NS & ES

Question 1

Function of cerebral cortex (grey matter)

Answer 1

Conscious thought & awareness of stimuli

Question 2

Describe pathway of sensory info.

Answer 2

Receptor -> Sensory neuron -> ascending/sensory tracks in SC -> brain stem -> Thalamus -> cerebral cortex

Question 3

Describe pathway for sensory info.

Answer 3

Receptor -> Sensory neuron -> ascending/sensory tracks in SC -> brain stem -> Thalamus -> Cerebral cortex (integration & awareness of stimuli)

Question 4

Describe pathway for motor info.

Answer 4

Cerebral cortex -> impulses for consious decision travel through cerebrum -> brainstem -> motor/descending tracts in SC -> synapse to motor/effterent neuron -> efffector organ

Question 5

Define reflex

Answer 5

Rapid (min. synapse), Involuntary, Predictable (same), Unlearnt (reflex arc) response to a stimulus. Bypass conscious part of brain => rapid resp.

Question 6

Path of reflex arc

Answer 6

1. Sensory receptor
2. Sensory neuron travel through nerve & dorsal root ganglion
3. Interneuron = Integration area
4. Motor neuron travels through ventral root
5. effector organ

Question 7

Somatic reflex & e.g.

Answer 7

• Effector: skeletal muscles
• Function: Prevent further damage from stimuli; balance/posture
• Integration: SC or brain
• E.g: Patellar reflex

Question 8

Autonomic reflex & e.g

Answer 8

• Effector: Smooth muscle, cardiac muscle, body viscera (salivary glands, gut wall)
• Function: maintain bodily functions (move food through digestive sys, HR, BP, CO2 levels)
• Integration: SC or brainstem through Autonomic NS
• E.g: Defecation & micturition reflex

Question 9

Briefly describe diff. b/w sub & conscious control

Answer 9

Sub: No decision making (less synapse); not complicated (quick resp.)
Conscious: Decision making (more); complicated resp (slow)

Question 10

Diff. b/w NS & endocrine

Answer 10

NS: rapid resp. (AP & neurotrans.), Sub/conscious control
ES: Slow resp. (hormones in blood), feedback loops

Question 11

Function of medulla oblongata

Answer 11

Integrate reflexes (many nuclei/grey matter)

• Respiratory (Medullary rhythmicity center)
• blood vessel (vasomotor center)
• HR (cardiac center)
• swallowing, coughing, vomiting, hiccuping

Question 12

Function of pons

Answer 12

(Nuclei)

• Sleep centre initiates REM (deep) sleep
• respiratory (Pontine respiratory centre)

Question 13

Function of midbrain

Answer 13

(nuclei stabilise somatic movement)

• VIsual reflexes (head & eye movements tracking objects)
• Auditory reflexes (startle reflex)

Question 14

what connects pituitary gland to hypothalamus

Answer 14

Anatomically: infundibulum (pituitary stalk)
Functionally: blood vessels & nervous tracts

Question 15

Functions of hypothalamus

Answer 15

• Homeostatic mechanism: Tb, sleep-wake cycles, food intake, water balance & thirst
• autonomic control: pituitary gland secretions, regulate cardiac & smooth muscle & glands

Question 16

2 pituitary glands & origin

Answer 16

Ant. (adenohypophysis) 70-80%: made of glandular cells from roof of mouth
Post. (neurohypophysis): made of neural tissue. Grew down from brain

Question 17

Name of network of capillaries in Ant. Pt gland, & the tract in the Post Pt gland

Answer 17

Ant: hypothalamohypophysial PORTAL system
Post: hypothalamohypophysial TRACT (allow neural secretion= release hormones)

Question 18

Tropic hormones & e.g

Answer 18

Secreted from one gland to stimulate another endocrine gland. E.g. FSH, LH, TSH, ACTH

Question 19

Types of communication: Differentiate autocrine, paracrine & endocrine cells

Answer 19

Auto: affects same cells that secrete chemicals
Para: affects local cells
Endo: affects (target) cells distant from source

Question 20

Diff. Endocrine & exocrine glands

Answer 20

Endo: ductless. Hormones diffuse into interstitial fluid into capillaries
Exo: ducts seccrete products (not hormones)

Question 21

2 types of hormones & e.g.

Answer 21

1. AA based = water soluble. E.g. all from Pt gland
2. steroid based = lipid soluble. E.g. hormones w/ -one
   * Thyroxine (T3 & T4) is AA but is LIPID soluble

Question 22

Describe transport w/water & lipid soluble

Answer 22

Water: dissolve in plasma & travel freely. Degrade rapidly
Lipid: combine w/ binding protein when in blood but released when going out

Question 23

Method of action for direct method

Answer 23

1. lipid soluble H diffuse in cell through membrane
2. attach to receptor inside cell (cytop. / nucleus)
3. Hormone-receptor complex travel to nucleus (nuclear envelop)
4. Activates specific genes (=> protein synthesis)

Question 24

3 ways hormones alter cell activity

Answer 24

1. Change activity of organelles
2. Change cell membrane permeability
3. Activate a cell mechanism

Question 25

Method of action for indirect method

Answer 25

1. water soluble H attach to receptor on membrane's surface activate G protein complex (alter activity of adenyl-cyclase) 2. Enzyme converts ATP -> cAMP (2nd messenger). 3. Protein-kinases (regulatory enzyme) activated 4. Cell processes altered (e.g. activate enzymes)

Question 26

HUMORAL stimuli for hormone release

Answer 26

Changing blood levels (substances in blood) as the stimulus. E.g. parathyroid gland secreted if low Ca2+

Question 27

NEURAL stimuli for hormone release

Answer 27

Neurotrans. (released from nerves) stimulate target cell (to release hormones). E.g. adrenal medulla stimulated by parasym. NS

Question 28

HORMONAL stimuli for hormone release

Answer 28

(tropic) hormones stimulate target cells to secrete hormones

Question 29

Diff. b/w -ve & +ve FB

Answer 29

-ve: reduce stimulus | +ve reinforces stimulus

Question 30

6 Major endocrine glands

Answer 30

hypothalamus, Pt gland, Thyroid & parathyroid gland, adrenal gland & pancreas

Question 31

Pancreatic islets produce # hormones which are and each produced by _ cells...

Answer 31

3. > Glucagon (alpha) > insulin (beta) > Somatastatin (delta)