Lecture 6 nervous and endocrine systems

Question 1

Label internal anatomy diagram

Answer 1

A. Brain
B. Gill
C. Spinal Cord
D. swim bladder
E. body muscles
F. urogenital opening
G. anus
H. Ovary
I. kidney
J. intestine
K. Stomach
L. Liver
M. oesophagus
N. Heart

Question 2

4 sections of fish brain

Answer 2

1. Forebrain (prosencephalon)
2. Midbrain (mesencephalon)
3. Hindbrain (rhombencephalon)
4. Spinal column (past the brain)

Question 3

Forebrain (prosencephalon) (3)

Answer 3

olfactory sense associated with the anterior telencephelon

pineal organ (“third eye”)

hypothalamus (connects to endocrine)

Question 3

Forebrain (prosencephalon) (3)

Answer 3

olfactory sense associated with the anterior telencephelon

pineal organ (“third eye”)

hypothalamus (connects to endocrine)

Question 4

Midbrain (mesencephalon) (3)

Answer 4

optic lobes

Associated w/ lateral line

Associated w/ learning

Question 5

Hindbrain (rhombencephalon) (2)

Answer 5

Cerebellum

Medula oblongata

Question 6

Cerebellum (3 functions)

Answer 6

auditory
electrosensory
coordination of movement

Question 7

Medula oblongata (2 functions)

Answer 7

controls spine and sensory -motor nerves through mauthner cells

Question 8

mauthner cells (functions and 3 parts)

Answer 8

escape reflex
paired cells on the floor of the medulla
axions to caudal muscle
dendrites to acoustic centers

Question 9

spinal column (2 traits)

Answer 9

hollow thick walled tube
unmyelinated nerve fibers

Question 10

Pituitary Gland

Answer 10

Located ventrally on posterior prosencephalon

neurohypophysis region from embryonic nervous tissue

adenohypophysis region from embryonic mouth cavity

Question 11

pituitary hormones (6)

Answer 11

ACTH - stimulates steroid production in internal tissue
GTH-stimulates eggs, sperm, and steroids
GH-promotes appetite and food conversions to growth
prolactin - osmotic balance
Thyrotropin - stimulates the thyroid
MSH and MCH - stimulate and contract pigment dispersal

Question 12

Pancreatic islets (3)

Answer 12

-dispersed around pyloric caeca
-metabolism regulation
-secretes insulin and glucagon

Question 13

Ultimobranchial Gland (4)

Answer 13

-located below esophagus near sinus venosus
-Secretes calcitonin
-calcium regulation
-seawater adaptation

Question 14

Gastrointestinal Mucosa (3)

Answer 14

-at least 16 types of cells
-many secretions regulate gut secretions and motility
-also may secrete glucagon, somatostatin, and insulin

Question 15

Chromaffin tissue (2)

Answer 15

-may intermingle with interrenal cells
-secrete adrenaline and noradrenaline involved in “fight or flight” responses

Question 16

Interrenal Tissue (2)

Answer 16

around head of kidney
secrete steroids (cortisol) for osmoregulation and metabolism

Question 17

Corpuscles of Stannius

Answer 17

-position varies greatly among species (associated with kidney)
-secretes stanniocalcin
suggests osmoregulatory function

Question 18

what is a hormone axis

Answer 18

-a pathway a hormone follows in order to do its function
-steps are not connected physically but through blood stream

Question 19

Pineal Organ (5)

Answer 19

-light receptor in hagfish, some elasmobranchs and teleosts
-glandular function in most teleost fishes
-pinealectomy disrupts circadian activity cycles
-may secrete melatonin, serotonin
-associated with “timed” events like gonad maturation

Question 19

Pineal Organ (5)

Answer 19

-light receptor in hagfish, some elasmobranchs and teleosts
-glandular function in most teleost fishes
-pinealectomy disrupts circadian activity cycles
-may secrete melatonin, serotonin
-associated with “timed” events like gonad maturation

Question 20

Thyroid Gland

Answer 20

-Produces hormones that contain iodine
-Action may differ between species (active research)
-associated with the regulation of many bodily functions

Question 21

Thyroid Gland regulations (5)

Answer 21

-skin & eye pigments
-guanine deposition in skin
-metabolism
-metamorphosis (flatfish)
-osmoregulation

Question 21

Thyroid Gland regulations (5)

Answer 21

-skin & eye pigments
-guanine deposition in skin
-metabolism
-metamorphosis (flatfish)
-osmoregulation

Question 22

Caudal Neurosecretory System (2)

Answer 22

secrete urotensin I and II
possible water balance, sodium regulatory functions

Question 23

Gonads

Answer 23

-Secrete steroids involved with reproductive development, behavior, and spawning
-male – androgens (esp. testosterone)
-female - estrogens

Question 24

Smoltification

Answer 24

-Smoltification is a complex series of physiological changes where young salmonid fish adapt from living in fresh water to living in seawater
-lose vertical “parr marks” to become more silvery (guanine)
-active uptake in NaCl in freshwater, active excretion of NaCl in saltwater