Homeostasis

Question 1

below normal range of partial pressure of oxygen

Answer 1

hypoxia

Question 2

above normal range of partial pressure of oxygen

Answer 2

hyperoxia

Question 3

below normal range of partial pressure of carbon dioxide

Answer 3

hypocapnia

Question 4

above normal range of partial pressure of carbon dioxide

Answer 4

hypercapnia

Question 5

below normal range of concentration of sodium

Answer 5

hyponatraemia

Question 6

above normal range of concentration of sodium

Answer 6

hypernatraemia

Question 7

below normal range of concentration of potassium

Answer 7

hypokalemia

Question 8

above normal range of concentration of potassium

Answer 8

hyperkalemia

Question 9

below normal range of concentration of calcium

Answer 9

hypocalcemia

Question 10

above normal range of concentration of calcium

Answer 10

hypercalcemia

Question 11

below normal range of concentration of glucose

Answer 11

hypoglycaemia

Question 12

above normal range of concentration of glucose

Answer 12

hyperglycemia

Question 13

below normal temperature

Answer 13

hypothermia

Question 14

above normal temperature

Answer 14

hyperthermia

Question 15

below normal pH

Answer 15

acidosis

Question 16

above normal pH

Answer 16

alkalosis

Question 17

control systems operate via

Answer 17

negative feedback - opposing the direction of change

Question 18

afferent pathway

Answer 18

goes from stimulus/receptor toward integrating centre

Question 19

efferent pathway

Answer 19

from integrating centre to effector

Question 20

positive feedback

Answer 20

rare, non-homeostatic, increases the instability

Question 21

positive feedback examples

Answer 21

blood clotting, nueronal excitation, childbirth

Question 22

feed forward control

Answer 22

anticipatory alteration of effectors, independent of feedback

Question 23

parametric feed forward control

Answer 23

type of feed forward control

motor learning eg. ball throwing

Question 24

predictive homeostasis

Answer 24

anticipatory control

eg. increasing cardiac function in anticipation of exertion

Question 25

postural responses

Answer 25

triggered centrally before voluntary movements

Question 26

2 types of direct cellular communication

Answer 26

juxtacrine, gap junctions

Question 27

5 types of cellular communication via ECF

Answer 27

autocrine, paracrine, endocrine, neuronal, neuroendocrine

Question 28

juxtacrine cell communication

Answer 28

physical contact between cells | transmembrane proteins and phospholipids

Question 29

gap junctions

Answer 29

physical contact between cells directly connects the two cytoplasms allows for free passage of molecules and ions heart, some smooth muscle

Question 30

autocrine signalling

Answer 30

cell signalling to itself short distances <20 micrometers monocytes use interleukin 1

Question 31

paracrine signalling

Answer 31

other cells not in physical contact | acts on nearby cells at short distances

Question 32

endocrine

Answer 32

long distances transport via the blood stream hormones binds to receptors e.g. insulin

Question 33

neuronal

Answer 33

long distances target noradrenaline, acetylcholine

Question 34

neuroendocrine

Answer 34

``` combined neuronal and endocrine signalling neuron secretes hormones into the blood adrenal medulla (adrenaline) and posterior pituitary (ADH and oxytocin) ```

Question 35

baroreceptor reflex

Answer 35

response to increase blood pressure

Question 36

low pressure pressure identified by

Answer 36

- Decreasing blood pressure is picked up by receptors between heart and brain ○ Barareceptors in arch of aorta are stretched less - Is the recepttors are triggered this is fed to medulla in control centre

Question 37

response to increase blood pressure

Answer 37

- Increases cardiac output by increasing heart rate ○ Increased sypathetic and decreased parasympathetic ○ Increased secretion of epinephrine and norephrine - Increases heart rate and stroke volume - Vasoconstricts to maintain blood pressure - Increases blood pressure - Stimulus is removed

Question 38

blood sugar control - sugar too high

Answer 38

- Beta cells in pancreases detect high blood glucose level and release insulin ○ Insulin released by beta cells in pancreas - Organs take up glucose and blood glucose drops and switches off initial signal ○ Liver converts glucose to glycogen fats and proteins ○ Muscle and other cells use glucose as an evergy source, or convert it to glycogen

Question 39

blood sugar control - glucose too low

Answer 39

- Pancreas alpha cells detects low blood glucose and releases glucagon which releases glucose into the blood and removes initial signal ○ Liver converts glycogen to glucose

Question 40

positive feedback in childbirth

Answer 40

- Head of fetus pushes against cervix - Nerve impulses from cervix transmitted to brain - Brain stimulates pituitary gland to secrete oxytocin - Oxytocin carried in bloodstream to uterus - Oxytocin stimulates uterine contractions and pushes fetus toward cervix