W15 Nervous & Endocrine system

Question 1

Describe the nervous system and its components parts

Answer 1

CNS and PNS

CNS-> BRain + spinal chord

PNS-> Autonomic + Somatic
Autonomic-> Afferent(sensory) + Efferent(motor)
Efferent-> Sympathetic (fight/flight) + Parasympathetic (rest/digest)

Somatic -> Afferent + Effernet
Afferent-> Somatic + Visceral

Question 2

Which 2 main cell types is the CNS made up of

Answer 2

Neurones (incl. relay) and Glial cells

Question 3

What is white matter
Does it have alternative names?
Where can it be found

Answer 3

Mainly axons
In spinal chord, “columns”: on the “outside” surrounding the horns
In brain, “tracts”: found underneath the cortex

Question 4

What is grey matter

Where can it be found

Answer 4

Mainly cell bodies
In spinal chord: forms internal column/the horns
In brain: forms the cortex (outer layer)

Question 5

Describe the route an impulse takes for a basic spinal reflex

Answer 5

Sensory afferent neurone -> relay neurone in spinal chord -> motor efferent neurone

Question 6

What are proprioceptors?

Answer 6

Sensory receptors in muscles and tendons that tell the CNS about stretch/tension

Question 7

Describe the process of the Muscle Spindle reflex and the Golgi Tendon reflex when you’re holding a set of weights

Answer 7

Muscle spindle fires to the CNS, which sends a signal back via motor neurone so we increase the tension in our muscles to keep the weights.

If the weight is excessive, the Golgi Tendon reflex comes into action: relaxes the muscle

Question 8

Somatic motor neurones and Autonomic neurones originate their signal in this part of the spinal cord

Answer 8

Ventral horn

Question 9

Somatic sensory (afferent) nerves goes through which part of the spinal chord?

Answer 9

Dorsal horn

Question 10

What are the 3 main veiscles of the brian and their constituent secondary vesicles?

Answer 10

Forebrain (cerebrum + thalamus+ hypothalamus) Midbrain,

Hindbrain (cerebellum + Pons + Medulla oblongata)

Question 11

What are ventricles (within the brain)?
How many are there?
Which purpose do they serve?

Answer 11

Sacs deep in the brain filled with Cerebral Spinal Fluid.
There are 4: Lateral ventricle, Third, Fourth, and the Midbrain aqueduct
Without this, the brian would be very heavy and
compress the neurons towards the ventral side of
the brain.

Question 12

What is CSF?
Where is it produced?
What is its significance?

Answer 12

Cerebral Spinal Fluid, is like plasma but with proteins
Continously produced in the Choroid plexus in the lateral ventricle
It cushions, acts as chemical buffer, is involved in homeostasis

Question 13

Which parts is the cerebrum made of, and what roles do they have?

Answer 13

Cerebral cortex (grey matter): no info
Subcortical white matter (what lies beneath): no info
Basal nuclei: concerned with movement
Lateral ventricle: supplies cerebrum with CSF

Question 14

Which roles do the thalamus and hypothalamus have?

Answer 14

Thalamus: communicates with cerebral cortex, passes info to and from
Hypothalamus: is the homeostatic centre
controls pituitary gland

Question 15

How come we are more intelligent than any other animal even though we don’t have the largest brains?

Answer 15

Our cerebral cortex has the highest amount of folding, and hence a high neurone density.

Question 16

What are the 4 main lobes of the cerebral cortex and their main functions?

Answer 16

Frontal - Motor functions
Temporal - Auditory functions
Pareital - General sensory (touch, pressure, etc)
Occipital - Visual cortex

Question 17

What two types of nerves is the PNS made up of? What are the subdivisions and where do they connect to?

Answer 17

Cranial and Spinal nerves

Cranial nerves come out of the lateral part of the brain = 12 pairs (connects to the head/face)

Spinal nerves = 31
Cervical (neck) , Thoracic (chest), Lumbar (abdominal), Sacral (pelvis + lower limbs), Coccygeal (bottom of pelv

Question 18

What are the 10 major endocrine glands? How are they regulated?

Answer 18

Pituitary, pineal, hypothalamus, thyroid, parathyroid, thymus, pancreas, adrenal, testes, ovaries.
Hypothalamus regulates pituitary which in turn regulates all but adrenal and parathyroid (which are regulated by blood ion levels)

Question 19

Which 3 ways is the endocrine system arranged?

Give examples of each

Answer 19

As glands (thyroid)
As clusters (Islets of Langerhans)
As individual cells (GI tract, skin)

Question 20

Which parts does the pituitary gland consist of? What are they made of?

Answer 20

Anterior and posterior

Posterior: nerve tissue, i.e. axons and nerve terminals of hypothalamus

Anterior: the real gland, recieves “releasing hormones” from hypothalamus

Question 21

Which hormones does the posterior pituitary release, what are their functions?

Answer 21

Oxytocin: stimulates uterine contraction during childbirth

Anti-diuretic hormone (ADH): Controls blood fluid and mineral levels in the body by affecting water retention by the kidneys.

Question 22

Which are the main hormones that the anterior pituitary releases?
What are their functions?

Answer 22

Thyroid-stimulating hormone (TSH) - Stimulates the thyroid gland to secrete thyroxine.
Luteinising hormone (LH) and FSH 
Stimulates ovaries to produce oestrogen/ progesterone and testes to produce testosterone 
Growth hormone (GH) - Stimulates growth and

Question 23

Which are the 4 classes of hormone? Give examples of hormones in each category

Answer 23

Amines - thyroxine
Eicosanoids, a.k.a postaglandins -
Peptides - insulin/glucagon
Steroids - testosterone/oestrogen/progesterone, cortisol

Question 24

Which hormones are involved in growth?

Answer 24

Gonadotrophin releasing hormone (GnRH) from hypothalamus stimluates release pf GH from ant. pituitary.
Also Insulin-like growth factor (IGF-1)

Question 25

How does GH work?

Answer 25

Stimulates glycogenolysis by the liver AND lipolysis

Represses glucose storage and uptake by muscle and adipose tissue, we use it instead to grow

Question 26

What effects does GnRH have?

Answer 26

It stimulates release of GH

It increases secretion of (FSH) and (LH) up to puberty

then ovarian follicles begin to mature (females)
testosterone secretion/spermatogenesis (males)

Question 27

List some tissue types that are:

• renewable from stem cells
• renewable but not from stem cells
• unrenewable cells

Answer 27

• skin epidermis, blood cells, intestinal epithelial cells
• beta cells (insluin producing)
• auditory + photoreceptive cells

Question 28

Describe some aging factors

Answer 28

• Reduction of growth hormones GH, FH, LSH
• Accumulation of genome mutations
• AND mitochondrial DNA mutations
• Senescense

Question 29

What is senescense?

Answer 29

Chromosome ends (telomere regions) gets shorter for every division and cannot replicate for eternity. Chromosomes are eventually labeled as damaged.