adhesion
molecules (CAMs)
membrane-spanning
proteins
-Cell junctions
-Gap/Communicating
-Tight

Question 9

Connective tissue

Answer 9

Support / protect/ connect
Cells dispersed in matrix (proteoglycans & insoluble proteins)
May be watery or mineralised

Question 10

True connective tissues

Answer 10

-Loose connective
tissue
-Dense connective
tissue

Question 11

Loose connective tissue

Answer 11

-Adipose (fat)
-Reticular (soft organs)

Question 12

Dense connective tissue

Answer 12

Regular:
-Tendon (muscle to
bone)
-Ligament (bone to
bone)
Irregular:
-Dermis

Question 13

Supportive connective
tissue

Answer 13

-Cartilage
-Bone

Question 14

Cartilage

Answer 14

-Hyaline
-Elastic
-Fibrocartilage

Question 15

Fluid connective
tissue

Answer 15

-Blood
-Lymph

Question 16

Epithelia

Answer 16

Protect/Regulate exchange
-One or more layers of cells
-Base: thin layer of matrix (basal lamina/membrane )

Question 17

Epithelia Functions - Exchange

Answer 17

Simple, thin flattened cells (squamous),
gaps/pores
- e.g., rapid gas exchange
- Blood vessels (also called
endothelium) / lung

Question 18

Epithelia Functions - Transporting

Answer 18

Simple, cuboidal or columnar
-Allow specific molecules to
be transported across them

Question 19

Epithelia Functions - Cilated

Answer 19

Sweep fluids across surface
-Line respiratory trace/ female reproductive

Question 20

Epithelia Functions - Protective

Answer 20

Prevent exchange
-Stacked layers of cells
-e.g., epidermis (skin)

Question 21

Homeostasis

Answer 21

Physiologically, keeping the body’s environment in a state of
equilibrium within “normal limits”

Question 22

Control of homeostasis

Answer 22

-Physiological response
-Reverses a change in a
controlled condition

Question 23

Negative feedback loop

Answer 23

Negative feedback brings a system back to its level of normal functioning
Regulated variables maintained within their acceptable (normal) range by physiological control mechanisms kick in if the variable moves too far from
its set point, or optimum value

Question 24

Regulation

Answer 24

Oscillations around a set point
Detectors have a threshold
-Minimal stimulus to set response in motion
Control: short distance or long
distance

Question 25

Control systems - long distance

Answer 25

Input signal (stimulus) -> Intergrating system -> Output signal -> response

Question 26

Intergration centres

Answer 26

Brain: Key -Negative feedback: the response reduces the intensity of the stimulus the system is operating -Positive feedback: the response enhances or intensifies the stimulus -Examples of integrators: include the hypothalamus and the pituitary (regions of the brain)

Question 27

Long distance control - negative feedback

Answer 27

1) Stimulus - produces a change in variable 2) Receptor - detects change 3) Input - information sent along afferent pathway to control centre 4) Output - information sent along efferent pathway to effector 5) Response - effector feeds back to reduce the effect of stimulus and returns variable to homeostatic level

Question 28

Afferent

Answer 28

Towards a centre

Question 29

Efferent

Answer 29

Away from a centre

Question 30

Circadian rhythms

Answer 30

Body temp set point changes throughout day (oscillations around set point occur)

Question 31

Positive feedback loop

Answer 31

Not homeostasis Positive feedback enhances or accelerates output created by an activated stimulus -Strengthens or reinforces a change in a controlled condition -Physiological response of effector reinforces the initial change -Continues until interrupted by a mechanism external to the loop Outside factor required is to shut off positive feedback cycle

Question 32

Reflex control

Answer 32

Reflex control consists of a stimulus, an integrating centre and a response